overview changedrelease-notes/overview
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1818
1919### October 22, 2026
2020
21* We've launched [Claude Models on Google Cloud (Anthropic managed)](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/anthropic-managed), the Claude API operated by Anthropic and reached through your Google Cloud project. Google Cloud IAM controls access. Google Cloud Marketplace handles billing.
21* We’ve launched [Claude Models on Google Cloud (Anthropic managed)](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/anthropic-managed), the Claude API operated by Anthropic and reached through your Google Cloud project. Google Cloud IAM controls access. Google Cloud Marketplace handles billing.
2222* [Fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) is available for Claude Opus 5.5 on Claude Models on Google Cloud (Anthropic managed).
2323
2424### October 21, 2026
2525
26* We've released API version `2026-10-21`. [Migrating to API version 2026-10-21](https://platform.claude.com/docs/en/api/migration-2026-10-21) shows how to upgrade.
27* We've released new versions of the [client SDKs](https://platform.claude.com/docs/en/cli-sdks-libraries/overview) and the [`ant` CLI](https://platform.claude.com/docs/en/cli-sdks-libraries/cli/quickstart) that send API version `2026-10-21` by default: Python SDK 2.0.0, TypeScript SDK 1.0.0, C# SDK 13.0.0, Go SDK 2.0.0, Java SDK 3.0.0, PHP SDK 1.0.0, Ruby SDK 2.0.0, and `ant` CLI 2.0.0. See [Switch to 2026-10-21](https://platform.claude.com/docs/en/api/migration-2026-10-21#upgrade).
28* The new SDK and CLI versions also have breaking changes that don't depend on the API version, and they are licensed under Apache 2.0 instead of the MIT License. See [SDK and CLI changes](https://platform.claude.com/docs/en/api/migration-2026-10-21#sdk-changes).
29* We've added the `enforcement_status` and `enforcement_actions` fields to [user profiles](https://platform.claude.com/docs/en/manage-claude/user-profiles), so you can see whether Anthropic has restricted or banned one of your end customers. To find the profiles that have an open restriction or ban, [list your profiles](https://platform.claude.com/docs/en/api/user_profiles/list) with the new `enforcement_status[]` filter. See [Check whether Anthropic has restricted or banned a profile](https://platform.claude.com/docs/en/manage-claude/user-profiles#check-whether-anthropic-has-restricted-or-banned-a-profile).
26* We’ve released API version `2026-10-21`. [Migrating to API version 2026-10-21](https://platform.claude.com/docs/en/api/migration-2026-10-21) shows how to upgrade.
27* We’ve released new versions of the [client SDKs](https://platform.claude.com/docs/en/cli-sdks-libraries/overview) and the [`ant` CLI](https://platform.claude.com/docs/en/cli-sdks-libraries/cli/quickstart) that send API version `2026-10-21` by default: Python SDK 2.0.0, TypeScript SDK 1.0.0, C# SDK 13.0.0, Go SDK 2.0.0, Java SDK 3.0.0, PHP SDK 1.0.0, Ruby SDK 2.0.0, and `ant` CLI 2.0.0. See [Switch to 2026-10-21](https://platform.claude.com/docs/en/api/migration-2026-10-21#upgrade).
28* The new SDK and CLI versions also have breaking changes that don’t depend on the API version, and they are licensed under Apache 2.0 instead of the MIT License. See [SDK and CLI changes](https://platform.claude.com/docs/en/api/migration-2026-10-21#sdk-changes).
29* We’ve added the `enforcement_status` and `enforcement_actions` fields to [user profiles](https://platform.claude.com/docs/en/manage-claude/user-profiles), so you can see whether Anthropic has restricted or banned one of your end customers. To find the profiles that have an open restriction or ban, [list your profiles](https://platform.claude.com/docs/en/api/user_profiles/list) with the new `enforcement_status[]` filter. See [Check whether Anthropic has restricted or banned a profile](https://platform.claude.com/docs/en/manage-claude/user-profiles#check-whether-anthropic-has-restricted-or-banned-a-profile).
3030
3131### October 20, 2026
3232
3333* [Inference hooks](https://platform.claude.com/docs/en/manage-claude/inference-hooks) are out of beta for Claude Enterprise organizations.
34* We've launched [user profiles](https://platform.claude.com/docs/en/manage-claude/user-profiles), so you can tell Anthropic which of your end customers each API request is for. If you operate a platform or gateway, or resell API access, a safety enforcement action can then apply to one end customer instead of your whole organization. The SDK and the `ant` CLI support the new [`/v1/user_profiles` endpoints](https://platform.claude.com/docs/en/api/user_profiles).
35* We've added [organization webhooks](https://platform.claude.com/docs/en/manage-claude/organization-webhooks) to the [Admin API](https://platform.claude.com/docs/en/manage-claude/admin-api), in beta with the `webhooks-2026-10-07` beta header. Its [`/v1/organizations/webhooks` endpoints](https://platform.claude.com/docs/en/api/beta/organization/webhooks) register webhook endpoints for two event types: one for when Anthropic restricts or bans one of your organization's user profiles, and one for when the restriction or ban ends. To request access, contact your Anthropic account team.
34* We’ve launched [user profiles](https://platform.claude.com/docs/en/manage-claude/user-profiles), so you can tell Anthropic which of your end customers each API request is for. If you operate a platform or gateway, or resell API access, a safety enforcement action can then apply to one end customer instead of your whole organization. The SDK and the `ant` CLI support the new [`/v1/user_profiles` endpoints](https://platform.claude.com/docs/en/api/user_profiles).
35* We’ve added [organization webhooks](https://platform.claude.com/docs/en/manage-claude/organization-webhooks) to the [Admin API](https://platform.claude.com/docs/en/manage-claude/admin-api), in beta with the `webhooks-2026-10-07` beta header. Its [`/v1/organizations/webhooks` endpoints](https://platform.claude.com/docs/en/api/beta/organization/webhooks) register webhook endpoints for two event types: one for when Anthropic restricts or bans one of your organization’s user profiles, and one for when the restriction or ban ends. To request access, contact your Anthropic account team.
3636* Organization admins can now turn off web fetch for their organization on the [**Capabilities**](https://platform.claude.com/settings/capabilities) page of the Claude Console. With web fetch off, a Messages API request that includes the web fetch tool fails with a 400 error. In a Claude Managed Agents session, `web_fetch` calls return an error result to the agent instead. With web fetch on, admins can also set allowed or blocked domains for web fetch on the same page. See [How to use web fetch](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool#how-to-use-web-fetch) and [Domain filtering](https://platform.claude.com/docs/en/agents-and-tools/tool-use/server-tools#domain-filtering).
37* In Claude Managed Agents, the [`web_fetch` tool](https://platform.claude.com/docs/en/managed-agents/tools#available-tools) now follows your organization's web fetch domain restrictions set on the [**Capabilities**](https://platform.claude.com/settings/capabilities) page of the Claude Console. A URL, including one reached by a redirect, must pass both the organization's list and the `allowed_domains` or `blocked_domains` list on the agent's `web_fetch` tool. See [Restrict web search and web fetch domains](https://platform.claude.com/docs/en/managed-agents/tools-web-restrictions).
38* In Claude Managed Agents, sessions follow your organization's web search settings on the [**Capabilities**](https://platform.claude.com/settings/capabilities) page of the Claude Console: the **Allow web search** setting since October 6, and its web search domain restrictions since October 14. The agent receives only the search results that both the organization's domain restrictions and the `allowed_domains` or `blocked_domains` list on the agent's [`web_search` tool](https://platform.claude.com/docs/en/managed-agents/tools#available-tools) allow. See [Restrict web search and web fetch domains](https://platform.claude.com/docs/en/managed-agents/tools-web-restrictions).
37* In Claude Managed Agents, the [`web_fetch` tool](https://platform.claude.com/docs/en/managed-agents/tools#available-tools) now follows your organization’s web fetch domain restrictions set on the [**Capabilities**](https://platform.claude.com/settings/capabilities) page of the Claude Console. A URL, including one reached by a redirect, must pass both the organization’s list and the `allowed_domains` or `blocked_domains` list on the agent’s `web_fetch` tool. See [Restrict web search and web fetch domains](https://platform.claude.com/docs/en/managed-agents/tools-web-restrictions).
38* In Claude Managed Agents, sessions follow your organization’s web search settings on the [**Capabilities**](https://platform.claude.com/settings/capabilities) page of the Claude Console: the **Allow web search** setting since October 6, and its web search domain restrictions since October 14. The agent receives only the search results that both the organization’s domain restrictions and the `allowed_domains` or `blocked_domains` list on the agent’s [`web_search` tool](https://platform.claude.com/docs/en/managed-agents/tools#available-tools) allow. See [Restrict web search and web fetch domains](https://platform.claude.com/docs/en/managed-agents/tools-web-restrictions).
3939
4040### October 15, 2026
4141
42* We've added `capabilities.thinking.types.between_tools` to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now report whether each model accepts `thinking: {type: "between_tools"}`, which turns off up-front thinking. See [Using the Models API](https://platform.claude.com/docs/en/models/overview#using-the-models-api).
42* We’ve added `capabilities.thinking.types.between_tools` to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now report whether each model accepts `thinking: {type: "between_tools"}`, which turns off up-front thinking. See [Using the Models API](https://platform.claude.com/docs/en/models/overview#using-the-models-api).
4343* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) now returns the text each organization member saved as **Instructions for Claude** in claude.ai and as **Global instructions** in Cowork, in beta for Claude Enterprise organizations. Call `GET /v1/compliance/organizations/{org_uuid}/user_preferences` with your existing Compliance Access Key and the `read:compliance_user_data` scope. See [List user preferences](https://platform.claude.com/docs/en/manage-claude/compliance-org-data#list-user-preferences).
4444* [Fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) is out of research preview for Claude Opus 5.5, and you no longer need to request access. Requests to Claude Opus 5.5 no longer require the `fast-mode-2026-02-01` beta header, and requests that still send it keep working. Claude Opus 5.5 now has a default fast mode rate limit in the Start, Build, and Scale usage tiers. Fast mode for Claude Opus 5 and Claude Opus 4.8 remains in research preview. Keep sending the beta header with fast mode requests to those models.
4545* [Fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 5.5 is now available on [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry) for deployments hosted on Azure.
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4646
4747### October 14, 2026
4848
49* We've launched [OpenTelemetry export](https://platform.claude.com/docs/en/manage-claude/opentelemetry) in beta, so you can trace Messages API requests and Claude Managed Agents sessions in your observability platform. The Claude SDK emits spans in Python, TypeScript, C#, Go, Java, PHP, and Ruby. To get spans from the API, [add an OpenTelemetry destination](https://platform.claude.com/docs/en/manage-claude/opentelemetry/api#add-a-destination) in the Claude Console.
49* We’ve launched [OpenTelemetry export](https://platform.claude.com/docs/en/manage-claude/opentelemetry) in beta, so you can trace Messages API requests and Claude Managed Agents sessions in your observability platform. The Claude SDK emits spans in Python, TypeScript, C#, Go, Java, PHP, and Ruby. To get spans from the API, [add an OpenTelemetry destination](https://platform.claude.com/docs/en/manage-claude/opentelemetry/api#add-a-destination) in the Claude Console.
5050* Claude Managed Agents [scheduled deployments](https://platform.claude.com/docs/en/managed-agents/scheduled-deployments) are now available on [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws#claude-managed-agents).
5151
5252### October 9, 2026
5353
54* You can now let a Claude Managed Agents agent use [dynamic workflows](https://platform.claude.com/docs/en/managed-agents/multiagent-orchestration#dynamic-workflows), in beta with the `managed-agents-2026-04-01` beta header. For work with many pieces, such as reviewing hundreds of documents, the agent can write a workflow. A workflow is a program that runs many agents in phases and combines their results. The server runs it in the background as a workflow run. To [turn dynamic workflows on](https://platform.claude.com/docs/en/managed-agents/multiagent-orchestration#turn-on-dynamic-workflows), set the agent's `multiagent` field to `{"type": "multiagent_20261001", "workflows": {"type": "enabled"}}`. To guide the agent, tell it in its system prompt when to start a run. Follow each run through `workflow_run.*` events on the session's event stream. See [Workflow runs](https://platform.claude.com/docs/en/managed-agents/workflow-runs).
54* You can now let a Claude Managed Agents agent use [dynamic workflows](https://platform.claude.com/docs/en/managed-agents/multiagent-orchestration#dynamic-workflows), in beta with the `managed-agents-2026-04-01` beta header. For work with many pieces, such as reviewing hundreds of documents, the agent can write a workflow. A workflow is a program that runs many agents in phases and combines their results. The server runs it in the background as a workflow run. To [turn dynamic workflows on](https://platform.claude.com/docs/en/managed-agents/multiagent-orchestration#turn-on-dynamic-workflows), set the agent’s `multiagent` field to `{"type": "multiagent_20261001", "workflows": {"type": "enabled"}}`. To guide the agent, tell it in its system prompt when to start a run. Follow each run through `workflow_run.*` events on the session’s event stream. See [Workflow runs](https://platform.claude.com/docs/en/managed-agents/workflow-runs).
5555
5656### October 8, 2026
5757
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6060
6161### October 7, 2026
6262
63* We've lowered the price of prompt cache reads on Claude Sonnet 5.5 from $0.20 USD to $0.10 USD per million tokens: 0.05x the base input price instead of 0.1x. Cache writes and all other prices are unchanged. See [Prompt caching pricing](https://platform.claude.com/docs/en/about-claude/pricing#prompt-caching).
64* We've launched **Claude Haiku 5.5** (`claude-haiku-5-5`), our most capable model tuned for high-volume and latency-sensitive work. It has a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows), 128k max output tokens, and [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) with the [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort). It's available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). See [What's new in Claude Haiku 5.5](https://platform.claude.com/docs/en/models/haiku-5-5/whats-new-haiku-5-5).
63* We’ve lowered the price of prompt cache reads on Claude Sonnet 5.5 from $0.20 USD to $0.10 USD per million tokens: 0.05x the base input price instead of 0.1x. Cache writes and all other prices are unchanged. See [Prompt caching pricing](https://platform.claude.com/docs/en/about-claude/pricing#prompt-caching).
64* We’ve launched **Claude Haiku 5.5** (`claude-haiku-5-5`), our most capable model tuned for high-volume and latency-sensitive work. It has a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows), 128k max output tokens, and [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) with the [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort). It’s available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). See [What’s new in Claude Haiku 5.5](https://platform.claude.com/docs/en/models/haiku-5-5/whats-new-haiku-5-5).
6565* Code written for Claude Haiku 4.5 can break on Claude Haiku 5.5. Manual extended thinking (`budget_tokens`), the sampling parameters `temperature`, `top_p`, and `top_k`, and assistant message prefill can each return a 400 error. `computer_20250124` also returns a 400 error: use the `computer_toolset_20260801` toolset on the Claude API and Google Cloud, or `computer_20251124` on Amazon Bedrock. A request that sends thinking blocks back after a change to `system`, `tools`, or earlier turns can also return a 400 error. Adaptive thinking is on by default, so a response can begin with `thinking` blocks, and their text is omitted unless you set `thinking.display` to `"summarized"`. The same text also counts as more tokens. See the [migration guide](https://platform.claude.com/docs/en/models/haiku-5-5/migration-guide) for each change. For model-specific prompting patterns, see [Prompting Claude Haiku 5.5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-haiku-5-5).
6666* The Python and TypeScript SDKs now include classes, in beta, for the [browser use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-tool) and the [computer use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool). You subclass one and write one method per tool against your own browser or desktop automation. The SDK runs the tool loop, the URL and file policies you set for the browser, and your approval callback. See [Browser and computer use with the SDK toolsets](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-sdk).
6767* Claude Max and Team plans now include monthly API credits. To learn how to claim them, see [API credits for Max and Team plans](https://platform.claude.com/docs/en/about-claude/api-credits-for-subscribers).
6868* In Claude Managed Agents, a cloud environment with `limited` networking now also applies its `allowed_hosts` to the `web_search` and `web_fetch` tools. A `web_fetch` call for a URL on a host that `allowed_hosts` does not match returns a `url_not_allowed` error result to the agent. `web_search` omits results from such hosts. When `allowed_hosts` lists no hosts, neither tool returns a page or a search result. `allow_package_managers` and `allow_mcp_servers` add no hosts for these tools. To let the tools reach a host, add it to `allowed_hosts`, which also opens it to the sandbox. `unrestricted` networking and self-hosted environments do not limit these tools. See [Environment networking](https://platform.claude.com/docs/en/managed-agents/environments#networking).
69* With `limited` networking, creating a session fails with a 400 error when an enabled web tool's `allowed_domains` has an entry not within `allowed_hosts`. So does a session update that adds such an entry. An `allowed_hosts` entry matches one exact host unless it starts with `*.`, so `docs.example.com` is not within `["example.com"]`. To fix the error, add the host to `allowed_hosts` or remove the entry from `allowed_domains`. See [Restrict web search and web fetch domains](https://platform.claude.com/docs/en/managed-agents/tools-web-restrictions).
70* In Claude Managed Agents, the [`web_fetch` tool](https://platform.claude.com/docs/en/managed-agents/tools#available-tools) now fetches only URLs that have already appeared in the session, for example in the text of a user message, in a `web_search` result, or in a page that `web_fetch` returned earlier. This reduces the risk of data exfiltration. A URL that appears only in Claude's own output, the agent's system prompt, an attached document, or the output of a tool such as `bash`, `read`, or an MCP tool does not count: a `web_fetch` call for it returns a `url_not_in_prior_context` error result to the agent. To let the agent fetch a URL, send it in the text of a `user.message` event.
69* With `limited` networking, creating a session fails with a 400 error when an enabled web tool’s `allowed_domains` has an entry not within `allowed_hosts`. So does a session update that adds such an entry. An `allowed_hosts` entry matches one exact host unless it starts with `*.`, so `docs.example.com` is not within `["example.com"]`. To fix the error, add the host to `allowed_hosts` or remove the entry from `allowed_domains`. See [Restrict web search and web fetch domains](https://platform.claude.com/docs/en/managed-agents/tools-web-restrictions).
