home / skills / jeremylongshore / claude-code-plugins-plus-skills / migrating-apis

This skill automates API migrations across versions and platforms, guiding design, implementation, and testing to minimize downtime.

npx playbooks add skill jeremylongshore/claude-code-plugins-plus-skills --skill migrating-apis

Review the files below or copy the command above to add this skill to your agents.

Files (4)
SKILL.md
2.4 KB
---
name: migrating-apis
description: |
  Implement API migrations between versions, platforms, or frameworks with minimal downtime.
  Use when upgrading APIs between versions.
  Trigger with phrases like "migrate the API", "upgrade API version", or "migrate to new API".
  
allowed-tools: Read, Write, Edit, Grep, Glob, Bash(api:migrate-*)
version: 1.0.0
author: Jeremy Longshore <[email protected]>
license: MIT
---

# Migrating Apis

## Overview


This skill provides automated assistance for api migration tool tasks.
This skill provides automated assistance for the described functionality.

## Prerequisites

Before using this skill, ensure you have:
- API design specifications or requirements documented
- Development environment with necessary frameworks installed
- Database or backend services accessible for integration
- Authentication and authorization strategies defined
- Testing tools and environments configured

## Instructions

1. Use Read tool to examine existing API specifications from {baseDir}/api-specs/
2. Define resource models, endpoints, and HTTP methods
3. Document request/response schemas and data types
4. Identify authentication and authorization requirements
5. Plan error handling and validation strategies
1. Generate boilerplate code using Bash(api:migrate-*) with framework scaffolding
2. Implement endpoint handlers with business logic
3. Add input validation and schema enforcement
4. Integrate authentication and authorization middleware
5. Configure database connections and ORM models
1. Write integration tests covering all endpoints


See `{baseDir}/references/implementation.md` for detailed implementation guide.

## Output

- `{baseDir}/src/routes/` - Endpoint route definitions
- `{baseDir}/src/controllers/` - Business logic handlers
- `{baseDir}/src/models/` - Data models and schemas
- `{baseDir}/src/middleware/` - Authentication, validation, logging
- `{baseDir}/src/config/` - Configuration and environment variables
- OpenAPI 3.0 specification with complete endpoint definitions

## Error Handling

See `{baseDir}/references/errors.md` for comprehensive error handling.

## Examples

See `{baseDir}/references/examples.md` for detailed examples.

## Resources

- Express.js and Fastify for Node.js APIs
- Flask and FastAPI for Python APIs
- Spring Boot for Java APIs
- Gin and Echo for Go APIs
- OpenAPI Specification 3.0+ for API documentation

Overview

This skill automates API migrations between versions, platforms, or frameworks with minimal downtime. It guides specification analysis, scaffolds code, implements handlers and middleware, and generates OpenAPI documentation. The goal is a predictable, testable migration path that preserves contracts and reduces production risk.

How this skill works

The skill inspects existing API specifications and resource models, then generates scaffolding for routes, controllers, models, and middleware. It applies validation, authentication hooks, database integrations, and produces OpenAPI 3.0 output. Migration steps include generating boilerplate, implementing business logic, adding tests, and preparing deployment patterns (blue/green or canary).

When to use it

  • Upgrading API major or minor versions while keeping client compatibility
  • Porting an API between frameworks (e.g., Flask → FastAPI, Express → Fastify)
  • Moving an API across platforms or languages (e.g., monolith → microservices)
  • Refactoring endpoints or data models that break existing contracts
  • Standardizing documentation and generating OpenAPI specs for clients

Best practices

  • Start from a documented API contract and run contract/contract-testing first
  • Use versioning, feature flags, and blue/green or canary deployments to minimize downtime
  • Automate generation of scaffolding and tests to reduce human error
  • Keep backward-compatible response shapes where possible and provide clear deprecation paths
  • Run integration and end-to-end tests against staging with production-like data and monitoring

Example use cases

  • Migrate REST v1 endpoints to a v2 schema while routing v1 traffic to legacy handlers
  • Port a Python Flask API to FastAPI to gain async performance and auto-generated docs
  • Convert monolithic endpoints into microservice routes with centralized auth middleware
  • Upgrade authentication flow (API key → OAuth2) and update client onboarding docs
  • Generate OpenAPI 3.0 spec from legacy code and scaffold new endpoints with validation

FAQ

How does this skill minimize downtime during migration?

It recommends blue/green or canary deployments, feature flags, and running both old and new routes in parallel while re-routing traffic gradually.

What testing is included or recommended?

Run contract tests, integration tests for all endpoints, and end-to-end tests in a staging environment that mirrors production. Automate tests in CI/CD.