fix(agent): complete opencode warmup before serving

The previous fire-and-forget startup only created the SDK client, leaving the first chat to await project and tool initialization. Warm the real session/tool path and gate port listening on completion.

src/runtime/opencode.ts

@@ -64,6 +64,38 @@ export class OpencodeRuntimeAdapter {
     return requireData(response.data, "global.health");
   }
 
+  async warmup(): Promise<void> {
+    const client = await this.ensureClient();
+    const healthResponse = await client.global.health();
+    requireData(healthResponse.data, "global.health");
+
+    const sessionResponse = await client.session.create({
+      title: "tjwater-agent-warmup",
+    });
+    const session = requireData(sessionResponse.data, "session.create");
+
+    try {
+      const [provider, model] = config.OPENCODE_MODEL.split("/");
+      if (!provider || !model) {
+        throw new Error(
+          `invalid OPENCODE_MODEL; expected provider/model, received ${config.OPENCODE_MODEL}`,
+        );
+      }
+      const toolsResponse = await client.tool.list({ provider, model });
+      requireData(toolsResponse.data, "tool.list");
+    } finally {
+      await client.session.delete(
+        { sessionID: session.id },
+        { throwOnError: true },
+      ).catch((error) => {
+        logger.warn(
+          { err: error, sessionId: session.id },
+          "failed to remove opencode warmup session",
+        );
+      });
+    }
+  }
+
   async createSession(title?: string) {
     const client = await this.ensureClient();
     const response = await client.session.create({

src/server.ts

@@ -488,23 +488,12 @@ const bootstrap = async () => {
     resultReferenceStore.initialize(),
     sessionTranscriptStore.initialize(),
   ]);
-  resultReferenceStore.startCleanupLoop();
 };
 
-await bootstrap();
-
-const server = app.listen(config.PORT, config.HOST, () => {
-  logger.info(
-    { host: config.HOST, port: config.PORT },
-    "TJWaterAgent listening",
-  );
-  void warmupOpencodeRuntime();
-});
-
 const warmupOpencodeRuntime = async () => {
   const startedAt = Date.now();
   try {
-    await opencodeRuntime.ensureClient();
+    await opencodeRuntime.warmup();
     logger.info(
       {
         elapsedMs: Math.max(0, Date.now() - startedAt),
@@ -521,9 +510,21 @@ const warmupOpencodeRuntime = async () => {
       },
       "failed to warm up opencode runtime",
     );
+    throw error;
   }
 };
 
+await bootstrap();
+await warmupOpencodeRuntime();
+resultReferenceStore.startCleanupLoop();
+
+const server = app.listen(config.PORT, config.HOST, () => {
+  logger.info(
+    { host: config.HOST, port: config.PORT },
+    "TJWaterAgent listening",
+  );
+});
+
 const shutdown = async () => {
   logger.info("shutting down TJWaterAgent");
   server.close();

tests/runtime/opencode.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from "bun:test";
 import { type OpencodeClient } from "@opencode-ai/sdk/v2";
 
+import { config } from "../../src/config.js";
 import { OpencodeRuntimeAdapter } from "../../src/runtime/opencode.js";
 
 const createRuntimeAdapter = (
@@ -85,3 +86,47 @@ describe("OpencodeRuntimeAdapter.ensureClient", () => {
     expect(attempts).toBe(2);
   });
 });
+
+describe("OpencodeRuntimeAdapter.warmup", () => {
+  it("initializes the project session and model tools before reporting ready", async () => {
+    const calls: string[] = [];
+    const client = {
+      global: {
+        health: async () => {
+          calls.push("health");
+          return { data: { healthy: true, version: "test" } };
+        },
+      },
+      session: {
+        create: async () => {
+          calls.push("session.create");
+          return { data: { id: "warmup-session" } };
+        },
+        delete: async ({ sessionID }: { sessionID: string }) => {
+          calls.push(`session.delete:${sessionID}`);
+          return { data: true };
+        },
+      },
+      tool: {
+        list: async (model: { provider: string; model: string }) => {
+          calls.push(`tool.list:${model.provider}/${model.model}`);
+          return { data: [] };
+        },
+      },
+    } as unknown as OpencodeClient;
+    const runtime = Object.assign(Object.create(OpencodeRuntimeAdapter.prototype), {
+      clientPromise: null,
+      closeServer: null,
+      ensureClient: async () => client,
+    }) as OpencodeRuntimeAdapter;
+
+    await runtime.warmup();
+
+    expect(calls).toEqual([
+      "health",
+      "session.create",
+      `tool.list:${config.OPENCODE_MODEL}`,
+      "session.delete:warmup-session",
+    ]);
+  });
+});