70* In Claude Managed Agents, the [`web_fetch` tool](https://platform.claude.com/docs/en/managed-agents/tools#available-tools) now fetches only URLs that have already appeared in the session, for example in the text of a user message, in a `web_search` result, or in a page that `web_fetch` returned earlier. This reduces the risk of data exfiltration. A URL that appears only in Claude’s own output, the agent’s system prompt, an attached document, or the output of a tool such as `bash`, `read`, or an MCP tool does not count: a `web_fetch` call for it returns a `url_not_in_prior_context` error result to the agent. To let the agent fetch a URL, send it in the text of a `user.message` event.
7171
7272### October 6, 2026
7373
74* We've added `capabilities.server_tools` to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now report whether each model accepts the web search and code execution tools. To check whether a model accepts the code execution tool, read `capabilities.server_tools.code_execution`. The top-level `capabilities.code_execution` reports whether code can call your request's other tools. See [Using the Models API](https://platform.claude.com/docs/en/models/overview#using-the-models-api).
74* We’ve added `capabilities.server_tools` to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now report whether each model accepts the web search and code execution tools. To check whether a model accepts the code execution tool, read `capabilities.server_tools.code_execution`. The top-level `capabilities.code_execution` reports whether code can call your request’s other tools. See [Using the Models API](https://platform.claude.com/docs/en/models/overview#using-the-models-api).
7575
7676### October 5, 2026
7777
78* We've added `capabilities.thinking.types.disabled` to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now report whether each model accepts `thinking: {type: "disabled"}`, which turns thinking off. See [Using the Models API](https://platform.claude.com/docs/en/models/overview#using-the-models-api).
78* We’ve added `capabilities.thinking.types.disabled` to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now report whether each model accepts `thinking: {type: "disabled"}`, which turns thinking off. See [Using the Models API](https://platform.claude.com/docs/en/models/overview#using-the-models-api).
7979
8080### October 1, 2026
8181
82* We've added a `line` field to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now return the model line each model belongs to. Claude Opus 4.5 and Claude Opus 4.6 both report `opus`, for example. Use `line` to group models without parsing their IDs. `line` is `null` for a model that belongs to no line. See [Using the Models API](https://platform.claude.com/docs/en/models/overview#using-the-models-api).
82* We’ve added a `line` field to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now return the model line each model belongs to. Claude Opus 4.5 and Claude Opus 4.6 both report `opus`, for example. Use `line` to group models without parsing their IDs. `line` is `null` for a model that belongs to no line. See [Using the Models API](https://platform.claude.com/docs/en/models/overview#using-the-models-api).
8383* [Dreams](https://platform.claude.com/docs/en/managed-agents/dreams) (research preview) now supports Claude Opus 5.5, Claude Fable 5.1, and Claude Sonnet 5.5. See [Supported models](https://platform.claude.com/docs/en/managed-agents/dreams#limits).
8484
8585### September 30, 2026
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8989
9090### September 28, 2026
9191
92* We've launched **Claude Sonnet 5.5** (`claude-sonnet-5-5`). It's available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). For its context window, output limits, and prices, see the [Claude Sonnet 5.5 model page](https://platform.claude.com/docs/en/models/sonnet-5-5/overview).
93* Code written for Claude Sonnet 5 can break on Claude Sonnet 5.5 in five ways. To turn off up-front thinking, send `thinking: {"type": "between_tools"}` instead of `"disabled"`, at `high` effort or below. Forced tool use (`tool_choice` types `any` and `tool`) returns a 400 error. Thinking blocks are tied to the model and the conversation. On the Claude API and Google Cloud, the earlier `computer_20251124` computer use tool isn't accepted. The advisor tool rejects Claude Opus 4.8, Claude Opus 4.7, and Claude Sonnet 5 as advisors. See [What's new in Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/whats-new-sonnet-5-5) for each change and the [Claude Sonnet 5.5 migration guide](https://platform.claude.com/docs/en/models/sonnet-5-5/migration-guide) for before-and-after requests. For model-specific prompting patterns, see [Prompting Claude Sonnet 5.5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-sonnet-5-5).
94* Thinking blocks that Claude Sonnet 5.5 produces work only in the account that produced them, or in an account linked to it. When another account sends one of these blocks, the API drops the block before the model sees it, and the request succeeds. Blocks from earlier models aren't affected. See [Preserved thinking](https://platform.claude.com/docs/en/build-with-claude/preserved-thinking#account-bound-thinking).
92* We’ve launched **Claude Sonnet 5.5** (`claude-sonnet-5-5`). It’s available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). For its context window, output limits, and prices, see the [Claude Sonnet 5.5 model page](https://platform.claude.com/docs/en/models/sonnet-5-5/overview).
93* Code written for Claude Sonnet 5 can break on Claude Sonnet 5.5 in five ways. To turn off up-front thinking, send `thinking: {"type": "between_tools"}` instead of `"disabled"`, at `high` effort or below. Forced tool use (`tool_choice` types `any` and `tool`) returns a 400 error. Thinking blocks are tied to the model and the conversation. On the Claude API and Google Cloud, the earlier `computer_20251124` computer use tool isn’t accepted. The advisor tool rejects Claude Opus 4.8, Claude Opus 4.7, and Claude Sonnet 5 as advisors. See [What’s new in Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/whats-new-sonnet-5-5) for each change and the [Claude Sonnet 5.5 migration guide](https://platform.claude.com/docs/en/models/sonnet-5-5/migration-guide) for before-and-after requests. For model-specific prompting patterns, see [Prompting Claude Sonnet 5.5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-sonnet-5-5).
94* Thinking blocks that Claude Sonnet 5.5 produces work only in the account that produced them, or in an account linked to it. When another account sends one of these blocks, the API drops the block before the model sees it, and the request succeeds. Blocks from earlier models aren’t affected. See [Preserved thinking](https://platform.claude.com/docs/en/build-with-claude/preserved-thinking#account-bound-thinking).
9595
9696### September 24, 2026
9797
98* We're resuming billing for refusals that arrive before any output when `stop_details.category` is `"bio"`, `"frontier_llm"`, or `"reasoning_extraction"`, the categories where we measure low volumes of false positives. Mid-stream refusals were already billed. Refusals billed under this change are charged like any other request, at the rates of the model that ran it. Refusals before any output in other categories are still not billed, and fallback credit is unchanged. This change applies on all platforms. See [How refusals are billed](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback#how-refusals-are-billed).
99* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) local session endpoints are out of beta for Claude for Microsoft 365 sessions in Excel, PowerPoint, Word, and Outlook (`product_surface` values beginning with `office_agents`). See [Sessions on users' machines](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-local-sessions).
98* We’re resuming billing for refusals that arrive before any output when `stop_details.category` is `"bio"`, `"frontier_llm"`, or `"reasoning_extraction"`, the categories where we measure low volumes of false positives. Mid-stream refusals were already billed. Refusals billed under this change are charged like any other request, at the rates of the model that ran it. Refusals before any output in other categories are still not billed, and fallback credit is unchanged. This change applies on all platforms. See [How refusals are billed](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback#how-refusals-are-billed).
99* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) local session endpoints are out of beta for Claude for Microsoft 365 sessions in Excel, PowerPoint, Word, and Outlook (`product_surface` values beginning with `office_agents`). See [Sessions on users’ machines](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-local-sessions).
100100* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) [Activity Feed](https://platform.claude.com/docs/en/manage-claude/compliance-activity-feed) no longer returns file names, project document names, or artifact titles. The `filename` and `title` fields on file, project document, and artifact activities are now always empty or omitted, including on activities recorded before this change. To look up a name or title by the ID on the activity, use a Compliance Access Key with the `read:compliance_user_data` scope. See [Understand the Activity object](https://platform.claude.com/docs/en/manage-claude/compliance-activity-feed#understand-the-activity-object).
101101
102102### September 23, 2026
from line 105
105105
106106### September 22, 2026
107107
108* We've launched **Claude Opus 5.5** (`claude-opus-5-5`), a model for long-running agentic coding and knowledge work. It has a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) by default, 128k max output tokens, and always-on [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking), at $4 / $20 USD per MTok (Claude Opus 5 is $5 / $25 USD). Claude Opus 5.5 is available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). See [What's new in Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/whats-new-opus-5-5) for capabilities, API changes, and migration guidance.
109* On Claude Opus 5.5, thinking can't be disabled: `thinking: {"type": "disabled"}` and `thinking: {"type": "enabled", ...}` return a 400 error. Omit the `thinking` field and control thinking depth with the [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort). `tool_choice` types `any` and `tool` also return a 400 error, as on Claude Fable 5.1; use `auto` with [strict tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/strict-tool-use). On the Claude API and Google Cloud, [computer use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool) on this model requires the `computer_toolset_20260801` toolset and the earlier `computer_20251124` tool returns a 400 error; on Amazon Bedrock, `computer_20251124` keeps working. See the [Claude Opus 5.5 migration guide](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-5).
108* We’ve launched **Claude Opus 5.5** (`claude-opus-5-5`), a model for long-running agentic coding and knowledge work. It has a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) by default, 128k max output tokens, and always-on [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking), at $4 / $20 USD per MTok (Claude Opus 5 is $5 / $25 USD). Claude Opus 5.5 is available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). See [What’s new in Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/whats-new-opus-5-5) for capabilities, API changes, and migration guidance.
109* On Claude Opus 5.5, thinking can’t be disabled: `thinking: {"type": "disabled"}` and `thinking: {"type": "enabled", ...}` return a 400 error. Omit the `thinking` field and control thinking depth with the [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort). `tool_choice` types `any` and `tool` also return a 400 error, as on Claude Fable 5.1; use `auto` with [strict tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/strict-tool-use). On the Claude API and Google Cloud, [computer use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool) on this model requires the `computer_toolset_20260801` toolset and the earlier `computer_20251124` tool returns a 400 error; on Amazon Bedrock, `computer_20251124` keeps working. See the [Claude Opus 5.5 migration guide](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-5).
110110* [Fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) (research preview) is available for Claude Opus 5.5 on the Claude API.
111* Tools can now be defined inside a [mid-conversation system message](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages#define-tools-in-a-message-beta), in beta on the Claude API with the `inline-tools-2026-09-15` beta header. A `tool_addition` block can carry the tool's full definition (`tool: {"type": "tool_definition", "definition": {...}}`), so you can add a tool, change its schema, or move a server tool to a newer version without editing `tools` or invalidating the prompt cache. The same header covers adding and removing tools by reference. With the MCP connector's `mcp-client-2026-09-15` beta header as well, the definition can be an MCP toolset, and a response records each server's fetched tool list in an `mcp_tool_listing` block, which pins that list when you send it back.
111* Tools can now be defined inside a [mid-conversation system message](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages#define-tools-in-a-message-beta), in beta on the Claude API with the `inline-tools-2026-09-15` beta header. A `tool_addition` block can carry the tool’s full definition (`tool: {"type": "tool_definition", "definition": {...}}`), so you can add a tool, change its schema, or move a server tool to a newer version without editing `tools` or invalidating the prompt cache. The same header covers adding and removing tools by reference. With the MCP connector’s `mcp-client-2026-09-15` beta header as well, the definition can be an MCP toolset, and a response records each server’s fetched tool list in an `mcp_tool_listing` block, which pins that list when you send it back.
112112
113113### September 18, 2026
114114
115115* For [cache diagnostics](https://platform.claude.com/docs/en/build-with-claude/cache-diagnostics), a response to a request that sends the `cache-diagnosis-2026-04-07` beta header now always includes the `diagnostics` field. The field is `null` when the request did not include the `diagnostics` object. Previously the field was omitted in that case.
116* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) local session endpoints now also return transcripts of Claude in Chrome sessions (`product_surface` value `claude_in_chrome`), in beta for Claude Enterprise organizations, with your existing Compliance Access Key and the `read:compliance_user_data` scope. See [Sessions on users' machines](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-local-sessions).
116* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) local session endpoints now also return transcripts of Claude in Chrome sessions (`product_surface` value `claude_in_chrome`), in beta for Claude Enterprise organizations, with your existing Compliance Access Key and the `read:compliance_user_data` scope. See [Sessions on users’ machines](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-local-sessions).
117117
118118### September 14, 2026
119119
120120* The Messages API can now [compact a conversation on demand](https://platform.claude.com/docs/en/build-with-claude/compaction-on-demand) on the Claude API, in beta with the `compact-2026-09-04` beta header. Send the top-level `compaction` parameter, and the API returns a signed `compaction` block that summarizes the messages you sent. On later requests, send that block first, in place of those messages. You choose when to compact, the request can run in the background, and you can keep recent turns word for word after the summary. On models with preserved thinking, the thinking in those kept turns can stay valid.
121* With the `thinking-binding-controls-2026-08-01` beta header, the `input_transformations` response field gains a second entry type, `thinking_mismatch_allowed`. It names a thinking block that failed the prefix check on a request where the API doesn't enforce that check: on Claude Fable 5.1, for example, a request from an account created before August 31, 2026, with `prefix_mismatch_behavior` unset. The block still reaches the model unchanged. Log these entries to find history edits in production traffic before you opt into enforcement. See [Set the mismatch behavior and read `input_transformations`](https://platform.claude.com/docs/en/build-with-claude/preserved-thinking#preserved-thinking-controls).
121* With the `thinking-binding-controls-2026-08-01` beta header, the `input_transformations` response field gains a second entry type, `thinking_mismatch_allowed`. It names a thinking block that failed the prefix check on a request where the API doesn’t enforce that check: on Claude Fable 5.1, for example, a request from an account created before August 31, 2026, with `prefix_mismatch_behavior` unset. The block still reaches the model unchanged. Log these entries to find history edits in production traffic before you opt into enforcement. See [Set the mismatch behavior and read `input_transformations`](https://platform.claude.com/docs/en/build-with-claude/preserved-thinking#preserved-thinking-controls).
122122
123123### September 10, 2026
124124
125125* Claude Managed Agents permission policies now include `auto`: the server evaluates each agent or MCP tool call and runs it, denies it, or pauses for your approval. `agent.tool_use` and `agent.mcp_tool_use` events report how each call was evaluated in an `evaluation` field alongside `evaluated_permission`. See [Let the server evaluate each call with `auto`](https://platform.claude.com/docs/en/managed-agents/permission-policies#let-the-server-evaluate-each-call-with-auto).
126* Version 1.32.0 of the `ant` CLI adds `ant beta:sessions connect`, which attaches your terminal to a Claude Managed Agents session. You can follow the session live, send messages, and allow or deny tool calls that are waiting for approval. Pass `--web` to serve the Claude Console's session viewer locally and open the session there instead. See [Connect to a Managed Agents session from your terminal](https://platform.claude.com/docs/en/cli-sdks-libraries/cli/sessions-connect).
126* Version 1.32.0 of the `ant` CLI adds `ant beta:sessions connect`, which attaches your terminal to a Claude Managed Agents session. You can follow the session live, send messages, and allow or deny tool calls that are waiting for approval. Pass `--web` to serve the Claude Console’s session viewer locally and open the session there instead. See [Connect to a Managed Agents session from your terminal](https://platform.claude.com/docs/en/cli-sdks-libraries/cli/sessions-connect).
127127
128128### September 9, 2026
129129
130* For [cache diagnostics](https://platform.claude.com/docs/en/build-with-claude/cache-diagnostics), the API now stores a request's fingerprint only when the request includes the `diagnostics` object. A request that sends only the `cache-diagnosis-2026-04-07` beta header is still accepted, but no fingerprint is stored. A later turn that points `previous_message_id` at it reports `previous_message_not_found`. Include `diagnostics` on every turn, with `"previous_message_id": null` on the first.
130* For [cache diagnostics](https://platform.claude.com/docs/en/build-with-claude/cache-diagnostics), the API now stores a request’s fingerprint only when the request includes the `diagnostics` object. A request that sends only the `cache-diagnosis-2026-04-07` beta header is still accepted, but no fingerprint is stored. A later turn that points `previous_message_id` at it reports `previous_message_not_found`. Include `diagnostics` on every turn, with `"previous_message_id": null` on the first.
131131
132132### September 3, 2026
133133
from line 136
136136
137137### September 1, 2026
138138
139* We've launched **Claude Fable 5.1** (`claude-fable-5-1`), the successor to Claude Fable 5 for long-running agentic coding, knowledge work, and research, alongside **Claude Mythos 5.1** (`claude-mythos-5-1`) for Project Glasswing participants. Both models support a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) by default, 128k max output tokens, and always-on [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking), at $10 / $50 USD per MTok, the same as Claude Fable 5, with cache reads cut to $0.25 USD per MTok. Claude Fable 5.1 is available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). See [What's new in Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1) for capabilities, API changes, and migration guidance.
139* We’ve launched **Claude Fable 5.1** (`claude-fable-5-1`), the successor to Claude Fable 5 for long-running agentic coding, knowledge work, and research, alongside **Claude Mythos 5.1** (`claude-mythos-5-1`) for Project Glasswing participants. Both models support a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) by default, 128k max output tokens, and always-on [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking), at $10 / $50 USD per MTok, the same as Claude Fable 5, with cache reads cut to $0.25 USD per MTok. Claude Fable 5.1 is available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). See [What’s new in Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1) for capabilities, API changes, and migration guidance.
140140* Prompt cache reads on Claude Fable 5.1 and Claude Mythos 5.1 cost $0.25 USD per million tokens: 0.025x the base input price, compared with 0.1x on other models. Cache writes are unchanged. See [Prompt caching pricing](https://platform.claude.com/docs/en/about-claude/pricing#prompt-caching).
141* On Claude Fable 5.1 and Claude Mythos 5.1, `tool_choice` types `any` and `tool` aren't supported and return a 400 error. `auto` and `none` are unchanged. To guarantee schema-conformant tool inputs, use [strict tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/strict-tool-use) or [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs).
142* Thinking blocks produced by Claude Fable 5.1 and Claude Mythos 5.1 are preserved only for the model that produced them or a newer one: earlier models can't read them, and the API drops one replayed to an earlier model. Claude Fable 5.1 accepts thinking blocks from Claude Opus 5, Claude Fable 5, Claude Mythos 5, and earlier Claude models. On Claude Fable 5.1, the API also [checks that nothing before a block has changed](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-in-conversation): for new accounts created on or after August 31, 2026, replaying one after the `system` prompt, `tools`, or an earlier message changed returns a 400 error. With the `thinking-binding-controls-2026-08-01` beta header, dropped blocks are reported in an `input_transformations` response field, and `thinking.block_binding.prefix_mismatch_behavior` chooses between rejecting and dropping blocks whose history changed. See [Preserved thinking](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-thinking).
