hono-dev_skill

Overview

This skill helps you build type-safe Hono APIs, generate OpenAPI docs with Zod, and create end-to-end typed RPC clients using hono/client. It bundles patterns for route chaining, factory-based context typing, centralized error handling, middleware, and testing with testClient. Use it to keep runtime behavior and TypeScript types aligned across server, docs, and client code.

How this skill works

It enforces critical patterns like chaining route definitions so TypeScript preserves full route inference, and exporting AppType = typeof app to derive client types. Use createFactory<Env>() to propagate typed context values through middleware and handlers. Integrations include zValidator for request validation, @hono/zod-openapi for OpenAPI generation, and testClient/hc for typed testing and RPC clients.

When to use it

• Building REST or RPC-style APIs with Hono where end-to-end types matter
• Creating a type-safe client with hono/client from your server AppType
• Generating OpenAPI documentation from Zod schemas and serving Swagger UI
• Writing integration tests with testClient that preserve API types
• Implementing middleware that shares typed context (database, user, requestId)

Best practices

• Always chain route definitions (app.get(...).post(...).put(...)) to preserve type inference
• Export type AppType = typeof app so hc<Client> can infer routes and payloads
• Use createFactory<Env>() for typed middleware state and c.get/c.set usage
• Validate inputs with Zod via zValidator and surface errors centrally with onError
• Test routes with testClient to validate behavior and keep typed request/response shapes

Example use cases

• A microservice exposing typed endpoints and a generated hc client for other services
• An API that publishes OpenAPI JSON from z.object schemas and serves Swagger UI
• A multi-module app where each route file is a factory.createApp() and mounted via .route()
• Integration tests that run against an in-memory DB using testClient to assert responses
• Middleware that injects a typed DB connection, requestId, and authenticated user into handlers