245 pages for preview.

Create Tunnel Claude Developer Platform · in the page api/beta/tunnels/create …Create Tunnel **POST** `/v1/tunnels` The Tunnels API is in research preview. It requires the `anthropic-beta: mcp-tunnels-2026-06-22` header and may change without a deprecation period. It supersede… List Tunnels Claude Developer Platform · in the page api/beta/tunnels/list …# List Tunnels **GET** `/v1/tunnels` The Tunnels API is in research preview. It requires the `anthropic-beta: mcp-tunnels-2026-06-22` header and may change without a deprecation period. It supersede… Get Tunnel Claude Developer Platform · in the page api/beta/tunnels/retrieve …el **GET** `/v1/tunnels/{tunnel_id}` The Tunnels API is in research preview. It requires the `anthropic-beta: mcp-tunnels-2026-06-22` header and may change without a deprecation period. It supersede… Reveal Tunnel Token Claude Developer Platform · in the page api/beta/tunnels/reveal_token …/v1/tunnels/{tunnel_id}/reveal_token` The Tunnels API is in research preview. It requires the `anthropic-beta: mcp-tunnels-2026-06-22` header and may change without a deprecation period. It supersede… Rotate Tunnel Token Claude Developer Platform · in the page api/beta/tunnels/rotate_token …/v1/tunnels/{tunnel_id}/rotate_token` The Tunnels API is in research preview. It requires the `anthropic-beta: mcp-tunnels-2026-06-22` header and may change without a deprecation period. It supersede… claude-models-on-google-cloud-anthropic-managed-iam-permissions Claude Developer Platform · in the page api/claude-models-on-google-cloud-anthropic-managed-iam-permissions …| `POST /v1/dreams/{dream_id}/cancel` | Dreams is a research preview feature. To request access, see [Dreams](https://platform.claude.com/docs/en/managed-agents/dreams). ### Encryption keys… Completions Claude Developer Platform · in the page api/completions …intelligence for long-running agents and coding - `"claude-mythos-preview"` **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.anth… Create a Text Completion Claude Developer Platform · in the page api/completions/create …intelligence for long-running agents and coding - `"claude-mythos-preview"` **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.anth… errors Claude Developer Platform · in the page api/errors …Prefill not supported Claude 4.6 and later models and [Claude Mythos Preview](https://anthropic.com/glasswing) do not support prefilling assistant messages. Sending a request with a prefilled last as… Messages Claude Developer Platform · in the page api/messages …intelligence for long-running agents and coding - `"claude-mythos-preview"` **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.anth… Batches Claude Developer Platform · in the page api/messages/batches …elligence for long-running agents and coding - `"claude-mythos-preview"` **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.… Create a Message Batch Claude Developer Platform · in the page api/messages/batches/create …elligence for long-running agents and coding - `"claude-mythos-preview"` **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.… Retrieve Message Batch results Claude Developer Platform · in the page api/messages/batches/results …gence for long-running agents and coding - `"claude-mythos-preview"` **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://d… Count tokens in a Message Claude Developer Platform · in the page api/messages/count_tokens …intelligence for long-running agents and coding - `"claude-mythos-preview"` **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.anth… Create a Message Claude Developer Platform · in the page api/messages/create …intelligence for long-running agents and coding - `"claude-mythos-preview"` **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.anth… rate-limits Claude Developer Platform · in the page api/rate-limits …tier. Fast mode for Claude Opus 5 and Claude Opus 4.8 is in research preview. To see your fast mode rate limits, go to the [Rate limits](https://platform.claude.com/usage/limits) page in the Claude C… service-tiers Claude Developer Platform · in the page api/service-tiers …Claude Haiku 5.5, Claude Mythos 5.1, Claude Mythos 5, [Claude Mythos Preview](https://anthropic.com/glasswing), Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, and Claude Sonnet 5. Check the [Mod… claude-in-amazon-bedrock