141* On Claude Fable 5.1 and Claude Mythos 5.1, `tool_choice` types `any` and `tool` aren’t supported and return a 400 error. `auto` and `none` are unchanged. To guarantee schema-conformant tool inputs, use [strict tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/strict-tool-use) or [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs).
142* Thinking blocks produced by Claude Fable 5.1 and Claude Mythos 5.1 are preserved only for the model that produced them or a newer one: earlier models can’t read them, and the API drops one replayed to an earlier model. Claude Fable 5.1 accepts thinking blocks from Claude Opus 5, Claude Fable 5, Claude Mythos 5, and earlier Claude models. On Claude Fable 5.1, the API also [checks that nothing before a block has changed](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-in-conversation): for new accounts created on or after August 31, 2026, replaying one after the `system` prompt, `tools`, or an earlier message changed returns a 400 error. With the `thinking-binding-controls-2026-08-01` beta header, dropped blocks are reported in an `input_transformations` response field, and `thinking.block_binding.prefix_mismatch_behavior` chooses between rejecting and dropping blocks whose history changed. See [Preserved thinking](https://platform.claude.com/docs/en/build-with-claude/thinking#preserved-thinking).
143143* Per-message effort changes are in beta on Claude Fable 5.1, Claude Mythos 5.1, and Claude Opus 5 on the Claude API. Add a `role: "system"` message with `output_config.effort` inside `messages` to change effort for later turns while preserving the prompt cache. Include the `mid-conversation-output-config-2026-07-01` beta header in your requests. See [Per-message effort](https://platform.claude.com/docs/en/build-with-claude/effort#change-effort-mid-conversation-beta).
144* [Turn-scoped system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages#turn-scoped-system-messages) are in beta (`mid-conversation-system-clear-at-2026-08-21` header). Set `clear_at: "next_user_message"` on a mid-conversation `role: "system"` message and it renders for the current turn only, then stays in the history at no token cost. Per-turn reminders don't accumulate and don't invalidate the prompt cache or later thinking blocks.
144* [Turn-scoped system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages#turn-scoped-system-messages) are in beta (`mid-conversation-system-clear-at-2026-08-21` header). Set `clear_at: "next_user_message"` on a mid-conversation `role: "system"` message and it renders for the current turn only, then stays in the history at no token cost. Per-turn reminders don’t accumulate and don’t invalidate the prompt cache or later thinking blocks.
145145* `thinking.display` accepts a third value, `"updates"`, in beta (`thinking-display-updates-2026-08-18` header). Reasoning comes back with an empty `thinking` field, as under `"omitted"`, and the short progress updates that Claude Fable 5.1, Claude Mythos 5.1, and Claude Fable 5 write between tool calls come back as text, at most one `thinking` block before a tool call. See [Progress updates between tool calls](https://platform.claude.com/docs/en/build-with-claude/thinking#progress-updates).
146* Text generated by Claude Fable 5.1 and Claude Mythos 5.1 carries Anthropic's text watermark, and supported image, video, and audio files that Claude produces through the [code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) carry C2PA Content Credentials when you retrieve them through the [Files API](https://platform.claude.com/docs/en/build-with-claude/files) on the Claude API. Marking requires no changes to your requests or response handling.
147* Like Claude Fable 5, both models require 30-day data retention and aren't available under zero data retention unless expressly authorized by Anthropic. See [Model-specific data retention requirements](https://platform.claude.com/docs/en/manage-claude/api-and-data-retention#model-specific-data-retention-requirements).
146* Text generated by Claude Fable 5.1 and Claude Mythos 5.1 carries Anthropic’s text watermark, and supported image, video, and audio files that Claude produces through the [code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) carry C2PA Content Credentials when you retrieve them through the [Files API](https://platform.claude.com/docs/en/build-with-claude/files) on the Claude API. Marking requires no changes to your requests or response handling.
147* Like Claude Fable 5, both models require 30-day data retention and aren’t available under zero data retention unless expressly authorized by Anthropic. See [Model-specific data retention requirements](https://platform.claude.com/docs/en/manage-claude/api-and-data-retention#model-specific-data-retention-requirements).
148148* The guides for the Claude Enterprise endpoints of the [Admin API](https://platform.claude.com/docs/en/api/beta/organization) ([user management](https://platform.claude.com/docs/en/manage-claude/user-management) and [spend limits](https://platform.claude.com/docs/en/manage-claude/spend-limits-api)), the [Claude Enterprise Analytics API](https://platform.claude.com/docs/en/manage-claude/analytics-api), and the [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) now show the `anthropic-version` header; send it on every request to these endpoints, as in the rest of the Claude API. See [API versions](https://platform.claude.com/docs/en/api/versioning).
149149
150150### August 27, 2026
from line 156
156156### August 26, 2026
157157
158158* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) session endpoints are out of beta for Cowork and Claude Code sessions. See [Retrieve session transcripts](https://platform.claude.com/docs/en/manage-claude/compliance-sessions).
159* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) local session endpoints now also return transcripts of Claude Science sessions (`product_surface` value `claude_science`) and Claude for Microsoft 365 sessions in Excel, PowerPoint, Word, and Outlook (`product_surface` values beginning with `office_agents`), in beta for Claude Enterprise organizations, with your existing Compliance Access Key and the `read:compliance_user_data` scope. See [Sessions on users' machines](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-local-sessions).
159* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) local session endpoints now also return transcripts of Claude Science sessions (`product_surface` value `claude_science`) and Claude for Microsoft 365 sessions in Excel, PowerPoint, Word, and Outlook (`product_surface` values beginning with `office_agents`), in beta for Claude Enterprise organizations, with your existing Compliance Access Key and the `read:compliance_user_data` scope. See [Sessions on users’ machines](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-local-sessions).
160160* The [Admin API](https://platform.claude.com/docs/en/manage-claude/admin-api) is now available in the `ant` CLI and the Python, TypeScript, C#, Go, Java, PHP, and Ruby SDKs under `client.beta.organization`. They cover organization info, members, invites, workspaces and workspace members, API keys, rate limits, service accounts, workload identity federation issuers and rules, and customer-managed encryption keys. Usage and cost reports and the Claude Enterprise user-management and analytics endpoints remain curl-only. The CLI and SDKs read an Admin API key from `ANTHROPIC_API_KEY` or an `org:admin` OAuth token from `ANTHROPIC_AUTH_TOKEN`.
161161
162162### August 20, 2026
163163
164* We've released **v1.0 of the [Python SDK](https://platform.claude.com/docs/en/cli-sdks-libraries/sdks/python)**. The SDK's HTTP layer moves from `httpx` to [httpx2](https://httpx2.pydantic.dev), a maintained, API-compatible fork: build custom `http_client`, `Timeout`, and transport objects from `httpx2` (the `DefaultHttpxClient` helpers are unchanged), and call `httpx2.alias_httpx()` at startup if you rely on tracing or mocking libraries that patch `httpx`. v1.0 requires Python 3.10 or later and removes long-deprecated surface, including the legacy Text Completions API, the `temperature`, `top_p`, and `top_k` parameters on Messages methods, and the tool runner's client-side `compaction_control`. On the async client, `.with_raw_response` results now need `await response.parse()`, and `AnthropicBedrock` now raises an error when no AWS region is configured instead of defaulting to `us-east-1`. See the [v1 migration guide](https://github.com/anthropics/anthropic-sdk-python/blob/main/MIGRATION.md) for every change with before-and-after snippets.
164* We’ve released **v1.0 of the [Python SDK](https://platform.claude.com/docs/en/cli-sdks-libraries/sdks/python)**. The SDK’s HTTP layer moves from `httpx` to [httpx2](https://httpx2.pydantic.dev), a maintained, API-compatible fork: build custom `http_client`, `Timeout`, and transport objects from `httpx2` (the `DefaultHttpxClient` helpers are unchanged), and call `httpx2.alias_httpx()` at startup if you rely on tracing or mocking libraries that patch `httpx`. v1.0 requires Python 3.10 or later and removes long-deprecated surface, including the legacy Text Completions API, the `temperature`, `top_p`, and `top_k` parameters on Messages methods, and the tool runner’s client-side `compaction_control`. On the async client, `.with_raw_response` results now need `await response.parse()`, and `AnthropicBedrock` now raises an error when no AWS region is configured instead of defaulting to `us-east-1`. See the [v1 migration guide](https://github.com/anthropics/anthropic-sdk-python/blob/main/MIGRATION.md) for every change with before-and-after snippets.
165165* The [computer use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool) and [browser use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-tool) toolsets (`computer_toolset_20260801` and `browser_toolset_20260801`) are now available on [Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed) for Claude Fable 5, Claude Mythos 5, Claude Opus 5, Claude Sonnet 5, and Claude Opus 4.8. Requests use the same `tools` entries as on the Claude API.
166166
167167### August 19, 2026
168168
169169* The [computer use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool) is out of beta on the Claude API as the `computer_toolset_20260801` toolset: no beta header, batch actions (several actions in one turn), `zoom` enabled by default, and per-member configuration through `configs`. Earlier beta versions remain available. Upgrading an existing integration changes the request shape and tool handling; see [Migrate from `computer_20251124`](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool#migrate-from-computer-20251124).
170* We've launched the [browser use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-tool) (`browser_toolset_20260801`), a client toolset for driving a browser that your application hosts. It works inside a browser viewport rather than a whole desktop, reading the page itself (its accessibility tree, elements, forms, and tabs) and adding element references, form input, tab management, download reporting, and opt-in file upload on top of screenshot-and-click control.
170* We’ve launched the [browser use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-tool) (`browser_toolset_20260801`), a client toolset for driving a browser that your application hosts. It works inside a browser viewport rather than a whole desktop, reading the page itself (its accessibility tree, elements, forms, and tabs) and adding element references, form input, tab management, download reporting, and opt-in file upload on top of screenshot-and-click control.
171171* Both toolsets are available for Claude Fable 5, Claude Mythos 5, Claude Opus 5, Claude Sonnet 5, and Claude Opus 4.8 on the Claude API.
172172* The [Files API](https://platform.claude.com/docs/en/build-with-claude/files) is out of beta on the Claude API. Requests to the `/v1/files` endpoints, and Messages API requests that reference an uploaded file, no longer require the `files-api-2025-04-14` beta header. Requests sent without the header use the current response format: [file expiration](https://platform.claude.com/docs/en/build-with-claude/files#file-expiration) (set `expires_in_seconds` when you upload a file; file objects report `expires_at`), and `page` and `next_page` [pagination](https://platform.claude.com/docs/en/api/overview#pagination) plus an `ids[]` filter when you [list files](https://platform.claude.com/docs/en/build-with-claude/files#list-files). `/v1/files` requests that still send the beta header keep working and return the previous response format. To move an existing integration off the header, see [Migrate from `files-api-2025-04-14`](https://platform.claude.com/docs/en/build-with-claude/files#migrate-from-files-api-2025-04-14).
173173* [Agent Skills](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview) and the Skills API (`/v1/skills`) are out of beta on the Claude API. Requests no longer require the `skills-2025-10-02` beta header, including Messages API requests that load Skills through the `container` parameter. Requests that still send the header continue to work unchanged. See [Using Agent Skills with the API](https://platform.claude.com/docs/en/build-with-claude/skills-guide). To move an existing integration off the header, see [Migrate from `skills-2025-10-02`](https://platform.claude.com/docs/en/build-with-claude/skills-guide#migrate-from-skills-2025-10-02).
174174* The [Admin API](https://platform.claude.com/docs/en/api/beta/organization) user-management endpoints for **Claude Enterprise** (claude.ai) organizations (members, invites, groups, and custom roles) are out of beta. The `anthropic-beta: ce-user-management-2026-07-13` header is no longer required on group and custom-role requests; requests that still send it are accepted unchanged. See [User management](https://platform.claude.com/docs/en/manage-claude/user-management).
175* You can now restrict which sites a Claude Managed Agents agent's `web_search` and `web_fetch` tools can reach. Set `allowed_domains` or `blocked_domains` on the tool's entry in the `agent_toolset_20260401` `configs` array; `web_fetch` also accepts `max_content_tokens` and `web_search` accepts `user_location`. Each `configs` entry is identified by its `name` and typed by an optional `type`, and requests that pass only `name`, `enabled`, and `permission_policy` continue to work; in the typed SDKs, `configs` entries become [per-tool types](https://platform.claude.com/docs/en/managed-agents/tools#config-entry-types-in-the-sdks). See [Restrict web search and web fetch domains](https://platform.claude.com/docs/en/managed-agents/tools-web-restrictions).
176* Claude Managed Agents sessions that run in a [self-hosted sandbox](https://platform.claude.com/docs/en/managed-agents/self-hosted-sandboxes) can now attach [memory stores](https://platform.claude.com/docs/en/managed-agents/memory). The Python, TypeScript, and Go SDK workers download each attached store into the sandbox at its `mount_path` and sync the agent's changes back to the store. See [Memory stores in self-hosted sandboxes](https://platform.claude.com/docs/en/managed-agents/self-hosted-sandboxes-memory).
175* You can now restrict which sites a Claude Managed Agents agent’s `web_search` and `web_fetch` tools can reach. Set `allowed_domains` or `blocked_domains` on the tool’s entry in the `agent_toolset_20260401` `configs` array; `web_fetch` also accepts `max_content_tokens` and `web_search` accepts `user_location`. Each `configs` entry is identified by its `name` and typed by an optional `type`, and requests that pass only `name`, `enabled`, and `permission_policy` continue to work; in the typed SDKs, `configs` entries become [per-tool types](https://platform.claude.com/docs/en/managed-agents/tools#config-entry-types-in-the-sdks). See [Restrict web search and web fetch domains](https://platform.claude.com/docs/en/managed-agents/tools-web-restrictions).
176* Claude Managed Agents sessions that run in a [self-hosted sandbox](https://platform.claude.com/docs/en/managed-agents/self-hosted-sandboxes) can now attach [memory stores](https://platform.claude.com/docs/en/managed-agents/memory). The Python, TypeScript, and Go SDK workers download each attached store into the sandbox at its `mount_path` and sync the agent’s changes back to the store. See [Memory stores in self-hosted sandboxes](https://platform.claude.com/docs/en/managed-agents/self-hosted-sandboxes-memory).
177177* The session viewer in the Claude Console has been redesigned with a timeline minimap, a transcript grouped by model request, and an Inspector panel for session details and cost, raw events, per-tool statistics, mounted resources, and per-thread activity. See [Inspect a session in the Console](https://platform.claude.com/docs/en/managed-agents/session-observability#inspect-a-session-in-the-console).
178178
179179### August 18, 2026
from line 182
182182
183183### August 11, 2026
184184
185* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) now returns transcripts of Cowork and Claude Code sessions that run on your users' machines, in beta for Claude Enterprise organizations. `GET /v1/compliance/apps/sessions/local` lists sessions across your organization, `GET /v1/compliance/apps/sessions/local/{session_id}` retrieves one session's metadata, and `GET /v1/compliance/apps/sessions/local/{session_id}/messages` returns its transcript, all with your existing Compliance Access Key and the `read:compliance_user_data` scope. See [Sessions on users' machines](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-local-sessions).
186* We've added the `anthropic-workspace-id` response header to the Claude API. It carries the `wrkspc_`-prefixed ID of the workspace that the request's API key or access token resolved to, including your organization's Default Workspace. See [Identify the workspace behind an API response](https://platform.claude.com/docs/en/manage-claude/workspaces#identify-the-workspace-behind-an-api-response).
185* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) now returns transcripts of Cowork and Claude Code sessions that run on your users’ machines, in beta for Claude Enterprise organizations. `GET /v1/compliance/apps/sessions/local` lists sessions across your organization, `GET /v1/compliance/apps/sessions/local/{session_id}` retrieves one session’s metadata, and `GET /v1/compliance/apps/sessions/local/{session_id}/messages` returns its transcript, all with your existing Compliance Access Key and the `read:compliance_user_data` scope. See [Sessions on users’ machines](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-local-sessions).
186* We’ve added the `anthropic-workspace-id` response header to the Claude API. It carries the `wrkspc_`-prefixed ID of the workspace that the request’s API key or access token resolved to, including your organization’s Default Workspace. See [Identify the workspace behind an API response](https://platform.claude.com/docs/en/manage-claude/workspaces#identify-the-workspace-behind-an-api-response).
187187
188188### August 10, 2026
189189
from line 191
191191
192192### August 7, 2026
193193
194* You can now set a budget on a Claude Managed Agents session: a hard cap on the session's spend, priced at public list rates. A session that reaches its budget pauses with the `budget_reached` stop reason instead of starting new model requests; changing or removing the budget resumes it. Deployments accept the same budget and apply it to each session they start. See [Session budgets](https://platform.claude.com/docs/en/managed-agents/budgets).
195* You can now give a Claude Managed Agents session an advisor: a model at least as capable as the agent's own that the session's primary thread can consult mid-turn for strategic guidance. Configure it as a `{"type": "advisor"}` entry in the agent's multiagent roster, naming the `model` to consult. See [Give the session an advisor](https://platform.claude.com/docs/en/managed-agents/multiagent-orchestration#give-the-session-an-advisor).
194* You can now set a budget on a Claude Managed Agents session: a hard cap on the session’s spend, priced at public list rates. A session that reaches its budget pauses with the `budget_reached` stop reason instead of starting new model requests; changing or removing the budget resumes it. Deployments accept the same budget and apply it to each session they start. See [Session budgets](https://platform.claude.com/docs/en/managed-agents/budgets).
195* You can now give a Claude Managed Agents session an advisor: a model at least as capable as the agent’s own that the session’s primary thread can consult mid-turn for strategic guidance. Configure it as a `{"type": "advisor"}` entry in the agent’s multiagent roster, naming the `model` to consult. See [Give the session an advisor](https://platform.claude.com/docs/en/managed-agents/multiagent-orchestration#give-the-session-an-advisor).
196196* You can now control where model inference runs for a Claude Managed Agents agent. Set `inference_geo` inside the `model` object when you [create the agent](https://platform.claude.com/docs/en/managed-agents/agent-setup#pin-the-inference-geo), or [override it for a single session](https://platform.claude.com/docs/en/managed-agents/sessions#pin-the-inference-geo-for-a-session). See [Data residency](https://platform.claude.com/docs/en/manage-claude/data-residency) for the available geos and pricing.
