chore: import upstream snapshot with attribution

showcase/integrations/langgraph-fastapi/src/app/api/copilotkit-ogui/route.ts

@@ -0,0 +1,71 @@
+import { NextRequest, NextResponse } from "next/server";
+import {
+  CopilotRuntime,
+  ExperimentalEmptyAdapter,
+  copilotRuntimeNextJSAppRouterEndpoint,
+} from "@copilotkit/runtime";
+import { LangGraphAgent } from "@copilotkit/runtime/langgraph";
+
+// Dedicated runtime for the Open Generative UI demos.
+// Isolated here because the `openGenerativeUI` runtime flag sets
+// `openGenerativeUIEnabled: true` globally on the probe response, which
+// causes the CopilotKit provider's setTools effect to wipe per-demo
+// `useFrontendTool`/`useComponent` registrations in the default runtime.
+
+const LANGGRAPH_URL =
+  process.env.AGENT_URL ||
+  process.env.LANGGRAPH_DEPLOYMENT_URL ||
+  "http://localhost:8123";
+
+const openGenUiAgent = new LangGraphAgent({
+  deploymentUrl: LANGGRAPH_URL,
+  graphId: "open_gen_ui",
+  langsmithApiKey: process.env.LANGSMITH_API_KEY || "",
+});
+const openGenUiAdvancedAgent = new LangGraphAgent({
+  deploymentUrl: LANGGRAPH_URL,
+  graphId: "open_gen_ui_advanced",
+  langsmithApiKey: process.env.LANGSMITH_API_KEY || "",
+});
+
+const agents: Record<string, LangGraphAgent> = {
+  "open-gen-ui": openGenUiAgent,
+  "open-gen-ui-advanced": openGenUiAdvancedAgent,
+  // Internal components (headless-chat, example-canvas) call `useAgent()` with
+  // no args, which defaults to agentId "default". Alias so those hooks resolve
+  // instead of throwing "Agent 'default' not found".
+  default: openGenUiAgent,
+};
+
+export const POST = async (req: NextRequest) => {
+  try {
+    const { handleRequest } = copilotRuntimeNextJSAppRouterEndpoint({
+      endpoint: "/api/copilotkit-ogui",
+      serviceAdapter: new ExperimentalEmptyAdapter(),
+      // @region[minimal-runtime-flag]
+      // @region[advanced-runtime-config]
+      // Server-side config is identical for the minimal and advanced cells —
+      // the advanced behaviour (sandbox -> host function calls) is wired
+      // entirely on the frontend via `openGenerativeUI.sandboxFunctions` on
+      // the provider. The single `openGenerativeUI` flag below turns on
+      // Open Generative UI for the listed agent(s); the runtime middleware
+      // converts each agent's streamed `generateSandboxedUi` tool call into
+      // `open-generative-ui` activity events.
+      runtime: new CopilotRuntime({
+        // @ts-ignore -- see main route.ts
+        agents,
+        openGenerativeUI: {
+          agents: ["open-gen-ui", "open-gen-ui-advanced"],
+        },
+      }),
+      // @endregion[advanced-runtime-config]
+      // @endregion[minimal-runtime-flag]
+    });
+    return await handleRequest(req);
+  } catch (error: any) {
+    return NextResponse.json(
+      { error: error.message, stack: error.stack },
+      { status: 500 },
+    );
+  }
+};