feat(httpapi): bridge event stream (#24518)

packages/opencode/src/server/routes/instance/httpapi/event.ts

@@ -0,0 +1,46 @@
+import { Bus } from "@/bus"
+import { Log } from "@/util"
+import { Effect } from "effect"
+import * as Stream from "effect/Stream"
+import { HttpRouter, HttpServerResponse } from "effect/unstable/http"
+
+const log = Log.create({ service: "server" })
+
+export const EventPaths = {
+  event: "/event",
+} as const
+
+function eventData(data: unknown) {
+  return `data: ${JSON.stringify(data)}\n\n`
+}
+
+export const eventRoute = HttpRouter.add(
+  "GET",
+  EventPaths.event,
+  Effect.gen(function* () {
+    const bus = yield* Bus.Service
+    const events = bus.subscribeAll().pipe(Stream.takeUntil((event) => event.type === Bus.InstanceDisposed.type))
+    const heartbeat = Stream.tick("10 seconds").pipe(
+      Stream.drop(1),
+      Stream.map(() => ({ type: "server.heartbeat", properties: {} })),
+    )
+
+    log.info("event connected")
+    return HttpServerResponse.stream(
+      Stream.make({ type: "server.connected", properties: {} }).pipe(
+        Stream.concat(events.pipe(Stream.merge(heartbeat, { haltStrategy: "left" }))),
+        Stream.map(eventData),
+        Stream.encodeText,
+        Stream.ensuring(Effect.sync(() => log.info("event disconnected"))),
+      ),
+      {
+        contentType: "text/event-stream",
+        headers: {
+          "Cache-Control": "no-cache, no-transform",
+          "X-Accel-Buffering": "no",
+          "X-Content-Type-Options": "nosniff",
+        },
+      },
+    )
+  }).pipe(Effect.provide(Bus.layer)),
+)

packages/opencode/src/server/routes/instance/httpapi/server.ts

@@ -10,6 +10,7 @@ import { lazy } from "@/util/lazy"
 import { Filesystem } from "@/util"
 import { authorizationLayer } from "./auth"
 import { ConfigApi, configHandlers } from "./config"
+import { eventRoute } from "./event"
 import { FileApi, fileHandlers } from "./file"
 import { ExperimentalApi, experimentalHandlers } from "./experimental"
 import { InstanceApi, instanceHandlers } from "./instance"
@@ -66,6 +67,7 @@ const instance = HttpRouter.middleware()(
 ).layer
 
 export const routes = Layer.mergeAll(
+  eventRoute,
   HttpApiBuilder.layer(ConfigApi).pipe(Layer.provide(configHandlers)),
   HttpApiBuilder.layer(ExperimentalApi).pipe(Layer.provide(experimentalHandlers)),
   HttpApiBuilder.layer(FileApi).pipe(Layer.provide(fileHandlers)),

packages/opencode/src/server/routes/instance/index.ts

@@ -16,6 +16,7 @@ import { QuestionRoutes } from "./question"
 import { PermissionRoutes } from "./permission"
 import { Flag } from "@opencode-ai/core/flag/flag"
 import { ExperimentalHttpApiServer } from "./httpapi/server"
+import { EventPaths } from "./httpapi/event"
 import { ExperimentalPaths } from "./httpapi/experimental"
 import { FilePaths } from "./httpapi/file"
 import { InstancePaths } from "./httpapi/instance"
@@ -41,6 +42,7 @@ export const InstanceRoutes = (upgrade: UpgradeWebSocket): Hono => {
   if (Flag.OPENCODE_EXPERIMENTAL_HTTPAPI) {
     const handler = ExperimentalHttpApiServer.webHandler().handler
     const context = Context.empty() as Context.Context<unknown>
+    app.get(EventPaths.event, (c) => handler(c.req.raw, context))
     app.get("/question", (c) => handler(c.req.raw, context))
     app.post("/question/:requestID/reply", (c) => handler(c.req.raw, context))
     app.post("/question/:requestID/reject", (c) => handler(c.req.raw, context))