Registry / devops / grpc-web-middleware

grpc-web-middleware

library0.2.3jsnpmunverified

grpc-web-middleware v0.2.3 is a lightweight Node.js middleware that acts as a gRPC-Web gateway, enabling gRPC-Web clients to communicate with gRPC servers via HTTP/1.1. It is designed for simplicity and minimal configuration, integrating easily with Express and Koa. The package has not been updated since 2019 and lacks TypeScript definitions, but remains functional for basic gRPC-Web proxying. It differs from alternatives like grpc-web by focusing on server-side middleware rather than client-side libraries.

devops

npm install grpc-web-middleware

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · GRPC-WEB-MIDDLEWAR

grpc-web-middleware

devopsjavascriptv0.2.3

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ const grpcWebMiddleware = require('grpc-web-middleware')

✗ import grpcWebMiddleware from 'grpc-web-middleware'

Package uses CommonJS only; ESM import may fail without default interop.

default

✓ import grpcWebMiddleware from 'grpc-web-middleware'

Only if using ESM with module bundler that supports CJS interop; Node.js native ESM may require createRequire.

default

✓ const { grpcWebMiddleware } = require('grpc-web-middleware')

✗ const grpcWebMiddleware = require('grpc-web-middleware').default

Package does not export named exports; avoid destructuring or accessing .default.

Create an Express server with CORS that proxies gRPC-Web requests to a gRPC server at localhost:6565.

const express = require('express'); const cors = require('cors'); const grpcWebMiddleware = require('grpc-web-middleware'); const app = express(); app.use(cors()); app.use(grpcWebMiddleware('http://localhost:6565')); app.listen(8080, () => { console.log('gRPC-Web proxy running on port 8080'); });

Debug

Known issues

gotchaMiddleware does not handle CORS automatically; you must add your own CORS middleware.

fix

Add cors() or @koa/cors before the gRPC middleware.

affects: >=0.0.0

gotchaThe middleware expects req and res objects similar to Node's http.ServerResponse; in Koa, you must pass ctx.req and ctx.res explicitly.

fix

Use async (ctx, next) => grpcWebMiddleware(url)(ctx.req, ctx.res, next).

affects: >=0.0.0

gotchaIf using a prefix, ensure it starts with '/' and does not end with '/', otherwise routing may fail.

fix

Use prefix like '/api' (not '/api/' or 'api').

affects: >=0.0.0

Errors

Common errors & fixes

Cannot find module 'grpc-web-middleware'

Package not installed or npm install failed.

fix

Run 'npm install grpc-web-middleware' in your project.

TypeError: grpcWebMiddleware is not a function

Incorrect import style (e.g., destructuring or trying to import default as named).

fix

Use 'const grpcWebMiddleware = require('grpc-web-middleware')' (no destructuring).

ERR_REQUIRE_ESM: require() of ES Module not supported

Package is CJS but you are trying to require it from an ESM context without proper interop.

fix

Use dynamic import or createRequire from 'module'.

Upgrade

Version history

0.2.3latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

6 hits · last 30 days

node

Resources

githubhttps://github.com/fb64/grpc-web-middleware ↗

packagegrpc-web-middleware ↗

homepagehttps://github.com/fb64/grpc-web-middleware#readme ↗