Claude Code Agent: API Architect — Design REST & GraphQL APIs

What it is

The API Architect agent is a specialized Claude Code agent for API design tasks. It handles REST endpoint design, GraphQL schema creation, authentication flow planning, rate limiting configuration, API versioning strategy, and documentation generation. The agent activates automatically when Claude Code detects API-related tasks in your project.

The agent targets backend developers and architects who are designing new APIs or refactoring existing ones. It applies API design best practices and generates implementation-ready code rather than generic advice.

How it saves time or tokens

The API Architect agent encodes API design patterns that would otherwise require reading documentation and best-practice guides. It generates consistent endpoint naming, proper HTTP status code usage, pagination patterns, and error response formats based on industry standards. For GraphQL, it handles schema stitching, resolver patterns, and N+1 query prevention. This reduces the design phase from hours of research to minutes of conversation.

How to use

1. Install the agent template:

npx claude-code-templates@latest --agent api-graphql/api-architect --yes

1. The agent activates automatically when you work on API design tasks.

1. Ask Claude Code to design API endpoints, and the API Architect patterns apply automatically.

Example

Designing a REST API with the architect agent:

# Ask Claude Code:
'Design a REST API for a task management system with users, projects, and tasks'

# The agent generates:

# Endpoints:
# GET    /api/v1/projects
# POST   /api/v1/projects
# GET    /api/v1/projects/:id
# PUT    /api/v1/projects/:id
# DELETE /api/v1/projects/:id
# GET    /api/v1/projects/:id/tasks
# POST   /api/v1/projects/:id/tasks

# Plus:
# - Request/response schemas with validation
# - Authentication middleware
# - Rate limiting configuration
# - Pagination with cursor-based approach
# - Error response format

The agent also generates OpenAPI/Swagger documentation for the designed endpoints.

Related on TokRepo

• AI Tools for API — API design and development tools
• AI Tools for Coding — AI coding agents for various development tasks

Common pitfalls

• The agent generates design patterns, not deployment infrastructure. You still need to implement the actual server code, database models, and deployment configuration.
• API versioning strategy (URL path vs header) should be decided early. The agent defaults to URL path versioning (/api/v1/) but can be configured for header-based versioning.
• Generated authentication flows need security review. The agent follows best practices but cannot audit your specific threat model.
• Always check the official documentation for the latest version-specific changes and migration guides before upgrading in production environments.
• For team deployments, establish clear guidelines on configuration and usage patterns to ensure consistency across developers.