Schema Basics

The .fexapi schema file is where you define your mock API endpoints.

File Location

fexapi/schema.fexapi

Created automatically by fexapi init.

Syntax

A schema file contains two things: a port declaration and route definitions.

port: 4000

GET /users:
  id:uuid
  name:name
  email:email
  age:number

GET /posts:
  id:uuid
  title:string
  body:string

Port

Declares the server port. Optional — defaults to 4000.

port: 4100

Routes

Each route has three parts:

METHOD /path:
  fieldName:fieldType

• METHOD — HTTP method (GET, POST, PUT, DELETE)
• /path — The endpoint path
• fields — One or more name:type pairs

Supported methods are: GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS.

Single-Line Format

You can also write fields on a single line, comma-separated:

GET /users: id:uuid,name:name,email:email

Both formats are equivalent. Use fexapi format to convert single-line to multi-line.

Comments

Lines starting with # are comments:

# Server configuration
port: 4000

# User endpoints
GET /users:
  id:uuid
  name:name

Inline comments are also supported:

port: 4000 # local dev port

GET /users:
  id:uuid # primary key
  name:name

Validation Rules

• Route definitions must be unique per METHOD + /path.
• Field names must use letters, numbers, or _ and cannot start with a number.
• Field definitions must use strict name:type format.
• Field names must be unique within a route.

Multiple Routes

Define as many routes as you need:

port: 4000

GET /users:
  id:uuid
  name:name
  email:email

GET /products:
  id:uuid
  title:string
  price:number

GET /orders:
  id:uuid
  total:number
  date:date