📄 claude/docs/agent-sdk/typescript

File: typescript.md | Updated: 11/15/2025

Source: https://docs.claude.com/en/docs/agent-sdk/typescript

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Agent SDK

Agent SDK reference - TypeScript

Home Developer Guide API Reference Model Context Protocol (MCP) Resources Release Notes

On this page

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Installation

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npm install @anthropic-ai/claude-agent-sdk

​

Functions

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query()

The primary function for interacting with Claude Code. Creates an async generator that streams messages as they arrive.

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function query({
  prompt,
  options
}: {
  prompt: string | AsyncIterable<SDKUserMessage>;
  options?: Options;
}): Query

​

Parameters

| Parameter | Type | Description | | --- | --- | --- | | prompt | string \| AsyncIterable<SDKUserMessage<br>> | The input prompt as a string or async iterable for streaming mode | | options | Options | Optional configuration object (see Options type below) |

​

Returns

Returns a Query object that extends AsyncGenerator<SDKMessage , void> with additional methods.

​

tool()

Creates a type-safe MCP tool definition for use with SDK MCP servers.

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function tool<Schema extends ZodRawShape>(
  name: string,
  description: string,
  inputSchema: Schema,
  handler: (args: z.infer<ZodObject<Schema>>, extra: unknown) => Promise<CallToolResult>
): SdkMcpToolDefinition<Schema>

​

Parameters

| Parameter | Type | Description | | --- | --- | --- | | name | string | The name of the tool | | description | string | A description of what the tool does | | inputSchema | Schema extends ZodRawShape | Zod schema defining the tool’s input parameters | | handler | (args, extra) => Promise<CallToolResult<br>> | Async function that executes the tool logic |

​

createSdkMcpServer()

Creates an MCP server instance that runs in the same process as your application.

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function createSdkMcpServer(options: {
  name: string;
  version?: string;
  tools?: Array<SdkMcpToolDefinition<any>>;
}): McpSdkServerConfigWithInstance

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Parameters

| Parameter | Type | Description | | --- | --- | --- | | options.name | string | The name of the MCP server | | options.version | string | Optional version string | | options.tools | Array<SdkMcpToolDefinition> | Array of tool definitions created with tool() |

​

Types

​

Options

Configuration object for the query() function.

| Property | Type | Default | Description | | --- | --- | --- | --- | | abortController | AbortController | new AbortController() | Controller for cancelling operations | | additionalDirectories | string[] | [] | Additional directories Claude can access | | agents | Record<string, [AgentDefinition](#agentdefinition)> | undefined | Programmatically define subagents | | allowedTools | string[] | All tools | List of allowed tool names | | canUseTool | CanUseTool | undefined | Custom permission function for tool usage | | continue | boolean | false | Continue the most recent conversation | | cwd | string | process.cwd() | Current working directory | | disallowedTools | string[] | [] | List of disallowed tool names | | env | Dict<string> | process.env | Environment variables | | executable | 'bun' \| 'deno' \| 'node' | Auto-detected | JavaScript runtime to use | | executableArgs | string[] | [] | Arguments to pass to the executable | | extraArgs | Record<string, string \| null> | {} | Additional arguments | | fallbackModel | string | undefined | Model to use if primary fails | | forkSession | boolean | false | When resuming with resume, fork to a new session ID instead of continuing the original session | | hooks | Partial<Record<HookEvent<br>, HookCallbackMatcher<br>[]>> | {} | Hook callbacks for events | | includePartialMessages | boolean | false | Include partial message events | | maxThinkingTokens | number | undefined | Maximum tokens for thinking process | | maxTurns | number | undefined | Maximum conversation turns | | mcpServers | Record<string, [McpServerConfig](#mcpserverconfig)> | {} | MCP server configurations | | model | string | Default from CLI | Claude model to use | | pathToClaudeCodeExecutable | string | Auto-detected | Path to Claude Code executable | | permissionMode | PermissionMode | 'default' | Permission mode for the session | | permissionPromptToolName | string | undefined | MCP tool name for permission prompts | | plugins | SdkPluginConfig<br>[] | [] | Load custom plugins from local paths. See Plugins<br> for details | | resume | string | undefined | Session ID to resume | | settingSources | SettingSource<br>[] | [] (no settings) | Control which filesystem settings to load. When omitted, no settings are loaded. Note: Must include 'project' to load CLAUDE.md files | | stderr | (data: string) => void | undefined | Callback for stderr output | | strictMcpConfig | boolean | false | Enforce strict MCP validation | | systemPrompt | string \| { type: 'preset'; preset: 'claude_code'; append?: string } | undefined (empty prompt) | System prompt configuration. Pass a string for custom prompt, or { type: 'preset', preset: 'claude_code' } to use Claude Code’s system prompt. When using the preset object form, add append to extend the system prompt with additional instructions |

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Query

Interface returned by the query() function.

