Claude Platform

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June 15, 2026

• 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 and Claude Opus 4.8 respectively. Researchers can request ongoing access through the External Researcher Access Program.

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June 10, 2026

• The 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.

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June 9, 2026

• We've launched Claude Fable 5 (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.
• Claude Fable 5 and Claude Mythos 5 use the tokenizer introduced with Claude Opus 4.7. Compared to models before Claude Opus 4.7, the same text produces roughly 30% more tokens. Use the token counting API with model: "claude-fable-5" to measure your prompts under the new tokenizer.
• Claude Fable 5 runs safety classifiers on requests and during response generation. When a classifier declines a request, the Messages API returns stop_reason: "refusal". You are not billed for a request refused before any output is generated. An opt-in fallbacks parameter (in beta on the Claude API and Claude Platform on AWS; not supported on the Message Batches API) re-runs refused requests on another model, billed at the fallback model's rates. See Handling stop reasons.
• The field on refusal responses now includes 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 and categories are unchanged. No beta header is required.

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June 5, 2026

• We announced the deprecation of the Claude Opus 4.1 model (claude-opus-4-1-20250805), with retirement on the Claude API scheduled for August 5, 2026. We recommend migrating to Claude Opus 4.8. Read more in model deprecations.

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June 2, 2026

• The 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.
• 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 for detecting and handling refusals.

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May 29, 2026

• Claude Managed Agents webhooks, multi-agent orchestration, and self-hosted sandboxes are now available on Claude Platform on AWS. See IAM actions for Claude Platform on AWS for the new IAM actions and the AnthropicSelfHostedEnvironmentAccess managed policy.

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May 28, 2026

• We've launched Claude Opus 4.8 (claude-opus-4-8), our most capable generally available model. Claude Opus 4.8 supports a 1M token context window by default on the Claude API, Amazon Bedrock, and Vertex AI (200k on Microsoft Foundry), 128k max output tokens, and the same set of tools and platform features as Claude Opus 4.7. See What's new in Claude Opus 4.8 for capability improvements, new features, and migration guidance.
• We've launched mid-conversation system messages. On Claude Opus 4.8, you can send 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.
• The 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.

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May 27, 2026

• The Messages API response now includes 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.

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May 19, 2026

• MCP tunnels is now available as a research preview, so you can connect to MCP servers in your private network.
• Self-hosted sandboxes are now available for Claude Managed Agents, as an alternative to running tool execution in Anthropic's infrastructure. See Self-hosted sandboxes.
• With Claude Managed Agents, you can now update the agent's MCP server and tool configurations associated with an active session.
• With Claude Managed Agents, large outputs from agent_toolset and MCP tools exceeding 100K 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.

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May 18, 2026

• The web search tool now returns richer SEC filing data, making it easier to ground financial research agents, earnings analysis, and due-diligence workflows in primary sources with citations.

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May 13, 2026

• We've launched 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.

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May 12, 2026

• Fast mode (research preview) now supports Claude Opus 4.7. Set 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.

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May 11, 2026

• We've launched Claude Platform on AWS, bringing the Claude API to Anthropic-managed infrastructure accessible through AWS, with AWS billing and IAM authentication. Access the full Messages API, Files API, Message Batches API, Claude Managed Agents, Agent Skills, code execution, and tool use through native AWS endpoints. Learn more in Claude Platform on AWS.

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May 6, 2026

• Multi-agent sessions and Outcomes are now in public beta under the standard managed-agents-2026-04-01 beta header.
• Claude Managed Agents vault credential background refresh is now supported for mcp_oauth credentials. See Authenticate with vaults.
• Webhooks for Claude Managed Agents are now supported. Webhook event types include session and vault lifecycle events. See Subscribe to webhooks.
• 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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April 30, 2026

• We've retired the 1M token context window beta (context-1m-2025-08-07) for Claude Sonnet 4.5 and Claude Sonnet 4. The beta header now has no effect on these models, and requests exceeding the standard 200k-token context window return an error. To use the 1M context window, migrate to Claude Sonnet 4.6 or Claude Opus 4.6, where it's generally available at standard pricing with no beta header required.

