@sarcio/middleware

Connects a Node.js web application to Sarcio, so an approved server-side fix takes effect on a running app without a deploy. It works with the Sarcio sidecar running on the same host, and has adapters for Express, Fastify, Koa, Hono and plain node:http.

Setup guides and the full reference are in the Sarcio docs.

Install

npm install @sarcio/middleware

import { createProtocolShim, ProtocolShimClient } from '@sarcio/middleware';

const client = new ProtocolShimClient({
  target: { socketPath: '/run/sarcio/sarcio.sock' },
  siteKey
});
await client.start();

app.use(express.json());
app.use(createProtocolShim(client));

Framework adapters

| Framework | Adapter | Notes | | --------------- | -------------------------------------- | ---------------------------------------------- | | Express | createProtocolShim(client) | read the fix context with sarcioContext(req) | | Fastify | createProtocolFastifyHook(client) | add as a global preHandler hook | | Koa | createProtocolKoaMiddleware(client) | register after your body parser | | Hono | createProtocolHonoMiddleware(client) | | | raw node:http | withProtocolSarcio(client, listener) | wraps your request listener |

Safe by default

• A request to a route with no active fix does no extra work beyond an in-memory lookup.
• If the sidecar is unreachable, slow or returns anything unexpected, the request runs exactly as it would without Sarcio. The client reconnects by itself when the sidecar comes back.
• Authorization, Cookie and other credential headers never leave your application, and request bodies are size-capped.

License

Business Source License 1.1: production use to connect your own applications to a Sarcio subscription or trial is granted; offering a competing service is not. Each version converts to Apache-2.0 four years after its release.