197197* Claude Managed Agents sessions can now [load skills from a GitHub repository](https://platform.claude.com/docs/en/managed-agents/skills#load-skills-from-a-github-repository). When a session [mounts a repository](https://platform.claude.com/docs/en/managed-agents/github), any skills in its root `.claude/skills` directory are discovered automatically at session start and available to the agent for that session.
198198
199199### August 5, 2026
200200
201* **Inference hooks** are now in beta for Claude Enterprise organizations. Point Claude at your organization's AI security server, and each governed prompt across claude.ai, Cowork, and Claude Code is held for the server's allow or deny verdict before inference proceeds. Requests are signed, failure handling is configurable, and every denial is recorded in the compliance [Activity Feed](https://platform.claude.com/docs/en/manage-claude/compliance-activity-feed). See [Inference hooks](https://platform.claude.com/docs/en/manage-claude/inference-hooks).
202* We've retired the Claude Opus 4.1 model (`claude-opus-4-1-20250805`). All requests to this model on the Claude API will now return an error. We recommend upgrading to [Claude Opus 5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison). Researchers can request ongoing access through the [External Researcher Access Program](https://support.claude.com/en/articles/9125743-what-is-the-external-researcher-access-program).
201* **Inference hooks** are now in beta for Claude Enterprise organizations. Point Claude at your organization’s AI security server, and each governed prompt across claude.ai, Cowork, and Claude Code is held for the server’s allow or deny verdict before inference proceeds. Requests are signed, failure handling is configurable, and every denial is recorded in the compliance [Activity Feed](https://platform.claude.com/docs/en/manage-claude/compliance-activity-feed). See [Inference hooks](https://platform.claude.com/docs/en/manage-claude/inference-hooks).
202* We’ve retired the Claude Opus 4.1 model (`claude-opus-4-1-20250805`). All requests to this model on the Claude API will now return an error. We recommend upgrading to [Claude Opus 5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison). Researchers can request ongoing access through the [External Researcher Access Program](https://support.claude.com/en/articles/9125743-what-is-the-external-researcher-access-program).
203203
204204### August 3, 2026
205205
206* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) now returns transcripts of Cowork sessions started on claude.ai web or mobile, in beta for Claude Enterprise organizations. `GET /v1/compliance/apps/sessions/remote` lists sessions and `GET /v1/compliance/apps/sessions/remote/{session_id}/messages` returns one session's transcript, using your existing Compliance Access Key with the `read:compliance_user_data` scope. See [Sessions in the cloud](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-remote-sessions).
206* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) now returns transcripts of Cowork sessions started on claude.ai web or mobile, in beta for Claude Enterprise organizations. `GET /v1/compliance/apps/sessions/remote` lists sessions and `GET /v1/compliance/apps/sessions/remote/{session_id}/messages` returns one session’s transcript, using your existing Compliance Access Key with the `read:compliance_user_data` scope. See [Sessions in the cloud](https://platform.claude.com/docs/en/manage-claude/compliance-sessions#retrieve-remote-sessions).
207207
208208### August 1, 2026
209209
from line 211
211211
212212### July 24, 2026
213213
214* We've launched **Claude Opus 5** (`claude-opus-5`), a step-change improvement over Claude Opus 4.8. Claude Opus 5 supports a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) (both the default and the maximum), 128k max output tokens, and [thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) on by default, at $5 / $25 USD per MTok, the same pricing as Claude Opus 4.8. It's available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). See [What's new in Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/overview) for new features, behavior changes, and migration guidance, and the [models overview](https://platform.claude.com/docs/en/models/overview) for complete specs.
215* On Claude Opus 5, disabling thinking is allowed only at effort `high` or below: `thinking: {"type": "disabled"}` with effort `xhigh` or `max` returns a 400 error, a breaking change from Claude Opus 4.8. See [What's new in Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/overview).
214* We’ve launched **Claude Opus 5** (`claude-opus-5`), a step-change improvement over Claude Opus 4.8. Claude Opus 5 supports a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) (both the default and the maximum), 128k max output tokens, and [thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) on by default, at $5 / $25 USD per MTok, the same pricing as Claude Opus 4.8. It’s available on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude on Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed), and [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). See [What’s new in Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/overview) for new features, behavior changes, and migration guidance, and the [models overview](https://platform.claude.com/docs/en/models/overview) for complete specs.
215* On Claude Opus 5, disabling thinking is allowed only at effort `high` or below: `thinking: {"type": "disabled"}` with effort `xhigh` or `max` returns a 400 error, a breaking change from Claude Opus 4.8. See [What’s new in Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/overview).
216216* [Effort](https://platform.claude.com/docs/en/build-with-claude/effort) is the primary control for steering Claude Opus 5: the model supports the full ladder (`low`, `medium`, `high`, `xhigh`, `max`), with `max` for capability-critical work.
217217* Mid-conversation tool changes are now in beta on Claude Fable 5, Claude Mythos 5, Claude Opus 4.8, and Claude Opus 5: add or remove tools between turns of a conversation while preserving the prompt cache. Include the `mid-conversation-tool-changes-2026-07-01` beta header in your requests.
218* The `fallbacks` parameter now supports a `"default"` mode, which applies Anthropic's recommended fallback models by refusal category. Server-side fallback is in beta, and the `"default"` mode requires the `server-side-fallback-2026-07-01` beta header. See [Refusals and fallback](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback).
219* We've removed [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.7. Requests to `claude-opus-4-7` with `speed: "fast"` now return an error; unlike Claude Opus 4.6, they do not fall back to standard speed. Claude Opus 4.7 itself remains available at standard speed. To continue using fast mode, migrate to [Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/overview) or Claude Opus 4.8. Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
218* The `fallbacks` parameter now supports a `"default"` mode, which applies Anthropic’s recommended fallback models by refusal category. Server-side fallback is in beta, and the `"default"` mode requires the `server-side-fallback-2026-07-01` beta header. See [Refusals and fallback](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback).
219* We’ve removed [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.7. Requests to `claude-opus-4-7` with `speed: "fast"` now return an error; unlike Claude Opus 4.6, they do not fall back to standard speed. Claude Opus 4.7 itself remains available at standard speed. To continue using fast mode, migrate to [Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/overview) or Claude Opus 4.8. Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
220220
221221### July 22, 2026
222222
223* You can now set an `effort` level on a Claude Managed Agents agent's model configuration. Pass `effort` inside the `model` object when you [create the agent](https://platform.claude.com/docs/en/managed-agents/agent-setup#create-an-agent). See [Effort levels](https://platform.claude.com/docs/en/build-with-claude/effort#effort-levels) for what each level does.
223* You can now set an `effort` level on a Claude Managed Agents agent’s model configuration. Pass `effort` inside the `model` object when you [create the agent](https://platform.claude.com/docs/en/managed-agents/agent-setup#create-an-agent). See [Effort levels](https://platform.claude.com/docs/en/build-with-claude/effort#effort-levels) for what each level does.
224224* Webhooks for Claude Managed Agents now cover the environment and memory store lifecycle: four `environment.*` event types and three `memory_store.*` event types. You can react to environment and memory store lifecycle changes without polling. See the Environment events and Memory store events tabs in [Supported event types](https://platform.claude.com/docs/en/managed-agents/webhooks#supported-event-types).
225* When creating a Claude Managed Agents session, you can now [seed it with initial events](https://platform.claude.com/docs/en/managed-agents/sessions#seed-the-session-with-initial-events). Pass `initial_events` on `POST /v1/sessions` with up to 50 `user.message` and `user.define_outcome` events. A non-empty list starts the agent loop in the same call, so you don't need a separate send-events request to start work.
225* When creating a Claude Managed Agents session, you can now [seed it with initial events](https://platform.claude.com/docs/en/managed-agents/sessions#seed-the-session-with-initial-events). Pass `initial_events` on `POST /v1/sessions` with up to 50 `user.message` and `user.define_outcome` events. A non-empty list starts the agent loop in the same call, so you don’t need a separate send-events request to start work.
226226* The `version` field is now optional when [updating a Claude Managed Agents agent](https://platform.claude.com/docs/en/managed-agents/agent-setup#update-an-agent). Supply it for optimistic concurrency (a mismatch returns a 409 error), or omit it to apply the update unconditionally. See [Update semantics](https://platform.claude.com/docs/en/managed-agents/agent-setup#update-semantics).
227* Claude Managed Agents session thread event streams now support [event deltas](https://platform.claude.com/docs/en/managed-agents/event-deltas). `GET /v1/sessions/{session_id}/threads/{thread_id}/stream` accepts the same `event_deltas[]` query parameter as the session-level stream, so you can preview a subagent's text as the model generates it. A connection previews only the thread it's reading. See [Preview session thread events](https://platform.claude.com/docs/en/managed-agents/event-deltas#preview-session-thread-events).
227* Claude Managed Agents session thread event streams now support [event deltas](https://platform.claude.com/docs/en/managed-agents/event-deltas). `GET /v1/sessions/{session_id}/threads/{thread_id}/stream` accepts the same `event_deltas[]` query parameter as the session-level stream, so you can preview a subagent’s text as the model generates it. A connection previews only the thread it’s reading. See [Preview session thread events](https://platform.claude.com/docs/en/managed-agents/event-deltas#preview-session-thread-events).
228228
229229### July 17, 2026
230230
from line 237
237237
238238### July 14, 2026
239239
240* You can now manage the people in your **Claude Enterprise** (claude.ai) organization with the [Admin API](https://platform.claude.com/docs/en/api/beta/organization), in beta for all Claude Enterprise organizations: list members and look them up by email address, change a member's role, remove members, send and withdraw invites, manage groups and their membership, and read custom roles. Group and custom-role requests require the `anthropic-beta: ce-user-management-2026-07-13` beta header; member and invite requests take no beta header. An Admin API key with the `read:org_audit` scope can also call every user-management `GET` endpoint. See [User management](https://platform.claude.com/docs/en/manage-claude/user-management).
240* You can now manage the people in your **Claude Enterprise** (claude.ai) organization with the [Admin API](https://platform.claude.com/docs/en/api/beta/organization), in beta for all Claude Enterprise organizations: list members and look them up by email address, change a member’s role, remove members, send and withdraw invites, manage groups and their membership, and read custom roles. Group and custom-role requests require the `anthropic-beta: ce-user-management-2026-07-13` beta header; member and invite requests take no beta header. An Admin API key with the `read:org_audit` scope can also call every user-management `GET` endpoint. See [User management](https://platform.claude.com/docs/en/manage-claude/user-management).
241241
242242### July 10, 2026
243243
244244* [Dreams](https://platform.claude.com/docs/en/managed-agents/dreams) (research preview) now supports Claude Fable 5 and Claude Sonnet 5. See [Supported models](https://platform.claude.com/docs/en/managed-agents/dreams#limits).
245* We've expanded the [Access Transparency](https://platform.claude.com/docs/en/manage-claude/access-transparency) documentation of `cmek_preserve` events with a filter example, an example event payload, and two preservation reason codes (`policy_violation_investigation`, `csae_report`). The documentation now also clarifies that a preservation event is written whether the preservation was initiated by a human reviewer or an automated safety pipeline. See [CMEK content preservation](https://platform.claude.com/docs/en/manage-claude/access-transparency#cmek-content-preservation).
245* We’ve expanded the [Access Transparency](https://platform.claude.com/docs/en/manage-claude/access-transparency) documentation of `cmek_preserve` events with a filter example, an example event payload, and two preservation reason codes (`policy_violation_investigation`, `csae_report`). The documentation now also clarifies that a preservation event is written whether the preservation was initiated by a human reviewer or an automated safety pipeline. See [CMEK content preservation](https://platform.claude.com/docs/en/manage-claude/access-transparency#cmek-content-preservation).
246246
247247### July 8, 2026
248248
249* You can now set an expiration when you create an API key or an Admin API key in the [Claude Console](https://platform.claude.com/settings/keys). Choose a preset, a custom duration, or **Never**. For keys with a lifetime of at least 7 days, Anthropic emails the creator before expiration. Existing keys are unaffected. The Admin API reports each key's expiration in the [`expires_at`](https://platform.claude.com/docs/en/api/beta/organization/api_keys/list) field. See [Key expiration in Authentication](https://platform.claude.com/docs/en/manage-claude/authentication#key-expiration).
249* You can now set an expiration when you create an API key or an Admin API key in the [Claude Console](https://platform.claude.com/settings/keys). Choose a preset, a custom duration, or **Never**. For keys with a lifetime of at least 7 days, Anthropic emails the creator before expiration. Existing keys are unaffected. The Admin API reports each key’s expiration in the [`expires_at`](https://platform.claude.com/docs/en/api/beta/organization/api_keys/list) field. See [Key expiration in Authentication](https://platform.claude.com/docs/en/manage-claude/authentication#key-expiration).
250250
251251### July 2, 2026
252252
253* We've added the `agent-memory-2026-07-22` beta header, which changes how [listing memories](https://platform.claude.com/docs/en/managed-agents/memory#list-memories) (`GET /v1/memory_stores/{memory_store_id}/memories`) behaves: results are returned in a stable, server-defined order and the `order_by` and `order` parameters are ignored; `depth` accepts only `0`, `1`, or being omitted (other values return a `400` error); and `path_prefix` must end with `/` and matches whole path segments instead of a substring. Page cursors issued without the header aren't valid with it, so restart from the first page when you adopt it. On memory store endpoints, `agent-memory-2026-07-22` replaces `managed-agents-2026-04-01`; sending both returns a `400` error. On July 22, 2026, the `managed-agents-2026-04-01` header adopts the same list behavior. See [Beta headers](https://platform.claude.com/docs/en/api/beta-headers#endpoint-specific-headers).
253* We’ve added the `agent-memory-2026-07-22` beta header, which changes how [listing memories](https://platform.claude.com/docs/en/managed-agents/memory#list-memories) (`GET /v1/memory_stores/{memory_store_id}/memories`) behaves: results are returned in a stable, server-defined order and the `order_by` and `order` parameters are ignored; `depth` accepts only `0`, `1`, or being omitted (other values return a `400` error); and `path_prefix` must end with `/` and matches whole path segments instead of a substring. Page cursors issued without the header aren’t valid with it, so restart from the first page when you adopt it. On memory store endpoints, `agent-memory-2026-07-22` replaces `managed-agents-2026-04-01`; sending both returns a `400` error. On July 22, 2026, the `managed-agents-2026-04-01` header adopts the same list behavior. See [Beta headers](https://platform.claude.com/docs/en/api/beta-headers#endpoint-specific-headers).
254254* The Python (0.116.0), TypeScript (0.110.0), Go (1.56.0), Java (2.48.0), Ruby (1.55.0), PHP (0.36.0), C# (12.35.0), and CLI (1.16.0) SDKs now send `agent-memory-2026-07-22` on all memory store calls instead of `managed-agents-2026-04-01`. If your code passes `betas` explicitly on memory store calls, replace `managed-agents-2026-04-01` with `agent-memory-2026-07-22` there rather than adding a second value.
255255
256256### July 1, 2026
257257
258* We've restored access to Claude Fable 5 and Claude Mythos 5. See [our statement](https://www.anthropic.com/news/redeploying-fable-5) for more information.
258* We’ve restored access to Claude Fable 5 and Claude Mythos 5. See [our statement](https://www.anthropic.com/news/redeploying-fable-5) for more information.
259259
260260### June 30, 2026
261261
262* We've launched **Claude Sonnet 5** (`claude-sonnet-5`), the next generation of our Sonnet model family, at introductory pricing of $2 / $10 USD per MTok (made the standard price on August 10, 2026). Claude Sonnet 5 supports a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows), 128k max output tokens, and the same set of tools and platform features as Claude Sonnet 4.6, except [Priority Tier](https://platform.claude.com/docs/en/api/service-tiers#supported-models), which is not available on Claude Sonnet 5. Three behavior changes apply when migrating: [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) is now on by default; manual extended thinking (`thinking: {type: "enabled", budget_tokens: N}`) is removed and returns a 400 error (it was deprecated on Sonnet 4.6); and setting sampling parameters (`temperature`, `top_p`, `top_k`) to non-default values returns a 400 error. Claude Sonnet 5 also uses a new tokenizer that produces approximately 30% more tokens for the same text. The exact increase depends on the content and workload shape. See [What's new in Claude Sonnet 5](https://platform.claude.com/docs/en/models/sonnet-5/overview) for details and migration guidance. For behavioral differences and model-specific prompting patterns, see [Prompting Claude Sonnet 5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-sonnet-5).
263* Claude Managed Agents session event streams now support [event deltas](https://platform.claude.com/docs/en/managed-agents/event-deltas). Opt in with the `event_deltas[]` query parameter on `GET /v1/sessions/{session_id}/events/stream`. The `event_start` and `event_delta` events preview an agent message's text as it's generated, before the complete `agent.message` event arrives.
262* We’ve launched **Claude Sonnet 5** (`claude-sonnet-5`), the next generation of our Sonnet model family, at introductory pricing of $2 / $10 USD per MTok (made the standard price on August 10, 2026). Claude Sonnet 5 supports a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows), 128k max output tokens, and the same set of tools and platform features as Claude Sonnet 4.6, except [Priority Tier](https://platform.claude.com/docs/en/api/service-tiers#supported-models), which is not available on Claude Sonnet 5. Three behavior changes apply when migrating: [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) is now on by default; manual extended thinking (`thinking: {type: "enabled", budget_tokens: N}`) is removed and returns a 400 error (it was deprecated on Sonnet 4.6); and setting sampling parameters (`temperature`, `top_p`, `top_k`) to non-default values returns a 400 error. Claude Sonnet 5 also uses a new tokenizer that produces approximately 30% more tokens for the same text. The exact increase depends on the content and workload shape. See [What’s new in Claude Sonnet 5](https://platform.claude.com/docs/en/models/sonnet-5/overview) for details and migration guidance. For behavioral differences and model-specific prompting patterns, see [Prompting Claude Sonnet 5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-sonnet-5).
263* Claude Managed Agents session event streams now support [event deltas](https://platform.claude.com/docs/en/managed-agents/event-deltas). Opt in with the `event_deltas[]` query parameter on `GET /v1/sessions/{session_id}/events/stream`. The `event_start` and `event_delta` events preview an agent message’s text as it’s generated, before the complete `agent.message` event arrives.
264264* [Listing sessions](https://platform.claude.com/docs/en/managed-agents/session-operations#listing-sessions) for Claude Managed Agents now supports backward pagination. `GET /v1/sessions` returns a `prev_page` cursor alongside `next_page`; pass it as the `page` parameter to return to the previous page. See [Pagination](https://platform.claude.com/docs/en/api/overview#pagination).
