37 pages for claude-mythos-5-1.

model-deprecations Claude Developer Platform · in the page about-claude/model-deprecations …e | N/A | Not sooner than September 1, 2027 | | claude-mythos-5-1 | Active | N/A | Not sooner than September 1, 2027 | | claude-fable-5… choosing-a-model Claude Developer Platform · in the page about-claude/models/choosing-a-model …s, with cache reads at a quarter of the cost. **Claude Mythos 5.1** (`claude-mythos-5-1`) offers the same capabilities to [Project Glasswing](https://anthropic.com/glasswing) participants only. Both m… advisor-tool Claude Developer Platform · in the page agents-and-tools/tool-use/advisor-tool …------ | | Claude Haiku 4.5 (claude-haiku-4-5) | Claude Mythos 5.1 (claude-mythos-5-1) Claude Fable 5.1 (claude-fable-5-1) Claude Mythos 5 (claude-mythos-5) Claude Fable 5 (claude-fable-5) Claude Op… browser-use-tool Claude Developer Platform · in the page agents-and-tools/tool-use/browser-use-tool …ention-requirements). supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-opus-5-5 - claude-opus-5 - claude-sonnet-5 -… code-execution-tool Claude Developer Platform · in the page agents-and-tools/tool-use/code-execution-tool …a zdr: not-eligible supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 -… computer-use-tool Claude Developer Platform · in the page agents-and-tools/tool-use/computer-use-tool …ention-requirements). supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-opus-5-5 - claude-opus-5 - claude-sonnet-5 -… Process results programmatically Claude Developer Platform · in the page agents-and-tools/tool-use/programmatic-tool-calling …a zdr: not-eligible supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 -… tool-search-tool Claude Developer Platform · in the page agents-and-tools/tool-use/tool-search-tool …ex_20251119`, `tool_search_tool_bm25_20251119` | | Claude Mythos 5.1 (claude-mythos-5-1) | `tool_search_tool_regex_20251119`, `tool_search_tool_bm25_20251119` | | Claude Fable 5 (claude-fable… Beta Claude Developer Platform · in the page api/beta …dditional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [m… Messages Claude Developer Platform · in the page api/beta/messages …dditional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [m… Batches Claude Developer Platform · in the page api/beta/messages/batches …ional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt.… Create a Message Batch Claude Developer Platform · in the page api/beta/messages/batches/create …ional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt.… Retrieve Message Batch results Claude Developer Platform · in the page api/beta/messages/batches/results …ional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt.… Count tokens in a Message Claude Developer Platform · in the page api/beta/messages/count_tokens …dditional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [m… Create a Message Claude Developer Platform · in the page api/beta/messages/create …dditional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [m… Completions Claude Developer Platform · in the page api/completions …iew) for additional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [models](https://docs.… Create a Text Completion Claude Developer Platform · in the page api/completions/create …iew) for additional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [models](https://docs.… Messages Claude Developer Platform · in the page api/messages …iew) for additional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [models](https://docs.… Batches Claude Developer Platform · in the page api/messages/batches …for additional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [models](https… Create a Message Batch Claude Developer Platform · in the page api/messages/batches/create …for additional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [models](https… Retrieve Message Batch results Claude Developer Platform · in the page api/messages/batches/results …additional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [model… Count tokens in a Message Claude Developer Platform · in the page api/messages/count_tokens …iew) for additional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [models](https://docs.… Create a Message Claude Developer Platform · in the page api/messages/create …iew) for additional details and options. - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more` The model that will complete your prompt. See [models](https://docs.… sent_count = len(messages sent in the compaction request) Claude Developer Platform · in the page build-with-claude/compaction …ata-retention-requirements)) - Supported models: `claude-fable-5-1`, `claude-mythos-5-1`, `claude-fable-5`, `claude-mythos-5`, `claude-mythos-preview`, `claude-opus-5`, `claude-opus-4-8`, `claude-opus… compaction-background Claude Developer Platform · in the page build-with-claude/compaction-background …r: compact-2026-09-04 supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5… compaction-keep-recent-turns Claude Developer Platform · in the page build-with-claude/compaction-keep-recent-turns …r: compact-2026-09-04 supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5… compaction-on-demand Claude Developer Platform · in the page build-with-claude/compaction-on-demand …r: compact-2026-09-04 supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5… compaction-thinking-blocks Claude Developer Platform · in the page build-with-claude/compaction-thinking-blocks …r: compact-2026-09-04 supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5… compaction-threshold Claude Developer Platform · in the page build-with-claude/compaction-threshold …ention-requirements). supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5… effort Claude Developer Platform · in the page build-with-claude/effort …ention-requirements). supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5… structured-outputs Claude Developer Platform · in the page build-with-claude/structured-outputs …ention-requirements). supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-mythos-preview - claude-opus-5-5 - claude-opus-5… task-budgets Claude Developer Platform · in the page build-with-claude/task-budgets …sk-budgets-2026-03-13 supportedModels: - claude-fable-5-1 - claude-mythos-5-1 - claude-fable-5 - claude-mythos-5 - claude-opus-5-5 - claude-opus-5 - claude-opus-4-8 -… Or, for the Project Glasswing model with the same capabilities: Claude Developer Platform · in the page models/fable-5-1/migration-guide …-fable-5-1). The baseline settings shared by `claude-fable-5-1` and `claude-mythos-5-1`: * **Thinking:** [Adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) is always… whats-new-fable-5-1 Claude Developer Platform · in the page models/fable-5-1/whats-new-fable-5-1 …ude API and partner platforms | | Claude Mythos 5.1 | claude-mythos-5-1 | Same capabilities as Claude Fable 5.1. Successor to Claude Mythos 5. | [Project Glasswin… overview Claude Developer Platform · in the page models/mythos-5-1/overview …026. Claude Fable 5.1 for Project Glasswing participants Model ID: `claude-mythos-5-1` Context window: 1M tokens · Max output: 128K tokens · Input pricing: $10 / MTok · Output pricing: $50 / MTok… overview Claude Developer Platform · in the page models/mythos-5/overview …en/models/fable-5-1/migration-guide#migrating-from-claude-mythos-5-to-claude-mythos-5-1) Claude Mythos 5 is offered separately, by invitation only, as part of Project Glasswing. It shares Claude Fabl… overview Claude Developer Platform · in the page release-notes/overview …ding, 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.co…