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April 24, 2026

• We've released the Rate Limits API, allowing administrators to programmatically query the rate limits configured for their organization and workspaces.

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April 23, 2026

• Memory for Claude Managed Agents is now in public beta under the standard managed-agents-2026-04-01 header. See Using agent memory for the full integration guide.

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April 20, 2026

• We've retired the Claude Haiku 3 model (claude-3-haiku-20240307). All requests to this model will now return an error. We recommend upgrading to Claude Haiku 4.5.

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April 16, 2026

• We've launched Claude Opus 4.7, our most capable generally available 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 for capability improvements, new features, and the updated tokenizer. Opus 4.7 includes API breaking changes versus Opus 4.6; see Migrating to Claude Opus 4.7 before upgrading.
• 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.

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April 14, 2026

• We announced the deprecation of the Claude Sonnet 4 model (claude-sonnet-4-20250514) and the Claude Opus 4 model (claude-opus-4-20250514), with retirement on the Claude API scheduled for June 15, 2026. We recommend migrating to Claude Sonnet 4.6 and Claude Opus 4.8 respectively. Read more in model deprecations.

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April 9, 2026

• We've launched the 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.

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April 8, 2026

• 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.
• 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.

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April 7, 2026

• We announced Claude Mythos Preview is available as a gated research preview for defensive cybersecurity work as part of Project Glasswing. Access is invitation-only.
• The Messages API is now available on Amazon Bedrock as a research preview. The new Claude in Amazon Bedrock endpoint at /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.

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March 30, 2026

• We've raised the 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.
• We're retiring the 1M token context window beta for Claude Sonnet 4.5 and Claude Sonnet 4 on April 30, 2026. After that date, the context-1m-2025-08-07 beta header will have no effect on these models, and requests that exceed the standard 200k-token context window will return an error. To continue using 1M context windows, migrate to Claude Sonnet 4.6 or Claude Opus 4.6, which support the full 1M token context window at standard pricing with no beta header required.

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March 18, 2026

• We've added model capability fields to the Models API. 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.

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March 16, 2026

• We've launched the display field for extended thinking, letting you omit thinking content from responses for faster streaming. Set thinking.display: "omitted" to receive thinking blocks with an empty thinking field and the signature preserved for multi-turn continuity. Billing is unchanged. Learn more in Controlling thinking display.

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March 13, 2026

• The 1M token context window is now generally available 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.
• We've removed the dedicated 1M rate limits for all supported models. Your standard account limits now apply across every context length.
• We've raised the media limit from 100 to 600 images or PDF pages per request when using the 1M token context window.

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February 19, 2026

• 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.
• 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 these models will now return an error. 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.
• 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. Read more in Model deprecations.

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February 17, 2026

• We've launched 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 and a 1M token context window (beta). See Models & Pricing for details.
• API code execution is now free when used with web search or web fetch. Sandboxed code execution improves model capability and token efficiency. See the pricing details for standalone usage.
• The web search tool and programmatic tool calling are now generally available (no beta header required). Web search and web fetch now support dynamic filtering, which uses code execution to filter results before they reach the context window for better performance and reduced token cost.
• The code execution tool, web fetch tool, tool search tool, tool use examples, and memory tool are now generally available (no beta header required).

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February 7, 2026

• We've launched fast mode in research preview for Opus 4.6, providing significantly faster output token generation via the speed parameter. Fast mode is up to 2.5x as fast at premium pricing. Interested customers should join the waitlist.

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February 5, 2026

• We've launched Claude Opus 4.6, our most intelligent model for complex agentic tasks and long-horizon work. Opus 4.6 recommends adaptive 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.
• The effort parameter is now generally available (no beta header required) and supports Claude Opus 4.6. Effort replaces budget_tokens for controlling thinking depth on new models.
• We've launched the compaction API in beta, providing server-side context summarization for effectively infinite conversations. Available on Opus 4.6.
• We've introduced data residency controls, 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.
• The 1M token context window is now available in beta for Claude Opus 4.6, in addition to Sonnet 4.5 and Sonnet 4. applies to requests exceeding 200k input tokens.

