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2323### October 30, 2026
2424
25* We’ve deprecated [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.8, with removal on November 30, 2026. After removal, requests to `claude-opus-4-8` with `speed: "fast"` will return an error. To continue using fast mode, migrate to [Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-4-8). Read more in [Fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
25* We’ve deprecated [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) for Claude Opus 4.8, with removal on November 30, 2026. After removal, requests to `claude-opus-4-8` with `speed: "fast"` will return an error. To continue using fast mode, migrate to [Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-4-8). Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
2626
2727### October 29, 2026
2828
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6868### October 14, 2026
6969
7070* 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.
71* 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).
71* 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).
7272
7373### October 9, 2026
7474
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8282### October 7, 2026
8383
8484* 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).
85* 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).
86* 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).
85* 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 Models on Google Cloud (Google managed)](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).
86* 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"`. Claude Haiku 5.5 also uses a tokenizer that produces more tokens for the same text. See the [Claude Haiku 5.5 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).
8787* Python SDK 1.12.0 and TypeScript SDK 0.132.0 add 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).
8888* Claude Max, Ultra, and Team plans now include monthly API credits. To learn how to claim them, see [API credits for Max, Ultra, and Team plans](https://platform.claude.com/docs/en/about-claude/api-credits-for-subscribers).
8989* 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).
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110110
111111### September 28, 2026
112112
113* 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).
113* 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 Models on Google Cloud (Google managed)](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).
114114* 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).
115* 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).
115* 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 [Thinking blocks stay with the account that produced them](https://platform.claude.com/docs/en/build-with-claude/preserved-thinking#account-bound-thinking).
116116
117117### September 24, 2026
118118
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126126
127127### September 22, 2026
128128
129* 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.
129* 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 Models on Google Cloud (Google managed)](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.
130130* 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).
131131* [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.
132132* 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.
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157157
158158### September 1, 2026
159159
160* 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.
160* 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 Models on Google Cloud (Google managed)](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.
161161* 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).
162162* 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).
163163* 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).
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166166* `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).
167167* 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.
168168* 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).
169* 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).
169* 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).
170170
171171### August 27, 2026
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191191* 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.
192192* 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).
193193* [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).
194* 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).
194* The [Admin API user-management endpoints](https://platform.claude.com/docs/en/api/beta/organization) 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).
195195* 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).
196196* 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).
197197* 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).
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213213
214214* 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).
215215* 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).
216* 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.
216* 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 (see [Pin the inference geo](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.
217217* 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.
218218
219219### August 5, 2026
220220
221221* **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).
222* 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).
222* 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/opus-5/overview). 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).
223223
224224### August 3, 2026
225225
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231231
232232### July 24, 2026
233233
234* 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.
234* 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 Models on Google Cloud (Google managed)](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.
235235* 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).
236236* [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.
237237* 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.
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253253
254254### July 15, 2026
255255
256* [Mid-conversation system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages) are available on Claude Fable 5, Claude Mythos 5, and Claude Opus 4.8, on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), and [Google Cloud](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed). No beta header is required. This corrects earlier availability notes.
256* [Mid-conversation system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages) are available on Claude Fable 5, Claude Mythos 5, and Claude Opus 4.8, on the Claude API, [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock), and [Claude Models on Google Cloud (Google managed)](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/google-managed). No beta header is required. This corrects earlier availability notes.
257257
258258### July 14, 2026
259259
260* 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).
260* You can now manage the people in your **Claude Enterprise** (claude.ai) organization with the Admin API (see the [Admin API reference](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).
261261
262262### July 10, 2026
263263
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288288
289289### June 29, 2026
290290
291* 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).
291* 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/models/opus-4-8/overview). Read more in [Fast mode model availability](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
292292
293293### June 26, 2026
294294
295* 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).
295* 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](https://platform.claude.com/settings/limits) in the Claude Console.
296296
297297### June 25, 2026
298298
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308308
309309### June 15, 2026
310310
311* 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).
311* 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/opus-4-8/overview) 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).
312312
313313### June 11, 2026
314314
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322322### June 9, 2026
323323
324324* 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.
325* 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.
325* 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 with `model: "claude-fable-5"` to measure your prompts under the new tokenizer. See [Token counts on Claude Fable and Claude Mythos models](https://platform.claude.com/docs/en/build-with-claude/token-counting#token-counts-on-claude-fable-5).
326326* 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).
327327* 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.
328328* 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).
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336336
337337### June 5, 2026
338338
339* We announced the deprecation of the Claude Opus 4.1 model (`claude-opus-4-1-20250805`), with retirement on the Claude API scheduled for August 5, 2026. We recommend migrating to [Claude Opus 4.8](https://platform.claude.com/docs/en/about-claude/models/migration-guide). Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
339* We announced the deprecation of the Claude Opus 4.1 model (`claude-opus-4-1-20250805`), with retirement on the Claude API scheduled for August 5, 2026. We recommend migrating to [Claude Opus 4.8](https://platform.claude.com/docs/en/models/opus-4-8/overview). Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
340340
341341### June 2, 2026
342342
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355355* 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.
356356* 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.
357357* With [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) enabled, Claude Opus 4.8 triggers reasoning only when a turn needs it, reducing wasted thinking tokens compared to Claude Opus 4.7 at the same effort level.
358* Claude Opus 4.8 supports [high-resolution image input](https://platform.claude.com/docs/en/build-with-claude/vision#high-resolution-image-support-on-claude-opus-4-7) (up to 2576 pixels on the long edge), same as Claude Opus 4.7.
