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API Doc Generator

Generate polished API documentation from OpenAPI or annotated comments

Generate polished API documentation from OpenAPI/Swagger specs or structured code comments.

Output formats

  • Interactive HTML
  • Markdown
  • PDF

Included sections

  • Endpoint overview
  • Parameters and request body
  • Response examples
  • Error code reference

Example Results

2 examples

Generate Markdown docs from an OpenAPI schema

Turn a compact OpenAPI document into a Markdown reference with parameters, responses, schemas, and error codes.

# Demo User API

Version: 1.2.0

## Endpoints

### GET /users/{id}

**Summary:** Get user by ID
View input parameters
{ "sourceText": "{\n \"openapi\": \"3.0.0\",\n \"info\": {\n \"title\": \"Demo User API\",\n \"version\": \"1.2.0\",\n \"description\": \"User management endpoints\"\n },\n \"servers\": [\n {\n \"url\": \"https://api.example.com\"\n }\n ],\n \"paths\": {\n \"/users/{id}\": {\n \"get\": {\n \"summary\": \"Get user by ID\",\n \"tags\": [\n \"users\"\n ],\n \"parameters\": [\n {\n \"in\": \"path\",\n \"name\": \"id\",\n \"required\": true,\n \"description\": \"User identifier\",\n \"schema\": {\n \"type\": \"string\",\n \"example\": \"u_123\"\n }\n }\n ],\n \"responses\": {\n \"200\": {\n \"description\": \"User payload\",\n \"content\": {\n \"application/json\": {\n \"example\": {\n \"id\": \"u_123\",\n \"name\": \"Ada\"\n }\n }\n }\n },\n \"404\": {\n \"description\": \"User not found\"\n }\n }\n }\n }\n },\n \"components\": {\n \"schemas\": {\n \"User\": {\n \"type\": \"object\",\n \"required\": [\n \"id\",\n \"name\"\n ],\n \"properties\": {\n \"id\": {\n \"type\": \"string\"\n },\n \"name\": {\n \"type\": \"string\"\n }\n }\n }\n }\n }\n}", "sourceFormat": "json", "outputFormat": "markdown", "documentTitle": "Demo User API", "theme": "slate", "includeExamples": true, "includeSchemas": true }

Render annotated comments as interactive HTML

Use structured comment tags to build an HTML API page while disabling examples and schema sections.

POST/invoices

Create invoice

View input parameters
{ "sourceText": "@title Billing API\n@version 0.9.0\n@description Lightweight annotated API example\n@route POST /invoices\n@summary Create invoice\n@tag billing\n@query customerId string - Customer identifier\n@bodyparam amount number optional - Requested invoice total\n@request {\"customerId\":\"cust_1\",\"amount\":129.5}\n@response 201 Created\n@error 422 Validation failed", "sourceFormat": "comments", "outputFormat": "html", "documentTitle": "Billing API", "theme": "paper", "includeExamples": false, "includeSchemas": false }

Key Facts

Category
Development
Input Types
textarea, select, text, checkbox
Output Type
file
Sample Coverage
4
API Ready
Yes

Overview

API Doc Generator turns OpenAPI specs or structured code comments into polished API references that are ready to share with engineering teams, partners, or internal consumers.

When to Use

  • •When you need HTML, Markdown, or PDF API documentation from the same source.
  • •When backend teams want request, response, and error details collected in one consistent reference.
  • •When you have Swagger or OpenAPI content but need a cleaner presentation for humans.
  • •When annotated code comments are available but a formal documentation page is missing.

How It Works

  • •Paste an OpenAPI JSON or YAML document, or provide structured API comment annotations.
  • •The tool extracts endpoint summaries, parameters, request bodies, responses, and error codes.
  • •It assembles the content into a polished documentation layout for HTML, Markdown, or PDF output.
  • •You can keep examples and schemas in the output for technical readers who need implementation detail.

Use Cases

Publishing internal API references for platform or backend teams.
Sharing partner-facing docs for third-party integrations.
Creating a PDF handoff for audits, vendor reviews, or onboarding packs.
Generating Markdown docs to store directly in a repository.

Examples

1. Produce partner-ready API docs from an existing spec

Backend developer
Background
A team already maintains an OpenAPI document for a payments service.
Problem
They need a cleaner, shareable documentation asset for partner onboarding.
How to Use
Paste the OpenAPI content, choose HTML or PDF, and keep examples enabled.
Example Config
Source format: Auto Detect. Output format: Interactive HTML or PDF.
Outcome
The team gets a polished API reference with endpoints, parameters, schemas, and response details.

Try with Samples

html, markdown, pdf
PDF Samples
Generated PDF samples from tools dated 2026-02-01 to 2026-02-10
matched family markdown,pdf,text
markdown, pdf
Markdown Slide Deck Samples
Remark/Marp style Markdown slide decks for testing PDF export layouts
matched family markdown,pdf,text
markdown, pdf
WebGPU Graphics API
Modern graphics API for high-performance 3D graphics and GPU computing in the browser
title token api
text
OpenAI API Samples
Comprehensive OpenAI API examples including GPT models, DALL-E image generation, embeddings, Whisper audio processing, and function calling
title token api
text

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FAQ

Can this tool work with Swagger or OpenAPI files?

Yes. It accepts OpenAPI and Swagger-style JSON or YAML input and converts the spec into structured endpoint documentation.

Does it support response examples and error codes?

Yes. The generated documentation can include request examples, response examples, and error code sections when those details exist in the source.

Can I export the result in multiple formats?

Yes. The same source can be rendered as interactive HTML, Markdown, or PDF depending on how you want to publish the docs.

What if I do not have a full OpenAPI file yet?

You can use structured comment annotations as input, which is helpful for early-stage APIs or partially documented services.

API Documentation

Request Endpoint

POST /en/api/tools/api-doc-generator

Request Parameters

Parameter Name Type Required Description
sourceText textarea Yes -
sourceFormat select No -
outputFormat select No -
documentTitle text No -
theme select No -
includeExamples checkbox No -
includeSchemas checkbox No -

Response Format

{
  "filePath": "/public/processing/randomid.ext",
  "fileName": "output.ext",
  "contentType": "application/octet-stream",
  "size": 1024,
  "metadata": {
    "key": "value"
  },
  "error": "Error message (optional)",
  "message": "Notification message (optional)"
}
File: File

AI MCP Documentation

Add this tool to your MCP server configuration: 

{
  "mcpServers": {
    "elysiatools-api-doc-generator": {
      "name": "api-doc-generator",
      "description": "Generate polished API documentation from OpenAPI or annotated comments",
      "baseUrl": "https://elysiatools.com/mcp/sse?toolId=api-doc-generator",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

You can chain multiple tools, e.g.: `https://elysiatools.com/mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp`, max 20 tools.

If you encounter any issues, please contact us at [email protected]