1,241 pages for model.

workflow-runs Claude Developer Platform · in the page managed-agents/workflow-runs …o: `Name`) and `description` (csharp, go: `Description`) are text the model wrote, so they can repeat words from your request. A run's `name` (csharp, go: `Name`) can also be one the server assigned.… overview Claude Developer Platform · in the page release-notes/overview …26 * We've added `capabilities.thinking.types.between_tools` to the [Models API](https://platform.claude.com/docs/en/api/models/list). `GET /v1/models` and `GET /v1/models/{model_id}` now report whet… claude-fable-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-fable-5 …e person asks: This iteration of Claude is Claude Fable 5, the first model in Anthropic's new Claude 5 family and part of a new Mythos-class model tier that sits above Claude Opus in capability. Clau… claude-fable-5-1 Claude Developer Platform · in the page release-notes/system-prompts/claude-fable-5-1 …erson asks: This iteration of Claude is Claude Fable 5.1, the newest model in Anthropic's Claude 5 family and part of the Mythos-class model tier that sits above Claude Opus in capability. Claude Fab… claude-haiku-3-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-haiku-3-5 …ase the human asks: This iteration of Claude is part of the Claude 3 model family, which was released in 2024. The Claude 3 family currently consists of Claude Haiku 3.5, Claude Opus 3, and Claude So… claude-haiku-4-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-haiku-4-5 …ks: This iteration of Claude is Claude Haiku 4.5 from the Claude 4.5 model family. The Claude 4.5 family currently consists of Claude Opus 4.5, Claude Sonnet 4.5, and Claude Haiku 4.5. Claude Haiku 4… claude-haiku-5-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-haiku-5-5 …ration of Claude is Claude Haiku 5.5. Claude Haiku 5.5 is the fastest model for quick questions. Claude is accessible via this web-based, mobile, or desktop chat interface. If the person asks, Claude… claude-opus-4 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-4 …on asks: This iteration of Claude is Claude Opus 4 from the Claude 4 model family. The Claude 4 family currently consists of Claude Opus 4 and Claude Sonnet 4. Claude Opus 4 is the most powerful mode… claude-opus-4-1 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-4-1 …asks: This iteration of Claude is Claude Opus 4.1 from the Claude 4 model family. The Claude 4 family currently consists of Claude Opus 4.1, Claude Opus 4, and Claude Sonnet 4. Claude Opus 4.1 is th… claude-opus-4-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-4-5 …sks: This iteration of Claude is Claude Opus 4.5 from the Claude 4.5 model family. The Claude 4.5 family currently consists of Claude Opus 4.5, Claude Sonnet 4.5, and Claude Haiku 4.5. Claude Opus 4.… claude-opus-4-6 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-4-6 …sks: This iteration of Claude is Claude Opus 4.6 from the Claude 4.5 model family. The Claude 4.5 family currently consists of Claude Opus 4.6, 4.5, Claude Sonnet 4.5, and Claude Haiku 4.5. Claude Op… claude-opus-4-7 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-4-7 …sks: This iteration of Claude is Claude Opus 4.7 from the Claude 4.7 model family. The Claude 4.7 family currently consists of Claude Opus 4.7. Claude Opus 4.7 is the most advanced and intelligent mo… claude-opus-4-8 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-4-8 …on of Claude is Claude Opus 4.8. Claude Opus 4.8 is the newest Claude model, and the most advanced model publicly available. Claude is accessible via this web-based, mobile, or desktop chat interface… claude-opus-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-5 …ected version of Claude is Claude Opus 5. Claude Opus 5 is a powerful model for complex challenges. Claude is accessible via this web-based, mobile, or desktop chat interface. If the person asks, Cla… claude-opus-5-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-opus-5-5 …d version of Claude is Claude Opus 5.5. Claude Opus 5.5 is a powerful model for complex challenges. Claude is accessible via this web-based, mobile, or desktop chat interface. If the person asks, Cla… claude-sonnet-3-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-3-5 …ase the human asks: This iteration of Claude is part of the Claude 3 model family, which was released in 2024. The Claude 3 family currently consists of Claude Haiku, Claude Opus, and Claude Sonnet 3… claude-sonnet-3-7 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-3-7 …se the person asks: This iteration of Claude is part of the Claude 3 model family. The Claude 3 family currently consists of Claude Haiku 3.5, Claude Opus 3, Claude Sonnet 3.5, and Claude Sonnet 3.7.