1,278 pages for version.

overview Claude Developer Platform · in the page models/sonnet-4-5/overview …nts and prompt caching rates. </Card> <Card title="Model IDs and versioning" icon="fingerprint" href="https://platform.claude.com/docs/en/about-claude/models/model-ids-and-versions"> How mode… overview Claude Developer Platform · in the page models/sonnet-4-6/overview …nts and prompt caching rates. </Card> <Card title="Model IDs and versioning" icon="fingerprint" href="https://platform.claude.com/docs/en/about-claude/models/model-ids-and-versions"> How mode… migration-guide Claude Developer Platform · in the page models/sonnet-5-5/migration-guide …messages \ -H "x-api-key: $ANTHROPIC_API_KEY" \ -H "anthropic-version: 2026-10-21" \ -H "content-type: application/json" \ -d '{ "model": "claude-sonnet-5-5", "max_tokens":… overview Claude Developer Platform · in the page models/sonnet-5-5/overview …nts and prompt caching rates. </Card> <Card title="Model IDs and versioning" icon="fingerprint" href="https://platform.claude.com/docs/en/about-claude/models/model-ids-and-versions"> How mode… whats-new-sonnet-5-5 Claude Developer Platform · in the page models/sonnet-5-5/whats-new-sonnet-5-5 …-are-tied-to-the-model-that-produced-them). * [Some computer use tool versions are not supported](https://platform.claude.com/docs/en/models/sonnet-5-5/whats-new-sonnet-5-5#computer-20251124-is-not-su… overview Claude Developer Platform · in the page models/sonnet-5/overview …nts and prompt caching rates. </Card> <Card title="Model IDs and versioning" icon="fingerprint" href="https://platform.claude.com/docs/en/about-claude/models/model-ids-and-versions"> How mode… overview Claude Developer Platform · in the page release-notes/overview …loud (Anthropic managed). ### October 21, 2026 * We’ve released API version `2026-10-21`. [Migrating to API version 2026-10-21](https://platform.claude.com/docs/en/api/migration-2026-10-21) shows ho… claude-fable-5-1 Claude Developer Platform · in the page release-notes/system-prompts/claude-fable-5-1 …a request in a conversation, it keeps declining narrower or reworded versions of it for the rest of that conversation, and offers to describe or analyze the work instead. Song lyrics and poems first… claude-haiku-3-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-haiku-3-5 …lex tasks. Claude Haiku 3.5 is the fastest model for daily tasks. The version of Claude in this chat is Claude 3.5 Haiku. If the human asks, Claude can let them know they can access Claude 3 models in… claude-haiku-4-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-haiku-4-5 …ps://anthropic.com/android). --- Changes between the following dated versions are marked with `**` around the changed text. ## October 23, 2026 ```text wrap <claude_behavior> <product_information>… claude-opus-4-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-4-5 …ps://anthropic.com/android). --- Changes between the following dated versions are marked with `**` around the changed text. ## January 18, 2026 ```text wrap <claude_behavior> <product_information>… claude-opus-4-8 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-4-8 …Anthropic's products in case the person asks: The currently selected version of Claude is Claude Opus 4.8. Claude Opus 4.8 is a powerful model for complex challenges. Claude is accessible via this w… claude-opus-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-5 …Anthropic's products in case the person asks: The currently selected version of Claude is Claude Opus 5. Claude Opus 5 is a powerful model for complex challenges. Claude is accessible via this web-b… claude-opus-5-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-5-5 …Anthropic's products in case the person asks: The currently selected version of Claude is Claude Opus 5.5. Claude Opus 5.5 is a powerful model for complex challenges. Claude is accessible via this w… claude-sonnet-3-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-3-5 …ps://anthropic.com/android). --- Changes between the following dated versions are marked with `**` around the changed text. ## November 22, 2024 Text only: ```text wrap The assistant is Claude, cr… claude-sonnet-3-7 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-3-7 …lex tasks. Claude Haiku 3.5 is the fastest model for daily tasks. The version of Claude in this chat is Claude Sonnet 3.7, which was released in February 2025. Claude Sonnet 3.7 is a reasoning model,… claude-sonnet-4-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-4-5 …ps://anthropic.com/android). --- Changes between the following dated versions are marked with `**` around the