Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
Loading
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./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 GA response format: file expiration (set expires_in_seconds when you upload a file; file objects report expires_at), and page and next_page pagination plus an ids[] filter when you list files. Storage is 1 TB per organization and the rate limit is 500 requests per minute. /v1/files requests that still send the beta header keep working and return the previous response format./v1/skills) are now generally available 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.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. See Restrict web search and web fetch domains.mount_path and sync the agent's changes back to the store. See Use memory stores.GET /v1/compliance/apps/sessions/local lists sessions across your organization, GET /v1/compliance/apps/sessions/local/{session_id} retrieves one session's metadata, and GET /v1/compliance/apps/sessions/local/{session_id}/messages returns its transcript, all with your existing Compliance Access Key and the read:compliance_user_data scope. See Sessions on users' machines.anthropic-workspace-id response header to the Claude API. It carries the wrkspc_-prefixed ID of the workspace that the request's API key or access token resolved to, including your organization's Default Workspace. See Identify the workspace behind an API response.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.{"type": "advisor"} entry in the agent's multiagent roster, naming the model to consult. See Give the session an advisor.inference_geo inside the model object when you create the agent, or override it for a single session. See Data residency for the available geos and pricing..claude/skills directory are discovered automatically at session start and available to the agent for that session.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. Researchers can request ongoing access through the External Researcher Access Program.GET /v1/compliance/apps/sessions/remote lists sessions and GET /v1/compliance/apps/sessions/remote/{session_id}/messages returns one session's transcript, using your existing Compliance Access Key with the read:compliance_user_data scope. See Sessions in the cloud.claude-opus-5), a step-change improvement over Claude Opus 4.8. Claude Opus 5 supports a 1M token context window (both the default and the maximum), 128k max output tokens, and 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, Claude on Google Cloud, and Claude in Microsoft Foundry. See What's new in Claude Opus 5 for new features, behavior changes, and migration guidance, and the models overview for complete specs.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.low, medium, high, xhigh, max), with max for capability-critical work.mid-conversation-tool-changes-2026-07-01 beta header in your requests.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.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 or Claude Opus 4.8. Read more in Fast mode.effort level on a Claude Managed Agents agent's model configuration. Pass effort inside the model object when you create the agent. See Effort levels for what each level does.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.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.version field is now optional when updating a Claude Managed Agents agent. Supply it for optimistic concurrency (a mismatch returns a 409 error), or omit it to apply the update unconditionally. See Update semantics.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./v1/experimental/generate_prompt, /v1/experimental/improve_prompt, and /v1/experimental/templatize_prompt) are being retired along with the Workbench on August 17, 2026. After removal, requests to these endpoints will return an error.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.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.expires_at field. See Authentication.agent-memory-2026-07-22 beta header, which changes how listing 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.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.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, 128k max output tokens, and the same set of tools and platform features as Claude Sonnet 4.6, except Priority Tier, which is not available on Claude Sonnet 5. Three behavior changes apply when migrating: 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 for details and migration guidance. For behavioral differences and model-specific prompting patterns, see Prompting Claude Sonnet 5.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.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.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.injection_location setting on environment variable credentials (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.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. Read more in Fast mode.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./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.code_execution_20260120, the code execution tool version that adds REPL state persistence and is the minimum version for 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.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 and Claude Opus 4.8 respectively. Researchers can request ongoing access through the External Researcher Access Program.code_execution_20260521, which discloses the 90-second per-cell execution time limit in the tool description so Claude can budget long-running cells. No beta header is required.web_search_20260318 and web_fetch_20260318, adding a response_inclusion parameter to drop consumed result blocks from the API response for agentic workflows. No beta header is required.GET /v1/environments/{id}/work endpoint, which lists pending work for a self-hosted sandbox, is now available on Claude Platform on AWS. See IAM actions for Claude Platform on AWS for the GetEnvironment action that authorizes it.claude-fable-5), our most capable widely released model, alongside Claude Mythos 5 (claude-mythos-5) for Project Glasswing participants. Both models support a 1M token context window by default, 128k max output tokens, and always-on adaptive thinking. See Introducing Claude Fable 5 and Claude Mythos 5 for capabilities, API changes, and availability.model: "claude-fable-5" to measure your prompts under the new tokenizer.