feat(sdk): expose live event stream (#34098)

packages/client/test/contract-identity.test.ts

@@ -20,7 +20,7 @@ import { Workspace } from "@opencode-ai/schema/workspace"
 import { Api } from "@opencode-ai/server/api"
 import { compile, emitPromise } from "@opencode-ai/httpapi-codegen"
 import { HttpApi } from "effect/unstable/httpapi"
-import { SessionGroup } from "../src/contract"
+import { EventGroup, SessionGroup } from "../src/contract"
 
 test("Core and Server reuse the authoritative Schema and Protocol values", () => {
   expect(AgentV2.ID).toBe(Agent.ID)
@@ -32,6 +32,7 @@ test("Core and Server reuse the authoritative Schema and Protocol values", () =>
   expect(CorePrompt).toBe(Prompt)
   expect(Api.groups["server.session"].identifier).toBe("server.session")
   expect(SessionGroup.identifier).toBe(Api.groups["server.session"].identifier)
+  expect(EventGroup.identifier).toBe(Api.groups["server.event"].identifier)
   expect(Session.ID.create()).toStartWith("ses_")
   expect(Project.ID.global).toBe("global")
   expect(Provider.ID.anthropic).toBe("anthropic")

packages/client/test/effect.test.ts

@@ -15,6 +15,50 @@ test("sessions.get returns the decoded Effect projection", async () => {
   expect(DateTime.toEpochMillis(result.time.created)).toBe(1_717_171_717_000)
 })
 
+test("events.subscribe exposes and decodes the native Effect event stream", async () => {
+  const httpClient = HttpClient.make((request) =>
+    Effect.succeed(
+      HttpClientResponse.fromWeb(
+        request,
+        new Response(
+          `data: ${JSON.stringify({ id: "evt_connected", type: "server.connected", data: {} })}\n\n` +
+            `data: ${JSON.stringify(modelSwitchedEvent)}\n\n`,
+          { headers: { "content-type": "text/event-stream" } },
+        ),
+      ),
+    ),
+  )
+  const events = await Effect.gen(function* () {
+    const client = yield* OpenCode.make({ baseUrl: "http://localhost:3000" })
+    return yield* client.events.subscribe().pipe(Stream.runCollect)
+  }).pipe(Effect.provideService(HttpClient.HttpClient, httpClient), Effect.runPromise)
+
+  expect(Array.from(events).map((event) => event.type)).toEqual(["server.connected", "session.next.model.switched"])
+  const durable = events[1]
+  if (durable?.type !== "session.next.model.switched") throw new Error("Expected model event")
+  expect(DateTime.toEpochMillis(durable.data.timestamp)).toBe(1_717_171_717_000)
+  expect(durable.durable).toEqual({ aggregateID: "ses_test", seq: 1, version: 1 })
+})
+
+test("events.subscribe terminates on Effect protocol decode failures", async () => {
+  const httpClient = HttpClient.make((request) =>
+    Effect.succeed(
+      HttpClientResponse.fromWeb(
+        request,
+        new Response(`data: {"type":"server.connected"}\n\n`, {
+          headers: { "content-type": "text/event-stream" },
+        }),
+      ),
+    ),
+  )
+  const error = await Effect.gen(function* () {
+    const client = yield* OpenCode.make({ baseUrl: "http://localhost:3000" })
+    return yield* client.events.subscribe().pipe(Stream.runCollect, Effect.flip)
+  }).pipe(Effect.provideService(HttpClient.HttpClient, httpClient), Effect.runPromise)
+
+  expect(error._tag).toBe("ClientError")
+})
+
 test("session methods retain decoded Effect inputs and outputs", async () => {
   const historyQueries: Array<Record<string, string>> = []
   let historyPage = 0

packages/client/test/promise.test.ts

@@ -17,6 +17,35 @@ test("sessions.get returns the wire projection", async () => {
   expect(result.time.created).toBe(1_717_171_717_000)
 })
 
+test("events.subscribe exposes the Promise event stream wire projection", async () => {
+  const client = OpenCode.make({
+    baseUrl: "http://localhost:3000",
+    fetch: async () =>
+      new Response(
+        `: heartbeat\n\ndata: ${JSON.stringify({ id: "evt_connected", type: "server.connected", data: {} })}\n\n` +
+          `data: ${JSON.stringify(modelSwitchedEvent)}\n\n`,
+        { headers: { "content-type": "text/event-stream" } },
+      ),
+  })
+  const events = []
+  for await (const event of client.events.subscribe()) events.push(event)
+
+  expect(events).toEqual([{ id: "evt_connected", type: "server.connected", data: {} }, modelSwitchedEvent])
+  expect(events[1]?.type === "session.next.model.switched" && events[1].data.timestamp).toBe(1_717_171_717_000)
+})
+
+test("events.subscribe terminates on malformed Promise SSE data", async () => {
+  const client = OpenCode.make({
+    baseUrl: "http://localhost:3000",
+    fetch: async () => new Response("data: {not-json}\n\n", { headers: { "content-type": "text/event-stream" } }),
+  })
+
+  await expect(client.events.subscribe()[Symbol.asyncIterator]().next()).rejects.toMatchObject({
+    name: "ClientError",
+    reason: "MalformedResponse",
+  })
+})
+
 test("session methods use the public HTTP contract", async () => {
   const requests: Array<{ url: string; init?: RequestInit }> = []
   let historyPage = 0