grpc-express

library1.0.1-betajsnpmunverified

An Express middleware that reverse-proxies HTTP 1.1 REST requests into HTTP 2.0 gRPC requests and back, making gRPC services accessible to browsers without additional client or server modifications. Version 1.0.1-beta is the latest and only release. It is Node.js only, supports unary and server-side streaming calls, and requires an existing gRPC client connection. Alternative solutions like gRPC-web require TypeScript or Go, while grpc-express integrates seamlessly with Express apps.

devops

npm install grpc-express

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · GRPC-EXPRESS

grpc-express

devopsjavascriptv1.0.1-beta

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.

grpcExpress

✓ const grpcExpress = require('grpc-express');

✗ import grpcExpress from 'grpc-express';

Package is CommonJS only; ESM import will fail. Use require() or dynamic import.

default

✓ app.use(grpcExpress(grpcClient));

✗ app.use(grpcExpress(grpcClient, {}));

The function expects a single argument (grpcClient). No options object supported.

grpc

✓ const grpc = require('grpc');

✗ import * as grpc from 'grpc';

grpc package is also CommonJS. Ensure you are using @grpc/grpc-js for newer projects; grpc-express may not be compatible.

Set up an Express server that proxies REST requests to a gRPC service using grpc-express middleware.

const grpc = require('grpc'); const grpcExpress = require('grpc-express'); const express = require('express'); const PROTO_PATH = __dirname + '/proto/helloworld.proto'; const hello_proto = grpc.load(PROTO_PATH).helloworld; const grpcClient = new hello_proto.Greeter('localhost:50051', grpc.credentials.createInsecure()); const app = express(); app.use(grpcExpress(grpcClient)); app.listen(3000, () => { console.log('gRPC proxy running on port 3000'); });

Debug

Known issues

breakingPackage only supports unary and server-side streaming calls; bidirectional and client-side streaming are not supported.

fix

Design your gRPC service to avoid bidirectional/client-side streaming endpoints.

affects: <=1.0.1-beta

deprecatedThe 'grpc' npm package is deprecated; use '@grpc/grpc-js' instead.

fix

Replace 'grpc' with '@grpc/grpc-js' and update imports accordingly. Note: grpc-express may not work with @grpc/grpc-js as it relies on grpc.load().

affects: *

gotchaThe middleware auto-generates REST endpoints based on proto package and service names; name collisions or incorrect URLs can occur if multiple services have the same method names.

fix

Ensure proto package and service names are unique to avoid endpoint conflicts.

affects: <=1.0.1-beta

gotchaNo support for request validation, authentication, or rate limiting; implement those in Express middleware before grpc-express.

fix

Add custom middleware before using grpcExpress to handle these concerns.

affects: <=1.0.1-beta

deprecatedgrpc.load() is deprecated; use @grpc/proto-loader for loading .proto files.

fix

Switch to @grpc/proto-loader and loadPackageDefinition to create gRPC clients.

affects: *

Errors

Common errors & fixes

Error: Cannot find module 'grpc'

The 'grpc' package is not installed or is deprecated and not installed.

fix

Run: npm install grpc (or switch to @grpc/grpc-js and adjust code accordingly).

TypeError: grpcExpress is not a function

CommonJS import with ES module syntax; package does not support default ESM import.

fix

Use: const grpcExpress = require('grpc-express');

Error: 12 UNIMPLEMENTED: Method not found

The gRPC method name does not match the REST endpoint URL.

fix

Check the proto package/service/method names and ensure the URL matches: /packageName/serviceName/methodName.

Upgrade

Version history

1.0.1-betalatest on npm

Audit

Dependencies

expressrequiredMiddleware framework required to run the middleware.

grpcrequiredOfficial gRPC Node.js library for client-server communication.

Agent activity

8 hits · last 30 days

node

Resources

githubhttps://github.com/sepehr-laal/grpc-express ↗

packagegrpc-express ↗

homepagehttps://github.com/sepehr-laal/grpc-express#readme ↗