Claude Platform

* We've expanded the [Access Transparency](/docs/en/manage-claude/access-transparency) documentation of `cmek_preserve` events with a filter example, an example event payload, and two preservation reason codes (`policy_violation_investigation`, `csae_report`). The documentation now also clarifies that a preservation event is written whether the preservation was initiated by a human reviewer or an automated safety pipeline. See [CMEK content preservation](/docs/en/manage-claude/access-transparency#cmek-content-preservation).

* 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`](/docs/en/api/admin/api_keys/list) field. See [Authentication](/docs/en/manage-claude/authentication#key-expiration).

* We've added the `agent-memory-2026-07-22` beta header, which changes how [listing memories](/docs/en/managed-agents/memory#list-memories) (`GET /v1/memory_stores/{memory_store_id}/memories`) behaves: results are returned in a stable, server-defined order and the `order_by` and `order` parameters are ignored; `depth` accepts only `0`, `1`, or being omitted (other values return a `400` error); and `path_prefix` must end with `/` and matches whole path segments instead of a substring. Page cursors issued without the header aren't valid with it, so restart from the first page when you adopt it. On memory store endpoints, `agent-memory-2026-07-22` replaces `managed-agents-2026-04-01`; sending both returns a `400` error. On July 22, 2026, the `managed-agents-2026-04-01` header adopts the same list behavior. See [Beta headers](/docs/en/api/beta-headers#endpoint-specific-headers). * The Python (0.116.0), TypeScript (0.110.0), Go (1.56.0), Java (2.48.0), Ruby (1.55.0), PHP (0.36.0), C# (12.35.0), and CLI (1.16.0) SDKs now send `agent-memory-2026-07-22` on all memory store calls instead of `managed-agents-2026-04-01`. If your code passes `betas` explicitly on memory store calls, replace `managed-agents-2026-04-01` with `agent-memory-2026-07-22` there rather than adding a second value.

* We've restored access to Claude Fable 5 and Claude Mythos 5. See [our statement](https://www.anthropic.com/news/redeploying-fable-5) for more information.

* 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 through August 31, 2026 (standard $3 / $15 thereafter). Claude Sonnet 5 supports a [1M token context window](/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](/docs/en/api/service-tiers#supported-models), which is not available on Claude Sonnet 5. Three behavior changes apply when migrating: [adaptive thinking](/docs/en/build-with-claude/adaptive-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](/docs/en/about-claude/models/whats-new-sonnet-5) for details and migration guidance. For behavioral differences and model-specific prompting patterns, see [Prompting Claude Sonnet 5](/docs/en/build-with-claude/prompt-engineering/prompting-claude-sonnet-5). * Claude Managed Agents session event streams now support [event deltas](/docs/en/managed-agents/events-and-streaming#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. * [Listing sessions](/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](/docs/en/api/overview#pagination). * When creating a Claude Managed Agents session, you can now [override the agent's configuration for that session](/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. * Claude Managed Agents vaults now support an `injection_location` setting on [environment variable credentials](/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. * 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](/docs/en/managed-agents/webhooks#supported-event-types).

* We've removed [fast mode](/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](/docs/en/about-claude/models/migration-guide). Read more in [Fast mode](/docs/en/build-with-claude/fast-mode#supported-models).

* We've raised [rate limits](/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](/settings/limits).

* We've deprecated [fast mode](/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](/docs/en/build-with-claude/fast-mode#supported-models).

* **MCP tunnels** (research preview): the management API moved from `/v1/organizations/tunnels` on the Admin API to `/v1/tunnels` on the Claude API. The new surface uses the `anthropic-beta: mcp-tunnels-2026-06-22` header and the `workspace:manage_tunnels` WIF scope. The previous surface remains available during a migration window. See the [Tunnels API reference](/docs/en/api/beta/tunnels).

* The Python, TypeScript, Go, Java, Ruby, PHP, and C# SDKs now include support for `code_execution_20260120`, the [code execution tool](/docs/en/agents-and-tools/tool-use/code-execution-tool) version that adds REPL state persistence and is the minimum version for [programmatic tool calling](/docs/en/agents-and-tools/tool-use/programmatic-tool-calling). To adopt it, set the tool's `type` to `code_execution_20260120`; no beta header is required. It's available on Claude Fable 5, Claude Mythos 5, Claude Opus 4.5 and newer, and Claude Sonnet 4.5 and newer; see the [model compatibility table](/docs/en/agents-and-tools/tool-use/code-execution-tool#model-compatibility).

* 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 will now return an error. We recommend upgrading to [Claude Sonnet 4.6](/docs/en/about-claude/models/overview#latest-models-comparison) and [Claude Opus 4.8](/docs/en/about-claude/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).