164 pages for claude-opus-5-5.

overview Claude Developer Platform · in the page release-notes/overview …ject. ### September 22, 2026 * We've launched **Claude Opus 5.5** (`claude-opus-5-5`), a model for long-running agentic coding and knowledge work. It has a [1M token context window](https://platform… overview Claude Developer Platform · in the page release-notes/system-prompts/overview …s), so those models have one entry. <CardGroup cols={3}> <Card id="claude-opus-5-5" title="Claude Opus 5.5" icon="file" href="https://platform.claude.com/docs/en/release-notes/system-prompts/claude… overview Claude Developer Platform · in the page resources/overview …ude Opus 5.5 System Card" icon="file" href="https://www.anthropic.com/claude-opus-5-5-system-card"> Detailed documentation of Claude Opus 5.5. </Card> <Card title="Claude Fable 5.1 and Mythos… develop-tests Claude Developer Platform · in the page test-and-evaluate/develop-tests …tr): message = client.messages.create( model="claude-opus-5-5", max_tokens=50, messages=[{"role": "user", "content": prompt}], )… handle-streaming-refusals Claude Developer Platform · in the page test-and-evaluate/strengthen-guardrails/handle-streaming-refusals …\ -H "x-api-key: $ANTHROPIC_API_KEY" \ -d '{ "model": "claude-opus-5-5", "messages": [{"role": "user", "content": "Hello"}], "max_tokens": 1024, "stream": true }')… Escalate hard decisions with the advisor tool Claude Code CLI · in the page advisor …new Claude Code releases. You can also pass a full model ID such as `claude-opus-5-5`. Subagents inherit the configured advisor and apply the same pairing check against their own model. Claude Code… Claude Code on Amazon Bedrock Claude Code CLI · in the page amazon-bedrock …IC_BEDROCK_REGION_PREFIX=eu` | `eu.anthropic.claude-opus-5-5`, the built-in default with your preferred prefix | For current and legacy model IDs, see [Models overview](https… Claude Code changelog Claude Code CLI · in the page changelog ….1.280" description="September 22, 2026"> * Added Claude Opus 5.5 (`claude-opus-5-5`), now the default Opus model — 1M context, $4/$20 per Mtok with \$0.20/Mtok cache reads * Added mouse support t… Claude Code GitHub Actions Claude Code CLI · in the page github-actions …commits and open issues" claude_args: | --model claude-opus-5-5 --allowedTools "mcp__github__list_commits,mcp__github__list_issues" ``` ## Best practices ### Define… Claude Code on Google Cloud's Agent Platform Claude Code CLI · in the page google-vertex-ai …-------------- | :--------------------------- | | Primary model | `claude-opus-5-5` | | Small/fast model | `claude-sonnet-4-5@20250929` | Background tasks such as session title generati… Model configuration Claude Code CLI · in the page model-config …. To pin to a specific version, use the full model name, for example `claude-opus-5-5`, or set the corresponding environment variable like `ANTHROPIC_DEFAULT_OPUS_MODEL`. <Note> Opus 5.5 requires C… All settings Claude Code CLI · in the page settings-reference …nt default version of that model family, or a full model ID such as `"claude-opus-5-5"` * **Default**: unset, so the advisor is off * **Per-session overrides**: `--advisor` takes precedence over this… Customize your status line Claude Code CLI · in the page statusline …cript_path": "/path/to/transcript.jsonl", "model": { "id": "claude-opus-5-5", "display_name": "Opus" }, "workspace": { "current_dir": "/current/working/directory",… Create custom subagents Claude Code CLI · in the page sub-agents …to use: `sonnet`, `opus`, `haiku`, `fable`, a full model ID such as `claude-opus-5-5`, or `inherit`. When you omit it, Claude Code picks the model in the [subagent model order](#choose-a-model)…