Claude Developer Platform · in the page build-with-claude/claude-in-amazon-bedrock …azon.com/bedrock/home#/modelaccess) in the AWS console. Claude Mythos Preview requires an invitation through [Project Glasswing](https://anthropic.com/glasswing). For region availability, see [Regions… claude-in-microsoft-foundry Claude Developer Platform · in the page build-with-claude/claude-in-microsoft-foundry …essarily the model ID) in your API requests. <Info> [Claude Mythos Preview](https://anthropic.com/glasswing) is a research preview available to invited customers on Microsoft Foundry. </Info> <Tip… google-managed Claude Developer Platform · in the page build-with-claude/claude-models-on-google-cloud/google-managed …com/docs/en/about-claude/model-deprecations). <Note> Claude Mythos Preview is a research preview. Claude Models on Google Cloud (Google managed) offers it to invited customers. For more information… claude-on-amazon-bedrock-legacy Claude Developer Platform · in the page build-with-claude/claude-on-amazon-bedrock-legacy …lo, world"}] ) ``` </Tab> </Tabs> <Note> **Claude Mythos Preview** is a research preview model available to invited customers on Amazon Bedrock. For more information, see [Project Glasswi… sent_count = len(messages sent in the compaction request) Claude Developer Platform · in the page build-with-claude/compaction …aude-mythos-5-1`, `claude-fable-5`, `claude-mythos-5`, `claude-mythos-preview`, `claude-opus-5`, `claude-opus-4-8`, `claude-opus-4-7`, `claude-opus-4-6`, `claude-sonnet-5`, `claude-sonnet-4-6` - Platf… compaction-background Claude Developer Platform · in the page build-with-claude/compaction-background …os-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-s… compaction-keep-recent-turns Claude Developer Platform · in the page build-with-claude/compaction-keep-recent-turns …os-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-s… compaction-on-demand Claude Developer Platform · in the page build-with-claude/compaction-on-demand …os-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-s… compaction-thinking-blocks Claude Developer Platform · in the page build-with-claude/compaction-thinking-blocks …os-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-s… compaction-threshold Claude Developer Platform · in the page build-with-claude/compaction-threshold …os-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-s… context-editing Claude Developer Platform · in the page build-with-claude/context-editing …token-counting) endpoint supports context management, allowing you to preview how many tokens your prompt will use after context editing is applied. <CodeGroup> ```bash cURL curl https://api.anth… context-windows Claude Developer Platform · in the page build-with-claude/context-windows …ude Sonnet 5, Claude Sonnet 4.6, Claude Haiku 5.5, and [Claude Mythos Preview](https://anthropic.com/glasswing) have a 1M-token context window. A single request to any of them can generate up to 128k… effort Claude Developer Platform · in the page build-with-claude/effort …os-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-o… extended-thinking Claude Developer Platform · in the page build-with-claude/extended-thinking …extended thinking is the only available thinking mode. Claude Mythos Preview supports both modes. Where both modes are available, use [adaptive thinking](https://platform.claude.com/docs/en/build-wit… fast-mode Claude Developer Platform · in the page build-with-claude/fast-mode …: - Fast mode on Claude Opus 5 and Claude Opus 4.8 is in research preview and needs the `fast-mode-2026-02-01` beta header. --- Fast mode delivers up to 2.5x higher output tokens per second at pr… overview Claude Developer Platform · in the page build-with-claude/overview …------------------------------------------------ | | **Beta** | Preview features used for gathering feedback and iterating on a less mature use case. Availability may be limited, including throu… Request 2 caches its request content (not the response) Claude Developer Platform · in the page build-with-claude/prompt-caching …s-5/overview), and Claude Haiku 5.5 * 2,048 tokens for [Claude Mythos Preview](https://anthropic.com/glasswing) and Claude Opus 4.7 * 4,096 tokens for Claude Opus 4.6 and Claude Opus 4.5 * 1,024 token… claude-prompting-best-practices Claude Developer Platform · in the page