overview changedrelease-notes/overview
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1515### October 22, 2026
1616
1717* 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.
18* [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).
1819
19- [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).
20
2120### October 21, 2026
2221
2322* 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.
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3029* [Inference hooks](https://platform.claude.com/docs/en/manage-claude/inference-hooks) are out of beta for Claude Enterprise organizations.
3130* 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).
3231* 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.
33* 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 [Web fetch tool](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).
32* 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).
3433* 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).
3534* 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).
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8786### September 28, 2026
8887
8988* 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).
90* 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 [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).
89* 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).
9190* 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).
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9392### September 24, 2026
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102101
103102### September 22, 2026
104103
105* 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). 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.
106* 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 [migration guide](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-5).
104* 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.
105* 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).
107106* [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.
108107* 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.
109108
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133132
134133### September 1, 2026
135134
136* 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 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.
135* 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.
137136* 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).
138137* 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).
139138* 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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148147
149148* In Python SDK 1.2.0, TypeScript SDK 0.122.0, Go SDK 1.68.0, Java SDK 2.59.0, Ruby SDK 1.67.0, and C# SDK 12.44.0, `client.beta.files` and `client.beta.skills` no longer send the `files-api-2025-04-14` and `skills-2025-10-02` beta headers and return the same shapes as `client.files` and `client.skills`. With this change, `client.beta.skills.delete()` deletes a Skill together with all of its versions, and the beta Messages type `BetaSkill` (the container Skill reference) is renamed `BetaContainerSkill`. Requests that still send the beta headers keep receiving the beta shapes. 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) and [Migrate from `skills-2025-10-02`](https://platform.claude.com/docs/en/build-with-claude/skills-guide#migrate-from-skills-2025-10-02).
150149
151- You can now create **personal keys** and **service account keys** in the Claude Console. They act as you or as a [service account](https://platform.claude.com/docs/en/manage-claude/workload-identity-federation#service-accounts), with the same permissions, and stop working when the linked account is removed from an organization. This lets organization admins more easily track usage for each account, and ensure key usage is legitimate. These API keys can be scoped to a specific workspace or [work on admin endpoints and across any workspace](https://platform.claude.com/docs/en/manage-claude/authentication#select-a-workspace) the account has access to. Workspace API keys remain supported as a legacy option. See [API keys](https://platform.claude.com/docs/en/manage-claude/authentication#api-keys) for more information.
150- You can now create **personal keys** and **service account keys** in the Claude Console. They act as you or as a [service account](https://platform.claude.com/docs/en/manage-claude/workload-identity-federation#service-accounts), with the same permissions, and stop working when the linked account is removed from an organization. This lets organization admins more easily track usage for each account, and ensure key usage is legitimate. These API keys can be scoped to a specific workspace or [work on admin endpoints and across any workspace](https://platform.claude.com/docs/en/manage-claude/authentication#select-a-workspace) the account has access to. Workspace API keys remain supported as a legacy option. See [API keys in Authentication](https://platform.claude.com/docs/en/manage-claude/authentication#api-keys) for more information.
152151
153152### August 26, 2026
154153
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184183
185184### August 10, 2026
186185
187* The introductory pricing for **Claude Sonnet 5** ($2 / $10 per MTok) is now the standard price: the previously scheduled increase to $3 / $15 per MTok on September 1, 2026 will not occur. See [Pricing](https://platform.claude.com/docs/en/about-claude/pricing).
186* The introductory pricing for **Claude Sonnet 5** ($2 / $10 USD per MTok) is now the standard price: the previously scheduled increase to $3 / $15 USD per MTok on September 1, 2026, will not occur. See [Pricing](https://platform.claude.com/docs/en/about-claude/pricing).
188187
189188### August 7, 2026
190189
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213212* [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.
214213* 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.
215214* 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).
216* 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](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
215* 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).
217216
218217### July 22, 2026
219218
220219* 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.
221* 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 [Subscribe to webhooks](https://platform.claude.com/docs/en/managed-agents/webhooks#supported-event-types).
220* 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).
222221* 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.
223222* 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).
224223* 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).
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243242
244243### July 8, 2026
245244
246* 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 [Authentication](https://platform.claude.com/docs/en/manage-claude/authentication#key-expiration).
245* 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).
247246
248247### July 2, 2026
249248
from line 255
256255
257256### June 30, 2026
258257
259* We've launched **Claude Sonnet 5** (`claude-sonnet-5`), the next generation of our Sonnet model family, at introductory pricing of $2 / $10 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).
258* 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).
260259* 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.
261260* [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).
262261* 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.
263262* 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.
264* 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 [Subscribe to webhooks](https://platform.claude.com/docs/en/managed-agents/webhooks#supported-event-types).
263* 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).
265264
266265### June 29, 2026
267266
268* 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](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
267* 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).
269268
270269### June 26, 2026
271270
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273272
274273### June 25, 2026
275274
276* 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](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
275* 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).
