playbooks

home / skills / partme-ai / full-stack-skills / koa

koa skill

/skills/koa

This skill helps you build, debug, and optimize Koa.js applications by guiding middleware, context usage, and project structure.

npx playbooks add skill partme-ai/full-stack-skills --skill koa

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

Files (2)
SKILL.md
663 B
---
name: koa
description: Provides comprehensive guidance for Koa.js framework including middleware, context, async/await patterns, and application structure. Use when the user asks about Koa, needs to create Koa applications, implement middleware, or build Node.js web applications.
license: Complete terms in LICENSE.txt
---

## When to use this skill

Use this skill whenever the user wants to:
- [待完善：根据具体工具添加使用场景]

## How to use this skill

[待完善：根据具体工具添加使用指南]

## Best Practices

[待完善：根据具体工具添加最佳实践]

## Keywords

[待完善：根据具体工具添加关键词]

Overview

This skill provides focused, practical guidance for building web applications with the Koa.js framework. It covers middleware patterns, context usage, async/await flow control, application architecture, and common integrations. Use it to design maintainable Koa apps, troubleshoot middleware, and apply performance and security best practices.

How this skill works

The skill inspects your goals and code patterns, then recommends idiomatic Koa solutions such as composing middleware, error-handling middleware, and proper use of ctx (context). It explains where to place async functions, how to await downstream middleware, and how to structure routers, services, and configuration. It also suggests testing strategies, debugging tips, and integration points (templating, static files, body parsing, authentication).

When to use it

  • Creating a new Koa application or migrating from Express.
  • Designing or refactoring middleware chains and context usage.
  • Implementing async/await flows, error handling, and control flow.
  • Integrating authentication, sessions, or third-party middleware.
  • Optimizing Koa apps for performance, security, or testability.

Best practices

  • Always await next() in middleware to preserve downstream execution and proper error propagation.
  • Keep middleware focused and composable—single responsibility improves reuse and testing.
  • Use ctx.state for passing request-scoped data between middleware instead of mutating ctx directly.
  • Centralize error handling with a top-level try/catch middleware to convert exceptions to consistent HTTP responses.
  • Avoid heavy synchronous work on the event loop; offload CPU tasks or use streams for large payloads.
  • Write small unit tests for middleware and integration tests for routes using in-memory servers or supertest.

Example use cases

  • Build a REST API with Koa, routing, validation, and centralized error handling.
  • Create authentication middleware that adds user info to ctx.state and protects routes.
  • Refactor a monolithic request handler into reusable middleware layers (logging, auth, rate limit).
  • Integrate file uploads and streaming responses while keeping backpressure and memory usage low.
  • Optimize response times by caching computed results in middleware or using conditional GET headers.

FAQ

How do I handle errors consistently in Koa?

Add a top-level error-handling middleware that wraps await next() in try/catch, formats the response, logs errors, and sets appropriate status codes.

Should I use async functions for all middleware?

Yes—use async functions and await next() to ensure predictable control flow and error propagation; non-async middleware can still work but may complicate flow management.