build-with-claude/prompt-engineering/claude-prompting-best-practices …efilled responses Starting with Claude 4.6 models and [Claude Mythos Preview](https://anthropic.com/glasswing), prefilled responses (providing a partial assistant message for Claude to continue from)… refusals-and-fallback Claude Developer Platform · in the page build-with-claude/refusals-and-fallback …rameter is rejected with a 400 error. If you built against an earlier preview of this feature, update the beta header and the request and response shapes together to the ones on this page. </Note> ##… structured-outputs Claude Developer Platform · in the page build-with-claude/structured-outputs …os-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 - claude-opus-4-7 - claude-opus-4-6 - claude-s… thinking Claude Developer Platform · in the page build-with-claude/thinking …| Thinking off | | Claude Mythos Preview | Adaptive thinking | Adaptive thinking | Extended thinking | 400 error… thinking-troubleshooting Claude Developer Platform · in the page build-with-claude/thinking-troubleshooting …extended thinking is the only available thinking mode. Claude Mythos Preview supports both modes. Where both modes are available, use [adaptive thinking](https://platform.claude.com/docs/en/build-wit… token-counting Claude Developer Platform · in the page build-with-claude/token-counting …ken counting. <Note> Claude 4.7 and later models and Claude Mythos Preview use a newer tokenizer. The same input text produces approximately 30 percent more tokens than on earlier models. The exact… working-with-messages Claude Developer Platform · in the page build-with-claude/working-with-messages …rs are not supported on Claude 4.7 and later models and Claude Mythos Preview, or on any model starting with [API version `2026-10-21`](https://platform.claude.com/docs/en/api/migration-2026-10-21#sam… API usage primer for Claude Claude Developer Platform · in the page claude_api_primer …from Claude. <Note> Claude 4.6 and later models and Claude Mythos Preview do not support assistant message prefill; requests to those models must end with a user message. The following examples us… apply Claude Developer Platform · in the page cli-sdks-libraries/cli/apply …0e-9a57-2e8d1c3b4a5f workspace wrkspc_01JwQvzr7rXLA5AGx3HKfFUJ Preview ./claude-lock.json (new) ± Name Plan + ./agents/summarizer.md create Resources + 1 to create Appl… openai-sdk Claude Developer Platform · in the page cli-sdks-libraries/libraries/openai-sdk …d through to the model. Claude 4.7 and later models and Claude Mythos Preview return a 400 error for any value other than `0.99`, the default, so omit it. A request that sets both `temperature` and `t… api-and-data-retention Claude Developer Platform · in the page manage-claude/api-and-data-retention …| <Eligible status="no">No</Eligible> | Research preview. See [MCP tunnels security](https://platform.claude.com/docs/en/agents-and-tools/mcp-tunnels/security) for the data-flow b… cmek Claude Developer Platform · in the page manage-claude/cmek …(https://platform.claude.com/docs/en/managed-agents/dreams) (research preview). * Data stored at rest by the Batch and Skills APIs, and by these tools: web search, web fetch, code execution, bash, tex… inference-hooks Claude Developer Platform · in the page manage-claude/inference-hooks …curity plugin in Claude Code, are governed. * **Code Review (research preview).** [Code Review](https://code.claude.com/docs/en/code-review) runs reviews on your GitHub pull requests. A review a user… user-management Claude Developer Platform · in the page manage-claude/user-management …product feature, that is, every feature not labeled beta or research preview) is a blanket grant (one that covers neither model access nor the `permission_`-prefixed admin-panel permissions) and is l… choosing-an-environment Claude Developer Platform · in the page managed-agents/choosing-an-environment …mcp-tunnels/overview) with either option. MCP tunnels are in research preview and need an access request. See [Self-hosted sandboxes and MCP tunnels](https://platform.claude.com/docs/en/managed-agents… dreams Claude Developer Platform · in the page managed-agents/dreams …memory and surface new insights. --- <Tip> Dreaming is a research preview feature. [Request access](https://claude.com/form/claude-managed-agents) to try it. </Tip> Agents write to their [memory…