FunctionSchema

FunctionSchema

Defines the JSON Schema for a tool or function that an LLM can invoke via function calling.

Import

import type { FunctionSchema } from '@adaline/api';

Definition

interface FunctionSchema {
  name: string;
  description: string;
  parameters: any;
  strict?: boolean | null;
}

---

Fields

Field	Type	Description
name	string	Function name. Must match ^[a-zA-Z0-9_]{1,64}$ — alphanumeric and underscores only, 1–64 characters.
description	string	Human-readable description of what the function does. Maximum 4096 characters. The LLM uses this to decide when to call the function.
parameters	any	A JSON Schema object describing the function’s input parameters. Typically an object schema with properties and required.
strict	boolean | null	When true, the LLM must produce arguments that strictly conform to the parameters schema. When false or null, the LLM may produce approximate matches.

---

Usage

Basic function schema

import type { FunctionSchema } from '@adaline/api';

const getWeather: FunctionSchema = {
  name: 'get_weather',
  description: 'Get the current weather for a given city',
  parameters: {
    type: 'object',
    properties: {
      city: {
        type: 'string',
        description: 'City name (e.g., "San Francisco")',
      },
      units: {
        type: 'string',
        enum: ['celsius', 'fahrenheit'],
        default: 'celsius',
        description: 'Temperature units',
      },
    },
    required: ['city'],
  },
  strict: true,
};

Complete tool definition

FunctionSchema is used inside a ToolFunction definition:

import type { ToolFunction, FunctionSchema } from '@adaline/api';

const schema: FunctionSchema = {
  name: 'search_database',
  description: 'Search the internal knowledge base for relevant documents',
  parameters: {
    type: 'object',
    properties: {
      query: {
        type: 'string',
        description: 'Natural language search query',
      },
      limit: {
        type: 'number',
        description: 'Maximum number of results to return',
        default: 10,
      },
      filters: {
        type: 'object',
        properties: {
          category: { type: 'string' },
          dateAfter: { type: 'string', format: 'date' },
        },
      },
    },
    required: ['query'],
  },
};

const tool: ToolFunction = {
  type: 'function',
  definition: { schema },
};

JSON representation

{
  "name": "get_weather",
  "description": "Get the current weather for a given city",
  "parameters": {
    "type": "object",
    "properties": {
      "city": { "type": "string", "description": "City name" },
      "units": { "type": "string", "enum": ["celsius", "fahrenheit"] }
    },
    "required": ["city"]
  },
  "strict": true
}

---

See Also

• ToolFunction — wraps FunctionSchema inside a tool definition