265* When creating a Claude Managed Agents session, you can now [override the agent's configuration for that session](https://platform.claude.com/docs/en/managed-agents/sessions#override-agent-configuration-for-a-session). Pass `agent` with `type: "agent_with_overrides"` to replace the model, system prompt, tools, MCP servers, or skills for a single session. The agent itself is unchanged.
266* Claude Managed Agents vaults now support an `injection_location` setting on [environment variable credentials](https://platform.claude.com/docs/en/managed-agents/vaults#add-a-credential) (the Environment variable tab). It controls whether the credential's value is substituted, at egress, into the agent's outbound request headers, the request body, or both.
265* When creating a Claude Managed Agents session, you can now [override the agent’s configuration for that session](https://platform.claude.com/docs/en/managed-agents/sessions#override-agent-configuration-for-a-session). Pass `agent` with `type: "agent_with_overrides"` to replace the model, system prompt, tools, MCP servers, or skills for a single session. The agent itself is unchanged.
266* Claude Managed Agents vaults now support an `injection_location` setting on [environment variable credentials](https://platform.claude.com/docs/en/managed-agents/vaults#add-a-credential) (the Environment variable tab). It controls whether the credential’s value is substituted, at egress, into the agent’s outbound request headers, the request body, or both.
267267* Webhooks for Claude Managed Agents now cover the agent, deployment, and deployment run lifecycle. You can react to a newly published agent version, a paused deployment, or a failed scheduled run without polling. See the Agent events, Deployment events, and Deployment run events tabs in [Supported event types](https://platform.claude.com/docs/en/managed-agents/webhooks#supported-event-types).
268268
269269### June 29, 2026
270270
271* We've removed [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.6. Requests to `claude-opus-4-6` with `speed: "fast"` no longer run at fast speed or premium pricing: they run at standard speed, are billed at standard rates, and do not return an error. The response's `usage.speed` field reports the speed used. To continue using fast mode, migrate to [Claude Opus 4.8](https://platform.claude.com/docs/en/about-claude/models/migration-guide). Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
271* We’ve removed [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.6. Requests to `claude-opus-4-6` with `speed: "fast"` no longer run at fast speed or premium pricing: they run at standard speed, are billed at standard rates, and do not return an error. The response’s `usage.speed` field reports the speed used. To continue using fast mode, migrate to [Claude Opus 4.8](https://platform.claude.com/docs/en/about-claude/models/migration-guide). Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
272272
273273### June 26, 2026
274274
275* We've raised [rate limits](https://platform.claude.com/docs/en/api/rate-limits) across the Claude API. Claude Sonnet and Claude Haiku rate limits now match Claude Opus at every usage tier, and usage tiers have been consolidated into three: Start, Build, and Scale. Most organizations move to a higher tier, no organization receives lower limits than before, and no action is required. You can view your tier and current limits in the [Claude Console](https://platform.claude.com/settings/limits).
275* We’ve raised [rate limits](https://platform.claude.com/docs/en/api/rate-limits) across the Claude API. Claude Sonnet and Claude Haiku rate limits now match Claude Opus at every usage tier, and usage tiers have been consolidated into three: Start, Build, and Scale. Most organizations move to a higher tier, no organization receives lower limits than before, and no action is required. You can view your tier and current limits in the [Claude Console](https://platform.claude.com/settings/limits).
276276
277277### June 25, 2026
278278
279* We've deprecated [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.7, with removal on July 24, 2026. After removal, requests to `claude-opus-4-7` with `speed: "fast"` will return an error. Migrate to fast mode for Claude Opus 4.8. Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
279* We’ve deprecated [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.7, with removal on July 24, 2026. After removal, requests to `claude-opus-4-7` with `speed: "fast"` will return an error. Migrate to fast mode for Claude Opus 4.8. Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
280280
281281### June 22, 2026
282282
from line 284
284284
285285### June 18, 2026
286286
287* The Python, TypeScript, Go, Java, Ruby, PHP, and C# SDKs now include support for `code_execution_20260120`, the [code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) version that adds REPL state persistence and is the minimum version for [programmatic tool calling](https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling). To adopt it, set the tool's `type` to `code_execution_20260120`; no beta header is required. It's available on Claude Fable 5, Claude Mythos 5, Claude Opus 4.5 and newer, and Claude Sonnet 4.5 and newer; see the code execution tool's [Compatibility](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool#compatibility) section.
287* The Python, TypeScript, Go, Java, Ruby, PHP, and C# SDKs now include support for `code_execution_20260120`, the [code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) version that adds REPL state persistence and is the minimum version for [programmatic tool calling](https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling). To adopt it, set the tool’s `type` to `code_execution_20260120`; no beta header is required. It’s available on Claude Fable 5, Claude Mythos 5, Claude Opus 4.5 and newer, and Claude Sonnet 4.5 and newer; see the code execution tool’s [Compatibility](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool#compatibility) section.
288288
289289### June 15, 2026
290290
291* We've retired the Claude Sonnet 4 model (`claude-sonnet-4-20250514`) and the Claude Opus 4 model (`claude-opus-4-20250514`). All requests to these models on the Claude API will now return an error. We recommend upgrading to [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) and [Claude Opus 4.8](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) respectively. Researchers can request ongoing access through the [External Researcher Access Program](https://support.claude.com/en/articles/9125743-what-is-the-external-researcher-access-program).
291* We’ve retired the Claude Sonnet 4 model (`claude-sonnet-4-20250514`) and the Claude Opus 4 model (`claude-opus-4-20250514`). All requests to these models on the Claude API will now return an error. We recommend upgrading to [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) and [Claude Opus 4.8](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) respectively. Researchers can request ongoing access through the [External Researcher Access Program](https://support.claude.com/en/articles/9125743-what-is-the-external-researcher-access-program).
292292
293293### June 11, 2026
294294
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301301
302302### June 9, 2026
303303
304* We've launched **Claude Fable 5** (`claude-fable-5`), our most capable model open to all customers, alongside **Claude Mythos 5** (`claude-mythos-5`) for Project Glasswing participants. Both models support a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) by default, 128k max output tokens, and always-on [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking). See [Claude Fable 5](https://platform.claude.com/docs/en/models/fable-5/overview) for specifications, pricing, and availability.
304* We’ve launched **Claude Fable 5** (`claude-fable-5`), our most capable model open to all customers, alongside **Claude Mythos 5** (`claude-mythos-5`) for Project Glasswing participants. Both models support a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) by default, 128k max output tokens, and always-on [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking). See [Claude Fable 5](https://platform.claude.com/docs/en/models/fable-5/overview) for specifications, pricing, and availability.
305305* Claude Fable 5 and Claude Mythos 5 use the tokenizer introduced with Claude Opus 4.7. Compared to models before Claude Opus 4.7, the same text produces roughly 30% more tokens. The exact increase depends on the content and workload shape. Use the [token counting API](https://platform.claude.com/docs/en/build-with-claude/token-counting#token-counts-on-claude-fable-5) with `model: "claude-fable-5"` to measure your prompts under the new tokenizer.
306* Claude Fable 5 runs safety classifiers on requests and during response generation. When a classifier declines a request, the Messages API returns `stop_reason: "refusal"`. You are not billed for a request refused before any output is generated. An opt-in `fallbacks` parameter (in beta on the Claude API and Claude Platform on AWS; not supported on the Message Batches API) re-runs refused requests on another model, billed at the fallback model's rates. See [Handling stop reasons](https://platform.claude.com/docs/en/build-with-claude/handling-stop-reasons).
307* The [`stop_details.category`](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback#refusal-response) field on refusal responses now includes `"reasoning_extraction"` on Claude Fable 5, returned when a request is blocked under Anthropic's Terms of Service restrictions on reverse engineering or duplicating model outputs. The existing `"cyber"` and `"bio"` categories are unchanged. No beta header is required.
306* Claude Fable 5 runs safety classifiers on requests and during response generation. When a classifier declines a request, the Messages API returns `stop_reason: "refusal"`. You are not billed for a request refused before any output is generated. An opt-in `fallbacks` parameter (in beta on the Claude API and Claude Platform on AWS; not supported on the Message Batches API) re-runs refused requests on another model, billed at the fallback model’s rates. See [Handling stop reasons](https://platform.claude.com/docs/en/build-with-claude/handling-stop-reasons).
307* The [`stop_details.category`](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback#refusal-response) field on refusal responses now includes `"reasoning_extraction"` on Claude Fable 5, returned when a request is blocked under Anthropic’s Terms of Service restrictions on reverse engineering or duplicating model outputs. The existing `"cyber"` and `"bio"` categories are unchanged. No beta header is required.
308308* On Claude Fable 5 and Claude Mythos 5, [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) is the only thinking mode: `thinking: {"type": "disabled"}` is not supported, and manual extended thinking budgets and assistant prefill are not supported (both return a 400 error).
309309* On Claude Fable 5 and Claude Mythos 5, `thinking.display` defaults to `"omitted"`, the same as Claude Opus 4.8, Claude Opus 4.7, and Claude Mythos Preview; set `display: "summarized"` to receive readable thinking summaries. The raw chain of thought is never returned; pass thinking blocks back unchanged in multi-turn conversations on the same model. See [Thinking output on Claude Fable 5 and Claude Mythos 5](https://platform.claude.com/docs/en/build-with-claude/thinking#thinking-output-on-claude-fable-5-and-claude-mythos-5).
310310* Claude Fable 5 requires 30-day data retention and is not available under zero data retention. See [Model-specific data retention requirements](https://platform.claude.com/docs/en/manage-claude/api-and-data-retention#model-specific-data-retention-requirements).
311311* Claude Managed Agents now supports [scheduled deployments](https://platform.claude.com/docs/en/managed-agents/scheduled-deployments), letting you run sessions on a cron schedule without managing your own scheduler.
312* Claude Managed Agents vaults now support [environment variable credentials](https://platform.claude.com/docs/en/managed-agents/vaults#add-a-credential), so you can securely inject secrets into the agent's sandbox for CLIs, SDKs, and other services that authenticate through environment variables.
312* Claude Managed Agents vaults now support [environment variable credentials](https://platform.claude.com/docs/en/managed-agents/vaults#add-a-credential), so you can securely inject secrets into the agent’s sandbox for CLIs, SDKs, and other services that authenticate through environment variables.
313313* The [Compliance API](https://platform.claude.com/docs/en/manage-claude/compliance-api) [Activity Feed](https://platform.claude.com/docs/en/manage-claude/compliance-activity-feed) (`GET /v1/compliance/activities`) is now available on [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws). See [Compliance IAM actions for Claude Platform on AWS](https://platform.claude.com/docs/en/api/claude-platform-on-aws-iam-actions#compliance) for the `ListComplianceActivities` action that authorizes it.
314314* The `session.thread_*` webhook events now include a `session_thread_id` field identifying the multiagent thread that triggered the event.
315* We've released a [Swift package](https://platform.claude.com/docs/en/cli-sdks-libraries/libraries/apple-foundation-models) in beta that adds Claude as a server-side `LanguageModel` in Apple's Foundation Models framework. Call Claude through the same `LanguageModelSession` API as Apple's on-device model on iOS 27, macOS 27, visionOS 27, and watchOS 27 (beta).
315* We’ve released a [Swift package](https://platform.claude.com/docs/en/cli-sdks-libraries/libraries/apple-foundation-models) in beta that adds Claude as a server-side `LanguageModel` in Apple’s Foundation Models framework. Call Claude through the same `LanguageModelSession` API as Apple’s on-device model on iOS 27, macOS 27, visionOS 27, and watchOS 27 (beta).
316316
317317### June 5, 2026
318318
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320320
321321### June 2, 2026
322322
323* The [advisor tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool) now supports a `max_tokens` parameter to cap the advisor model's output for each call, reducing latency and output token cost for workloads that don't need full-length advisor responses. Set `tools[].max_tokens` on the advisor tool definition; see [Capping advisor output](https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool#capping-advisor-output).
323* The [advisor tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool) now supports a `max_tokens` parameter to cap the advisor model’s output for each call, reducing latency and output token cost for workloads that don’t need full-length advisor responses. Set `tools[].max_tokens` on the advisor tool definition; see [Capping advisor output](https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool#capping-advisor-output).
324324* On the Claude API, you are no longer billed for a request when it returns `stop_reason: "refusal"` without Claude having generated any output. See [Streaming refusals](https://platform.claude.com/docs/en/test-and-evaluate/strengthen-guardrails/handle-streaming-refusals) for detecting and handling refusals.
325325
326326### May 29, 2026
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329329
330330### May 28, 2026
331331
332* We've launched **Claude Opus 4.8** (claude-opus-4-8), our most capable model. Claude Opus 4.8 supports a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) by default on the Claude API, Amazon Bedrock, Google Cloud, and Microsoft Foundry, 128k max output tokens, and the same set of tools and platform features as Claude Opus 4.7. See the [migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide) for baseline settings, features, and migration guidance.
333* We've launched [mid-conversation system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages). On Claude Opus 4.8, you can send `role: "system"` messages after a user turn (subject to [placement rules](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages#limitations)) in the `messages` array, preserving prompt cache hits when instructions change during a long-running session. No beta header is required.
332* We’ve launched **Claude Opus 4.8** (claude-opus-4-8), our most capable model. Claude Opus 4.8 supports a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) by default on the Claude API, Amazon Bedrock, Google Cloud, and Microsoft Foundry, 128k max output tokens, and the same set of tools and platform features as Claude Opus 4.7. See the [migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide) for baseline settings, features, and migration guidance.
333* We’ve launched [mid-conversation system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages). On Claude Opus 4.8, you can send `role: "system"` messages after a user turn (subject to [placement rules](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages#limitations)) in the `messages` array, preserving prompt cache hits when instructions change during a long-running session. No beta header is required.
334334* The [`stop_details`](https://platform.claude.com/docs/en/build-with-claude/refusals-and-fallback#refusal-response) field on refusal responses is now publicly documented; it returns a `category` (`cyber`, `bio`, or `null`) and a human-readable `explanation`, so your application can route different classes of refusal to the right next step. No beta header is required.
335335* On Claude Opus 4.8, the [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort) defaults to `high` across all surfaces, including Claude Code and the Messages API.
336336* On Claude Opus 4.8, the minimum cacheable prompt length for [prompt caching](https://platform.claude.com/docs/en/build-with-claude/prompt-caching) is 1,024 tokens, lower than on Claude Opus 4.7.
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341341* [Computer use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool) now supports Claude Opus 4.8.
342342* [Fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.8 is available as a research preview on the Claude API only.
343343* Setting the sampling parameters `temperature`, `top_p`, or `top_k` to a non-default value returns a 400 error on Claude Opus 4.8, same as on Claude Opus 4.7. See the [migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide) for details.
344* In Claude Code, we've expanded Auto mode to more users for long-running tasks. See the [Claude Code documentation](https://code.claude.com/docs).
344* In Claude Code, we’ve expanded Auto mode to more users for long-running tasks. See the [Claude Code documentation](https://code.claude.com/docs).
345345* In Claude Code, Max plan users now default to [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) on Claude Opus 4.8. See the [Claude Code documentation](https://code.claude.com/docs).
346346* In Claude Code, Workflows are available as a research preview, letting you define and run multistep agentic plans. See the [Claude Code documentation](https://code.claude.com/docs).
347* We've deprecated [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.6, with removal approximately 30 days after launch. Migrate to fast mode for Claude Opus 4.8 or Claude Opus 4.7. Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
347* We’ve deprecated [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.6, with removal approximately 30 days after launch. Migrate to fast mode for Claude Opus 4.8 or Claude Opus 4.7. Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
348348* For updates to claude.ai, Cowork, Claude for Microsoft 365, and other Claude apps in this release, see the [release notes for Claude Apps](https://support.claude.com/en/articles/12138966-release-notes).
349349
350350### May 27, 2026
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354354### May 19, 2026
355355
356356* [MCP tunnels](https://platform.claude.com/docs/en/agents-and-tools/mcp-tunnels/overview) is now available as a research preview, so you can connect to MCP servers in your private network.
357* Self-hosted sandboxes are now available for Claude Managed Agents, as an alternative to running tool execution in Anthropic's infrastructure. See [Self-hosted sandboxes](https://platform.claude.com/docs/en/managed-agents/self-hosted-sandboxes).
358* With Claude Managed Agents, you can now update the agent's MCP server and tool configurations associated with an active session.
357* Self-hosted sandboxes are now available for Claude Managed Agents, as an alternative to running tool execution in Anthropic’s infrastructure. See [Self-hosted sandboxes](https://platform.claude.com/docs/en/managed-agents/self-hosted-sandboxes).
358* With Claude Managed Agents, you can now update the agent’s MCP server and tool configurations associated with an active session.
359359* With Claude Managed Agents, large outputs from `agent_toolset` and MCP tools exceeding 100K characters (about 25K tokens) are now automatically spilled to a file in the sandbox. The model receives a truncated preview with the file path and can read the full content from there.
360360
361361### May 18, 2026
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364364
365365### May 13, 2026
366366
367* We've launched [cache diagnostics](https://platform.claude.com/docs/en/build-with-claude/cache-diagnostics) in beta. Pass `diagnostics.previous_message_id` on a Messages request and the API reports a `cache_miss_reason` explaining where the prompt cache prefix diverged from the previous turn. Include the `cache-diagnosis-2026-04-07` beta header in your requests.
367* We’ve launched [cache diagnostics](https://platform.claude.com/docs/en/build-with-claude/cache-diagnostics) in beta. Pass `diagnostics.previous_message_id` on a Messages request and the API reports a `cache_miss_reason` explaining where the prompt cache prefix diverged from the previous turn. Include the `cache-diagnosis-2026-04-07` beta header in your requests.
368368
369369### May 12, 2026
370370
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372372
373373### May 11, 2026
374374
375* We've launched **Claude Platform on AWS**, bringing the Claude API to Anthropic-managed infrastructure accessible through AWS, with AWS billing and IAM authentication. Access the full Messages API, Files API, Message Batches API, Claude Managed Agents, Agent Skills, code execution, and tool use through native AWS endpoints. Learn more in [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws).
375* We’ve launched **Claude Platform on AWS**, bringing the Claude API to Anthropic-managed infrastructure accessible through AWS, with AWS billing and IAM authentication. Access the full Messages API, Files API, Message Batches API, Claude Managed Agents, Agent Skills, code execution, and tool use through native AWS endpoints. Learn more in [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws).