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January 29, 2026

• Structured outputs are now generally available on the Claude API for Claude Sonnet 4.5, Claude Opus 4.5, and Claude Haiku 4.5. GA 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.

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January 12, 2026

• 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 via automatic redirect. For more details, see the September 16, 2025 announcement.

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January 5, 2026

• We've retired the Claude Opus 3 model (claude-3-opus-20240229). All requests to this model will now return an error. We recommend upgrading to Claude Opus 4.5, 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.

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December 19, 2025

• We announced the deprecation of the Claude Haiku 3.5 model. Read more in Model deprecations.

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December 4, 2025

• Structured outputs now supports Claude Haiku 4.5.

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November 24, 2025

• We've launched 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.
• We've launched 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.
• We've launched the tool search tool in public beta, enabling Claude to dynamically discover and load tools on-demand from large tool catalogs.
• We've launched the effort parameter in public beta for Claude Opus 4.5, allowing you to control token usage by trading off between response thoroughness and efficiency.
• We've added client-side compaction to our Python and TypeScript SDKs, automatically managing conversation context through summarization when using tool_runner.

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November 21, 2025

• Search result content blocks are now generally available on Amazon Bedrock. Learn more in Search results.

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November 19, 2025

• We've launched a new documentation platform at platform.claude.com/docs. Our documentation now lives side by side with the Claude Console, providing a unified developer experience. The previous docs site at docs.claude.com will redirect to the new location.

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November 18, 2025

• We've launched Claude in Microsoft Foundry, bringing Claude models to Azure customers with Azure billing and OAuth authentication. Access the full Messages API including extended thinking, prompt caching (5-minute and 1-hour), PDF support, Files API, Agent Skills, and tool use. Learn more in Claude in Microsoft Foundry.

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November 14, 2025

• We've launched 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.

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October 28, 2025

• We announced the deprecation of the Claude Sonnet 3.7 model. Read more in Model deprecations.
• We've retired the Claude Sonnet 3.5 models. All requests to these models will now return an error.
• We've expanded context editing with thinking block clearing (clear_thinking_20251015), enabling automatic management of thinking blocks. Learn more in Context editing.

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October 16, 2025

• We've launched 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:
  • Anthropic-managed Skills: Pre-built Skills for working with PowerPoint (.pptx), Excel (.xlsx), Word (.docx), and PDF files
  • Custom Skills: Upload your own Skills via the Skills API (/v1/skills endpoints) to package domain expertise and organizational workflows
  • Skills require the code execution tool to be enabled
  • Learn more in Agent Skills and API reference

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October 15, 2025

• We've launched 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.

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September 29, 2025

• We've launched Claude Sonnet 4.5, our best model for complex agents and coding, with the highest intelligence across most tasks. Learn more in the models overview.
• We've introduced global endpoint pricing for Amazon Bedrock and Vertex AI. The Claude API (1P) pricing is unaffected.
• We've introduced a new stop reason model_context_window_exceeded that allows you to request the maximum possible tokens without calculating input size. Learn more in Handling stop reasons.
• We've launched the memory tool in beta, enabling Claude to store and consult information across conversations. Learn more in Memory tool.
• We've launched context editing in beta, providing strategies to automatically manage conversation context. The initial release supports clearing older tool results and calls when approaching token limits. Learn more in Context editing.

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September 17, 2025

• We've launched tool helpers in beta for the Python and TypeScript SDKs, simplifying tool creation and execution with type-safe input validation and a tool runner for automated tool handling in conversations. For details, see the documentation for the Python SDK and the TypeScript SDK.

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September 16, 2025

• We've unified our developer offerings under the Claude brand. You should see updated naming and URLs across our platform and documentation, but our developer interfaces will remain the same. Here are some notable changes:
  • Claude Console (console.anthropic.com) → Claude Console (platform.claude.com). The console will be available at both URLs until January 12, 2026. After that date, console.anthropic.com will automatically redirect to platform.claude.com.
  • Anthropic Docs (docs.anthropic.com) → Claude Docs (docs.claude.com)
  • Anthropic Help Center (support.anthropic.com) → Claude Help Center (support.claude.com)
  • API endpoints, headers, environment variables, and SDKs remain the same. Your existing integrations will continue working without any changes.

