RAML

RAML is a YAML-based language for describing REST APIs with a strong emphasis on:

• Reusability
• Modularity
• Design-first approach

Developed by MuleSoft.

Role in Documentation & Discoverability

Documentation

RAML provides:

• Highly structured API descriptions
• Automatic documentation generation
• Consistent API modeling

Discoverability

RAML improves discoverability through:

• Clear resource hierarchy
• Reusable traits and resource types
• Consistent patterns across APIs

RAML is ideal for large, enterprise APIs.

Key Concepts in RAML

Concept	Description
Resources	URI paths
Methods	HTTP verbs
Traits	Reusable behaviors (e.g., pagination)
Resource Types	Templates for endpoints
Data Types	Schema definitions

RAML Example

Example: User Management API

#%RAML 1.0
title: User Management API
version: v1
baseUri: https://api.example.com/{version}

types:
  User:
    type: object
    properties:
      id: number
      name: string
      email: string

/users:
  get:
    description: Get all users
    responses:
      200:
        body:
          application/json:
            type: User[]
  post:
    description: Create a new user
    body:
      application/json:
        type: object
        properties:
          name: string
          email: string
    responses:
      201:
        body:
          application/json:
            type: User

/users/{id}:
  uriParameters:
    id:
      type: number
      description: User ID
  get:
    description: Get user by ID
    responses:
      200:
        body:
          application/json:
            type: User
      404:
        description: User not found

• Header (#%RAML 1.0) Specifies the RAML version.

• API Metadata

  title:
  version:
  baseUri:

  Provides API identity and versioning.

• Types

  types:
    User:

  Reusable schema definitions improve:

  • Consistency
  • Discoverability
  • Maintainability

• Resources & Methods

  /users:
    get:
    post:

  Hierarchical resource modeling reflects REST structure.

• Responses

  responses:
    200:
    404:

Explicit response definitions clarify behavior.

API Blueprint vs RAML

Feature	API Blueprint	RAML
Format	Markdown-based	YAML-based
Readability	Very high	High
Tooling	Apiary	MuleSoft Anypoint
Reusability	Limited	Strong
Discoverability	Example-driven	Structure-driven
Validation	Lightweight	Strong

When to Use Which?

Use API Blueprint if:

• You want human-friendly documentation
• API is small to medium
• Tutorial-style docs matter

Use RAML if:

• You build large or enterprise APIs
• Reusability & consistency are critical
• You use MuleSoft ecosystem