277276
278277### June 22, 2026
279278
from line 306
307306* 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).
308307* 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.
309308* 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.
310* 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 [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.
309* 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.
311310* The `session.thread_*` webhook events now include a `session_thread_id` field identifying the multiagent thread that triggered the event.
312311* 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).
313312
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317316
318317### June 2, 2026
319318
320* 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 per 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).
319* 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).
321320* 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.
322321
323322### May 29, 2026
from line 340
341340* 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).
342341* 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).
343342* 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).
344* 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](https://platform.claude.com/docs/en/build-with-claude/fast-mode#supported-models).
343* 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).
345344* 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).
346345
347346### May 27, 2026
from line 360
361360
362361### May 13, 2026
363362
364* We've launched [cache diagnostics](https://platform.claude.com/docs/en/build-with-claude/cache-diagnostics) in public 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.
363* 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.
365364
366365### May 12, 2026
367366
from line 372
373372
374373### May 6, 2026
375374
376* [Multiagent orchestration](https://platform.claude.com/docs/en/managed-agents/multiagent-orchestration) and [Outcomes](https://platform.claude.com/docs/en/managed-agents/define-outcomes) are now in public beta under the standard `managed-agents-2026-04-01` beta header.
375* [Multiagent orchestration](https://platform.claude.com/docs/en/managed-agents/multiagent-orchestration) and [Outcomes](https://platform.claude.com/docs/en/managed-agents/define-outcomes) are now in beta under the standard `managed-agents-2026-04-01` beta header.
377376* Claude Managed Agents vault credential background refresh is now supported for `mcp_oauth` credentials. See [Authenticate with vaults](https://platform.claude.com/docs/en/managed-agents/vaults).
378377* Webhooks for Claude Managed Agents are now supported. Webhook event types include session and vault lifecycle events. See [Subscribe to webhooks](https://platform.claude.com/docs/en/managed-agents/webhooks).
379378* Additional filtering and sorting options are now supported for Claude Managed Agents. Sessions can be filtered by status, and events can be filtered by type. Events can now be filtered by creation time.
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397396
398397### April 23, 2026
399398
400* Memory for Claude Managed Agents is now in public beta under the standard `managed-agents-2026-04-01` header. See [Using agent memory](https://platform.claude.com/docs/en/managed-agents/memory) for the full integration guide.
399* Memory for Claude Managed Agents is now in beta under the standard `managed-agents-2026-04-01` header. See [Using agent memory](https://platform.claude.com/docs/en/managed-agents/memory) for the full integration guide.
401400
402401### April 20, 2026
403402
from line 404
405404
406405### April 16, 2026
407406
408* 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 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.
407* 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.
409408* [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.
410409* 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.
411410* 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.
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417416
418417### April 9, 2026
419418
420* We've launched the [advisor tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool) in public 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.
419* 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.
421420
422421### April 8, 2026
423422
424* We've launched **Claude Managed Agents** in public 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).
423* 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).
425424* 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).
426425
427426### April 7, 2026
from line 445
446445
447446* 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.
448447* We've removed the dedicated 1M rate limits for all supported models. Your standard account limits now apply across every context length.
449* We've raised the media limit from 100 to 600 images or PDF pages per request when using the 1M token context window.
448* We've raised the media limit from 100 to 600 images or PDF pages for each request when using the 1M token context window.
450449
451450### February 19, 2026
452451
453* 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 [Prompt caching](https://platform.claude.com/docs/en/build-with-claude/prompt-caching#automatic-caching).
452* 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).
454453* 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).
455454* 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).
456455
457456### February 17, 2026
458457
459* 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.
458* 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.
460459* 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.
461460* 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.
462461* 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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467466
468467### February 5, 2026
469468
470* 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).
469* 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).
471470* 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.
472471* 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.
473472* 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.
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476475
477476### January 29, 2026
478477
479* [Structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) are out of beta on the Claude API for Claude Sonnet 4.5, Claude Opus 4.5, and Claude Haiku 4.5. This release includes expanded schema support, improved grammar compilation latency, and a simplified integration path with no beta header required. The `output_format` parameter has moved to `output_config.format`. Existing beta users can continue using the beta header during the transition period. Structured outputs remain in public beta on Amazon Bedrock and Microsoft Foundry.
478* [Structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) are out of beta on the Claude API for Claude Sonnet 4.5, Claude Opus 4.5, and Claude Haiku 4.5. This release includes expanded schema support, improved grammar compilation latency, and a simplified integration path with no beta header required. The `output_format` parameter has moved to `output_config.format`. Existing beta users can continue using the beta header during the transition period. Structured outputs remain in beta on Amazon Bedrock and Microsoft Foundry.
480479
481480### January 12, 2026
482481
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492491
493492### December 4, 2025
494493
495* [Structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) now supports Claude Haiku 4.5.
494* [Structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) now support Claude Haiku 4.5.
496495
497496### November 24, 2025
498497
499* 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).