… claude-sonnet-4 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-4 …asks: This iteration of Claude is Claude Sonnet 4 from the Claude 4 model family. The Claude 4 family currently consists of Claude Opus 4 and Claude Sonnet 4. Claude Sonnet 4 is a smart, efficient m… claude-sonnet-4-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-4-5 …This iteration of Claude is Claude Sonnet 4.5 from the **Claude 4.5** model family. The **Claude 4.5** family currently consists of **Claude Opus 4.5, Claude Sonnet 4.5, and Claude Haiku 4.5**. Claude… claude-sonnet-4-6 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-4-6 …s: This iteration of Claude is Claude Sonnet 4.6, a smart, efficient model for everyday use in the Claude 4.6 family (which currently consists of Claude Opus 4.6 and Claude Sonnet 4.6). If the perso… claude-sonnet-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-5 …Claude is accessible via an API and Claude Platform. The most recent models are Claude Opus 4.8, Claude Sonnet 5, and Claude Haiku 4.5, with model strings 'claude-opus-4-8', 'claude-sonnet-5', and 'c… claude-sonnet-5-5 Claude Developer Platform · in the page release-notes/system-prompts/claude-sonnet-5-5 …Claude is accessible via an API and Claude Platform. The most recent models are Claude Fable 5.1, Claude Opus 5.5, Claude Sonnet 5.5, and Claude Haiku 5.5, with model strings 'claude-fable-5-1', 'cla… overview Claude Developer Platform · in the page release-notes/system-prompts/overview …ses. These system prompt updates do not apply to the Claude API. Some models have multiple dated entries on their pages. <CardGroup cols={3}> <Card id="claude-haiku-5-5" title="Claude Haiku 5.5" ic… overview Claude Developer Platform · in the page resources/overview --- title: Model cards url: https://platform.claude.com/docs/en/resources/overview description: Model cards with detailed documentation for Claude models. --- <CardGroup cols={3}> <Card title="Clau… develop-tests Claude Developer Platform · in the page test-and-evaluate/develop-tests …methods:** * A/B testing: Compare performance against a baseline model or earlier version. * User feedback: Implicit measures such as task completion rates. * Edge case analysis: Percenta… handle-streaming-refusals Claude Developer Platform · in the page test-and-evaluate/strengthen-guardrails/handle-streaming-refusals …sons in streaming responses, and retry refused requests on a fallback model. --- Starting with Claude 4 models, streaming responses from Claude's API return **`stop_reason`: `"refusal"`** when stream… increase-consistency Claude Developer Platform · in the page test-and-evaluate/strengthen-guardrails/increase-consistency …esponse <Note> Prefilling is not supported on Claude 4.6 and later models and [Claude Mythos Preview](https://anthropic.com/glasswing) . Use [structured outputs](https://platform.claude.… mitigate-jailbreaks Claude Developer Platform · in the page test-and-evaluate/strengthen-guardrails/mitigate-jailbreaks …l/aup). These attacks fall into two categories with different threat models: * **Jailbreaks and direct prompt injection**, where the *user* of your application is the adversary and crafts inputs int… reduce-hallucinations Claude Developer Platform · in the page test-and-evaluate/strengthen-guardrails/reduce-hallucinations …verifying claims with citations. --- Even the most advanced language models, such as Claude, can sometimes generate text that is factually incorrect or inconsistent with the given context. This pheno… reduce-latency Claude Developer Platform · in the page test-and-evaluate/strengthen-guardrails/reduce-latency …cy description: Reduce Claude's response latency by choosing a faster model such as Claude Haiku 5.5, trimming prompt and output tokens, and streaming responses. --- Latency refers to the time it tak… reduce-prompt-leak Claude Developer Platform · in the page test-and-evaluate/strengthen-guardrails/reduce-prompt-leak …ly to ensure that the added complexity does not negatively impact the model’s performance or the quality of its outputs. <Tip> Try monitoring techniques first, such as output screening and post-pro… Use Claude Code with a screen reader Claude Code CLI · in the page accessibility …arning:` | A warning from Claude Code, such as a switch to a fallback model | | `Permission Required:` | A permission prompt waiting for your answer | | `Cost:` | The session cost summary when Claude… Set up Claude Code for your organization Claude Code CLI · in the page admin-setup …opers can extend managed lists but not remove from them. For `fallbackModel`, `availableModels`, and [`modelPicker`](/docs/en/settings-reference#modelpicker), the managed value replaces lower layers r… Escalate hard decisions