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September 10, 2025

• We've launched the web fetch tool in beta, allowing Claude to retrieve full content from specified web pages and PDF documents. Learn more in Web fetch tool.
• We've launched the Claude Code Analytics API, enabling organizations to programmatically access daily aggregated usage metrics for Claude Code, including productivity metrics, tool usage statistics, and cost data.

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September 8, 2025

• We launched a beta version of the C# SDK.

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September 5, 2025

• We've launched rate limit charts in the Console Usage page, allowing you to monitor your API rate limit usage and caching rates over time.

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September 3, 2025

• We've launched support for citable documents in client-side tool results. Learn more in Handle tool calls.

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September 2, 2025

• We've launched v2 of the 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.

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August 27, 2025

• We launched a beta version of the PHP SDK.

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August 26, 2025

• We've increased rate limits on the 1M token context window for Claude Sonnet 4 on the Claude API.
• The 1M token context window is now available on Vertex AI. For more information, see Claude on Vertex AI.

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August 19, 2025

• Request IDs are now included directly in error response bodies alongside the existing request-id header. Learn more in Errors.

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August 18, 2025

• We've released the Usage & Cost API, allowing administrators to programmatically monitor their organization's usage and cost data.
• We've added a new endpoint to the Admin API for retrieving organization information. For details, see the Organization Info Admin API reference.

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August 13, 2025

• 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.
• The 1-hour cache duration for prompt caching is now generally available. You can now use the extended cache TTL without a beta header. Learn more in Prompt caching.

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August 12, 2025

• We've launched beta support for a 1M token context window in Claude Sonnet 4 on the Claude API and Amazon Bedrock.

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August 11, 2025

• Some customers might encounter 429 (rate_limit_error) errors following a sharp increase in API usage due to acceleration limits on the API. Previously, 529 (overloaded_error) errors would occur in similar scenarios.

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August 8, 2025

• Search result content blocks are now generally available on the Claude API and Vertex AI. This feature enables natural citations for RAG applications with proper source attribution. The beta header search-results-2025-06-09 is no longer required. Learn more in Search results.

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August 5, 2025

• We've launched Claude Opus 4.1, an incremental update to Claude Opus 4 with enhanced capabilities and performance improvements.^* Learn more in Models overview.

^{* - Opus 4.1 does not allow both temperature and top_p parameters to be specified. Please use only one.}

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July 28, 2025

• We've released text_editor_20250728, an updated text editor tool that fixes some issues from the previous versions and adds an optional max_characters parameter that allows you to control the truncation length when viewing large files.

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July 24, 2025

• We've increased rate limits for Claude Opus 4 on the Claude API to give you more capacity to build and scale with Claude. For customers with usage tier 1-4 rate limits, these changes apply immediately to your account - no action needed.

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July 21, 2025

• We've retired the Claude 2.0, Claude 2.1, and Claude Sonnet 3 models. All requests to these models will now return an error. Read more in Model deprecations.

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July 17, 2025

• We've increased rate limits for Claude Sonnet 4 on the Claude API to give you more capacity to build and scale with Claude. For customers with usage tier 1-4 rate limits, these changes apply immediately to your account - no action needed.

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July 3, 2025

• We've launched search result content blocks in beta, enabling natural citations for RAG applications. Tools can now return search results with proper source attribution, and Claude will automatically cite these sources in its responses - matching the citation quality of web search. This eliminates the need for document workarounds in custom knowledge base applications. Learn more in Search results. To enable this feature, use the beta header search-results-2025-06-09.

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June 30, 2025

• We announced the deprecation of the Claude Opus 3 model. Read more in Model deprecations.

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June 23, 2025

• Console users with the Developer role can now access the Cost page. Previously, the Developer role allowed access to the Usage page, but not the Cost page.

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June 11, 2025

• We've launched 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 fine-grained-tool-streaming-2025-05-14.

