feathers-hooks

FeathersJS Hooks

Hooks are transport-independent middleware registered around / before / after / error of service methods, without touching the service code. They run in registration order; if one throws, the remaining hooks and the service call are skipped and the error propagates.

Two hook shapes

Around hooks wrap the call and receive (context, next). They must await next() to run the rest of the chain. Everything before await next() happens on the way in; everything after happens on the way out. Use these for timing, transactions, error wrapping, and the schema resolvers.

import type { HookContext, NextFunction } from '../declarations'
import { logger } from '../logger'

export const logRuntime = async (context: HookContext, next: NextFunction) => {
  const start = Date.now()
  await next()
  logger.info(`${context.method} on ${context.path} took ${Date.now() - start}ms`)
}

before / after / error hooks receive only (context) — no next. Use these for the common cases.

import type { HookContext } from '../declarations'

export const setTimestamp = async (context: HookContext) => {
  context.data = { ...context.data, createdAt: Date.now() }
  return context
}

A before hook that throws blocks the method. An after hook can transform context.result. Always return context.

The hook context

Read-only: context.app (call other services via context.app.service('users')), context.service, context.path, context.method, context.type.

Writable: context.params — includes context.params.query (query filter), context.params.provider ('rest' | 'socketio', undefined for internal calls — use this to distinguish external from internal requests), and context.params.user (the authenticated user, if any). Also context.id, context.data (on create/update/patch), context.error (in error hooks), and context.result (after await next() or in after hooks).

Registering hooks

Hooks are wired in the service's configure file (src/services/<name>/<name>.ts) via app.service(path).hooks({...}). The object is keyed by type, then by method, with all running before method-specific hooks: