Azure Functions V4 adapter for Hono. Run Hono on Azure Functions.

npm i @marplex/hono-azurefunc-adapter

The adapter exposes an handler that converts between standard web Request/Response (used by Hono) and HttpRequest/HttpResponse (used by Azure Functions). This handler is then called by the function http trigger.

//app.ts

import { Hono } from "hono";
const app = new Hono();

...

export default app

//httpTrigger.ts

import honoApp from "./app";

import { azureHonoHandler } from "@marplex/hono-azurefunc-adapter";
import { app } from "@azure/functions";

app.http("httpTrigger", {
  methods: [
    "GET",
    "POST",
    "DELETE",
    "HEAD",
    "PATCH",
    "PUT",
    "OPTIONS",
    "TRACE",
    "CONNECT",
  ],
  authLevel: "anonymous",
  route: "{*proxy}",
  handler: azureHonoHandler(honoApp.fetch),
});

There are some limitations and other things you should keep in mind when running Hono inside Azure Functions.

The default Azure Functions route prefix is /api. Be sure to start all your Hono routes with /api or change the default Azure Functions route prefix in host.json

//host.json
{
    [...]

    "extensions": {
        "http": {
            "routePrefix": ""
        }
    }
}

If you are using hono/bearer-auth or any other library that uses crypto, be sure to define global.crypto = require("crypto"); before registering the http trigger.

Azure Functions does not expose any signal or event for listening to http request interruptions. c.req.raw.signal is useless and its never aborted.

• SSE (streaming response)