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.stop_details.category 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.thinking: {"type": "disabled"} is not supported, and manual extended thinking budgets and assistant prefill are not supported (both return a 400 error). See Migrating from Claude Mythos Preview to Claude Mythos 5.thinking.display defaults to "omitted", the same as Claude Opus 4.8, Claude Opus 4.7, and Claude Mythos Preview; set display: "summarized" to receive readable thinking summaries. The raw chain of thought is never returned; pass thinking blocks back unchanged in multi-turn conversations on the same model. See Thinking output on Claude Fable 5 and Claude Mythos 5.GET /v1/compliance/activities) is now available on Claude Platform on AWS. See IAM actions for Claude Platform on AWS for the ListComplianceActivities action that authorizes it.session.thread_* webhook events now include a session_thread_id field identifying the multiagent thread that triggered the event.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).claude-opus-4-1-20250805), with retirement on the Claude API scheduled for August 5, 2026. We recommend migrating to Claude Opus 4.8. Read more in Model deprecations.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.stop_reason: "refusal" without Claude having generated any output. See Streaming refusals for detecting and handling refusals.AnthropicSelfHostedEnvironmentAccess managed policy.role: "system" messages after a user turn (subject to placement rules) in the messages array, preserving prompt cache hits when instructions change during a long-running session. No beta header is required.stop_details field on refusal responses is now publicly documented; it returns a category (cyber, bio, or null) and a human-readable explanation, so your application can route different classes of refusal to the right next step. No beta header is required.high across all surfaces, including Claude Code and the Messages API.temperature, top_p, or top_k to a non-default value returns a 400 error on Claude Opus 4.8, same as on Claude Opus 4.7. See the migration guide for details.usage.output_tokens_details.thinking_tokens, reporting how many of the billed output tokens were extended thinking. When streaming, the breakdown appears only on the final message_delta event. No beta header is required.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.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.speed: "fast" with model: "claude-opus-4-7" and the fast-mode-2026-02-01 beta header for significantly faster output token generation at premium pricing. Pricing, rate limits, and access are the same as for Opus 4.6 fast mode; interested customers should join the waitlist.managed-agents-2026-04-01 beta header.mcp_oauth credentials. See Authenticate with vaults.dreaming-2026-04-21 beta header. Request access to try it.context-1m-2025-08-07) for Claude Sonnet 4.5 and Claude Sonnet 4. The beta header now has no effect on these models, and requests exceeding the standard 200k-token context window return an error. To use the 1M context window, migrate to Claude Sonnet 4.6 or Claude Opus 4.6, where it's generally available at standard pricing with no beta header required.managed-agents-2026-04-01 header. See Using agent memory for the full integration guide.claude-3-haiku-20240307). All requests to this model will now return an error. We recommend upgrading to Claude Haiku 4.5./anthropic/v1/messages, in 27 AWS regions with global and regional endpoints.task-budgets-2026-03-13 beta header in your requests.xhigh 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.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 and Claude Opus 4.8 respectively. Read more in Model deprecations.advisor-tool-2026-03-01 in your requests.managed-agents-2026-04-01 beta header. Learn more in Claude Managed Agents overview.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./anthropic/v1/messages uses the same request shape as the first-party Claude API and runs on AWS-managed infrastructure with zero operator access. Available in us-east-1; contact your Anthropic account executive to request access. Learn more in Claude in Amazon Bedrock.max_tokens cap to 300k on the Message Batches API 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.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 or Claude Opus 4.6, which support the full 1M token context window at standard pricing with no beta header required.GET /v1/models and GET /v1/models/{model_id} now return max_input_tokens, max_tokens, and a capabilities object. Query the API to discover what each model supports.display field for extended thinking, letting you omit thinking content from responses for faster streaming. Set thinking.display: "omitted" to receive thinking blocks with an empty thinking field and the signature preserved for multi-turn continuity. Billing is unchanged. Learn more in Controlling thinking display.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.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 and Claude Haiku 4.5 respectively. Researchers can request ongoing access through the External Researcher Access Program.claude-3-haiku-20240307), with retirement scheduled for April 20, 2026. We recommend migrating to Claude Haiku 4.5. Read more in Model deprecations.speed parameter. Fast mode is up to 2.5x as fast at premium pricing. Interested customers should join the waitlist.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.budget_tokens for controlling thinking depth on new models.inference_geo parameter. US-only inference is available at 1.1x pricing for models released after February 1, 2026.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.console.anthropic.com now redirects to platform.claude.com. The Claude Console has moved to its new home as part of our Claude brand consolidation. Existing bookmarks and links will continue working through an automatic redirect. For more details, see the September 16, 2025 announcement.claude-3-opus-20240229). All requests to this model will now return an error. We recommend upgrading to Claude Opus 4.5, which offers significantly improved intelligence at a third of the cost. Researchers can request ongoing access to Claude Opus 3 on the API through the External Researcher Access Program.tool_runner.structured-outputs-2025-11-13.clear_thinking_20251015), enabling automatic management of thinking blocks. Learn more in Context editing.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:
/v1/skills endpoints) to package domain expertise and organizational workflows