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interface Query extends AsyncGenerator<SDKMessage, void> {
  interrupt(): Promise<void>;
  setPermissionMode(mode: PermissionMode): Promise<void>;
}

​

Methods

| Method | Description | | --- | --- | | interrupt() | Interrupts the query (only available in streaming input mode) | | setPermissionMode() | Changes the permission mode (only available in streaming input mode) |

​

AgentDefinition

Configuration for a subagent defined programmatically.

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type AgentDefinition = {
  description: string;
  tools?: string[];
  prompt: string;
  model?: 'sonnet' | 'opus' | 'haiku' | 'inherit';
}

| Field | Required | Description | | --- | --- | --- | | description | Yes | Natural language description of when to use this agent | | tools | No | Array of allowed tool names. If omitted, inherits all tools | | prompt | Yes | The agent’s system prompt | | model | No | Model override for this agent. If omitted, uses the main model |

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SettingSource

Controls which filesystem-based configuration sources the SDK loads settings from.

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type SettingSource = 'user' | 'project' | 'local';

| Value | Description | Location | | --- | --- | --- | | 'user' | Global user settings | ~/.claude/settings.json | | 'project' | Shared project settings (version controlled) | .claude/settings.json | | 'local' | Local project settings (gitignored) | .claude/settings.local.json |

​

Default behavior

When settingSources is omitted or undefined, the SDK does not load any filesystem settings. This provides isolation for SDK applications.

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Why use settingSources?

Load all filesystem settings (legacy behavior):

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// Load all settings like SDK v0.0.x did
const result = query({
  prompt: "Analyze this code",
  options: {
    settingSources: ['user', 'project', 'local']  // Load all settings
  }
});

Load only specific setting sources:

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// Load only project settings, ignore user and local
const result = query({
  prompt: "Run CI checks",
  options: {
    settingSources: ['project']  // Only .claude/settings.json
  }
});

Testing and CI environments:

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// Ensure consistent behavior in CI by excluding local settings
const result = query({
  prompt: "Run tests",
  options: {
    settingSources: ['project'],  // Only team-shared settings
    permissionMode: 'bypassPermissions'
  }
});

SDK-only applications:

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// Define everything programmatically (default behavior)
// No filesystem dependencies - settingSources defaults to []
const result = query({
  prompt: "Review this PR",
  options: {
    // settingSources: [] is the default, no need to specify
    agents: { /* ... */ },
    mcpServers: { /* ... */ },
    allowedTools: ['Read', 'Grep', 'Glob']
  }
});

Loading CLAUDE.md project instructions:

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// Load project settings to include CLAUDE.md files
const result = query({
  prompt: "Add a new feature following project conventions",
  options: {
    systemPrompt: {
      type: 'preset',
      preset: 'claude_code'  // Required to use CLAUDE.md
    },
    settingSources: ['project'],  // Loads CLAUDE.md from project directory
    allowedTools: ['Read', 'Write', 'Edit']
  }
});

​

Settings precedence

When multiple sources are loaded, settings are merged with this precedence (highest to lowest):

  1. Local settings (.claude/settings.local.json)
  2. Project settings (.claude/settings.json)
  3. User settings (~/.claude/settings.json)

Programmatic options (like agents, allowedTools) always override filesystem settings.

​

PermissionMode

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type PermissionMode =
  | 'default'           // Standard permission behavior
  | 'acceptEdits'       // Auto-accept file edits
  | 'bypassPermissions' // Bypass all permission checks
  | 'plan'              // Planning mode - no execution

​

CanUseTool

Custom permission function type for controlling tool usage.

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type CanUseTool = (
  toolName: string,
  input: ToolInput,
  options: {
    signal: AbortSignal;
    suggestions?: PermissionUpdate[];
  }
) => Promise<PermissionResult>;

​

PermissionResult

Result of a permission check.