376376
377377### May 6, 2026
378378
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384384
385385### May 4, 2026
386386
387* We've launched [Workload Identity Federation](https://platform.claude.com/docs/en/manage-claude/workload-identity-federation). Authenticate workloads to the Claude API with short-lived OIDC tokens from your own identity provider (AWS IAM, Google Cloud, GitHub Actions, Kubernetes, Microsoft Entra ID, Okta, SPIFFE, and more) instead of long-lived static API keys. Configure issuers and federation rules in the Claude Console, and the SDK handles token exchange and refresh automatically. See [Authentication](https://platform.claude.com/docs/en/manage-claude/authentication).
387* We’ve launched [Workload Identity Federation](https://platform.claude.com/docs/en/manage-claude/workload-identity-federation). Authenticate workloads to the Claude API with short-lived OIDC tokens from your own identity provider (AWS IAM, Google Cloud, GitHub Actions, Kubernetes, Microsoft Entra ID, Okta, SPIFFE, and more) instead of long-lived static API keys. Configure issuers and federation rules in the Claude Console, and the SDK handles token exchange and refresh automatically. See [Authentication](https://platform.claude.com/docs/en/manage-claude/authentication).
388388
389389### April 30, 2026
390390
391* We've retired the 1M token context window beta (`context-1m-2025-08-07`) for Claude Sonnet 4.5 and Claude Sonnet 4. The beta header now has no effect on these models, and requests exceeding the standard 200k-token context window return an error. To use the 1M context window, migrate to [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) or [Claude Opus 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison), where it's included at standard pricing with no beta header required.
391* We’ve retired the 1M token context window beta (`context-1m-2025-08-07`) for Claude Sonnet 4.5 and Claude Sonnet 4. The beta header now has no effect on these models, and requests exceeding the standard 200k-token context window return an error. To use the 1M context window, migrate to [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) or [Claude Opus 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison), where it’s included at standard pricing with no beta header required.
392392
393393### April 29, 2026
394394
395* We've released the [Claude API skill](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/claude-api-skill), an open-source [Agent Skill](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview) that gives Claude up-to-date reference material for building on the Messages API and Claude Managed Agents across 8 languages. The skill is bundled with Claude Code and available in the [Anthropic skills repository](https://github.com/anthropics/skills/tree/main/skills/claude-api).
395* We’ve released the [Claude API skill](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/claude-api-skill), an open-source [Agent Skill](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview) that gives Claude up-to-date reference material for building on the Messages API and Claude Managed Agents across 8 languages. The skill is bundled with Claude Code and available in the [Anthropic skills repository](https://github.com/anthropics/skills/tree/main/skills/claude-api).
396396
397397### April 24, 2026
398398
399* We've released the [Rate Limits API](https://platform.claude.com/docs/en/manage-claude/rate-limits-api), allowing administrators to programmatically query the rate limits configured for their organization and workspaces.
399* We’ve released the [Rate Limits API](https://platform.claude.com/docs/en/manage-claude/rate-limits-api), allowing administrators to programmatically query the rate limits configured for their organization and workspaces.
400400
401401### April 23, 2026
402402
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404404
405405### April 20, 2026
406406
407* We've retired the Claude Haiku 3 model (`claude-3-haiku-20240307`). All requests to this model will now return an error. We recommend upgrading to [Claude Haiku 4.5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison).
407* We’ve retired the Claude Haiku 3 model (`claude-3-haiku-20240307`). All requests to this model will now return an error. We recommend upgrading to [Claude Haiku 4.5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison).
408408
409409### April 16, 2026
410410
411* We've launched [Claude Opus 4.7](https://www.anthropic.com/news/claude-opus-4-7), our most capable model for complex reasoning and agentic coding, at the same $5 / $25 USD per MTok pricing as Opus 4.6. See [What's new in Claude Opus 4.7](https://platform.claude.com/docs/en/about-claude/models/whats-new-claude-4-7) for capability improvements, new features, and the updated tokenizer. Opus 4.7 includes API breaking changes versus Opus 4.6; see the [migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide) before upgrading.
411* We’ve launched [Claude Opus 4.7](https://www.anthropic.com/news/claude-opus-4-7), our most capable model for complex reasoning and agentic coding, at the same $5 / $25 USD per MTok pricing as Opus 4.6. See [What’s new in Claude Opus 4.7](https://platform.claude.com/docs/en/about-claude/models/whats-new-claude-4-7) for capability improvements, new features, and the updated tokenizer. Opus 4.7 includes API breaking changes versus Opus 4.6; see the [migration guide](https://platform.claude.com/docs/en/about-claude/models/migration-guide) before upgrading.
412412* [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock) is now open to all Amazon Bedrock customers. Claude Opus 4.7 and Claude Haiku 4.5 are available self-serve from the Bedrock console through the Messages API endpoint at `/anthropic/v1/messages`, in 27 AWS regions with global and regional endpoints.
413* We've launched [task budgets](https://platform.claude.com/docs/en/build-with-claude/task-budgets) in beta on Claude Opus 4.7. Give Claude an advisory token budget for a full agentic loop (thinking, tool calls, tool results, and output) and the model sees a running countdown, using it to prioritize work and finish gracefully as the budget is consumed. Include the `task-budgets-2026-03-13` beta header in your requests.
413* We’ve launched [task budgets](https://platform.claude.com/docs/en/build-with-claude/task-budgets) in beta on Claude Opus 4.7. Give Claude an advisory token budget for a full agentic loop (thinking, tool calls, tool results, and output) and the model sees a running countdown, using it to prioritize work and finish gracefully as the budget is consumed. Include the `task-budgets-2026-03-13` beta header in your requests.
414414* Claude Opus 4.7 supports [high-resolution image input](https://platform.claude.com/docs/en/build-with-claude/vision#high-resolution-image-support-on-claude-opus-4-7), raising the maximum image resolution from 1568 to 2576 pixels on the long edge for improved performance on computer use, screenshot understanding, and document analysis. High-resolution support is automatic and requires no beta header; images may use up to approximately 3x more image tokens than on prior models.
415* We've added the `xhigh` [effort](https://platform.claude.com/docs/en/build-with-claude/effort) level on Claude Opus 4.7. `xhigh` sits between `high` and `max` and is tuned for long-running agentic and coding tasks (over 30 minutes) with token budgets in the millions. No beta header is required.
415* We’ve added the `xhigh` [effort](https://platform.claude.com/docs/en/build-with-claude/effort) level on Claude Opus 4.7. `xhigh` sits between `high` and `max` and is tuned for long-running agentic and coding tasks (over 30 minutes) with token budgets in the millions. No beta header is required.
416416
417417### April 14, 2026
418418
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420420
421421### April 9, 2026
422422
423* We've launched the [advisor tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool) in beta. Pair a faster executor model with a higher-intelligence advisor model that provides strategic guidance mid-generation, so long-horizon agentic workloads get close to advisor-solo quality while the bulk of token generation happens at executor-model rates. Include the beta header `advisor-tool-2026-03-01` in your requests.
423* We’ve launched the [advisor tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool) in beta. Pair a faster executor model with a higher-intelligence advisor model that provides strategic guidance mid-generation, so long-horizon agentic workloads get close to advisor-solo quality while the bulk of token generation happens at executor-model rates. Include the beta header `advisor-tool-2026-03-01` in your requests.
424424
425425### April 8, 2026
426426
427* We've launched **Claude Managed Agents** in beta, a fully managed agent harness for running Claude as an autonomous agent with secure sandboxing, built-in tools, and server-sent event streaming. Create agents, configure containers, and run sessions through the API. All endpoints require the `managed-agents-2026-04-01` beta header. Learn more in [Claude Managed Agents overview](https://platform.claude.com/docs/en/managed-agents/overview).
428* We've launched the **`ant` CLI**, a command-line client for the Claude API that enables faster interaction with the Claude API, native integration with Claude Code, and versioning of API resources in YAML files. Learn more in the [CLI quickstart](https://platform.claude.com/docs/en/cli-sdks-libraries/cli/quickstart).
427* We’ve launched **Claude Managed Agents** in beta, a fully managed agent harness for running Claude as an autonomous agent with secure sandboxing, built-in tools, and server-sent event streaming. Create agents, configure containers, and run sessions through the API. All endpoints require the `managed-agents-2026-04-01` beta header. Learn more in [Claude Managed Agents overview](https://platform.claude.com/docs/en/managed-agents/overview).
428* We’ve launched the **`ant` CLI**, a command-line client for the Claude API that enables faster interaction with the Claude API, native integration with Claude Code, and versioning of API resources in YAML files. Learn more in the [CLI quickstart](https://platform.claude.com/docs/en/cli-sdks-libraries/cli/quickstart).
429429
430430### April 7, 2026
431431
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434434
435435### March 30, 2026
436436
437* We've raised the `max_tokens` cap to 300k on the [Message Batches API](https://platform.claude.com/docs/en/build-with-claude/batch-processing#extended-output-beta) for Claude Opus 4.6 and Sonnet 4.6. Include the `output-300k-2026-03-24` beta header to generate longer single-turn outputs for long-form content, structured data, and large code generation tasks.
438* We're retiring the 1M token context window beta for Claude Sonnet 4.5 and Claude Sonnet 4 on **April 30, 2026**. After that date, the `context-1m-2025-08-07` beta header will have no effect on these models, and requests that exceed the standard 200k-token context window will return an error. To continue using 1M context windows, migrate to [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) or [Claude Opus 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison), which support the full 1M token context window at standard pricing with no beta header required.
437* We’ve raised the `max_tokens` cap to 300k on the [Message Batches API](https://platform.claude.com/docs/en/build-with-claude/batch-processing#extended-output-beta) for Claude Opus 4.6 and Sonnet 4.6. Include the `output-300k-2026-03-24` beta header to generate longer single-turn outputs for long-form content, structured data, and large code generation tasks.
438* We’re retiring the 1M token context window beta for Claude Sonnet 4.5 and Claude Sonnet 4 on **April 30, 2026**. After that date, the `context-1m-2025-08-07` beta header will have no effect on these models, and requests that exceed the standard 200k-token context window will return an error. To continue using 1M context windows, migrate to [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) or [Claude Opus 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison), which support the full 1M token context window at standard pricing with no beta header required.
439439
440440### March 18, 2026
441441
442* We've added model capability fields to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now return `max_input_tokens`, `max_tokens`, and a `capabilities` object. Query the API to discover what each model supports.
442* We’ve added model capability fields to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now return `max_input_tokens`, `max_tokens`, and a `capabilities` object. Query the API to discover what each model supports.
443443
444444### March 16, 2026
445445
446* We've launched the `display` field for extended thinking, letting you omit thinking content from responses for faster streaming. Set `thinking.display: "omitted"` to receive thinking blocks with an empty `thinking` field and the `signature` preserved for multi-turn continuity. Billing is unchanged. Learn more in [Controlling thinking display](https://platform.claude.com/docs/en/build-with-claude/thinking#controlling-thinking-display).
446* We’ve launched the `display` field for extended thinking, letting you omit thinking content from responses for faster streaming. Set `thinking.display: "omitted"` to receive thinking blocks with an empty `thinking` field and the `signature` preserved for multi-turn continuity. Billing is unchanged. Learn more in [Controlling thinking display](https://platform.claude.com/docs/en/build-with-claude/thinking#controlling-thinking-display).
447447
448448### March 13, 2026
449449
450450* The [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) is out of beta for Claude Opus 4.6 and Sonnet 4.6, at standard pricing. Requests over 200k tokens work automatically for these models with no beta header required. The 1M token context window remains in beta for Claude Sonnet 4.5 and Sonnet 4.
451* We've removed the dedicated 1M rate limits for all supported models. Your standard account limits now apply across every context length.
452* We've raised the media limit from 100 to 600 images or PDF pages for each request when using the 1M token context window.
451* We’ve removed the dedicated 1M rate limits for all supported models. Your standard account limits now apply across every context length.
452* We’ve raised the media limit from 100 to 600 images or PDF pages for each request when using the 1M token context window.
453453
454454### February 19, 2026
455455
456* We've launched **automatic caching** for the Messages API. Add a single `cache_control` field to your request body and the system automatically caches the last cacheable block, moving the cache point forward as conversations grow. No manual breakpoint management required. Works alongside existing block-level cache control for fine-grained optimization. Available on the Claude API and Microsoft Foundry (preview). Learn more in [Automatic caching](https://platform.claude.com/docs/en/build-with-claude/prompt-caching#automatic-caching).
457* We've retired the Claude Sonnet 3.7 model (`claude-3-7-sonnet-20250219`) and the Claude Haiku 3.5 model (`claude-3-5-haiku-20241022`). All requests to Claude Sonnet 3.7 will now return an error. Requests to Claude Haiku 3.5 on the Claude API will now return an error; it remains available on Amazon Bedrock and Google Cloud. We recommend upgrading to [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) and [Claude Haiku 4.5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) respectively. Researchers can request ongoing access through the [External Researcher Access Program](https://support.claude.com/en/articles/9125743-what-is-the-external-researcher-access-program).
456* We’ve launched **automatic caching** for the Messages API. Add a single `cache_control` field to your request body and the system automatically caches the last cacheable block, moving the cache point forward as conversations grow. No manual breakpoint management required. Works alongside existing block-level cache control for fine-grained optimization. Available on the Claude API and Microsoft Foundry (preview). Learn more in [Automatic caching](https://platform.claude.com/docs/en/build-with-claude/prompt-caching#automatic-caching).
457* We’ve retired the Claude Sonnet 3.7 model (`claude-3-7-sonnet-20250219`) and the Claude Haiku 3.5 model (`claude-3-5-haiku-20241022`). All requests to Claude Sonnet 3.7 will now return an error. Requests to Claude Haiku 3.5 on the Claude API will now return an error; it remains available on Amazon Bedrock and Google Cloud. We recommend upgrading to [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) and [Claude Haiku 4.5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison) respectively. Researchers can request ongoing access through the [External Researcher Access Program](https://support.claude.com/en/articles/9125743-what-is-the-external-researcher-access-program).
458458* We announced the deprecation of the Claude Haiku 3 model (`claude-3-haiku-20240307`), with retirement scheduled for April 20, 2026. We recommend migrating to [Claude Haiku 4.5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison). Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
459459
460460### February 17, 2026
461461
462* We've [launched Claude Sonnet 4.6](https://www.anthropic.com/news/claude-sonnet-4-6), our latest balanced model combining speed and intelligence for everyday tasks. Sonnet 4.6 delivers improved agentic search performance while consuming fewer tokens. Sonnet 4.6 supports [extended thinking](https://platform.claude.com/docs/en/build-with-claude/extended-thinking) and a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) (beta). See [Models & Pricing](https://platform.claude.com/docs/en/models/overview) for details.
462* We’ve [launched Claude Sonnet 4.6](https://www.anthropic.com/news/claude-sonnet-4-6), our latest balanced model combining speed and intelligence for everyday tasks. Sonnet 4.6 delivers improved agentic search performance while consuming fewer tokens. Sonnet 4.6 supports [extended thinking](https://platform.claude.com/docs/en/build-with-claude/extended-thinking) and a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) (beta). See [Models & Pricing](https://platform.claude.com/docs/en/models/overview) for details.
463463* API [code execution](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) is now **free when used with web search or web fetch**. Sandboxed code execution improves model capability and token efficiency. See the [pricing details](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool#usage-and-pricing) for standalone usage.
464464* The [web search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool) and [programmatic tool calling](https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling) are available with no beta header required. Web search and web fetch now support [dynamic filtering](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool#dynamic-filtering), which uses code execution to filter results before they reach the context window for better performance and reduced token cost.
465465* The [code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool), [web fetch tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool), [tool search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool), [tool use examples](https://platform.claude.com/docs/en/agents-and-tools/tool-use/define-tools#providing-tool-use-examples), and [memory tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/memory-tool) no longer require a beta header.
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466466
467467### February 7, 2026
468468
469* We've launched [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) in research preview for Opus 4.6, providing significantly faster output token generation through the `speed` parameter. Fast mode is up to 2.5x as fast at premium pricing. Interested customers should join the [waitlist](https://claude.com/fast-mode).
469* We’ve launched [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) in research preview for Opus 4.6, providing significantly faster output token generation through the `speed` parameter. Fast mode is up to 2.5x as fast at premium pricing. Interested customers should join the [waitlist](https://claude.com/fast-mode).
470470
471471### February 5, 2026
472472
473* We've [launched Claude Opus 4.6](https://www.anthropic.com/news/claude-opus-4-6), our most intelligent model for complex agentic tasks and long-horizon work. Opus 4.6 recommends [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) (`thinking: {type: "adaptive"}`); manual thinking (`type: "enabled"` with `budget_tokens`) is deprecated. Opus 4.6 does not support prefilling assistant messages. Learn more in [What's new in Claude 4.6](https://platform.claude.com/docs/en/about-claude/models/whats-new-claude-4-6).
473* We’ve [launched Claude Opus 4.6](https://www.anthropic.com/news/claude-opus-4-6), our most intelligent model for complex agentic tasks and long-horizon work. Opus 4.6 recommends [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) (`thinking: {type: "adaptive"}`); manual thinking (`type: "enabled"` with `budget_tokens`) is deprecated. Opus 4.6 does not support prefilling assistant messages. Learn more in [What’s new in Claude 4.6](https://platform.claude.com/docs/en/about-claude/models/whats-new-claude-4-6).
474474* The [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort) no longer requires a beta header and now supports Claude Opus 4.6. Effort replaces `budget_tokens` for controlling thinking depth on new models.
475* We've launched the [compaction API](https://platform.claude.com/docs/en/build-with-claude/compaction-threshold) in beta, providing server-side context summarization for effectively infinite conversations. Available on Opus 4.6.
476* We've introduced [data residency controls](https://platform.claude.com/docs/en/manage-claude/data-residency), allowing you to specify where model inference runs with the `inference_geo` parameter. US-only inference is available at 1.1x pricing for models released after February 1, 2026.
475* We’ve launched the [compaction API](https://platform.claude.com/docs/en/build-with-claude/compaction-threshold) in beta, providing server-side context summarization for effectively infinite conversations. Available on Opus 4.6.
476* We’ve introduced [data residency controls](https://platform.claude.com/docs/en/manage-claude/data-residency), allowing you to specify where model inference runs with the `inference_geo` parameter. US-only inference is available at 1.1x pricing for models released after February 1, 2026.
