FexAPI

Frontend Experience API - Mock API generation CLI tool for local development and testing.

Installation

npm install -g fexapi

Usage

fexapi [options]

Prisma-like Flow (Dynamic)

1) Initialize

npx fexapi@latest init

or

pnpm dlx fexapi@latest init

or

yarn dlx fexapi@latest init

or

bunx fexapi@latest init

fexapi init runs an interactive setup wizard and asks:

• What port? (default: 4000)
• Enable CORS? (Y/n)

Creates:

• fexapi/schema.fexapi
• fexapi.config.js

Tip: if you see old prompts (for example default 3000 or "Generate sample schemas"), run with @latest as shown above to ensure every package manager resolves the same release.

2) Edit schema file

fexapi/schema.fexapi supports readable multi-line route fields (single-line still works):

# Server
port: 4100

# Routes
GET /users:
  id:uuid
  name:name
  email:email
  age:number
  phone:phone
  pic:url
  courseName:string

GET /courses:
  id:uuid
  courseName:string
  mentor:name

# one-line format is also valid:
# GET /users: id:uuid,name:name,email:email

3) Generate artifacts (updates migration)

npx fexapi generate

Generates:

• fexapi/generated.api.json
• fexapi/migrations/schema.json

3a) Format schema (optional)

Auto-format your schema to use readable multi-line field formatting:

npx fexapi format

This rewrites fexapi/schema.fexapi with each field on its own indented line for better readability.

4) Start server

npx fexapi run
# or
npx fexapi serve
# request/response logging
npx fexapi serve --log
# or dev watch mode (nodemon-like)
npx fexapi dev --watch
# watch mode + request logs
npx fexapi dev --watch --log
# or (inside local workspace package)
npm run serve

Server port is read from schema.fexapi unless overridden by CLI --port.

fexapi dev --watch auto-reloads when these files change:

• fexapi/schema.fexapi
• fexapi/generated.api.json
• fexapi.config.js
• fexapi.config.json
• schemas/*.yaml

fexapi serve --log prints request logs like:

• [GET] /users/1 → 200 (45ms)
• [POST] /posts → 201 (12ms)

Configuration File Support

Create a fexapi.config.js in your project root:

// fexapi.config.js
module.exports = {
  port: 3000,
  routes: {
    "/users": { count: 50, schema: "user" },
    "/posts": { count: 100, schema: "post" },
  },
  cors: true,
  delay: 200,
};

Then run:

fexapi serve

Notes:

• port sets the default server port (CLI --port still has priority).
• routes maps endpoint paths to generated payload settings.
• schema maps to files under fexapi/schemas/ (for example schema: "user" -> fexapi/schemas/user.yaml); unknown names fall back to a generic record.
• cors: true enables CORS headers and OPTIONS preflight handling.
• delay adds response latency in milliseconds.

Custom Schema Definitions

You can define custom schemas in YAML files under fexapi/schemas/.

# fexapi/schemas/user.yaml
name:
  type: string
  faker: person.fullName
email:
  type: string
  faker: internet.email
age:
  type: number
  min: 18
  max: 80

Then reference it in fexapi.config.js:

routes: {
  "/users": { count: 50, schema: "user" }
}

Notes:

• Supported file extensions: .yaml, .yml
• Schema name is taken from filename (for example fexapi/schemas/user.yaml -> schema: "user")
• faker values map to Faker paths like person.fullName, internet.email

Features

• Schema-based mock API generation
• Local development server
• Faker.js integration
• Easy setup for testing workflows

License

MIT