changed text. ## January 18, 2026 ```text wrap <claude_behavior> <product_information>… develop-tests Claude Developer Platform · in the page test-and-evaluate/develop-tests …A/B testing: Compare performance against a baseline model or earlier version. * User feedback: Implicit measures such as task completion rates. * Edge case analysis: Percentage of edge cases… reduce-latency Claude Developer Platform · in the page test-and-evaluate/strengthen-guardrails/reduce-latency …messages \ -H "x-api-key: $ANTHROPIC_API_KEY" \ -H "anthropic-version: 2026-10-21" \ -H "content-type: application/json" \ -d '{ "model": "claude-haiku-5-5", "max_tokens":… Use Claude Code with a screen reader Claude Code CLI · in the page accessibility …ating system, terminal application, and assistive technology name and version in the report. Set up Claude Code for your organization Claude Code CLI · in the page admin-setup …r every model or per model, on every provider | `maxEffortLevel` | | [Version floor](https://code.claude.com/docs/en/settings-reference.md#minimumversion) | Prevent auto-update from installing below a… Escalate hard decisions with the advisor tool Claude Code CLI · in the page advisor …or `sonnet`. These aliases resolve to Claude Code's [built-in default version](https://code.claude.com/docs/en/model-config.md#model-aliases) for each model family, which advances with new Claude Code… Configure your agent Claude Code CLI · in the page agent-sdk/configuration …. The value takes a model alias or a full model name; aliases and the versions they resolve to are listed under [Model aliases](https://code.claude.com/docs/en/model-config.md#model-aliases). Set `fa… Track cost and usage Claude Code CLI · in the page agent-sdk/cost-tracking …are actually billed when: > > * pricing changes > * the installed SDK version does not recognize a model > * billing rules apply that the client cannot model > > One billing rule the SDK does model is… Give Claude custom tools Claude Code CLI · in the page agent-sdk/custom-tools …erver weather_server = create_sdk_mcp_server( name="weather", version="1.0.0", tools=[get_temperature], ) ``` ```typescript TypeScript theme={null} import { tool, createSdkMcpServer } fro… Rewind file changes with checkpointing Claude Code CLI · in the page agent-sdk/file-checkpointing …nting` or `rewindFiles()` isn't available, you may be on an older SDK version. **Solution**: Update to the latest SDK version: * **Python**: `pip install --upgrade claude-agent-sdk` * **TypeScript**… Intercept and control agent behavior with hooks Claude Code CLI · in the page agent-sdk/hooks …ments the exact-string and regular-expression evaluation paths, their version requirements, and the matcher values for each event type. | Option | Type | Default | Description | | - | - | - | - | | `… Hosting the Agent SDK Claude Code CLI · in the page agent-sdk/hosting …Claude Code install. The bundled binary is pinned to the SDK package version, so updating the SDK is how you update the CLI. The SDK follows semver: take patch releases continuously and review the [T… Connect to external tools with MCP Claude Code CLI · in the page agent-sdk/mcp …be converted to JSON Schema ``` The rest of the warning gives the conversion error's message when it has one, then says what to check and change. Before TypeScript Agent SDK v0.3.286, one unconverti… Migrate to Claude Agent SDK Claude Code CLI · in the page agent-sdk/migration-guide …son`, replace it with `@anthropic-ai/claude-agent-sdk` and update the version range as well, for example from `"^0.0.42"` to `"^0.3.0"`. **5. Review [breaking changes](#breaking-changes)** Make any… Modifying system prompts Claude Code CLI · in the page agent-sdk/modifying-system-prompts …onment details such as the working directory, platform, shell, and OS version don't affect the system prompt cache, because Claude Code delivers them in the conversation, not the system prompt. To ma… Observability with OpenTelemetry Claude Code CLI · in the page agent-sdk/observability …"support-triage-agent", "OTEL_RESOURCE_ATTRIBUTES": "service.version=1.4.0,deployment.environment=production", }, ) ``` ```typescript TypeScript theme={null} const options = { env: {… Agent SDK reference - Python Claude Code CLI · in the page agent-sdk/python …`maxResultSizeChars` field require Python Agent SDK 0.2.140 or later. Versions 0.1.31 through 0.2.139 re-export `mcp.types.ToolAnnotations` unchanged. On versions 0.1.55 through 0.2.139 you can still… Work with sessions Claude Code CLI · in the page agent-sdk/sessions …as scoped to the current project directory and its git worktrees; SDK