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 }

API Source *

Source Format

Output Format

Document Title

Theme

Include Examples

Include Schemas

Key Facts

Category: Developer & Web
Input Types: textarea, select, text, checkbox
Output Type: file
Sample Coverage: 4
API Ready: Yes

Overview

Generate polished API documentation from OpenAPI/Swagger specifications or structured code comments. Convert JSON, YAML, or annotated tags into interactive HTML, Markdown, or PDF files complete with endpoint details, parameters, request bodies, response examples, and error codes.

When to Use

•Transforming machine-readable OpenAPI specs into human-friendly reference guides
•Converting inline code annotations into shareable documentation formats
•Producing offline-ready PDF or web-ready HTML docs for stakeholders

How It Works

•Paste your OpenAPI JSON/YAML or structured annotated comments into the API Source field
•Select the output format (Interactive HTML, Markdown, or PDF) and configure options like title and theme
•Toggle inclusion of request/response examples and schema definitions as needed
•Download the generated documentation file with organized endpoint sections and parameter tables

Use Cases

Publishing developer portals from OpenAPI specifications

Creating internal API guides from annotated source code comments

Distributing printable PDF reference sheets to integration partners

Examples

1. Markdown API Guide for GitHub

Open Source Maintainer

Background: Maintainer has an OpenAPI 3.0 specification for a public API but contributors need readable documentation in the repository.
Problem: Raw JSON spec files are difficult to read in GitHub and lack formatted parameter tables.
How to Use: Paste the OpenAPI JSON into API Source, set Output Format to Markdown, enable Include Schemas, and set Document Title.
Outcome: A README-compatible Markdown file with organized endpoint sections, parameter tables, and error code references.

2. Interactive HTML API Explorer

Developer Advocate

Background: Team documents endpoints using structured comment tags in source code, but support staff need a searchable web interface.
Problem: Static code comments are inaccessible to non-technical teams and lack visual hierarchy.
How to Use: Paste annotated comments with @route and @param tags, select Interactive HTML output, choose Slate theme, and check Include Examples.
Outcome: A navigable HTML page with styled endpoint cards, expandable parameter details, and syntax-highlighted request samples.

3. Client PDF Specification

Solutions Architect

Background: External partners require a formal PDF document for compliance reviews of the integration endpoints.
Problem: Web-based documentation cannot be attached to contracts and needs to work offline.
How to Use: Paste OpenAPI YAML into API Source, select PDF output, set Document Title to 'Integration API v2.1', and uncheck Include Examples for brevity.
Outcome: A professionally formatted PDF with endpoint overview, parameter specifications, and error codes suitable for legal review.

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

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

WebGPU Graphics API

Modern graphics API for high-performance 3D graphics and GPU computing in the browser

title token api

text

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FAQ

What input formats does the generator accept?

OpenAPI JSON, OpenAPI YAML, and structured annotated comments.

Can I change the appearance of the HTML output?

Yes, choose between Slate or Paper themes in the Theme selector.

Is it possible to exclude code examples from the generated docs?

Yes, uncheck the Include Examples option to omit response samples.

Does the tool support auto-detecting OpenAPI versions?

Yes, set Source Format to Auto Detect to parse JSON or YAML automatically.

Can I generate a PDF suitable for printing?

Yes, select PDF as the Output Format for a print-ready document.

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]