api-documentation

An OpenAPI 3.0 generator driven from code-defined routes, not YAML. Call define(method, path, {...}) with a tiny schema notation, get back a structurally valid openapi.json plus a markdown reference page.

What this is

• ApiDocumentation.define(method, path, routeDef) — path params ({id}) are auto-extracted from the path string; params/query/body/ responses are declared with a tiny notation: 'string' | 'number' | 'boolean', { type: 'array', items: SchemaNode }, nested objects as plain { field: SchemaNode } with 'field?' for optional.
• .toOpenApi() — emits a spec with openapi / info / servers / paths / components keys, each operation carrying correctly-typed parameters (in: 'path' vs 'query'), requestBody, and responses.
• toMarkdown(docs) — an endpoints table followed by a per-route section (params, request body, responses) rendered from the same route definitions — the two outputs can't drift apart.

What this is NOT

• Not a request router / server framework — it documents routes, it doesn't serve them. Call define() next to your actual route handlers.
• Not a full JSON Schema implementation — the body/response notation is intentionally small (primitives, arrays, nested objects, optional keys).
• Not a Swagger UI server — it emits the JSON; point any OpenAPI viewer at it.

Quickstart

npm install
npm run build
node dist/examples/demo.js

API

import { ApiDocumentation, toMarkdown } from 'api-documentation';

const docs = new ApiDocumentation({ title: 'Users API', version: '1.0.0' }, ['https://api.example.com']);

docs.define('get', '/users/{id}', {
  summary: 'Get a user',
  params: { id: { type: 'number', description: 'user id' } },
  responses: {
    200: { description: 'OK', body: { id: 'number', name: 'string', 'email?': 'string' } },
    404: { description: 'Not found' },
  },
});

const openapi = docs.toOpenApi(); // { openapi: '3.0.0', info, servers, paths, components }
const markdown = toMarkdown(docs);

Demo: 4 routes → openapi.json + markdown

$ node dist/examples/demo.js
--- structural checks ---
has openapi key: true 3.0.0
has info key: true
has paths key: true
path count: 2
/users/{id} GET param: {"name":"id","in":"path","required":true,"description":"user id","schema":{"type":"number"}}
...
## GET /users/{id}
**Path parameters**
- `id` (number, required) — user id
**Responses**
- `200` — OK
- `404` — Not found

License

MIT

Sponsored by Ferrow

Part of the ferrow-toolkit collection · Sponsored by Ferrow