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grpc-ts-middleware

library1.0.11jsnpmunverified

A TypeScript library providing pre-call and post-call middleware for gRPC Node.js servers. Currently at version 1.0.11, it has zero external dependencies but requires the 'grpc' package as a peer dependency. It supports adding middleware functions that run before and after gRPC calls, and includes built-in support for Jaeger tracing header propagation. Unlike manual interception, it allows adding middleware without modifying service implementations.

devops

npm install grpc-ts-middleware

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · GRPC-TS-MIDDLEWARE

grpc-ts-middleware

devopsjavascriptv1.0.11

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.

GrpcMiddleware

✓ import GrpcMiddleware from 'grpc-ts-middleware';

✗ const GrpcMiddleware = require('grpc-ts-middleware').default;

Default import, but CommonJS users may need .default or use require().

GrpcCall

✓ import { GrpcCall } from 'grpc-ts-middleware';

✗ import GrpcCall from 'grpc-ts-middleware';

GrpcCall is a named export, not default.

GrpcMiddleware (TypeScript)

✓ import GrpcMiddleware from 'grpc-ts-middleware';

✗ import { GrpcMiddleware } from 'grpc-ts-middleware';

GrpcMiddleware is the default export. Named export pattern will fail.

Creates a gRPC server with pre- and post-call middleware that logs calls before and after handling the echo RPC.

import * as grpc from 'grpc'; import GrpcMiddleware, { GrpcCall } from 'grpc-ts-middleware'; import { EchoReply, EchoRequest } from './proto/echo_pb'; import { EchoManagerService } from './proto/echo_grpc_pb'; function doEcho(call: grpc.ServerUnaryCall<EchoRequest>, callback: grpc.sendUnaryData<EchoReply>) { const reply = new EchoReply(); reply.setMessage(call.request.getMessage()); callback(null, reply); } function start(): grpc.Server { const server: grpc.Server = new grpc.Server(); const grpcMiddleware = new GrpcMiddleware( server, [(call: GrpcCall) => console.log('Pre-call handler 1', call)], [(error: grpc.ServiceError | null, call: GrpcCall) => console.log('Post-call handler', call, error)] ); grpcMiddleware.addService(EchoManagerService, { echo: doEcho }); grpcMiddleware.enableTracing(); server.bind('0.0.0.0:9090', grpc.ServerCredentials.createInsecure()); server.start(); return server; } start();

Debug

Known issues

gotchaGrpcMiddleware must receive the server instance and add services via addService, not through server.addService.

fix

Always call new GrpcMiddleware(server, preHandlers, postHandlers) and then grpcMiddleware.addService(service, implementations).

affects: >=1.0.0

gotchaThe grpc package must be installed separately; it is not bundled. Using a different gRPC library like @grpc/grpc-js will cause conflicts.

fix

Install grpc (the legacy gRPC library) alongside grpc-ts-middleware. For @grpc/grpc-js, this library does not support it.

affects: >=1.0.0

gotchaThe call object passed to post-call handlers includes metadata modified by pre-call handlers, but pre-call handlers cannot modify the call request body.

fix

Use pre-call handlers for logging/validation only; use post-call handlers to inspect errors or modify response metadata.

affects: >=1.0.0

gotchaenableTracing() only propagates Jaeger-style tracing headers; other tracing systems require custom middleware.

fix

Implement custom pre/post handlers for other tracing formats.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: GrpcMiddleware is not a constructor

Using named import instead of default import.

fix

Use 'import GrpcMiddleware from 'grpc-ts-middleware';' (without braces).

Error: Cannot find module 'grpc'

The grpc peer dependency is not installed.

fix

Run 'npm install grpc --save'.

TypeError: grpcMiddleware.addService is not a function

GrpcMiddleware constructor was called without passing the server instance correctly.

fix

Ensure the first argument to new GrpcMiddleware is a valid grpc.Server instance.

Upgrade

Version history

1.0.11latest on npm

Audit

Dependencies

grpcrequiredPeer dependency: the library wraps gRPC server methods and requires the gRPC package to be installed separately.

Agent activity

6 hits · last 30 days

node

Resources

githubhttps://github.com/nicolaspearson/grpc.ts.middleware ↗

packagegrpc-ts-middleware ↗

homepagehttps://github.com/nicolaspearson/grpc.ts.middleware#readme ↗