twirp-ts
v2.5.0
Published
Typescript implementation of the Twirp protocol
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Twirp-TS
A complete server and client implementation of the awesome Twirp Specification written in typescript.
Supported spec v7 and v8
Table of Contents:
Getting Started
Installation
Run the following to install the package
npm i twirp-ts @protobuf-ts/plugin@next -S
or
yarn add twirp-ts @protobuf-ts/plugin@next
Install ts-proto
instead if you prefer it over @protobuf-ts
Install Protoc
Make sure you have protoc
or buf
installed.
Mac:
brew install protobuf
Linux:
apt-get install protobuf
Optional: This plugin works with buf too, follow the link to see how to install it
Code Generation
twirp-ts relies on either protobuf-ts or ts-proto to generate protobuf message definitions
The protoc-gen-twirp_ts
is instead used to generate server
and client
code for twirp-ts
It is as simple as adding the following options in your protoc
command
PROTOC_GEN_TWIRP_BIN="./node_modules/.bin/protoc-gen-twirp_ts"
--plugin=protoc-gen-twirp_ts=${PROTOC_GEN_TWIRP_BIN} \
--twirp_ts_out=$(OUT_DIR)
Here's an example working command with the recomended flags:
PROTOC_GEN_TWIRP_BIN="./node_modules/.bin/protoc-gen-twirp_ts"
PROTOC_GEN_TS_BIN="./node_modules/.bin/protoc-gen-ts_proto"
OUT_DIR="./generated"
protoc \
-I ./protos \
--plugin=protoc-gen-ts_proto=${PROTOC_GEN_TS_BIN} \
--plugin=protoc-gen-twirp_ts=${PROTOC_GEN_TWIRP_BIN} \
--ts_proto_opt=esModuleInterop=true \
--ts_proto_opt=outputClientImpl=false \
--ts_proto_out=${OUT_DIR} \
--twirp_ts_opt="ts_proto" \
--twirp_ts_out=${OUT_DIR} \
./protos/*.proto
PROTOC_GEN_TWIRP_BIN="./node_modules/.bin/protoc-gen-twirp_ts"
PROTOC_GEN_TS_BIN="./node_modules/.bin/protoc-gen-ts"
OUT_DIR="./generated"
protoc \
-I ./protos \
--plugin=protoc-gen-ts=$(PROTOC_GEN_TS_BIN) \
--plugin=protoc-gen-twirp_ts=$(PROTOC_GEN_TWIRP_BIN) \
--ts_opt=client_none \
--ts_opt=generate_dependencies \
--ts_out=$(OUT_DIR) \
--twirp_ts_out=$(OUT_DIR) \
./protos/*.proto
OUT_DIR="./generated"
protoc \
-I ./protos \
--plugin=protoc-gen-ts=.\\node_modules\\.bin\\protoc-gen-ts.cmd \
--plugin=protoc-gen-twirp_ts=.\\node_modules\\.bin\\protoc-gen-twirp_ts.cmd \
--ts_opt=client_none \
--ts_opt=generate_dependencies \
--ts_out=${OUT_DIR} \
--twirp_ts_out=${OUT_DIR} \
./protos/*.proto
If you'd like the plugin to generate an index.ts
file exporting all your generated code
simply add --twirp_ts_opt="index_file"
Server
Once you've generated the server code you can simply start a server as following:
import * as http from "http";
import {TwirpContext} from "twirp-ts";
import {createHaberdasherServer} from "./generated/haberdasher.twirp";
import {Hat, Size} from "./generated/service";
const server = createHaberdasherServer({
async MakeHat(ctx: TwirpContext, request: Size): Promise<Hat> {
// Your implementation
},
});
http.createServer(server.httpHandler())
.listen(8080);
Path prefix
By default the server uses the /twirp
prefix for every request.
You can change or remove the prefix passing the prefix
option to the handler
const server = createHaberdasherServer({
async MakeHat(ctx: TwirpContext, request: Size): Promise<Hat> {
// Your implementation
},
});
server.withPrefix("/custom-prefix") // or false to remove it
http.createServer(server.httpHandler())
.listen(8080);
or you can pass it to the handler directly:
http.createServer(server.httpHandler({
prefix: "/custom-prefix",
})).listen(8080);
Integrating with express
If you'd like to use express
as your drop in solution to add more routes, or middlewares you can do as following:
const server = createHaberdasherServer({
async MakeHat(ctx: TwirpContext, request: Size): Promise<Hat> {
// ... implementation
},
});
const app = express();
app.post(server.matchingPath(), server.httpHandler());
app.listen(8000);
Note: if you want to change the default prefix use server.withPrefix()
Server Hooks & Interceptors
Interceptors are a form of middleware for Twirp requests. Interceptors can mutate the request and responses, which can enable some powerful integrations, but in most cases, it is better to use Hooks for observability at key points during a request. Mutating the request adds complexity to the request lifecycle.