358* Claude Opus 4.8 supports [high-resolution image input](https://platform.claude.com/docs/en/build-with-claude/vision#high-resolution-image-support-on-claude-opus-4-7) (up to 2,576 pixels on the long edge), same as Claude Opus 4.7.
359359* [Task budgets](https://platform.claude.com/docs/en/build-with-claude/task-budgets) now support Claude Opus 4.8.
360360* The [advisor tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool) now supports Claude Opus 4.8.
361361* [Computer use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool) now supports Claude Opus 4.8.
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376376* [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.
377377* 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).
378378* With Claude Managed Agents, you can now update the agent’s MCP server and tool configurations associated with an active session.
379* 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.
379* 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.
380380
381381### May 18, 2026
382382
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412412
413413### April 29, 2026
414414
415* 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).
415* 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 eight 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).
416416
417417### April 24, 2026
418418
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431431* 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.
432432* [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.
433433* 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.
434* 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.
434* 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 1,568 to 2,576 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 might use up to approximately 3x more image tokens than on prior models.
435435* 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.
436436
437437### April 14, 2026
438438
439* We announced the deprecation of the Claude Sonnet 4 model (`claude-sonnet-4-20250514`) and the Claude Opus 4 model (`claude-opus-4-20250514`), with retirement on the Claude API scheduled for June 15, 2026. We recommend migrating 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/about-claude/models/migration-guide) respectively. Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
439* We announced the deprecation of the Claude Sonnet 4 model (`claude-sonnet-4-20250514`) and the Claude Opus 4 model (`claude-opus-4-20250514`), with retirement on the Claude API scheduled for June 15, 2026. We recommend migrating 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/opus-4-8/overview) respectively. Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
440440
441441### April 9, 2026
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454454
455455### March 30, 2026
456456
457* 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.
457* 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.
458458* 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.
459459
460460### March 18, 2026
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551551
552552* 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:
553553
554 * **Anthropic-managed Skills**: Pre-built Skills for working with PowerPoint (.pptx), Excel (.xlsx), Word (.docx), and PDF files
555 * **Custom Skills**: Upload your own Skills through the Skills API (`/v1/skills` endpoints) to package domain expertise and organizational workflows
554 * **Anthropic-managed Skills:** Pre-built Skills for working with PowerPoint (.pptx), Excel (.xlsx), Word (.docx), and PDF files
555 * **Custom Skills:** Upload your own Skills through the Skills API (`/v1/skills` endpoints) to package domain expertise and organizational workflows
556556 * Skills require the [code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) to be enabled
557557 * Learn more in [Agent Skills](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview) and [API reference](https://platform.claude.com/docs/en/api/skills/create)
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570570
571571### September 17, 2025
572572
573* 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).
573* 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 tool helpers](https://github.com/anthropics/anthropic-sdk-python/blob/main/tools.md) and the [TypeScript SDK tool helpers](https://github.com/anthropics/anthropic-sdk-typescript/blob/main/helpers.md#tool-helpers).
574574
575575### September 16, 2025
576576
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631631
632632### August 11, 2025
633633
634* Some customers might encounter 429 (`rate_limit_error`) [errors](https://platform.claude.com/docs/en/api/errors) following a sharp increase in API usage due to acceleration limits on the API. Previously, 529 (`overloaded_error`) errors would occur in similar scenarios.
634* Some customers might encounter [429 (`rate_limit_error`) errors](https://platform.claude.com/docs/en/api/errors) following a sharp increase in API usage because of acceleration limits on the API. Previously, 529 (`overloaded_error`) errors would occur in similar scenarios.
635635
636636### August 8, 2025
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641641
642642* 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.<sup>\*</sup> Learn more in [Models overview](https://platform.claude.com/docs/en/models/overview).
643643
644*<sup>\*Opus 4.1 does not allow both `temperature` and `top_p` parameters to be specified. Please use only one.</sup>*
644*<sup>\*Opus 4.1 does not allow both `temperature` and `top_p` parameters to be specified. Use only one.</sup>*
645645
646646### July 28, 2025
647647
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649649
650650### July 24, 2025
651651
652* 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.
652* 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.
653653
654654### July 21, 2025
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657657
658658### July 17, 2025
659659
660* 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.
660* 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.
661661
662662### July 3, 2025
663663
664* 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`.
664* 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`.
665665
666666### June 30, 2025
667667
from line 750
750750### January 15th, 2025
751751
752752* 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.
753* You can now put words in Claude’s mouth when using tools.
753* You can now prefill Claude’s response when using tools.
754754
755755### January 10th, 2025
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from line 787
787787### November 20th, 2024
788788
789789* 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).
790* 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).
790* 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).
791791
792792### November 13th, 2024
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865865
866866### May 10th, 2024
867867
868* Our prompt generator tool is now available in the [Developer Console](https://console.anthropic.com). Prompt Generator makes it easy to guide Claude to generate high-quality prompts tailored to your specific tasks. Read more in our [blog post](https://www.anthropic.com/news/prompt-generator).
868* Our prompt generator tool is now available in the [Developer Console](https://console.anthropic.com). The prompt generator helps you guide Claude to generate high-quality prompts tailored to your specific tasks. Read more in our [prompt generator blog post](https://www.anthropic.com/news/prompt-generator).
869869
No line in this hunk matches that.