EasyFunctionCall

EasyFunctionCall is a web-based service that converts OpenAPI and Swagger API specifications into AI-ready function call parameters. It helps developers integrate their existing REST APIs with large language models (LLMs) that support function calling, such as OpenAI, Claude, Gemini, and others. By parsing standard API definition files, the tool generates structured function call schemas that AI models can use to invoke API operations directly.

Key Features

• OpenAPI and Swagger Conversion: Upload standard OpenAPI or Swagger specification files, and the service extracts all defined API endpoints, request parameters, and response schemas into structured function call definitions.
• Automatic Function Selection: When a user sends a natural language message, EasyFunctionCall identifies the most suitable API operation and returns its function call parameters, so you can use them directly with the AI model of your choice.
• API Dashboard: Manage and organize all uploaded API definitions from a central dashboard. Review endpoints, update specifications, and track your function library.
• Token Optimization: By generating precise function call schemas from your existing API definitions, the service helps reduce token usage when working with LLM function calling, saving on API costs.

How It Works

• Upload: Upload an OpenAPI or Swagger JSON or YAML file. The service extracts all API operations, parameters, and data models.
• Query: Send a natural language user message describing what you need. EasyFunctionCall matches the intent to the appropriate API operation.
• Execute with AI: Receive the function call parameters for the matched API and pass them to your preferred LLM for execution with function calling.

Pricing

EasyFunctionCall offers a free tier with support for up to 5 APIs and 100 requests per month, suitable for small projects and evaluation. The Enterprise plan supports up to 100 APIs and 100,000 requests per month with priority customer service. Annual billing saves 15% compared to monthly.

Integrations

The service works with any LLM that supports function calling, including OpenAI, Anthropic Claude, Google Gemini, and open-source models. Generated function call parameters follow standard formats compatible with major AI providers.

Use Cases

• AI-Powered API Assistants: Build conversational agents that can query databases, place orders, retrieve information, or trigger workflows through your existing API endpoints.
• Rapid Prototyping: Quickly set up function calling for new APIs by uploading their OpenAPI specifications rather than manually crafting function schemas.
• Legacy API Integration: Wrap existing REST APIs with AI function calling without modifying the API code, using the OpenAPI spec as the bridge.