Be mindful to not hide too much behind interceptors as with every middleware
alike implementation is easy to increase complexity making it harder to reason about.
Example:
const server = createHaberdasherServer({
// ...
});
async function exampleInterceptor(ctx: TwirpContext, req: any, next: Next) {
console.log("Before response");
const response = await next(ctx, req);
console.log("After response");
return response;
}
server.use(exampleInterceptor)
Server Hooks They provide callbacks for before and after the request is handled. The Error hook is called only if an error was returned by the handler.
A great place for metrics
and logging
const server = createHaberdasherServer({
// ...
});
const serverHooks: ServerHooks = {
requestReceived: (ctx) => {
console.log("Received");
},
requestRouted: (ctx) => {
console.log("Requested");
},
responsePrepared: (ctx) => {
console.log("Prepared");
},
responseSent: (ctx) => {
console.log("Sent");
},
error: (ctx, err) => {
console.log(err);
}
};
server.use(serverHooks);
Errors
The library comes with a built in TwirpError
which is the default and standard error for all of your errors.
You can certainly create custom errors that extend a TwirpError
For Example:
import {TwirpError, TwirpErrorCode} from "twirp-ts";
class UnauthenticatedError extends TwirpError {
constructor(traceId: string) {
super(TwirpErrorCode.Unauthenticated, "you must login");
this.withMeta("trace-id", traceId)
}
}
Gateway
The gateway allows to expose custom http endpoints that automatically maps to your twirp handlers.
The mapping is done in your proto file using the google.api.http annotations spec.
Add the annotation
service Haberdasher {
// MakeHat produces a hat of mysterious, randomly-selected color!
rpc MakeHat(Size) returns (Hat) {
option (google.api.http) = {
post: "/hat"
body: "*"
};
};
}
Generating the gateway
add the following option in your protoc
command:
--twirp_ts_opt=gateway
Don't forget to regenerate your proto files.
Gateway Reverse Proxy
Once we generated the gateway we can use it as a stand-alone reverse-proxy server or as a request rewriter.
The following example creates a stand-alone reverse proxy:
import express from 'express';
import {createGateway} from './generated/gateway.twirp.ts';
const app = express();
const gateway = createGateway();
app.use(gateway.reverseProxy({
baseUrl: "http://localhost:8000/twirp",
}));
app.listen(8001);
Gateway rewriter
If you prefer to have the gateway in the same server as your twirp endpoint and save a round-trip, you'd want to use the rewriter
The rewriter will automatically rewrite the request (once it finds a match) to the corresponded twirp handler
import express from 'express';
import {createGateway} from './generated/gateway.twirp.ts';
const app = express();
const gateway = createGateway();
app.use(gateway.twirpRewrite());
// All your twirp handlers
app.post(server.matchingPath(), server.httpHandler());
app.listen(8001);
Note: make sure the middleware is register before your twirp handlers
Twirp Client
As well as the server you've also got generated client code, ready for you to use.
You can choose between JSON
client and Protobuf
client.
The generated code doesn't include an actual library to make http
requests, but it gives you an interface to implement the one that you like the most.
Alternatively you can use the provided implementation based on node http
and https
package.
For example:
const jsonClient = new HaberdasherClientJSON(NodeHttpRPC({
baseUrl: "http://localhost:8000/twirp",
}));
const protobufClient = new HaberdasherClientProtobuf(NodeHttpRPC({
baseUrl: "http://localhost:8000/twirp",
}));
For us in the browser, you can use the provided fetch
based implementation,
For example:
export const jsonClient = new HaberdasherClientJSON(FetchRPC({
baseUrl: "http://localhost:8000/twirp",
}));
export const protobufClient = new HaberdasherClientProtobuf(FetchRPC({
baseUrl: "http://localhost:8000/twirp",
}));
Alternatively provided your own implementation.
You can check the full example on how to integrate the client with axios
.
Open API V3
You can now generate automatically an OpenAPI V3 compliant spec out of your twirp protobuf definitions!
We support the Gateway too!
Add the following options to your protoc
command:
--twirp_ts_opt="openapi_twirp"
--twirp_ts_opt="openapi_gateway"
Enjoy!
Migrate to V2
The v2 offers new functionalities and stability improvements, a few simple to migrate breaking changes have been made during the upgrade.
ts-proto & @protobuf-ts are now
peerDepedencies
which means that you can now update them at your pace.- Install either one of the 2 libraries (refer to Getting Started)
The twirp generator now uses
protobuf-ts
as the default generator. pass the--twirp_ts_opt="ts_proto"
to usets-proto
We now generate a single
*.twirp.ts
per.proto
file instead of 1 file perservice
definition. if you have multiple services in one file you'd simply need to fix the imports
How to upgrade
The package uses Semver Versioning system. However, keep in mind that the code-generation plugin is tightly coupled to the twirp-ts library.
Make sure that whenever you update twirp-ts
you re-generate the server and client code. This make sure that the generated code will be using the updated library
Licence
MIT <3