477477* The [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) is now available in beta for Claude Opus 4.6, in addition to Sonnet 4.5 and Sonnet 4. [Long context pricing](https://platform.claude.com/docs/en/about-claude/pricing#long-context-pricing) applies to requests exceeding 200k input tokens.
478478* [Fine-grained tool streaming](https://platform.claude.com/docs/en/agents-and-tools/tool-use/fine-grained-tool-streaming) no longer requires a beta header on any model or platform.
479479
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487487
488488### January 5, 2026
489489
490* We've retired the Claude Opus 3 model (`claude-3-opus-20240229`). All requests to this model will now return an error. We recommend upgrading to [Claude Opus 4.5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison), which offers significantly improved intelligence at a third of the cost. Researchers can request ongoing access to Claude Opus 3 on the API through the [External Researcher Access Program](https://support.claude.com/en/articles/9125743-what-is-the-external-researcher-access-program).
490* We’ve retired the Claude Opus 3 model (`claude-3-opus-20240229`). All requests to this model will now return an error. We recommend upgrading to [Claude Opus 4.5](https://platform.claude.com/docs/en/models/overview#latest-models-comparison), which offers significantly improved intelligence at a third of the cost. Researchers can request ongoing access to Claude Opus 3 on the API through the [External Researcher Access Program](https://support.claude.com/en/articles/9125743-what-is-the-external-researcher-access-program).
491491
492492### December 19, 2025
493493
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499499
500500### November 24, 2025
501501
502* We've [launched Claude Opus 4.5](https://www.anthropic.com/news/claude-opus-4-5), our most intelligent model combining maximum capability with practical performance. Ideal for complex specialized tasks, professional software engineering, and advanced agents. Features step-change improvements in vision, coding, and computer use at a more accessible price point than previous Opus models. Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
503* We've launched [programmatic tool calling](https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling) in beta, allowing Claude to call tools from within code execution to reduce latency and token usage in multi-tool workflows.
504* We've launched the [tool search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool) in beta, enabling Claude to dynamically discover and load tools on-demand from large tool catalogs.
505* We've launched the [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort) in beta for Claude Opus 4.5, allowing you to control token usage by trading off between response thoroughness and efficiency.
506* We've added [client-side compaction](https://platform.claude.com/docs/en/build-with-claude/context-editing#client-side-compaction-sdk) to our Python and TypeScript SDKs, automatically managing conversation context through summarization when using `tool_runner`.
502* We’ve [launched Claude Opus 4.5](https://www.anthropic.com/news/claude-opus-4-5), our most intelligent model combining maximum capability with practical performance. Ideal for complex specialized tasks, professional software engineering, and advanced agents. Features step-change improvements in vision, coding, and computer use at a more accessible price point than previous Opus models. Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
503* We’ve launched [programmatic tool calling](https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling) in beta, allowing Claude to call tools from within code execution to reduce latency and token usage in multi-tool workflows.
504* We’ve launched the [tool search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool) in beta, enabling Claude to dynamically discover and load tools on-demand from large tool catalogs.
505* We’ve launched the [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort) in beta for Claude Opus 4.5, allowing you to control token usage by trading off between response thoroughness and efficiency.
506* We’ve added [client-side compaction](https://platform.claude.com/docs/en/build-with-claude/context-editing#client-side-compaction-sdk) to our Python and TypeScript SDKs, automatically managing conversation context through summarization when using `tool_runner`.
507507
508508### November 21, 2025
509509
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511511
512512### November 19, 2025
513513
514* We've launched a **new documentation platform** at [platform.claude.com/docs](https://platform.claude.com/docs). Our documentation now lives side by side with the Claude Console, providing a unified developer experience. The previous docs site at docs.claude.com will redirect to the new location.
514* We’ve launched a **new documentation platform** at [platform.claude.com/docs](https://platform.claude.com/docs). Our documentation now lives side by side with the Claude Console, providing a unified developer experience. The previous docs site at docs.claude.com will redirect to the new location.
515515
516516### November 18, 2025
517517
518* We've launched **Claude in Microsoft Foundry**, bringing Claude models to Azure customers with Azure billing and OAuth authentication. Access the full Messages API including extended thinking, prompt caching (5-minute and 1-hour), PDF support, Files API, Agent Skills, and tool use. Learn more in [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry).
518* We’ve launched **Claude in Microsoft Foundry**, bringing Claude models to Azure customers with Azure billing and OAuth authentication. Access the full Messages API including extended thinking, prompt caching (5-minute and 1-hour), PDF support, Files API, Agent Skills, and tool use. Learn more in [Claude in Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry).
519519
520520### November 14, 2025
521521
522* We've launched [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) in beta, providing guaranteed schema conformance for Claude's responses. Use JSON outputs for structured data responses or strict tool use for validated tool inputs. Available for Claude Sonnet 4.5 and Claude Opus 4.1. To enable, use the beta header `structured-outputs-2025-11-13`.
522* We’ve launched [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) in beta, providing guaranteed schema conformance for Claude’s responses. Use JSON outputs for structured data responses or strict tool use for validated tool inputs. Available for Claude Sonnet 4.5 and Claude Opus 4.1. To enable, use the beta header `structured-outputs-2025-11-13`.
523523
524524### October 28, 2025
525525
526526* We announced the deprecation of the Claude Sonnet 3.7 model. Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
527* We've retired the Claude Sonnet 3.5 models. All requests to these models will now return an error.
528* We've expanded context editing with thinking block clearing (`clear_thinking_20251015`), enabling automatic management of thinking blocks. Learn more in [Context editing](https://platform.claude.com/docs/en/build-with-claude/context-editing).
527* We’ve retired the Claude Sonnet 3.5 models. All requests to these models will now return an error.
528* We’ve expanded context editing with thinking block clearing (`clear_thinking_20251015`), enabling automatic management of thinking blocks. Learn more in [Context editing](https://platform.claude.com/docs/en/build-with-claude/context-editing).
529529
530530### October 16, 2025
531531
532* We've [launched Agent Skills](https://www.anthropic.com/engineering/equipping-agents-for-the-real-world-with-agent-skills) (`skills-2025-10-02` beta), a new way to extend Claude's capabilities. Skills are organized folders of instructions, scripts, and resources that Claude loads dynamically to perform specialized tasks. The initial release includes:
532* We’ve [launched Agent Skills](https://www.anthropic.com/engineering/equipping-agents-for-the-real-world-with-agent-skills) (`skills-2025-10-02` beta), a new way to extend Claude’s capabilities. Skills are organized folders of instructions, scripts, and resources that Claude loads dynamically to perform specialized tasks. The initial release includes:
533533
534534 * **Anthropic-managed Skills**: Pre-built Skills for working with PowerPoint (.pptx), Excel (.xlsx), Word (.docx), and PDF files
535535 * **Custom Skills**: Upload your own Skills through the Skills API (`/v1/skills` endpoints) to package domain expertise and organizational workflows
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538538
539539### October 15, 2025
540540
541* We've [launched Claude Haiku 4.5](https://www.anthropic.com/news/claude-haiku-4-5), our fastest and most intelligent Haiku model with near-frontier performance. Ideal for real-time applications, high-volume processing, and cost-sensitive deployments requiring strong reasoning. Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
541* We’ve [launched Claude Haiku 4.5](https://www.anthropic.com/news/claude-haiku-4-5), our fastest and most intelligent Haiku model with near-frontier performance. Ideal for real-time applications, high-volume processing, and cost-sensitive deployments requiring strong reasoning. Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
542542
543543### September 29, 2025
544544
545* We've launched [Claude Sonnet 4.5](https://www.anthropic.com/news/claude-sonnet-4-5), our best model for complex agents and coding, with the highest intelligence across most tasks. Learn more in the [models overview](https://platform.claude.com/docs/en/models/overview).
546* We've introduced [global endpoint pricing](https://platform.claude.com/docs/en/about-claude/pricing#cloud-platform-pricing) for Amazon Bedrock and Vertex AI. The Claude API (1P) pricing is unaffected.
547* We've introduced a new stop reason `model_context_window_exceeded` that allows you to request the maximum possible tokens without calculating input size. Learn more in [Handling stop reasons](https://platform.claude.com/docs/en/build-with-claude/handling-stop-reasons).
548* We've launched the memory tool in beta, enabling Claude to store and consult information across conversations. Learn more in [Memory tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/memory-tool).
549* We've launched context editing in beta, providing strategies to automatically manage conversation context. The initial release supports clearing older tool results and calls when approaching token limits. Learn more in [Context editing](https://platform.claude.com/docs/en/build-with-claude/context-editing).
545* We’ve launched [Claude Sonnet 4.5](https://www.anthropic.com/news/claude-sonnet-4-5), our best model for complex agents and coding, with the highest intelligence across most tasks. Learn more in the [models overview](https://platform.claude.com/docs/en/models/overview).
546* We’ve introduced [global endpoint pricing](https://platform.claude.com/docs/en/about-claude/pricing#cloud-platform-pricing) for Amazon Bedrock and Vertex AI. The Claude API (1P) pricing is unaffected.
547* We’ve introduced a new stop reason `model_context_window_exceeded` that allows you to request the maximum possible tokens without calculating input size. Learn more in [Handling stop reasons](https://platform.claude.com/docs/en/build-with-claude/handling-stop-reasons).
548* We’ve launched the memory tool in beta, enabling Claude to store and consult information across conversations. Learn more in [Memory tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/memory-tool).
549* We’ve launched context editing in beta, providing strategies to automatically manage conversation context. The initial release supports clearing older tool results and calls when approaching token limits. Learn more in [Context editing](https://platform.claude.com/docs/en/build-with-claude/context-editing).
550550
551551### September 17, 2025
552552
553* We've launched tool helpers in beta for the Python and TypeScript SDKs, simplifying tool creation and execution with type-safe input validation and a tool runner for automated tool handling in conversations. For details, see the documentation for [the Python SDK](https://github.com/anthropics/anthropic-sdk-python/blob/main/tools.md) and [the TypeScript SDK](https://github.com/anthropics/anthropic-sdk-typescript/blob/main/helpers.md#tool-helpers).
553* We’ve launched tool helpers in beta for the Python and TypeScript SDKs, simplifying tool creation and execution with type-safe input validation and a tool runner for automated tool handling in conversations. For details, see the documentation for [the Python SDK](https://github.com/anthropics/anthropic-sdk-python/blob/main/tools.md) and [the TypeScript SDK](https://github.com/anthropics/anthropic-sdk-typescript/blob/main/helpers.md#tool-helpers).
554554
555555### September 16, 2025
556556
557* We've unified our developer offerings under the Claude brand. You should see updated naming and URLs across our platform and documentation, but **our developer interfaces will remain the same**. Here are some notable changes:
557* We’ve unified our developer offerings under the Claude brand. You should see updated naming and URLs across our platform and documentation, but **our developer interfaces will remain the same**. Here are some notable changes:
558558
559559 * Claude Console ([console.anthropic.com](https://console.anthropic.com)) → Claude Console ([platform.claude.com](https://platform.claude.com)). The console will be available at both URLs until January 12, 2026. After that date, [console.anthropic.com](https://console.anthropic.com) will automatically redirect to [platform.claude.com](https://platform.claude.com).
560560 * Anthropic Docs ([docs.anthropic.com](https://docs.anthropic.com)) → Claude Docs ([docs.claude.com](https://docs.claude.com))
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563563
564564### September 10, 2025
565565
566* We've launched the web fetch tool in beta, allowing Claude to retrieve full content from specified web pages and PDF documents. Learn more in [Web fetch tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool).
567* We've launched the [Claude Code Analytics API](https://platform.claude.com/docs/en/manage-claude/claude-code-analytics-api), enabling organizations to programmatically access daily aggregated usage metrics for Claude Code, including productivity metrics, tool usage statistics, and cost data.
566* We’ve launched the web fetch tool in beta, allowing Claude to retrieve full content from specified web pages and PDF documents. Learn more in [Web fetch tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool).
567* We’ve launched the [Claude Code Analytics API](https://platform.claude.com/docs/en/manage-claude/claude-code-analytics-api), enabling organizations to programmatically access daily aggregated usage metrics for Claude Code, including productivity metrics, tool usage statistics, and cost data.
568568
569569### September 8, 2025
570570
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572572
573573### September 5, 2025
574574
575* We've launched [rate limit charts](https://platform.claude.com/docs/en/api/rate-limits#monitoring-your-rate-limits-in-the-console) in the Console [Usage](https://console.anthropic.com/settings/usage) page, allowing you to monitor your API rate limit usage and caching rates over time.
575* We’ve launched [rate limit charts](https://platform.claude.com/docs/en/api/rate-limits#monitoring-your-rate-limits-in-the-console) in the Console [Usage](https://console.anthropic.com/settings/usage) page, allowing you to monitor your API rate limit usage and caching rates over time.
576576
577577### September 3, 2025
578578
579* We've launched support for citable documents in client-side tool results. Learn more in [Handle tool calls](https://platform.claude.com/docs/en/agents-and-tools/tool-use/handle-tool-calls).
579* We’ve launched support for citable documents in client-side tool results. Learn more in [Handle tool calls](https://platform.claude.com/docs/en/agents-and-tools/tool-use/handle-tool-calls).
580580
581581### September 2, 2025
582582
583* We've launched v2 of the [Code Execution Tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) in beta, replacing the original Python-only tool with Bash command execution and direct file manipulation capabilities, including writing code in other languages.
583* We’ve launched v2 of the [Code Execution Tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) in beta, replacing the original Python-only tool with Bash command execution and direct file manipulation capabilities, including writing code in other languages.
584584
585585### August 27, 2025
586586
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588588
589589### August 26, 2025
590590
591* We've increased rate limits on the [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) for Claude Sonnet 4 on the Claude API.
591* We’ve increased rate limits on the [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) for Claude Sonnet 4 on the Claude API.
592592* The 1M token context window is now available on Vertex AI. For more information, see [Claude on Vertex AI](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed).
593593
594594### August 19, 2025
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597597
598598### August 18, 2025
599599
600* We've released the [Usage & Cost API](https://platform.claude.com/docs/en/manage-claude/usage-cost-api), allowing administrators to programmatically monitor their organization's usage and cost data.
601* We've added a new endpoint to the Admin API for retrieving organization information. For details, see the [Organization Info Admin API reference](https://platform.claude.com/docs/en/api/beta/organization/retrieve).
600* We’ve released the [Usage & Cost API](https://platform.claude.com/docs/en/manage-claude/usage-cost-api), allowing administrators to programmatically monitor their organization’s usage and cost data.
601* We’ve added a new endpoint to the Admin API for retrieving organization information. For details, see the [Organization Info Admin API reference](https://platform.claude.com/docs/en/api/beta/organization/retrieve).
602602
603603### August 13, 2025
604604
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607607
608608### August 12, 2025
609609
610* We've launched beta support for a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) in Claude Sonnet 4 on the Claude API and Amazon Bedrock.
610* We’ve launched beta support for a [1M token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) in Claude Sonnet 4 on the Claude API and Amazon Bedrock.
611611
612612### August 11, 2025
613613
from line 619
619619
620620### August 5, 2025
621621
622* We've launched [Claude Opus 4.1](https://www.anthropic.com/news/claude-opus-4-1), an incremental update to Claude Opus 4 with enhanced capabilities and performance improvements.\* Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
622* We’ve launched [Claude Opus 4.1](https://www.anthropic.com/news/claude-opus-4-1), an incremental update to Claude Opus 4 with enhanced capabilities and performance improvements.\* Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
623623
624624*\*Opus 4.1 does not allow both `temperature` and `top_p` parameters to be specified. Please use only one.*
625625
626626### July 28, 2025
627627
628* We've released `text_editor_20250728`, an updated text editor tool that fixes some issues from the previous versions and adds an optional `max_characters` parameter that allows you to control the truncation length when viewing large files.
628* We’ve released `text_editor_20250728`, an updated text editor tool that fixes some issues from the previous versions and adds an optional `max_characters` parameter that allows you to control the truncation length when viewing large files.
629629
630630### July 24, 2025
631631
632* We've increased [rate limits](https://platform.claude.com/docs/en/api/rate-limits) for Claude Opus 4 on the Claude API to give you more capacity to build and scale with Claude. For customers with [usage tier 1-4 rate limits](https://platform.claude.com/docs/en/api/rate-limits#rate-limits), these changes apply immediately to your account - no action needed.
632* We’ve increased [rate limits](https://platform.claude.com/docs/en/api/rate-limits) for Claude Opus 4 on the Claude API to give you more capacity to build and scale with Claude. For customers with [usage tier 1-4 rate limits](https://platform.claude.com/docs/en/api/rate-limits#rate-limits), these changes apply immediately to your account - no action needed.
633633
634634### July 21, 2025
635635
636* We've retired the Claude 2.0, Claude 2.1, and Claude Sonnet 3 models. All requests to these models will now return an error. Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
636* We’ve retired the Claude 2.0, Claude 2.1, and Claude Sonnet 3 models. All requests to these models will now return an error. Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
637637
638638### July 17, 2025
639639
640* We've increased [rate limits](https://platform.claude.com/docs/en/api/rate-limits) for Claude Sonnet 4 on the Claude API to give you more capacity to build and scale with Claude. For customers with [usage tier 1-4 rate limits](https://platform.claude.com/docs/en/api/rate-limits#rate-limits), these changes apply immediately to your account - no action needed.
640* We’ve increased [rate limits](https://platform.claude.com/docs/en/api/rate-limits) for Claude Sonnet 4 on the Claude API to give you more capacity to build and scale with Claude. For customers with [usage tier 1-4 rate limits](https://platform.claude.com/docs/en/api/rate-limits#rate-limits), these changes apply immediately to your account - no action needed.
641641
642642### July 3, 2025
643643
644* We've launched search result content blocks in beta, enabling natural citations for RAG applications. Tools can now return search results with proper source attribution, and Claude will automatically cite these sources in its responses - matching the citation quality of web search. This eliminates the need for document workarounds in custom knowledge base applications. Learn more in [Search results](https://platform.claude.com/docs/en/build-with-claude/search-results). To enable this feature, use the beta header `search-results-2025-06-09`.