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type PermissionResult = 
  | {
      behavior: 'allow';
      updatedInput: ToolInput;
      updatedPermissions?: PermissionUpdate[];
    }
  | {
      behavior: 'deny';
      message: string;
      interrupt?: boolean;
    }

​

McpServerConfig

Configuration for MCP servers.

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type McpServerConfig = 
  | McpStdioServerConfig
  | McpSSEServerConfig
  | McpHttpServerConfig
  | McpSdkServerConfigWithInstance;

​

McpStdioServerConfig

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type McpStdioServerConfig = {
  type?: 'stdio';
  command: string;
  args?: string[];
  env?: Record<string, string>;
}

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McpSSEServerConfig

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type McpSSEServerConfig = {
  type: 'sse';
  url: string;
  headers?: Record<string, string>;
}

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McpHttpServerConfig

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type McpHttpServerConfig = {
  type: 'http';
  url: string;
  headers?: Record<string, string>;
}

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McpSdkServerConfigWithInstance

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type McpSdkServerConfigWithInstance = {
  type: 'sdk';
  name: string;
  instance: McpServer;
}

​

SdkPluginConfig

Configuration for loading plugins in the SDK.

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type SdkPluginConfig = {
  type: 'local';
  path: string;
}

| Field | Type | Description | | --- | --- | --- | | type | 'local' | Must be 'local' (only local plugins currently supported) | | path | string | Absolute or relative path to the plugin directory |

Example:

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plugins: [\
  { type: 'local', path: './my-plugin' },\
  { type: 'local', path: '/absolute/path/to/plugin' }\
]

For complete information on creating and using plugins, see Plugins .

​

Message Types

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SDKMessage

Union type of all possible messages returned by the query.

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type SDKMessage = 
  | SDKAssistantMessage
  | SDKUserMessage
  | SDKUserMessageReplay
  | SDKResultMessage
  | SDKSystemMessage
  | SDKPartialAssistantMessage
  | SDKCompactBoundaryMessage;

​

SDKAssistantMessage

Assistant response message.

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type SDKAssistantMessage = {
  type: 'assistant';
  uuid: UUID;
  session_id: string;
  message: APIAssistantMessage; // From Anthropic SDK
  parent_tool_use_id: string | null;
}

​

SDKUserMessage

User input message.

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type SDKUserMessage = {
  type: 'user';
  uuid?: UUID;
  session_id: string;
  message: APIUserMessage; // From Anthropic SDK
  parent_tool_use_id: string | null;
}

​

SDKUserMessageReplay

Replayed user message with required UUID.

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type SDKUserMessageReplay = {
  type: 'user';
  uuid: UUID;
  session_id: string;
  message: APIUserMessage;
  parent_tool_use_id: string | null;
}

​

SDKResultMessage

Final result message.

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type SDKResultMessage = 
  | {
      type: 'result';
      subtype: 'success';
      uuid: UUID;
      session_id: string;
      duration_ms: number;
      duration_api_ms: number;
      is_error: boolean;
      num_turns: number;
      result: string;
      total_cost_usd: number;
      usage: NonNullableUsage;
      permission_denials: SDKPermissionDenial[];
    }
  | {
      type: 'result';
      subtype: 'error_max_turns' | 'error_during_execution';
      uuid: UUID;
      session_id: string;
      duration_ms: number;
      duration_api_ms: number;
      is_error: boolean;
      num_turns: number;
      total_cost_usd: number;
      usage: NonNullableUsage;
      permission_denials: SDKPermissionDenial[];
    }

​

SDKSystemMessage

System initialization message.

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type SDKSystemMessage = {
  type: 'system';
  subtype: 'init';
  uuid: UUID;
  session_id: string;
  apiKeySource: ApiKeySource;
  cwd: string;
  tools: string[];
  mcp_servers: {
    name: string;
    status: string;
  }[];
  model: string;
  permissionMode: PermissionMode;
  slash_commands: string[];
  output_style: string;
}

​

SDKPartialAssistantMessage

Streaming partial message (only when includePartialMessages is true).

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type SDKPartialAssistantMessage = {
  type: 'stream_event';
  event: RawMessageStreamEvent; // From Anthropic SDK
  parent_tool_use_id: string | null;
  uuid: UUID;
  session_id: string;
}

​

SDKCompactBoundaryMessage

Message indicating a conversation compaction boundary.