versions that bundle an older CLI still behave this way. To resume sessions across machines or in serverless environments, mirror… Streaming Input Claude Code CLI · in the page agent-sdk/streaming-vs-single-mode …n(streaming_analysis()) ``` When you run the example, the TypeScript version prints each response as it completes. The Python version's `receive_response()` loop ends at the first result message, so… Get structured output from agents Claude Code CLI · in the page agent-sdk/structured-outputs …es schemas with JSON Schema draft-07, so schemas that declare a newer version are rejected. Zod targets draft 2020-12 by default, so pass `target: "draft-7"` when converting your schema. ```typescrip… Subagents in the SDK Claude Code CLI · in the page agent-sdk/subagents …` blocks also named it `"Task"`. To keep detection working across SDK versions, match both values in `block.name`. The message structure differs between SDKs. In Python, you access content blocks dir… Troubleshoot the Agent SDK Claude Code CLI · in the page agent-sdk/troubleshooting …de` executable. * If you rely on `PATH` resolution, confirm `claude --version` works in the same environment your application runs in. Processes you launch outside your shell, such as from an IDE or a… Agent SDK reference - TypeScript Claude Code CLI · in the page agent-sdk/typescript …n-arm64`. Most installs need no separate Claude Code install. The SDK version tracks the bundled Claude Code version. SDK v0.3.191 bundles Claude Code v2.1.191, so a feature on this page that requires… TypeScript SDK V2 session API (removed) Claude Code CLI · in the page agent-sdk/typescript-v2-preview …am()`: Get the response ## Installation Agent SDK 0.2.x is the last version that includes the V2 interface. The package version jumped from 0.2.x directly to 0.3.142, so the removal version above an… Handle approvals and user input Claude Code CLI · in the page agent-sdk/user-input …inal `questions` array and the `answers` mapping Save the TypeScript version as `ask.ts` and run it with `npx tsx ask.ts`, or save the Python version as `ask.py` and run it with `python ask.py`. ```… Orchestrate teams of Claude Code sessions Claude Code CLI · in the page agent-teams …d Claude Platform on AWS, Claude Code runs the teammate on the newest version of that family the allowlist permits. On providers with provider-specific model IDs, where the [substitution doesn't opera… Manage multiple agents with agent view Claude Code CLI · in the page agent-view …ng parallel sessions that edit the same files. If you use a different version control system, configure a [`WorktreeCreate` hook](https://code.claude.com/docs/en/worktrees#non-git-version-control) and… Claude Code on Amazon Bedrock Claude Code CLI · in the page amazon-bedrock …m, use the [manual setup](#set-up-manually) steps and [pin your model versions](#4-pin-model-versions) before rolling out. ## Sign in with Bedrock If you have AWS credentials and want to start using… Share session output as artifacts Claude Code CLI · in the page artifacts …he author avatar. The Share menu is open with the Always share latest version toggle, a version picker reading Sharing version 2, an Everyone at Acme audience selector, and a Copy link button. Below t… Authentication Claude Code CLI · in the page authentication …oesn't. Log in with the kind of account that setting names. * **Older version**: before v2.1.290, the prompt appeared during setup whether or not you were signed in. [Update Claude Code](https://code.… Auto mode classifier request charges Claude Code CLI · in the page auto-mode-classifier-billing …: which sessions ask the server to check actions, and the Claude Code version each one requires * [Gateway compatibility guide](https://code.claude.com/docs/en/llm-gateway-protocol.md#feature-pass-thr… Configure auto mode Claude Code CLI · in the page auto-mode-config …/env-vars.md#first-session-after-an-install-or-upgrade). * **Outdated version**: run `claude --version` in your shell. If the version is below [the minimum for your plan](#generate-environment-entries… Best practices for Claude Code Claude Code CLI · in the page best-practices …e it can't see how much you were hoping for. When you want the fuller version, with the edge cases handled and the natural follow-on included, say so: ```text theme={null} build the settings page fro… Champion kit Claude Code CLI · in the page champion-kit …is stated. | > [!TIP] > > Claude Code is updated frequently. Verify version-specific details against the [documentation home page](https://code.claude.com/docs/en/overview.md) before distributing th…