644* We’ve launched search result content blocks in beta, enabling natural citations for RAG applications. Tools can now return search results with proper source attribution, and Claude will automatically cite these sources in its responses - matching the citation quality of web search. This eliminates the need for document workarounds in custom knowledge base applications. Learn more in [Search results](https://platform.claude.com/docs/en/build-with-claude/search-results). To enable this feature, use the beta header `search-results-2025-06-09`.
645645
646646### June 30, 2025
647647
from line 653
653653
654654### June 11, 2025
655655
656* We've launched [fine-grained tool streaming](https://platform.claude.com/docs/en/agents-and-tools/tool-use/fine-grained-tool-streaming) in beta, a feature that enables Claude to stream tool use parameters without buffering / JSON validation. To enable fine-grained tool streaming, use the [beta header](https://platform.claude.com/docs/en/api/beta-headers) `fine-grained-tool-streaming-2025-05-14`.
656* We’ve launched [fine-grained tool streaming](https://platform.claude.com/docs/en/agents-and-tools/tool-use/fine-grained-tool-streaming) in beta, a feature that enables Claude to stream tool use parameters without buffering / JSON validation. To enable fine-grained tool streaming, use the [beta header](https://platform.claude.com/docs/en/api/beta-headers) `fine-grained-tool-streaming-2025-05-14`.
657657
658658### May 22, 2025
659659
660* We've launched [Claude Opus 4 and Claude Sonnet 4](https://www.anthropic.com/news/claude-4), our latest models with extended thinking capabilities. Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
661* The default behavior of [extended thinking](https://platform.claude.com/docs/en/build-with-claude/extended-thinking) in Claude 4 models returns a summary of Claude's full thinking process, with the full thinking encrypted and returned in the `signature` field of `thinking` block output.
662* We've launched [interleaved thinking](https://platform.claude.com/docs/en/build-with-claude/thinking#interleaved-thinking) in beta, a feature that enables Claude to think in between tool calls. To enable interleaved thinking, use the [beta header](https://platform.claude.com/docs/en/api/beta-headers) `interleaved-thinking-2025-05-14`.
663* We've launched the [Files API](https://platform.claude.com/docs/en/build-with-claude/files) in beta, enabling you to upload files and reference them in the Messages API and code execution tool.
664* We've launched the [Code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) in beta, a tool that enables Claude to execute Python code in a secure, sandboxed environment.
665* We've launched the [MCP connector](https://platform.claude.com/docs/en/agents-and-tools/mcp-connector) in beta, a feature that allows you to connect to remote MCP servers directly from the Messages API.
666* To increase answer quality and decrease tool errors, we've changed the default value for the `top_p` [nucleus sampling](https://en.wikipedia.org/wiki/Top-p_sampling) parameter in the Messages API from 0.999 to 0.99 for all models. To revert this change, set `top_p` to 0.999. Additionally, when extended thinking is enabled, you can now set `top_p` to values between 0.95 and 1.
660* We’ve launched [Claude Opus 4 and Claude Sonnet 4](https://www.anthropic.com/news/claude-4), our latest models with extended thinking capabilities. Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
661* The default behavior of [extended thinking](https://platform.claude.com/docs/en/build-with-claude/extended-thinking) in Claude 4 models returns a summary of Claude’s full thinking process, with the full thinking encrypted and returned in the `signature` field of `thinking` block output.
662* We’ve launched [interleaved thinking](https://platform.claude.com/docs/en/build-with-claude/thinking#interleaved-thinking) in beta, a feature that enables Claude to think in between tool calls. To enable interleaved thinking, use the [beta header](https://platform.claude.com/docs/en/api/beta-headers) `interleaved-thinking-2025-05-14`.
663* We’ve launched the [Files API](https://platform.claude.com/docs/en/build-with-claude/files) in beta, enabling you to upload files and reference them in the Messages API and code execution tool.
664* We’ve launched the [Code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) in beta, a tool that enables Claude to execute Python code in a secure, sandboxed environment.
665* We’ve launched the [MCP connector](https://platform.claude.com/docs/en/agents-and-tools/mcp-connector) in beta, a feature that allows you to connect to remote MCP servers directly from the Messages API.
666* To increase answer quality and decrease tool errors, we’ve changed the default value for the `top_p` [nucleus sampling](https://en.wikipedia.org/wiki/Top-p_sampling) parameter in the Messages API from 0.999 to 0.99 for all models. To revert this change, set `top_p` to 0.999. Additionally, when extended thinking is enabled, you can now set `top_p` to values between 0.95 and 1.
667667* Our [Go SDK](https://github.com/anthropics/anthropic-sdk-go) has moved from beta to its first stable release.
668* We've added minute and hour level granularity to the [Usage](https://console.anthropic.com/settings/usage) page of Console alongside 429 error rates on the Usage page.
668* We’ve added minute and hour level granularity to the [Usage](https://console.anthropic.com/settings/usage) page of Console alongside 429 error rates on the Usage page.
669669
670670### May 21, 2025
671671
from line 673
673673
674674### May 7, 2025
675675
676* We've launched a web search tool in the API, allowing Claude to access up-to-date information from the web. Learn more in [Web search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool).
676* We’ve launched a web search tool in the API, allowing Claude to access up-to-date information from the web. Learn more in [Web search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool).
677677
678678### May 1, 2025
679679
from line 686
686686### March 31st, 2025
687687
688688* Our [Java SDK](https://github.com/anthropics/anthropic-sdk-java) has moved from beta to its first stable release.
689* We've moved our [Go SDK](https://github.com/anthropics/anthropic-sdk-go) from alpha to beta.
689* We’ve moved our [Go SDK](https://github.com/anthropics/anthropic-sdk-go) from alpha to beta.
690690
691691### February 27th, 2025
692692
693* We've added URL source blocks for images and PDFs in the Messages API. You can now reference images and PDFs directly through a URL instead of having to base64-encode them. Learn more in [Vision](https://platform.claude.com/docs/en/build-with-claude/vision) and [PDF support](https://platform.claude.com/docs/en/build-with-claude/pdf-support).
694* We've added support for a `none` option to the `tool_choice` parameter in the Messages API that prevents Claude from calling any tools. Additionally, you're no longer required to provide any `tools` when including `tool_use` and `tool_result` blocks.
695* We've launched an OpenAI-compatible API endpoint, allowing you to test Claude models by changing just your API key, base URL, and model name in existing OpenAI integrations. This compatibility layer supports core chat completions functionality. Learn more in [OpenAI SDK compatibility](https://platform.claude.com/docs/en/cli-sdks-libraries/libraries/openai-sdk).
693* We’ve added URL source blocks for images and PDFs in the Messages API. You can now reference images and PDFs directly through a URL instead of having to base64-encode them. Learn more in [Vision](https://platform.claude.com/docs/en/build-with-claude/vision) and [PDF support](https://platform.claude.com/docs/en/build-with-claude/pdf-support).
694* We’ve added support for a `none` option to the `tool_choice` parameter in the Messages API that prevents Claude from calling any tools. Additionally, you’re no longer required to provide any `tools` when including `tool_use` and `tool_result` blocks.
695* We’ve launched an OpenAI-compatible API endpoint, allowing you to test Claude models by changing just your API key, base URL, and model name in existing OpenAI integrations. This compatibility layer supports core chat completions functionality. Learn more in [OpenAI SDK compatibility](https://platform.claude.com/docs/en/cli-sdks-libraries/libraries/openai-sdk).
696696
697697### February 24th, 2025
698698
699* We've launched [Claude Sonnet 3.7](https://www.anthropic.com/news/claude-3-7-sonnet), our most intelligent model yet. Claude Sonnet 3.7 can produce near-instant responses or show its extended thinking step-by-step. One model, two ways to think. Learn more about all Claude models in [Models overview](https://platform.claude.com/docs/en/models/overview).
699* We’ve launched [Claude Sonnet 3.7](https://www.anthropic.com/news/claude-3-7-sonnet), our most intelligent model yet. Claude Sonnet 3.7 can produce near-instant responses or show its extended thinking step-by-step. One model, two ways to think. Learn more about all Claude models in [Models overview](https://platform.claude.com/docs/en/models/overview).
700700
701* We've added vision support to Claude Haiku 3.5, enabling the model to analyze and understand images.
701* We’ve added vision support to Claude Haiku 3.5, enabling the model to analyze and understand images.
702702
703* We've released a token-efficient tool use implementation, improving overall performance when using tools with Claude. Learn more in [Tool use with Claude](https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview).
703* We’ve released a token-efficient tool use implementation, improving overall performance when using tools with Claude. Learn more in [Tool use with Claude](https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview).
704704
705* We've changed the default temperature in the [Console](https://console.anthropic.com/workbench) for new prompts from 0 to 1 for consistency with the default temperature in the API. Existing saved prompts are unchanged.
705* We’ve changed the default temperature in the [Console](https://console.anthropic.com/workbench) for new prompts from 0 to 1 for consistency with the default temperature in the API. Existing saved prompts are unchanged.
706706
707* We've released updated versions of our tools that decouple the text edit and bash tools from the computer use system prompt:
707* We’ve released updated versions of our tools that decouple the text edit and bash tools from the computer use system prompt:
708708
709709 * `bash_20250124`: Same functionality as previous version but is independent from computer use. Does not require a beta header.
710710 * `text_editor_20250124`: Same functionality as previous version but is independent from computer use. Does not require a beta header.
711 * `computer_20250124`: Updated computer use tool with new command options including "hold\_key", "left\_mouse\_down", "left\_mouse\_up", "scroll", "triple\_click", and "wait". This tool requires the "computer-use-2025-01-24" anthropic-beta header. Learn more in [Tool use with Claude](https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview).
711 * `computer_20250124`: Updated computer use tool with new command options including `hold_key`, `left_mouse_down`, `left_mouse_up`, `scroll`, `triple_click`, and `wait`. This tool requires the `computer-use-2025-01-24` anthropic-beta header. Learn more in [Tool use with Claude](https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview).
712712
713713### February 10th, 2025
714714
715* We've added the `anthropic-organization-id` response header to all API responses. This header provides the organization ID associated with the API key used in the request.
715* We’ve added the `anthropic-organization-id` response header to all API responses. This header provides the organization ID associated with the API key used in the request.
716716
717717### January 31st, 2025
718718
719* We've moved our [Java SDK](https://github.com/anthropics/anthropic-sdk-java) from alpha to beta.
719* We’ve moved our [Java SDK](https://github.com/anthropics/anthropic-sdk-java) from alpha to beta.
720720
721721### January 23rd, 2025
722722
723* We've launched citations capability in the API, allowing Claude to provide source attribution for information. Learn more in [Citations](https://platform.claude.com/docs/en/build-with-claude/citations).
724* We've added support for plain text documents and custom content documents in the Messages API.
723* We’ve launched citations capability in the API, allowing Claude to provide source attribution for information. Learn more in [Citations](https://platform.claude.com/docs/en/build-with-claude/citations).
724* We’ve added support for plain text documents and custom content documents in the Messages API.
725725
726726### January 21st, 2025
727727
from line 729
729729
730730### January 15th, 2025
731731
732* We've updated [prompt caching](https://platform.claude.com/docs/en/build-with-claude/prompt-caching) to be easier to use. Now, when you set a cache breakpoint, we'll automatically read from your longest previously cached prefix.
733* You can now put words in Claude's mouth when using tools.
732* We’ve updated [prompt caching](https://platform.claude.com/docs/en/build-with-claude/prompt-caching) to be easier to use. Now, when you set a cache breakpoint, we’ll automatically read from your longest previously cached prefix.
733* You can now put words in Claude’s mouth when using tools.
734734
735735### January 10th, 2025
736736
737* We've optimized support for [prompt caching in the Message Batches API](https://platform.claude.com/docs/en/build-with-claude/batch-processing#using-prompt-caching-with-message-batches) to improve cache hit rate.
737* We’ve optimized support for [prompt caching in the Message Batches API](https://platform.claude.com/docs/en/build-with-claude/batch-processing#using-prompt-caching-with-message-batches) to improve cache hit rate.
738738
739739### December 19th, 2024
740740
741* We've added support for a [delete endpoint](https://platform.claude.com/docs/en/api/messages/batches/delete) in the Message Batches API.
741* We’ve added support for a [delete endpoint](https://platform.claude.com/docs/en/api/messages/batches/delete) in the Message Batches API.
742742
743743### December 17th, 2024
744744
from line 757
757757
758758### December 4th, 2024
759759
760* We've added the ability to group by API key on the [Usage](https://console.anthropic.com/settings/usage) and [Cost](https://console.anthropic.com/settings/cost) pages of the [Developer Console](https://console.anthropic.com).
761* We've added two new **Last used at** and **Cost** columns and the ability to sort by any column on the [API keys](https://console.anthropic.com/settings/keys) page of the [Developer Console](https://console.anthropic.com).
760* We’ve added the ability to group by API key on the [Usage](https://console.anthropic.com/settings/usage) and [Cost](https://console.anthropic.com/settings/cost) pages of the [Developer Console](https://console.anthropic.com).
761* We’ve added two new **Last used at** and **Cost** columns and the ability to sort by any column on the [API keys](https://console.anthropic.com/settings/keys) page of the [Developer Console](https://console.anthropic.com).
762762
763763### November 21st, 2024
764764
765* We've released the [Admin API](https://platform.claude.com/docs/en/manage-claude/admin-api), allowing users to programmatically manage their organization's resources.
765* We’ve released the [Admin API](https://platform.claude.com/docs/en/manage-claude/admin-api), allowing users to programmatically manage their organization’s resources.
766766
767767### November 20th, 2024
768768
769* We've updated our rate limits for the Messages API. We've replaced the tokens per minute rate limit with new input and output tokens per minute rate limits. Read more in [Rate limits](https://platform.claude.com/docs/en/api/rate-limits).
770* We've added support for [tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview) in the Console [Workbench](https://console.anthropic.com/workbench).
769* We’ve updated our rate limits for the Messages API. We’ve replaced the tokens per minute rate limit with new input and output tokens per minute rate limits. Read more in [Rate limits](https://platform.claude.com/docs/en/api/rate-limits).
770* We’ve added support for [tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview) in the Console [Workbench](https://console.anthropic.com/workbench).
771771
772772### November 13th, 2024
773773
774* We've added PDF support for all Claude Sonnet 3.5 models. Read more in [PDF support](https://platform.claude.com/docs/en/build-with-claude/pdf-support).
774* We’ve added PDF support for all Claude Sonnet 3.5 models. Read more in [PDF support](https://platform.claude.com/docs/en/build-with-claude/pdf-support).
775775
776776### November 6th, 2024
777777
778* We've retired the Claude 1 and Instant models. Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
778* We’ve retired the Claude 1 and Instant models. Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
779779
780780### November 4th, 2024
781781
from line 783
783783
784784### November 1st, 2024
785785
786* We've added PDF support for use with the new Claude Sonnet 3.5. Read more in [PDF support](https://platform.claude.com/docs/en/build-with-claude/pdf-support).
787* We've also added token counting, which allows you to determine the total number of tokens in a Message prior to sending it to Claude. Read more in [Token counting](https://platform.claude.com/docs/en/build-with-claude/token-counting).
786* We’ve added PDF support for use with the new Claude Sonnet 3.5. Read more in [PDF support](https://platform.claude.com/docs/en/build-with-claude/pdf-support).
787* We’ve also added token counting, which allows you to determine the total number of tokens in a Message prior to sending it to Claude. Read more in [Token counting](https://platform.claude.com/docs/en/build-with-claude/token-counting).
788788
789789### October 22nd, 2024
790790
791* We've added Anthropic-defined computer use tools to our API for use with the new Claude Sonnet 3.5. Read more in [Computer use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool).
791* We’ve added Anthropic-defined computer use tools to our API for use with the new Claude Sonnet 3.5. Read more in [Computer use tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool).
792792* Claude Sonnet 3.5, our most intelligent model yet, just got an upgrade and is now available on the Claude API. Read more in the [Claude Sonnet documentation](https://www.anthropic.com/claude/sonnet).
793793
794794### October 8th, 2024
795795
796796* The Message Batches API is now available in beta. Process large batches of queries asynchronously in the Claude API for 50% less cost. Read more in [Batch processing](https://platform.claude.com/docs/en/build-with-claude/batch-processing).
797* We've loosened restrictions on the ordering of `user`/`assistant` turns in our Messages API. Consecutive `user`/`assistant` messages will be combined into a single message instead of erroring, and we no longer require the first input message to be a `user` message.
798* We've deprecated the Build and Scale plans in favor of a standard feature suite (formerly referred to as Build), along with additional features that are available through sales. Read more in our [API pricing information](https://claude.com/platform/api).
797* We’ve loosened restrictions on the ordering of `user`/`assistant` turns in our Messages API. Consecutive `user`/`assistant` messages will be combined into a single message instead of erroring, and we no longer require the first input message to be a `user` message.
798* We’ve deprecated the Build and Scale plans in favor of a standard feature suite (formerly referred to as Build), along with additional features that are available through sales. Read more in our [API pricing information](https://claude.com/platform/api).
799799
800800### October 3rd, 2024
801801
802* We've added the ability to disable parallel tool use in the API. Set `disable_parallel_tool_use: true` in the `tool_choice` field to ensure that Claude uses at most one tool. Read more in [Parallel tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/parallel-tool-use).
802* We’ve added the ability to disable parallel tool use in the API. Set `disable_parallel_tool_use: true` in the `tool_choice` field to ensure that Claude uses at most one tool. Read more in [Parallel tool use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/parallel-tool-use).
803803
804804### September 10th, 2024
805805
806* We've added Workspaces to the [Developer Console](https://console.anthropic.com). Workspaces allow you to set custom spend or rate limits, group API keys, track usage by project, and control access with user roles. Read more in our [Workspaces blog post](https://www.anthropic.com/news/workspaces).
806* We’ve added Workspaces to the [Developer Console](https://console.anthropic.com). Workspaces allow you to set custom spend or rate limits, group API keys, track usage by project, and control access with user roles. Read more in our [Workspaces blog post](https://www.anthropic.com/news/workspaces).
807807
808808### September 4th, 2024
809809
from line 811
811811
812812### August 22nd, 2024
813813
814* We've added support for usage of the SDK in browsers by returning CORS headers in the API responses. Set `dangerouslyAllowBrowser: true` in the SDK instantiation to enable this feature.
814* We’ve added support for usage of the SDK in browsers by returning CORS headers in the API responses. Set `dangerouslyAllowBrowser: true` in the SDK instantiation to enable this feature.
815815
816816### August 19th, 2024
817817
No line in this hunk matches that.