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type SDKCompactBoundaryMessage = {
  type: 'system';
  subtype: 'compact_boundary';
  uuid: UUID;
  session_id: string;
  compact_metadata: {
    trigger: 'manual' | 'auto';
    pre_tokens: number;
  };
}

​

SDKPermissionDenial

Information about a denied tool use.

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type SDKPermissionDenial = {
  tool_name: string;
  tool_use_id: string;
  tool_input: ToolInput;
}

​

Hook Types

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HookEvent

Available hook events.

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type HookEvent = 
  | 'PreToolUse'
  | 'PostToolUse'
  | 'Notification'
  | 'UserPromptSubmit'
  | 'SessionStart'
  | 'SessionEnd'
  | 'Stop'
  | 'SubagentStop'
  | 'PreCompact';

​

HookCallback

Hook callback function type.

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type HookCallback = (
  input: HookInput, // Union of all hook input types
  toolUseID: string | undefined,
  options: { signal: AbortSignal }
) => Promise<HookJSONOutput>;

​

HookCallbackMatcher

Hook configuration with optional matcher.

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interface HookCallbackMatcher {
  matcher?: string;
  hooks: HookCallback[];
}

​

HookInput

Union type of all hook input types.

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type HookInput = 
  | PreToolUseHookInput
  | PostToolUseHookInput
  | NotificationHookInput
  | UserPromptSubmitHookInput
  | SessionStartHookInput
  | SessionEndHookInput
  | StopHookInput
  | SubagentStopHookInput
  | PreCompactHookInput;

​

BaseHookInput

Base interface that all hook input types extend.

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type BaseHookInput = {
  session_id: string;
  transcript_path: string;
  cwd: string;
  permission_mode?: string;
}

​

PreToolUseHookInput

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type PreToolUseHookInput = BaseHookInput & {
  hook_event_name: 'PreToolUse';
  tool_name: string;
  tool_input: ToolInput;
}

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PostToolUseHookInput

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type PostToolUseHookInput = BaseHookInput & {
  hook_event_name: 'PostToolUse';
  tool_name: string;
  tool_input: ToolInput;
  tool_response: ToolOutput;
}

​

NotificationHookInput

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type NotificationHookInput = BaseHookInput & {
  hook_event_name: 'Notification';
  message: string;
  title?: string;
}

​

UserPromptSubmitHookInput

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type UserPromptSubmitHookInput = BaseHookInput & {
  hook_event_name: 'UserPromptSubmit';
  prompt: string;
}

​

SessionStartHookInput

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type SessionStartHookInput = BaseHookInput & {
  hook_event_name: 'SessionStart';
  source: 'startup' | 'resume' | 'clear' | 'compact';
}

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SessionEndHookInput

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type SessionEndHookInput = BaseHookInput & {
  hook_event_name: 'SessionEnd';
  reason: 'clear' | 'logout' | 'prompt_input_exit' | 'other';
}

​

StopHookInput

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type StopHookInput = BaseHookInput & {
  hook_event_name: 'Stop';
  stop_hook_active: boolean;
}

​

SubagentStopHookInput

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type SubagentStopHookInput = BaseHookInput & {
  hook_event_name: 'SubagentStop';
  stop_hook_active: boolean;
}

​

PreCompactHookInput

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type PreCompactHookInput = BaseHookInput & {
  hook_event_name: 'PreCompact';
  trigger: 'manual' | 'auto';
  custom_instructions: string | null;
}

​

HookJSONOutput

Hook return value.

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type HookJSONOutput = AsyncHookJSONOutput | SyncHookJSONOutput;

​

AsyncHookJSONOutput

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type AsyncHookJSONOutput = {
  async: true;
  asyncTimeout?: number;
}

​

SyncHookJSONOutput

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type SyncHookJSONOutput = {
  continue?: boolean;
  suppressOutput?: boolean;
  stopReason?: string;
  decision?: 'approve' | 'block';
  systemMessage?: string;
  reason?: string;
  hookSpecificOutput?:
    | {
        hookEventName: 'PreToolUse';
        permissionDecision?: 'allow' | 'deny' | 'ask';
        permissionDecisionReason?: string;
      }
    | {
        hookEventName: 'UserPromptSubmit';
        additionalContext?: string;
      }
    | {
        hookEventName: 'SessionStart';
        additionalContext?: string;
      }
    | {
        hookEventName: 'PostToolUse';
        additionalContext?: string;
      };
}

​

Tool Input Types

Documentation of input schemas for all built-in Claude Code tools. These types are exported from @anthropic-ai/claude-agent-sdk and can be used for type-safe tool interactions.

