Express HTTP Context

Get and set request-scoped context anywhere. This package is an unopinionated, zero-dependency, Express-idiomatic implementation of Node AsyncLocalStorage. It's a great place to store user state, claims from a JWT, request/correlation IDs, and any other request-scoped data.

How to use it

Install: npm i express-http-context

Use the context middleware before the first middleware or handler that needs to have access to the context.

`` js
import express from 'express';
import * as httpContext from 'express-http-context';

const app = express();
app.use(httpContext.middleware);
// All code from here on has access to the same context for each request
`

Set values based on the incoming request:

` js
// Example authentication middleware
app.use(async (req, res, next) => {
try {
// Get user from data on request
const bearer = req.get('Authorization');
const user = await userService.getUser(bearer);

// Add user to the request-scoped context
httpContext.set('user', user);

return next();
} catch (err) {
return next(err);
}
});
`

Get them from code that doesn't have access to the express req object:

` js
import * as httpContext from 'express-http-context';

// Somewhere deep in the Todo Service
async function createTodoItem(title, content) {
// Get the user from the request-scoped context
const user = httpContext.get('user');

await db.insert({ title, content, userId: user.id });
}
`

Legacy versions

* For Node <7: npm install --save express-http-context@0
* For Node >=8 <12: npm install --save express-http-context@1`

Contributors

* Steve Konves (@skonves)
* Amiram Korach (@amiram)
* Yoni Rabinovitch (@yonirab)
* DontRelaX (@dontrelax)
* William Durand (@willdurand)
* Kristopher Morris (@beeduck)

Interesting in contributing? Take a look at the Contributing Guidlines