Instant Express

Brand: Instant Express · npm: express-instant

JSON-configured Express server — define routes, auth, CRUD, and custom handlers in one config file. Ship a REST API without boilerplate.

Live demo: express-instant.vercel.app

Why this exists

| Tool | What it does | |------|----------------| | JSON Server | Mock API from a data JSON file | | PocketBase | Full backend platform with admin UI | | Instant Express | Route config JSON + templates + escape hatches — you stay on Express |

Not a game backend (Nakama). Not a mock server. A composable library for real small APIs.

Install

npm install express-instant

Quick start (CLI)

cp slices.example.json my-api.json
cp .env.example .env
npx express-instant --config-file my-api.json

Or add to package.json:

{
  "scripts": {
    "start": "express-instant --config-file my-api.json"
  }
}

Quick start (library)

import { createApp, loadConfigFromFile } from "express-instant";

const config = loadConfigFromFile("./my-api.json");
const app = await createApp(config);
app.listen(3000);

Example config — Todo API with auth

{
  "port": 3000,
  "dotenv": true,
  "cors": true,
  "mongoDB": true,
  "bodyParser": { "json": true },
  "routes": {
    "/health": { "GET": { "type": "template", "template": "health" } },
    "/auth/sign-up": { "POST": { "type": "template", "template": "signUp" } },
    "/auth/sign-in": { "POST": { "type": "template", "template": "signIn" } },
    "/items/:collection": {
      "GET": { "type": "template", "template": "listItems" },
      "POST": {
        "type": "template",
        "template": "listItems",
        "middleware": ["requireAuth"]
      }
    }
  }
}

See slices.example.json for the full copy-paste example.

Route types

| Type | Description | |------|-------------| | template | Built-in handler (health, signUp, signIn, listItems) | | function | Inline handler string | | module | Load a local .js module | | import | Import ES module handler | | static | Serve static files | | routes | Nested router |

Middleware on routes

{
  "POST": {
    "type": "template",
    "template": "listItems",
    "middleware": ["requireAuth"]
  }
}

Built-in templates

| Template | Description | |----------|-------------| | health | { success, status, uptime } | | signUp | Register user → MongoDB + bcrypt + JWT | | signIn | Login → JWT | | listItems | In-memory CRUD on /items/:collection | | mongoItems | MongoDB CRUD on /db/:collection (requires mongoDB: true) |

WebSockets

{
  "websockets": {
    "/ws": { "template": "echo" }
  }
}

Built-in echo template sends { type: "connected" } on connect and echoes messages back.

Built-in middleware

| Middleware | Description | |------------|-------------| | requireAuth | Validates Authorization: Bearer <jwt> |

Extend the library

import { registerTemplate, registerMiddleware } from "express-instant";

registerTemplate("myHandler", (req, res) => res.json({ ok: true }));
registerMiddleware("adminOnly", (req, res, next) => { /* ... */ next(); });

Environment variables

MONGODB_STRING=mongodb://localhost:27017
MONGODB_NAME=express-instant
JWT_SECRET=change-me-in-production
EXPRESS_INSTANT_CONFIG=./my-api.json
PORT=3000

Development

git clone https://github.com/m3yevn/express-instant.git
cd express-instant
npm install
npm run dev
npm test

License

MIT © Kevin Moe Myint Myat