500* We've launched [programmatic tool calling](https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling) in public beta, allowing Claude to call tools from within code execution to reduce latency and token usage in multi-tool workflows.
501* We've launched the [tool search tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool) in public beta, enabling Claude to dynamically discover and load tools on-demand from large tool catalogs.
502* We've launched the [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort) in public beta for Claude Opus 4.5, allowing you to control token usage by trading off between response thoroughness and efficiency.
498* 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).
499* 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.
500* 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.
501* 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.
503502* 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`.
504503
505504### November 21, 2025
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516515
517516### November 14, 2025
518517
519* We've launched [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) in public 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`.
518* 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`.
520519
521520### October 28, 2025
522521
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526525
527526### October 16, 2025
528527
529* 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:
528* 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:
530529
531530 * **Anthropic-managed Skills**: Pre-built Skills for working with PowerPoint (.pptx), Excel (.xlsx), Word (.docx), and PDF files
532531 * **Custom Skills**: Upload your own Skills through the Skills API (`/v1/skills` endpoints) to package domain expertise and organizational workflows
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535534
536535### October 15, 2025
537536
538* 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).
537* 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).
539538
540539### September 29, 2025
541540
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577576
578577### September 2, 2025
579578
580* We've launched v2 of the [Code Execution Tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) in public beta, replacing the original Python-only tool with Bash command execution and direct file manipulation capabilities, including writing code in other languages.
579* 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.
581580
582581### August 27, 2025
583582
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590589
591590### August 19, 2025
592591
593* Request IDs are now included directly in error response bodies alongside the existing `request-id` header. Learn more in [Errors](https://platform.claude.com/docs/en/api/errors#error-shapes).
592* Request IDs are now included directly in error response bodies alongside the existing `request-id` header. Learn more in [Error shapes](https://platform.claude.com/docs/en/api/errors#error-shapes).
594593
595594### August 18, 2025
596595
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600599### August 13, 2025
601600
602601* We announced the deprecation of the Claude Sonnet 3.5 models (`claude-3-5-sonnet-20240620` and `claude-3-5-sonnet-20241022`). These models will be retired on October 28, 2025. We recommend migrating to Claude Sonnet 4.5 (`claude-sonnet-4-5-20250929`) for improved performance and capabilities. Read more in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations).
603* The 1-hour cache duration for prompt caching no longer requires a beta header. Learn more in [Prompt caching](https://platform.claude.com/docs/en/build-with-claude/prompt-caching#1-hour-cache-duration).
602* The 1-hour cache duration for prompt caching no longer requires a beta header. Learn more in [1-hour cache duration](https://platform.claude.com/docs/en/build-with-claude/prompt-caching#1-hour-cache-duration).
604603
605604### August 12, 2025
606605
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650649
651650### June 11, 2025
652651
653* We've launched [fine-grained tool streaming](https://platform.claude.com/docs/en/agents-and-tools/tool-use/fine-grained-tool-streaming) in public 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`.
652* 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`.
654653
655654### May 22, 2025
656655
657656* 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).
658657* 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.
659* We've launched [interleaved thinking](https://platform.claude.com/docs/en/build-with-claude/thinking#interleaved-thinking) in public 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`.
660* We've launched the [Files API](https://platform.claude.com/docs/en/build-with-claude/files) in public beta, enabling you to upload files and reference them in the Messages API and code execution tool.
661* We've launched the [Code execution tool](https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool) in public beta, a tool that enables Claude to execute Python code in a secure, sandboxed environment.
662* We've launched the [MCP connector](https://platform.claude.com/docs/en/agents-and-tools/mcp-connector) in public beta, a feature that allows you to connect to remote MCP servers directly from the Messages API.
658* 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`.
659* 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.
660* 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.
661* 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.
663662* 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.
664663* Our [Go SDK](https://github.com/anthropics/anthropic-sdk-go) has moved from beta to its first stable release.
665* We've included 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.
664* 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.
666665
667666### May 21, 2025
668667
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800799
801800### September 10th, 2024
802801
803* 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 [blog post](https://www.anthropic.com/news/workspaces).
802* 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).
804803
805804### September 4th, 2024
806805
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830829### June 27th, 2024
831830
832831* View API usage and billing broken down by dollar amount, token count, and API keys in the new [Usage](https://console.anthropic.com/settings/usage) and [Cost](https://console.anthropic.com/settings/cost) tabs in the [Developer Console](https://console.anthropic.com).
833* View your current API rate limits in the new [Rate Limits](https://console.anthropic.com/settings/limits) tab in the [Developer Console](https://console.anthropic.com).
832* View your current API rate limits in the new [Rate Limits tab](https://console.anthropic.com/settings/limits) in the [Developer Console](https://console.anthropic.com).
834833
835834### June 20th, 2024
836835
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842841
843842### May 10th, 2024
844843
845* 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 a high-quality prompts tailored to your specific tasks. Read more in our [blog post](https://www.anthropic.com/news/prompt-generator).
844* 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).
846845
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