​

ToolInput

Note: This is a documentation-only type for clarity. It represents the union of all tool input types.

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type ToolInput = 
  | AgentInput
  | BashInput
  | BashOutputInput
  | FileEditInput
  | FileReadInput
  | FileWriteInput
  | GlobInput
  | GrepInput
  | KillShellInput
  | NotebookEditInput
  | WebFetchInput
  | WebSearchInput
  | TodoWriteInput
  | ExitPlanModeInput
  | ListMcpResourcesInput
  | ReadMcpResourceInput;

​

Task

Tool name: Task

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interface AgentInput {
  /**
   * A short (3-5 word) description of the task
   */
  description: string;
  /**
   * The task for the agent to perform
   */
  prompt: string;
  /**
   * The type of specialized agent to use for this task
   */
  subagent_type: string;
}

Launches a new agent to handle complex, multi-step tasks autonomously.

​

Bash

Tool name: Bash

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interface BashInput {
  /**
   * The command to execute
   */
  command: string;
  /**
   * Optional timeout in milliseconds (max 600000)
   */
  timeout?: number;
  /**
   * Clear, concise description of what this command does in 5-10 words
   */
  description?: string;
  /**
   * Set to true to run this command in the background
   */
  run_in_background?: boolean;
}

Executes bash commands in a persistent shell session with optional timeout and background execution.

​

BashOutput

Tool name: BashOutput

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interface BashOutputInput {
  /**
   * The ID of the background shell to retrieve output from
   */
  bash_id: string;
  /**
   * Optional regex to filter output lines
   */
  filter?: string;
}

Retrieves output from a running or completed background bash shell.

​

Edit

Tool name: Edit

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interface FileEditInput {
  /**
   * The absolute path to the file to modify
   */
  file_path: string;
  /**
   * The text to replace
   */
  old_string: string;
  /**
   * The text to replace it with (must be different from old_string)
   */
  new_string: string;
  /**
   * Replace all occurrences of old_string (default false)
   */
  replace_all?: boolean;
}

Performs exact string replacements in files.

​

Read

Tool name: Read

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interface FileReadInput {
  /**
   * The absolute path to the file to read
   */
  file_path: string;
  /**
   * The line number to start reading from
   */
  offset?: number;
  /**
   * The number of lines to read
   */
  limit?: number;
}

Reads files from the local filesystem, including text, images, PDFs, and Jupyter notebooks.

​

Write

Tool name: Write

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interface FileWriteInput {
  /**
   * The absolute path to the file to write
   */
  file_path: string;
  /**
   * The content to write to the file
   */
  content: string;
}

Writes a file to the local filesystem, overwriting if it exists.

​

Glob

Tool name: Glob

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interface GlobInput {
  /**
   * The glob pattern to match files against
   */
  pattern: string;
  /**
   * The directory to search in (defaults to cwd)
   */
  path?: string;
}

Fast file pattern matching that works with any codebase size.

​

Grep

Tool name: Grep

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interface GrepInput {
  /**
   * The regular expression pattern to search for
   */
  pattern: string;
  /**
   * File or directory to search in (defaults to cwd)
   */
  path?: string;
  /**
   * Glob pattern to filter files (e.g. "*.js")
   */
  glob?: string;
  /**
   * File type to search (e.g. "js", "py", "rust")
   */
  type?: string;
  /**
   * Output mode: "content", "files_with_matches", or "count"
   */
  output_mode?: 'content' | 'files_with_matches' | 'count';
  /**
   * Case insensitive search
   */
  '-i'?: boolean;
  /**
   * Show line numbers (for content mode)
   */
  '-n'?: boolean;
  /**
   * Lines to show before each match
   */
  '-B'?: number;
  /**
   * Lines to show after each match
   */
  '-A'?: number;
  /**
   * Lines to show before and after each match
   */
  '-C'?: number;
  /**
   * Limit output to first N lines/entries
   */
  head_limit?: number;
  /**
   * Enable multiline mode
   */
  multiline?: boolean;
}

Powerful search tool built on ripgrep with regex support.

