Middy Invocation Middleware

1.0.0 verified Sat Apr 25 auth: no javascript

A middleware for the Middy framework (v2.5.3+ peer dependency) that provides global access to current AWS Lambda invocation event and context from anywhere in your code, eliminating the need to pass them as arguments through function calls. This is a small, focused utility with no active development since v1.0.0 (2022). Key differentiator: it uses async hooks (presumably) to store the invocation context, enabling access from deeply nested modules. Similar libraries include @middy/core's built-in context sharing, but this offers a simpler getter pattern. Only one known release (v1.0.0) with no changelog or updates.

Common errors

error TypeError: invocation is not a function ↓

cause Trying to use `invocation` as a function after import, but it's already a middleware factory.

fix

Correct: middy(handler).use(invocation())

error ReferenceError: Cannot access 'event' before initialization ↓

cause Attempting to destructure `event` before calling the function, or using it outside of handler scope.

fix

Use const { event } = require('middy-invocation'); const evt = event(); inside the handler.

error Cannot find module 'middy-invocation' ↓

cause Package not installed or peer dependency @middy/core missing.

fix

Run npm install @middy/core@^2.5.3 middy-invocation

Warnings

gotcha The event and context functions must be called after the middleware has run (i.e., only within the handler function or its async chain). ↓

fix Ensure usage is always inside a handler invocation, not at module load time.

deprecated Package requires @middy/core ^2.5.3 peer dependency; no support for @middy/core v3+. ↓

fix Pin @middy/core to ^2.5.3 or migrate to a maintained alternative.

breaking Only CJS exports; no ES module support. ↓

fix Use require() instead of import, or use dynamic import() if your runtime supports it.

gotcha If multiple invocations run concurrently (e.g., with context reuse in warm containers), the stored event/context may be overwritten by a later invocation. ↓

fix Capture event/context immediately in the handler and pass explicitly, or use AsyncLocalStorage for isolation.

gotcha No TypeScript types are provided; using the package in TypeScript requires manual type declarations or @types/middy-invocation (which does not exist). ↓

fix Create a local .d.ts file or use `any` typecasting.

Install

npm install middy-invocation

yarn add middy-invocation

pnpm add middy-invocation

Imports

invocation

wrong

import invocation from 'middy-invocation';

correct

const invocation = require('middy-invocation');

CJS default export; package does not ship ESM types or exports.

event

wrong

import { event } from 'middy-invocation'; const evt = event;

correct

const { event } = require('middy-invocation'); const evt = event();

Named export is a function that returns the current event; do not destructure if you need to call later.

context

wrong

const context = require('middy-invocation').context; const ctx = context;

correct

const { context } = require('middy-invocation'); const ctx = context();

Same as event: context is a function, not the actual context object.

Quickstart

Shows middleware registration and how to access event/context via getter functions in a handler.

const middy = require('@middy/core');
const invocation = require('middy-invocation');

const baseHandler = async (event, context) => {
  // Access event and context from anywhere
  const { event: getEvent, context: getContext } = require('middy-invocation');
  const evt = getEvent();
  const ctx = getContext();
  console.log('Request ID:', ctx.awsRequestId);
  return { statusCode: 200, body: JSON.stringify(evt) };
};

module.exports.handler = middy(baseHandler).use(invocation());