API Reference

View as Markdown

View as Markdown

Copy Markdown

---

Open in Claude

Open in ChatGPT

Tools

Delete Tool

client.tools.delete(stringtoolID, RequestOptionsoptions?): ToolDeleteResponse

delete/v1/tools/{tool_id}

Retrieve Tool

client.tools.retrieve(stringtoolID, RequestOptionsoptions?): Tool { id, args_json_schema, created_by_id, 15 more }

get/v1/tools/{tool_id}

Update Tool

client.tools.update(stringtoolID, ToolUpdateParams { args_json_schema, default_requires_approval, description, 9 more } body, RequestOptionsoptions?): Tool { id, args_json_schema, created_by_id, 15 more }

patch/v1/tools/{tool_id}

List Tools

client.tools.list(ToolListParams { after, before, exclude_tool_types, 9 more } query?, RequestOptionsoptions?): ArrayPage<Tool { id, args_json_schema, created_by_id, 15 more } >

get/v1/tools/

Create Tool

client.tools.create(ToolCreateParams { source_code, args_json_schema, default_requires_approval, 8 more } body, RequestOptionsoptions?): Tool { id, args_json_schema, created_by_id, 15 more }

post/v1/tools/

Upsert Tool

client.tools.upsert(ToolUpsertParams { source_code, args_json_schema, default_requires_approval, 8 more } body, RequestOptionsoptions?): Tool { id, args_json_schema, created_by_id, 15 more }

put/v1/tools/

Search Tools

client.tools.search(ToolSearchParams { limit, query, search_mode, 2 more } body, RequestOptionsoptions?): ToolSearchResponse { combined_score, tool, embedded_text, 2 more }

post/v1/tools/search

ModelsExpand Collapse

NpmRequirement { name, version }

name: string

Name of the npm package.

minLength1

version?: string | null

Optional version of the package, following semantic versioning.

PipRequirement { name, version }

name: string

Name of the pip package.

minLength1

version?: string | null

Optional version of the package, following semantic versioning.

Tool { id, args_json_schema, created_by_id, 15 more }

Representation of a tool, which is a function that can be called by the agent.

id: string

The human-friendly ID of the Tool

args_json_schema?: Record<string, unknown> | null

The args JSON schema of the function.

created_by_id?: string | null

The id of the user that made this Tool.

default_requires_approval?: boolean | null

Default value for whether or not executing this tool requires approval.

description?: string | null

The description of the tool.

enable_parallel_execution?: boolean | null

If set to True, then this tool will potentially be executed concurrently with other tools. Default False.

json_schema?: Record<string, unknown> | null

The JSON schema of the function.

last_updated_by_id?: string | null

The id of the user that made this Tool.

metadata_?: Record<string, unknown> | null

A dictionary of additional metadata for the tool.

name?: string | null

The name of the function.

npm_requirements?: Array<NpmRequirement { name, version } > | null

Optional list of npm packages required by this tool.

name: string

Name of the npm package.

minLength1

version?: string | null

Optional version of the package, following semantic versioning.

pip_requirements?: Array<PipRequirement { name, version } > | null

Optional list of pip packages required by this tool.

name: string

Name of the pip package.

minLength1

version?: string | null

Optional version of the package, following semantic versioning.

project_id?: string | null

The project id of the tool.

return_char_limit?: number

The maximum number of characters in the response.

maximum1000000

minimum1

source_code?: string | null

The source code of the function.

source_type?: string | null

The type of the source code.

tags?: Array<string>

Metadata tags.

tool_type?: ToolType

The type of the tool.

Accepts one of the following:

"custom"

"letta_core"

"letta_memory_core"

"letta_multi_agent_core"

"letta_sleeptime_core"

"letta_voice_sleeptime_core"

"letta_builtin"

"letta_files_core"

"external_langchain"

"external_composio"

"external_mcp"

ToolCreate { source_code, args_json_schema, default_requires_approval, 8 more }

source_code: string

The source code of the function.

args_json_schema?: Record<string, unknown> | null

The args JSON schema of the function.

default_requires_approval?: boolean | null

Whether or not to require approval before executing this tool.

description?: string | null

The description of the tool.

enable_parallel_execution?: boolean | null

If set to True, then this tool will potentially be executed concurrently with other tools. Default False.

json_schema?: Record<string, unknown> | null

The JSON schema of the function (auto-generated from source_code if not provided)

npm_requirements?: Array<NpmRequirement { name, version } > | null

Optional list of npm packages required by this tool.

name: string

Name of the npm package.

minLength1

version?: string | null

Optional version of the package, following semantic versioning.

pip_requirements?: Array<PipRequirement { name, version } > | null

Optional list of pip packages required by this tool.

name: string

Name of the pip package.

minLength1

version?: string | null

Optional version of the package, following semantic versioning.

return_char_limit?: number

The maximum number of characters in the response.

maximum1000000

minimum1

source_type?: string

The source type of the function.

tags?: Array<string> | null

Metadata tags.