​

KillBash

Tool name: KillBash

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interface KillShellInput {
  /**
   * The ID of the background shell to kill
   */
  shell_id: string;
}

Kills a running background bash shell by its ID.

​

NotebookEdit

Tool name: NotebookEdit

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interface NotebookEditInput {
  /**
   * The absolute path to the Jupyter notebook file
   */
  notebook_path: string;
  /**
   * The ID of the cell to edit
   */
  cell_id?: string;
  /**
   * The new source for the cell
   */
  new_source: string;
  /**
   * The type of the cell (code or markdown)
   */
  cell_type?: 'code' | 'markdown';
  /**
   * The type of edit (replace, insert, delete)
   */
  edit_mode?: 'replace' | 'insert' | 'delete';
}

Edits cells in Jupyter notebook files.

​

WebFetch

Tool name: WebFetch

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interface WebFetchInput {
  /**
   * The URL to fetch content from
   */
  url: string;
  /**
   * The prompt to run on the fetched content
   */
  prompt: string;
}

Fetches content from a URL and processes it with an AI model.

​

WebSearch

Tool name: WebSearch

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interface WebSearchInput {
  /**
   * The search query to use
   */
  query: string;
  /**
   * Only include results from these domains
   */
  allowed_domains?: string[];
  /**
   * Never include results from these domains
   */
  blocked_domains?: string[];
}

Searches the web and returns formatted results.

​

TodoWrite

Tool name: TodoWrite

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interface TodoWriteInput {
  /**
   * The updated todo list
   */
  todos: Array<{
    /**
     * The task description
     */
    content: string;
    /**
     * The task status
     */
    status: 'pending' | 'in_progress' | 'completed';
    /**
     * Active form of the task description
     */
    activeForm: string;
  }>;
}

Creates and manages a structured task list for tracking progress.

​

ExitPlanMode

Tool name: ExitPlanMode

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interface ExitPlanModeInput {
  /**
   * The plan to run by the user for approval
   */
  plan: string;
}

Exits planning mode and prompts the user to approve the plan.

​

ListMcpResources

Tool name: ListMcpResources

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interface ListMcpResourcesInput {
  /**
   * Optional server name to filter resources by
   */
  server?: string;
}

Lists available MCP resources from connected servers.

​

ReadMcpResource

Tool name: ReadMcpResource

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interface ReadMcpResourceInput {
  /**
   * The MCP server name
   */
  server: string;
  /**
   * The resource URI to read
   */
  uri: string;
}

Reads a specific MCP resource from a server.

​

Tool Output Types

Documentation of output schemas for all built-in Claude Code tools. These types represent the actual response data returned by each tool.

​

ToolOutput

Note: This is a documentation-only type for clarity. It represents the union of all tool output types.

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type ToolOutput = 
  | TaskOutput
  | BashOutput
  | BashOutputToolOutput
  | EditOutput
  | ReadOutput
  | WriteOutput
  | GlobOutput
  | GrepOutput
  | KillBashOutput
  | NotebookEditOutput
  | WebFetchOutput
  | WebSearchOutput
  | TodoWriteOutput
  | ExitPlanModeOutput
  | ListMcpResourcesOutput
  | ReadMcpResourceOutput;

​

Task

Tool name: Task

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interface TaskOutput {
  /**
   * Final result message from the subagent
   */
  result: string;
  /**
   * Token usage statistics
   */
  usage?: {
    input_tokens: number;
    output_tokens: number;
    cache_creation_input_tokens?: number;
    cache_read_input_tokens?: number;
  };
  /**
   * Total cost in USD
   */
  total_cost_usd?: number;
  /**
   * Execution duration in milliseconds
   */
  duration_ms?: number;
}

Returns the final result from the subagent after completing the delegated task.

​

Bash

Tool name: Bash

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interface BashOutput {
  /**
   * Combined stdout and stderr output
   */
  output: string;
  /**
   * Exit code of the command
   */
  exitCode: number;
  /**
   * Whether the command was killed due to timeout
   */
  killed?: boolean;
  /**
   * Shell ID for background processes
   */
  shellId?: string;
}

Returns command output with exit status. Background commands return immediately with a shellId.

