KosmoJS extends the standard Koa/Hono context with two additions: a unified bodyparser API and ctx.validated for type-safe access to validated request data.

🔋 Unified Bodyparser

ctx.bodyparser works the same regardless of framework:

await ctx.bodyparser.json()   // JSON request body
await ctx.bodyparser.form()   // URL-encoded or multipart form
await ctx.bodyparser.raw()    // raw body buffer

Results are cached - calling the same parser multiple times doesn't re-parse the request.

In practice you rarely call this directly. Define a validation schema in your handler and the appropriate parser runs automatically, placing the result in ctx.validated.

☔ Validated Data Access

ctx.validated holds the validated, typed result for each target you defined:

export default defineRoute(({ POST }) => [
  POST<{
    json: Payload<CreateUser>,
    query: { limit: number },
    headers: { "x-api-key": string },
  }>(async (ctx) => {
    const user = ctx.validated.json;      // validated JSON body
    const limit = ctx.validated.query;    // validated query params
    const apiKey = ctx.validated.headers; // validated headers
  }),
]);

🔗 Route Parameters

Validated params are available at ctx.validated.params, typed according to your refinements:

api/users/[id]/index.ts

export default defineRoute<"users/[id]", [number]>(({ GET, POST }) => [
  GET<{
    query: { page: string; filter?: string },
  }>(async (ctx) => {
    const { id } = ctx.validated.params;    // number
    const { page, filter } = ctx.validated.query;
  }),

  POST<{
    json: Payload<User>,
  }>(async (ctx) => {
    const { id } = ctx.validated.params;    // number
    const user = ctx.validated.json;
  }),
]);

The underlying ctx.params (Koa) and ctx.req.param() (Hono) still exist if you need the raw strings.