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May 22, 2025

• We've launched Claude Opus 4 and Claude Sonnet 4, our latest models with extended thinking capabilities. Learn more in Models overview.
• The default behavior of 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.
• We've launched interleaved thinking in public beta, a feature that enables Claude to think in between tool calls. To enable interleaved thinking, use the beta header interleaved-thinking-2025-05-14.
• We've launched the Files API in public beta, enabling you to upload files and reference them in the Messages API and code execution tool.
• We've launched the Code execution tool in public beta, a tool that enables Claude to execute Python code in a secure, sandboxed environment.
• We've launched the MCP connector in public beta, a feature that allows you to connect to remote MCP servers directly from the Messages API.

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May 21, 2025

• We've moved our Ruby SDK from beta to GA.

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May 7, 2025

• We've launched a web search tool in the API, allowing Claude to access up-to-date information from the web. Learn more in Web search tool.

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May 1, 2025

• Cache control must now be specified directly in the parent content block of tool_result and document.source. For backwards compatibility, if cache control is detected on the last block in tool_result.content or document.source.content, it will be automatically applied to the parent block instead. Cache control on any other blocks within tool_result.content and document.source.content will result in a validation error.

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April 9th, 2025

• We launched a beta version of the Ruby SDK.

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March 31st, 2025

• We've moved our Java SDK from beta to GA.
• We've moved our Go SDK from alpha to beta.

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February 27th, 2025

• We've added URL source blocks for images and PDFs in the Messages API. You can now reference images and PDFs directly via URL instead of having to base64-encode them. Learn more in Vision and PDF support.
• We've added support for a none option to the tool_choice parameter in the Messages API that prevents Claude from calling any tools. Additionally, you're no longer required to provide any tools when including tool_use and tool_result blocks.
• We've launched an OpenAI-compatible API endpoint, allowing you to test Claude models by changing just your API key, base URL, and model name in existing OpenAI integrations. This compatibility layer supports core chat completions functionality. Learn more in OpenAI SDK compatibility.

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February 24th, 2025

• We've launched Claude Sonnet 3.7, our most intelligent model yet. Claude Sonnet 3.7 can produce near-instant responses or show its extended thinking step-by-step. One model, two ways to think. Learn more about all Claude models in Models overview.
• We've added vision support to Claude Haiku 3.5, enabling the model to analyze and understand images.
• We've released a token-efficient tool use implementation, improving overall performance when using tools with Claude. Learn more in Tool use with Claude.
• We've changed the default temperature in the Console for new prompts from 0 to 1 for consistency with the default temperature in the API. Existing saved prompts are unchanged.
• We've released updated versions of our tools that decouple the text edit and bash tools from the computer use system prompt:
  • bash_20250124: Same functionality as previous version but is independent from computer use. Does not require a beta header.
  • text_editor_20250124: Same functionality as previous version but is independent from computer use. Does not require a beta header.

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February 10th, 2025

• We've added the anthropic-organization-id response header to all API responses. This header provides the organization ID associated with the API key used in the request.

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January 31st, 2025

• We've moved our Java SDK from alpha to beta.

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January 23rd, 2025

• We've launched citations capability in the API, allowing Claude to provide source attribution for information. Learn more in Citations.
• We've added support for plain text documents and custom content documents in the Messages API.

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January 21st, 2025

• We announced the deprecation of the Claude 2, Claude 2.1, and Claude Sonnet 3 models. Read more in Model deprecations.

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January 15th, 2025

• We've updated prompt caching to be easier to use. Now, when you set a cache breakpoint, we'll automatically read from your longest previously cached prefix.
• You can now put words in Claude's mouth when using tools.

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January 10th, 2025

• We've optimized support for prompt caching in the Message Batches API to improve cache hit rate.

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December 19th, 2024

• We've added support for a delete endpoint in the Message Batches API.