with the advisor tool Claude Code CLI · in the page advisor # Escalate hard decisions with the advisor tool > Pair your main model with a stronger advisor model that Claude consults at key moments during a task. > [!NOTE] > > The advisor tool is experimental… How the agent loop works Claude Code CLI · in the page agent-sdk/agent-loop …Spawn subagents, invoke skills, ask the user, track tasks | On the [models that don't get the task-tracking tools](/docs/en/agent-sdk/todo-tracking.md#model-availability), Claude Code provides `Task… Use Claude Code features in the SDK Claude Code CLI · in the page agent-sdk/claude-code-features …s/en/authentication#generate-a-long-lived-token), which can only make model requests. Passing `mcpServers: {}` does not suppress the connectors | Set `strictMcpConfig: true`, [`disableClaudeAiConnecto… Configure your agent Claude Code CLI · in the page agent-sdk/configuration …> Configure Agent SDK sessions: compose the options object, set the model, environment, and limits, and find each feature option's page. An Agent SDK session reads configuration from settings files… Track cost and usage Claude Code CLI · in the page agent-sdk/cost-tracking …tes them locally from a price table bundled at build time, unless a [`modelPricing`](/docs/en/settings-reference#modelpricing) table is in effect. They can drift from what you are actually billed when… Give Claude custom tools Claude Code CLI · in the page agent-sdk/custom-tools …initial prompt. ### Add tool annotations [Tool annotations](https://modelcontextprotocol.io/docs/concepts/tools#tool-annotations) are optional metadata describing how a tool behaves. Pass them as th… Intercept and control agent behavior with hooks Claude Code CLI · in the page agent-sdk/hooks …| A full batch of tool calls resolves, once per batch before the next model call | Inject conventions once for the whole batch | | [`UserPromptSubmit`](/docs/en/hooks#userpromptsubmit) | Yes | Yes | A… Hosting the Agent SDK Claude Code CLI · in the page agent-sdk/hosting …self-hosted-sandboxes) on your own infrastructure. ## The subprocess model Every hosting decision on this page follows from how the SDK runs the agent. When your code calls `query()`, the SDK spawns… Connect to external tools with MCP Claude Code CLI · in the page agent-sdk/mcp …search for large tool sets, authentication, and error handling. The [Model Context Protocol (MCP)](https://modelcontextprotocol.io/docs/getting-started/intro) is an open standard for connecting AI ag… Migrate to Claude Agent SDK Claude Code CLI · in the page agent-sdk/migration-guide …code_sdk import query, ClaudeCodeOptions options = ClaudeCodeOptions(model="claude-opus-4-7", permission_mode="acceptEdits") # AFTER (claude-agent-sdk) from claude_agent_sdk import query, ClaudeAgen… Modifying system prompts Claude Code CLI · in the page agent-sdk/modifying-system-prompts …n prompt for agents with a different surface, identity, or permission model. ## How system prompts work A system prompt is the initial instruction set that shapes how Claude behaves throughout a con… Observability with OpenTelemetry Claude Code CLI · in the page agent-sdk/observability …bility into what they did: * which tools they called * how long each model request took * how many tokens were spent * where failures occurred The Agent SDK can export this data as OpenTelemetry tra… Agent SDK overview Claude Code CLI · in the page agent-sdk/overview …bagents.md) | | MCP | Connect external tools and data sources via the Model Context Protocol | [MCP](/docs/en/agent-sdk/mcp.md) | | Permissions | Control which tools run automatically, which need appr… Configure permissions Claude Code CLI · in the page agent-sdk/permissions …one of the [task-tracking tools](/docs/en/agent-sdk/todo-tracking.md#model-availability) in `allowed_tools`, Claude Code also opts the session in. Any other tool not listed in `allowed_tools` is stil… Plugins in the SDK Claude Code CLI · in the page agent-sdk/plugins …se and other events * **MCP servers**: external tool integrations via Model Context Protocol For complete information on plugin structure and how to create plugins, see [Plugins](/docs/en/plugins/ove… Agent SDK reference - Python Claude Code CLI · in the page agent-sdk/python …permission_mode(self, mode: PermissionMode) -> None async def set_model(self, model: str | None = None) -> None async def rewind_files(self, user_message_id: str) -> None async def get_mcp… Securely deploying AI agents Claude Code CLI · in the page agent-sdk/secure-deployment …architectures, so you can choose what fits your situation. ## Threat model Agents can take unintended actions due to prompt injection (instructions embedded in content they process) or model error.…