​

BashOutput

Tool name: BashOutput

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interface BashOutputToolOutput {
  /**
   * New output since last check
   */
  output: string;
  /**
   * Current shell status
   */
  status: 'running' | 'completed' | 'failed';
  /**
   * Exit code (when completed)
   */
  exitCode?: number;
}

Returns incremental output from background shells.

​

Edit

Tool name: Edit

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interface EditOutput {
  /**
   * Confirmation message
   */
  message: string;
  /**
   * Number of replacements made
   */
  replacements: number;
  /**
   * File path that was edited
   */
  file_path: string;
}

Returns confirmation of successful edits with replacement count.

​

Read

Tool name: Read

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type ReadOutput = 
  | TextFileOutput
  | ImageFileOutput
  | PDFFileOutput
  | NotebookFileOutput;

interface TextFileOutput {
  /**
   * File contents with line numbers
   */
  content: string;
  /**
   * Total number of lines in file
   */
  total_lines: number;
  /**
   * Lines actually returned
   */
  lines_returned: number;
}

interface ImageFileOutput {
  /**
   * Base64 encoded image data
   */
  image: string;
  /**
   * Image MIME type
   */
  mime_type: string;
  /**
   * File size in bytes
   */
  file_size: number;
}

interface PDFFileOutput {
  /**
   * Array of page contents
   */
  pages: Array<{
    page_number: number;
    text?: string;
    images?: Array<{
      image: string;
      mime_type: string;
    }>;
  }>;
  /**
   * Total number of pages
   */
  total_pages: number;
}

interface NotebookFileOutput {
  /**
   * Jupyter notebook cells
   */
  cells: Array<{
    cell_type: 'code' | 'markdown';
    source: string;
    outputs?: any[];
    execution_count?: number;
  }>;
  /**
   * Notebook metadata
   */
  metadata?: Record<string, any>;
}

Returns file contents in format appropriate to file type.

​

Write

Tool name: Write

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interface WriteOutput {
  /**
   * Success message
   */
  message: string;
  /**
   * Number of bytes written
   */
  bytes_written: number;
  /**
   * File path that was written
   */
  file_path: string;
}

Returns confirmation after successfully writing the file.

​

Glob

Tool name: Glob

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interface GlobOutput {
  /**
   * Array of matching file paths
   */
  matches: string[];
  /**
   * Number of matches found
   */
  count: number;
  /**
   * Search directory used
   */
  search_path: string;
}

Returns file paths matching the glob pattern, sorted by modification time.

​

Grep

Tool name: Grep

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type GrepOutput = 
  | GrepContentOutput
  | GrepFilesOutput
  | GrepCountOutput;

interface GrepContentOutput {
  /**
   * Matching lines with context
   */
  matches: Array<{
    file: string;
    line_number?: number;
    line: string;
    before_context?: string[];
    after_context?: string[];
  }>;
  /**
   * Total number of matches
   */
  total_matches: number;
}

interface GrepFilesOutput {
  /**
   * Files containing matches
   */
  files: string[];
  /**
   * Number of files with matches
   */
  count: number;
}

interface GrepCountOutput {
  /**
   * Match counts per file
   */
  counts: Array<{
    file: string;
    count: number;
  }>;
  /**
   * Total matches across all files
   */
  total: number;
}

Returns search results in the format specified by output_mode.

​

KillBash

Tool name: KillBash

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interface KillBashOutput {
  /**
   * Success message
   */
  message: string;
  /**
   * ID of the killed shell
   */
  shell_id: string;
}

Returns confirmation after terminating the background shell.

​

NotebookEdit

Tool name: NotebookEdit

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interface NotebookEditOutput {
  /**
   * Success message
   */
  message: string;
  /**
   * Type of edit performed
   */
  edit_type: 'replaced' | 'inserted' | 'deleted';
  /**
   * Cell ID that was affected
   */
  cell_id?: string;
  /**
   * Total cells in notebook after edit
   */
  total_cells: number;
}

Returns confirmation after modifying the Jupyter notebook.

​

WebFetch

Tool name: WebFetch

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interface WebFetchOutput {
  /**
   * AI model's response to the prompt
   */
  response: string;
  /**
   * URL that was fetched
   */
  url: string;
  /**
   * Final URL after redirects
   */
  final_url?: string;
  /**
   * HTTP status code
   */
  status_code?: number;
}

Returns the AI’s analysis of the fetched web content.

