API Reference

The plugin exports a single default, the plugin function itself, and two error constructors. The plugin is also responsible for augmenting the Fastify type to add the query route shorthand.

fastifyHttpQuery (default export)

import type { FastifyPluginAsync } from 'fastify'

const fastifyHttpQuery: FastifyPluginAsync
export default fastifyHttpQuery

A standard FastifyPluginAsync that wraps the implementation with fastify-plugin so its effects (added HTTP method, onRequest hook) are visible to the parent scope.

The plugin takes no options.

What it does

1. Registers the QUERY method via fastify.addHttpMethod('QUERY', { hasBody: true }) if it is not already in fastify.supportedMethods. The guard prevents double-registration when the plugin is loaded twice.
2. Installs an onRequest hook that, for QUERY requests only:
   • Rejects requests without a Content-Type header with FST_ERR_QUERY_MISSING_CONTENT_TYPE (400).
   • Rejects requests without a body (no Content-Length > 0 and no Transfer-Encoding) with FST_ERR_QUERY_EMPTY_BODY (400).

See index.js for the implementation.

app.query (Fastify instance augmentation)

The plugin augments FastifyInstance with a query route shorthand so you can write:

app.query('/search', { schema: { body: { ... } } }, async (request) => {
  return runSearch(request.body)
})

This is exactly the shape of every other Fastify route shorthand (get, post, put, ...). The TypeScript declaration is in types/index.d.ts:

declare module 'fastify' {
  interface FastifyInstance<...> {
    query: RouteShorthandMethod<RawServer, RawRequest, RawReply, TypeProvider, Logger>
  }
}

After await app.register(fastifyHttpQuery), app.query is available and fully typed against your route's schema.

Error constructors

import {
  MissingContentTypeError,
  EmptyBodyError
} from '@thecodepace/fastify-http-query'

Both are thrown by the plugin's onRequest hook and are also exported so you can match them in a custom error handler. See Error codes for details.

Constructor	Code	Status
MissingContentTypeError	FST_ERR_QUERY_MISSING_CONTENT_TYPE	400
EmptyBodyError	FST_ERR_QUERY_EMPTY_BODY	400