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December 17th, 2024

The following features are now generally available in the Claude API:

• Models API: Query available models, validate model IDs, and resolve model aliases to their canonical model IDs.
• Message Batches API: Process large batches of messages asynchronously at 50% of the standard API cost.
• Token counting API: Calculate token counts for Messages before sending them to Claude.
• Prompt Caching: Reduce costs by up to 90% and latency by up to 80% by caching and reusing prompt content.
• PDF support: Process PDFs to analyze both text and visual content within documents.

We also released new official SDKs:

• Java SDK (alpha)
• Go SDK (alpha)

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December 4th, 2024

• We've added the ability to group by API key on the Usage and Cost pages of the Developer Console.
• We've added two new Last used at and Cost columns and the ability to sort by any column on the API keys page of the Developer Console.

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November 21st, 2024

• We've released the Admin API, allowing users to programmatically manage their organization's resources.

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November 20th, 2024

• We've updated our rate limits for the Messages API. We've replaced the tokens per minute rate limit with new input and output tokens per minute rate limits. Read more in Rate limits.
• We've added support for tool use in the Workbench.

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November 13th, 2024

• We've added PDF support for all Claude Sonnet 3.5 models. Read more in PDF support.

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November 6th, 2024

• We've retired the Claude 1 and Instant models. Read more in Model deprecations.

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November 4th, 2024

• Claude Haiku 3.5 is now available on the Claude API as a text-only model.

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November 1st, 2024

• We've added PDF support for use with the new Claude Sonnet 3.5. Read more in PDF support.
• We've also added token counting, which allows you to determine the total number of tokens in a Message prior to sending it to Claude. Read more in Token counting.

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October 22nd, 2024

• We've added Anthropic-defined computer use tools to our API for use with the new Claude Sonnet 3.5. Read more in Computer use tool.
• Claude Sonnet 3.5, our most intelligent model yet, just got an upgrade and is now available on the Claude API. Read more in the Claude Sonnet documentation.

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October 8th, 2024

• The Message Batches API is now available in beta. Process large batches of queries asynchronously in the Claude API for 50% less cost. Read more in Batch processing.
• We've loosened restrictions on the ordering of user/assistant turns in our Messages API. Consecutive user/assistant messages will be combined into a single message instead of erroring, and we no longer require the first input message to be a user message.
• We've deprecated the Build and Scale plans in favor of a standard feature suite (formerly referred to as Build), along with additional features that are available through sales. Read more in our API pricing information.

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October 3rd, 2024

• We've added the ability to disable parallel tool use in the API. Set disable_parallel_tool_use: true in the tool_choice field to ensure that Claude uses at most one tool. Read more in Parallel tool use.

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September 10th, 2024

• We've added Workspaces to the Developer Console. 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.

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September 4th, 2024

• We announced the deprecation of the Claude 1 models. Read more in Model deprecations.

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August 22nd, 2024

• We've added support for usage of the SDK in browsers by returning CORS headers in the API responses. Set dangerouslyAllowBrowser: true in the SDK instantiation to enable this feature.

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August 19th, 2024

• We've moved 8,192 token outputs from beta to general availability for Claude Sonnet 3.5.

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August 14th, 2024

• Prompt caching is now available as a beta feature in the Claude API. Cache and re-use prompts to reduce latency by up to 80% and costs by up to 90%.

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July 15th, 2024

• Generate outputs up to 8,192 tokens in length from Claude Sonnet 3.5 with the new anthropic-beta: max-tokens-3-5-sonnet-2024-07-15 header.

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July 9th, 2024

• Automatically generate test cases for your prompts using Claude in the Developer Console.
• Compare the outputs from different prompts side by side in the new output comparison mode in the Developer Console.

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June 27th, 2024

• View API usage and billing broken down by dollar amount, token count, and API keys in the new Usage and Cost tabs in the Developer Console.
• View your current API rate limits in the new Rate Limits tab in the Developer Console.

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June 20th, 2024

• Claude Sonnet 3.5, our most intelligent model yet, is now generally available across the Claude API, Amazon Bedrock, and Vertex AI.

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May 30th, 2024

• Tool use is now generally available across the Claude API, Amazon Bedrock, and Vertex AI.

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May 10th, 2024

• Our prompt generator tool is now available in the Developer Console. 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.