feat(agent): add frontend action bridge

src/server.ts

@@ -16,6 +16,7 @@ import {
   ResultReferenceStore,
 } from "./results/store.js";
 import { buildChatRouter } from "./routes/chat.js";
+import { FrontendActionCoordinator, FrontendActionError } from "./frontendAction/coordinator.js";
 import { opencodeRuntime } from "./runtime/opencode.js";
 import {
   getRuntimeSessionContext,
@@ -38,6 +39,7 @@ const learningOrchestrator = new LearningOrchestrator(
 const resultReferenceStore = new ResultReferenceStore();
 const resultReferenceResolver = new ResultReferenceResolver(resultReferenceStore);
 const internalToken = config.AGENT_INTERNAL_TOKEN ?? randomUUID();
+const frontendActionCoordinator = new FrontendActionCoordinator();
 
 // 这个 token 只用于仍需服务端上下文的工具桥（store_render_ref）。
 process.env.TJWATER_AGENT_INTERNAL_TOKEN = internalToken;
@@ -45,6 +47,42 @@ process.env.TJWATER_AGENT_INTERNAL_TOKEN = internalToken;
 app.use(cors());
 app.use(express.json({ limit: "1mb" }));
 
+app.post("/internal/frontend-actions/request", async (req, res) => {
+  if (req.header("x-agent-internal-token") !== internalToken) {
+    res.status(403).json({ message: "forbidden" });
+    return;
+  }
+  const runtimeSessionId = typeof req.body?.session_id === "string" ? req.body.session_id.trim() : "";
+  const context = runtimeSessionId ? getRuntimeSessionContext(runtimeSessionId) : null;
+  if (!context) {
+    res.status(404).json({ message: "session context not found" });
+    return;
+  }
+  if (!context.capabilities?.includes("frontend-action@1")) {
+    // Legacy clients still execute the existing UIEnvelope emitted from the tool call.
+    res.json({
+      version: "frontend-action-result@1",
+      status: "succeeded",
+      output: { legacy: true },
+      detail: "legacy client executes the action from its UIEnvelope",
+    });
+    return;
+  }
+  try {
+    const result = await frontendActionCoordinator.request({
+      sessionId: context.clientSessionId,
+      toolCallId: typeof req.body?.call_id === "string" ? req.body.call_id : "",
+      name: typeof req.body?.name === "string" ? req.body.name : "",
+      params: req.body?.params,
+      fallbackText: typeof req.body?.fallback_text === "string" ? req.body.fallback_text : undefined,
+    });
+    res.json(result);
+  } catch (error) {
+    const status = error instanceof FrontendActionError ? error.status : 500;
+    res.status(status).json({ message: error instanceof Error ? error.message : String(error) });
+  }
+});
+
 app.get("/health", async (_req, res) => {
   try {
     const runtime = await opencodeRuntime.health();
@@ -308,6 +346,7 @@ app.use(
     sessionTranscriptStore,
     learningOrchestrator,
     resultReferenceResolver,
+    frontendActionCoordinator,
   ),
 );