simulation: don't start worker HTTP server

.changeset/simulation-http-server.md

@@ -0,0 +1,5 @@
+---
+'@livekit/agents': patch
+---
+
+Do not start the worker HTTP server while running simulations.

agents/src/cli.ts

@@ -29,7 +29,9 @@ const runServer = async (args: CliArgs) => {
 
   // though `production` is defined in ServerOptions, it will always be overridden by CLI.
   const { production: _, ...opts } = args.opts; // eslint-disable-line @typescript-eslint/no-unused-vars
-  const server = new AgentServer(new ServerOptions({ production: args.production, ...opts }));
+  const server = new AgentServer(
+    new ServerOptions({ ...opts, production: args.production, simulation: !!args.room }),
+  );
 
   if (args.room) {
     server.event.once('worker_registered', () => {

agents/src/worker.ts

@@ -144,6 +144,7 @@ export class ServerOptions {
   port: number;
   logLevel: string;
   production: boolean;
+  simulation: boolean;
   jobMemoryWarnMB: number;
   jobMemoryLimitMB: number;
 
@@ -169,6 +170,7 @@ export class ServerOptions {
     port = undefined,
     logLevel = 'info',
     production = false,
+    simulation = false,
     jobMemoryWarnMB = 500,
     jobMemoryLimitMB = 0,
   }: {
@@ -210,6 +212,7 @@ export class ServerOptions {
     port?: number;
     logLevel?: string;
     production?: boolean;
+    simulation?: boolean;
     jobMemoryWarnMB?: number;
     jobMemoryLimitMB?: number;
   }) {
@@ -246,6 +249,7 @@ export class ServerOptions {
     this.port = port || Default.port(production);
     this.logLevel = logLevel;
     this.production = production;
+    this.simulation = simulation;
     this.jobMemoryWarnMB = jobMemoryWarnMB;
     this.jobMemoryLimitMB = jobMemoryLimitMB;
   }
@@ -283,7 +287,7 @@ export class AgentServer {
 
   event = new EventEmitter();
   #session: WebSocket | undefined = undefined;
-  #httpServer: HTTPServer;
+  #httpServer?: HTTPServer;
   #logger = log().child({ version });
   #inferenceExecutor?: InferenceProcExecutor;
 
@@ -353,35 +357,39 @@ export class AgentServer {
 
     this.#opts = opts;
 
-    const healthCheck = () => {
-      // Check if inference executor exists and is not alive
-      if (this.#inferenceExecutor && !this.#inferenceExecutor.isAlive) {
-        return { healthy: false, message: 'inference process not running' };
-      }
+    // Simulations run ephemeral workers side by side; a health endpoint on a fixed port would make
+    // concurrent runs collide.
+    if (!opts.simulation) {
+      const healthCheck = () => {
+        // Check if inference executor exists and is not alive
+        if (this.#inferenceExecutor && !this.#inferenceExecutor.isAlive) {
+          return { healthy: false, message: 'inference process not running' };
+        }
 
-      // Only healthy when fully connected with an active WebSocket
-      if (
-        this.#closed ||
-        this.#connecting ||
-        !this.#session ||
-        this.#session.readyState !== WebSocket.OPEN
-      ) {
-        return { healthy: false, message: 'not connected to livekit' };
-      }
+        // Only healthy when fully connected with an active WebSocket
+        if (
+          this.#closed ||
+          this.#connecting ||
+          !this.#session ||
+          this.#session.readyState !== WebSocket.OPEN
+        ) {
+          return { healthy: false, message: 'not connected to livekit' };
+        }
 
-      return { healthy: true, message: 'OK' };
-    };
+        return { healthy: true, message: 'OK' };
+      };
 
-    const getWorkerInfo = () => ({
-      agent_name: opts.agentName,
-      agent_name_is_env: opts.agentNameIsEnv,
-      worker_type: JobType[opts.serverType],
-      active_jobs: this.activeJobs.length,
-      sdk_version: version,
-      project_type: PROJECT_TYPE,
-    });
+      const getWorkerInfo = () => ({
+        agent_name: opts.agentName,
+        agent_name_is_env: opts.agentNameIsEnv,
+        worker_type: JobType[opts.serverType],
+        active_jobs: this.activeJobs.length,
+        sdk_version: version,
+        project_type: PROJECT_TYPE,
+      });
 
-    this.#httpServer = new HTTPServer(opts.host, opts.port, healthCheck, getWorkerInfo);
+      this.#httpServer = new HTTPServer(opts.host, opts.port, healthCheck, getWorkerInfo);
+    }
   }
 
   /** @throws {@link WorkerError} if worker failed to connect or already running */
@@ -448,7 +456,11 @@ export class AgentServer {
       }
     };
 
-    await ThrowsPromise.all([workerWS(), this.#httpServer.run()]);
+    const tasks = [workerWS()];
+    if (this.#httpServer) {
+      tasks.push(this.#httpServer.run());
+    }
+    await ThrowsPromise.all(tasks);
     this.#close.resolve();
   }
 
@@ -881,7 +893,7 @@ export class AgentServer {
 
     await this.#inferenceExecutor?.close();
     await this.#procPool.close();
-    await this.#httpServer.close();
+    await this.#httpServer?.close();
     await ThrowsPromise.allSettled(this.#tasks);
 
     this.#session?.close();