ToolReturnMessage { id, date, status, 13 more }

A message representing the return value of a tool call (generated by Letta executing the requested tool).

Args: id (str): The ID of the message date (datetime): The date the message was created in ISO format name (Optional[str]): The name of the sender of the message tool_return (str): The return value of the tool (deprecated, use tool_returns) status (Literal["success", "error"]): The status of the tool call (deprecated, use tool_returns) tool_call_id (str): A unique identifier for the tool call that generated this message (deprecated, use tool_returns) stdout (Optional[List(str)]): Captured stdout (e.g. prints, logs) from the tool invocation (deprecated, use tool_returns) stderr (Optional[List(str)]): Captured stderr from the tool invocation (deprecated, use tool_returns) tool_returns (Optional[List[ToolReturn]]): List of tool returns for multi-tool support

id: string

date: string

Deprecatedstatus: "success" | "error"

Accepts one of the following:

"success"

"error"

Deprecatedtool_call_id: string

Deprecatedtool_return: string

is_err?: boolean | null

message_type?: "tool_return_message"

The type of the message.

Accepts one of the following:

"tool_return_message"

name?: string | null

otid?: string | null

run_id?: string | null

sender_id?: string | null

seq_id?: number | null

Deprecatedstderr?: Array<string> | null

Deprecatedstdout?: Array<string> | null

step_id?: string | null

tool_returns?: Array<ToolReturn { status, tool_call_id, tool_return, 3 more } > | null

status: "success" | "error"

Accepts one of the following:

"success"

"error"

tool_call_id: string

tool_return: string

stderr?: Array<string> | null

stdout?: Array<string> | null

type?: "tool"

The message type to be created.

Accepts one of the following:

"tool"

ToolSearchRequest { limit, query, search_mode, 2 more }

Request model for searching tools using semantic search.

limit?: number

Maximum number of results to return.

maximum100

minimum1

query?: string | null

Text query for semantic search.

search_mode?: "vector" | "fts" | "hybrid"

Search mode: vector, fts, or hybrid.

Accepts one of the following:

"vector"

"fts"

"hybrid"

tags?: Array<string> | null

Filter by tags (match any).

tool_types?: Array<string> | null

Filter by tool types (e.g., 'custom', 'letta_core').

ToolSearchResult { combined_score, tool, embedded_text, 2 more }

Result from a tool search operation.

combined_score: number

Combined relevance score (RRF for hybrid mode).

tool: Tool { id, args_json_schema, created_by_id, 15 more }

The matched tool.

id: string

The human-friendly ID of the Tool

args_json_schema?: Record<string, unknown> | null

The args JSON schema of the function.

created_by_id?: string | null

The id of the user that made this Tool.

default_requires_approval?: boolean | null

Default value for whether or not executing this tool requires approval.

description?: string | null

The description of the tool.

enable_parallel_execution?: boolean | null

If set to True, then this tool will potentially be executed concurrently with other tools. Default False.

json_schema?: Record<string, unknown> | null

The JSON schema of the function.

last_updated_by_id?: string | null

The id of the user that made this Tool.

metadata_?: Record<string, unknown> | null

A dictionary of additional metadata for the tool.

name?: string | null

The name of the function.

npm_requirements?: Array<NpmRequirement { name, version } > | null

Optional list of npm packages required by this tool.

name: string

Name of the npm package.

minLength1

version?: string | null

Optional version of the package, following semantic versioning.

pip_requirements?: Array<PipRequirement { name, version } > | null

Optional list of pip packages required by this tool.

name: string

Name of the pip package.

minLength1

version?: string | null

Optional version of the package, following semantic versioning.

project_id?: string | null

The project id of the tool.

return_char_limit?: number

The maximum number of characters in the response.

maximum1000000

minimum1

source_code?: string | null

The source code of the function.

source_type?: string | null

The type of the source code.

tags?: Array<string>

Metadata tags.

tool_type?: ToolType

The type of the tool.

Accepts one of the following:

"custom"

"letta_core"

"letta_memory_core"

"letta_multi_agent_core"

"letta_sleeptime_core"

"letta_voice_sleeptime_core"

"letta_builtin"

"letta_files_core"

"external_langchain"

"external_composio"

"external_mcp"

embedded_text?: string | null

The embedded text content used for matching.

fts_rank?: number | null

Full-text search rank position.

vector_rank?: number | null

Vector search rank position.

ToolType = "custom" | "letta_core" | "letta_memory_core" | 8 more

Accepts one of the following:

"custom"

"letta_core"

"letta_memory_core"

"letta_multi_agent_core"

"letta_sleeptime_core"

"letta_voice_sleeptime_core"

"letta_builtin"

"letta_files_core"

"external_langchain"

"external_composio"

"external_mcp"