openapi-to-llm-text

Convert OpenAPI specifications to LLM-optimized text.

Overview

This library transforms OpenAPI specifications (OpenAPI 2.0, 3.0, and 3.1) into a concise, structured text format optimized for Large Language Model (LLM) consumption. It extracts API endpoints, schemas, security configurations, and other relevant information into an easy-to-parse text format.

Installation

npm install openapi-to-llm-text

Usage

import { openApiToLlmText } from 'openapi-to-llm-text';
import { readFileSync } from 'fs';

// Load your OpenAPI spec
const openApiSpec = JSON.parse(readFileSync('path/to/openapi.json', 'utf-8'));

// Convert to text
const text = openApiToLlmText(openApiSpec);

console.log(text);

For YAML files:

import { openApiToLlmText } from 'openapi-to-llm-text';
import { readFileSync } from 'fs';
import { parse } from 'yaml';

const openApiSpec = parse(readFileSync('path/to/openapi.yaml', 'utf-8'));
const text = openApiToLlmText(openApiSpec);

Output Format

The generated text includes:

• API Information: Title, version, description, and base URL
• Endpoints: All HTTP methods with summaries, parameters, request bodies, and responses
• Schemas: Data models with property types and requirements
• Security: Authentication schemes (OAuth2, API Key, HTTP Bearer, etc.)

Example Output

API: Swagger Petstore - OpenAPI 3.0 v1.0.27
Description: This is a sample Pet Store Server...

Base URL: /api/v3

ENDPOINTS:

GET /pet/{petId}
  Summary: Find pet by ID
  Parameters:
    - petId (path, integer (required)): ID of pet to return
  Responses:
    200: Successful operation
      Content: application/json
      Schema: Pet

SCHEMAS:

Pet:
  - id: integer (format: int64)
  - name: string (required)
  - status: string

SECURITY:
- API Key authentication (header: api_key)

Features

• ✅ Supports OpenAPI 3.0 and 3.1
• ✅ Handles references, compositions (allOf, oneOf, anyOf)
• ✅ Extracts schema properties with required fields
• ✅ Formats arrays and nested objects
• ✅ Includes all HTTP methods (GET, POST, PUT, DELETE, PATCH, etc.)
• ✅ Captures security schemes

Development

# Install dependencies
pnpm install

# Run tests
pnpm test

# Build
pnpm build

# Watch tests
pnpm test:watch

License

MIT