Create Tool

client.tools.create(, ?): Tool { id, args_json_schema, created_by_id, 14 more }

post/v1/tools/

Create a new tool

ParametersExpand Collapse

body: ToolCreateParams { 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 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 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.

ReturnsExpand Collapse

Tool { id, args_json_schema, created_by_id, 14 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 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 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_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"

Create Tool

import Letta from '@letta-ai/letta-client';

const client = new Letta({
  apiKey: 'My API Key',
});

const tool = await client.tools.create({ source_code: 'source_code' });

console.log(tool.id);

{
  "id": "tool-123e4567-e89b-12d3-a456-426614174000",
  "args_json_schema": {
    "foo": "bar"
  },
  "created_by_id": "created_by_id",
  "default_requires_approval": true,
  "description": "description",
  "enable_parallel_execution": true,
  "json_schema": {
    "foo": "bar"
  },
  "last_updated_by_id": "last_updated_by_id",
  "metadata_": {
    "foo": "bar"
  },
  "name": "name",
  "npm_requirements": [
    {
      "name": "x",
      "version": "version"
    }
  ],
  "pip_requirements": [
    {
      "name": "x",
      "version": "version"
    }
  ],
  "return_char_limit": 1,
  "source_code": "source_code",
  "source_type": "source_type",
  "tags": [
    "string"
  ],
  "tool_type": "custom"
}

Returns Examples

{
  "id": "tool-123e4567-e89b-12d3-a456-426614174000",
  "args_json_schema": {
    "foo": "bar"
  },
  "created_by_id": "created_by_id",
  "default_requires_approval": true,
  "description": "description",
  "enable_parallel_execution": true,
  "json_schema": {
    "foo": "bar"
  },
  "last_updated_by_id": "last_updated_by_id",
  "metadata_": {
    "foo": "bar"
  },
  "name": "name",
  "npm_requirements": [
    {
      "name": "x",
      "version": "version"
    }
  ],
  "pip_requirements": [
    {
      "name": "x",
      "version": "version"
    }
  ],
  "return_char_limit": 1,
  "source_code": "source_code",
  "source_type": "source_type",
  "tags": [
    "string"
  ],
  "tool_type": "custom"
}