​

WebSearch

Tool name: WebSearch

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interface WebSearchOutput {
  /**
   * Search results
   */
  results: Array<{
    title: string;
    url: string;
    snippet: string;
    /**
     * Additional metadata if available
     */
    metadata?: Record<string, any>;
  }>;
  /**
   * Total number of results
   */
  total_results: number;
  /**
   * The query that was searched
   */
  query: string;
}

Returns formatted search results from the web.

​

TodoWrite

Tool name: TodoWrite

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interface TodoWriteOutput {
  /**
   * Success message
   */
  message: string;
  /**
   * Current todo statistics
   */
  stats: {
    total: number;
    pending: number;
    in_progress: number;
    completed: number;
  };
}

Returns confirmation with current task statistics.

​

ExitPlanMode

Tool name: ExitPlanMode

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interface ExitPlanModeOutput {
  /**
   * Confirmation message
   */
  message: string;
  /**
   * Whether user approved the plan
   */
  approved?: boolean;
}

Returns confirmation after exiting plan mode.

​

ListMcpResources

Tool name: ListMcpResources

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interface ListMcpResourcesOutput {
  /**
   * Available resources
   */
  resources: Array<{
    uri: string;
    name: string;
    description?: string;
    mimeType?: string;
    server: string;
  }>;
  /**
   * Total number of resources
   */
  total: number;
}

Returns list of available MCP resources.

​

ReadMcpResource

Tool name: ReadMcpResource

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interface ReadMcpResourceOutput {
  /**
   * Resource contents
   */
  contents: Array<{
    uri: string;
    mimeType?: string;
    text?: string;
    blob?: string;
  }>;
  /**
   * Server that provided the resource
   */
  server: string;
}

Returns the contents of the requested MCP resource.

​

Permission Types

​

PermissionUpdate

Operations for updating permissions.

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type PermissionUpdate = 
  | {
      type: 'addRules';
      rules: PermissionRuleValue[];
      behavior: PermissionBehavior;
      destination: PermissionUpdateDestination;
    }
  | {
      type: 'replaceRules';
      rules: PermissionRuleValue[];
      behavior: PermissionBehavior;
      destination: PermissionUpdateDestination;
    }
  | {
      type: 'removeRules';
      rules: PermissionRuleValue[];
      behavior: PermissionBehavior;
      destination: PermissionUpdateDestination;
    }
  | {
      type: 'setMode';
      mode: PermissionMode;
      destination: PermissionUpdateDestination;
    }
  | {
      type: 'addDirectories';
      directories: string[];
      destination: PermissionUpdateDestination;
    }
  | {
      type: 'removeDirectories';
      directories: string[];
      destination: PermissionUpdateDestination;
    }

​

PermissionBehavior

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type PermissionBehavior = 'allow' | 'deny' | 'ask';

​

PermissionUpdateDestination

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type PermissionUpdateDestination = 
  | 'userSettings'     // Global user settings
  | 'projectSettings'  // Per-directory project settings
  | 'localSettings'    // Gitignored local settings
  | 'session'          // Current session only

​

PermissionRuleValue

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type PermissionRuleValue = {
  toolName: string;
  ruleContent?: string;
}

​

Other Types

​

ApiKeySource

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type ApiKeySource = 'user' | 'project' | 'org' | 'temporary';

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ConfigScope

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type ConfigScope = 'local' | 'user' | 'project';

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NonNullableUsage

A version of Usage with all nullable fields made non-nullable.

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type NonNullableUsage = {
  [K in keyof Usage]: NonNullable<Usage[K]>;
}

​

Usage

Token usage statistics (from @anthropic-ai/sdk).

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type Usage = {
  input_tokens: number | null;
  output_tokens: number | null;
  cache_creation_input_tokens?: number | null;
  cache_read_input_tokens?: number | null;
}

​

CallToolResult

MCP tool result type (from @modelcontextprotocol/sdk/types.js).

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type CallToolResult = {
  content: Array<{
    type: 'text' | 'image' | 'resource';
    // Additional fields vary by type
  }>;
  isError?: boolean;
}

​

AbortError

Custom error class for abort operations.

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class AbortError extends Error {}

​

See also

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