flowdoc

Auto-generate beautiful API documentation from your Express codebase — no annotations required.

flowdoc scans your TypeScript source files, extracts Express routes, infers Zod schemas, and produces an interactive docs UI served directly from your server.

Install

npm install flowdoc-gen
# or
pnpm add flowdoc-gen

Quick start

1. Scaffold a config

npx flowdoc init

This creates flowdoc.config.ts in your project root.

2. Serve docs from your own Express server

import express from "express";
import { flowdoc } from "flowdoc-gen";

const app = express();
app.use("/docs", flowdoc());

app.listen(3000);
// Docs are live at http://localhost:3000/docs

The baseUrl is auto-detected from every incoming request — no manual config needed.

3. Or generate a static site

npx flowdoc generate        # writes docs-output/
npx flowdoc serve           # generate + open in browser
npx flowdoc serve --watch   # re-generate on file changes

CLI reference

| Command | Description | |---------|-------------| | flowdoc init | Scaffold flowdoc.config.ts | | flowdoc generate | Parse routes and write docs-output/ | | flowdoc serve | Generate and open docs in browser | | flowdoc serve --watch | Same, but re-generates on source changes | | flowdoc serve --port 5000 | Custom port (default 4000) |

Config

// flowdoc.config.ts
import { defineConfig } from "flowdoc-gen";

export default defineConfig({
  name: "My API",
  entry: "src/**/*.ts",
  framework: "express",
  output: "docs-output",
  groups: [
    { name: "Auth",  match: "/auth/**" },
    { name: "Users", match: "/users/**" },
  ],
  theme: {
    brand: "#6366f1",
    darkMode: true,
  },
});

What gets inferred automatically

• All Express routes (app.get, app.post, router.use, etc.)
• Path parameters (/users/:id → id: string in path params)
• Zod request body schemas passed to validation middleware
• Route grouping by path prefix

License

MIT