fix(agent): bound oversized Codex conversations (#3567)

Co-authored-by: posthog[bot] <206114724+posthog[bot]@users.noreply.github.com>
Co-authored-by: richardsolomou <2622273+richardsolomou@users.noreply.github.com>

Author: richardsolomou

apps/code/scripts/download-binaries.mjs

@@ -22,7 +22,7 @@ const DEST_DIR = join(__dirname, "..", "resources", "codex-acp");
 const BINARIES = [
   {
     name: "codex",
-    version: "0.140.0",
+    version: "0.144.0",
     getUrl: (version, target) => {
       if (target.includes("windows")) {
         return `https://github.com/openai/codex/releases/download/rust-v${version}/codex-${target}.exe.zip`;

packages/agent/package.json

@@ -142,7 +142,7 @@
     "@anthropic-ai/sdk": "0.109.0",
     "@earendil-works/pi-coding-agent": "catalog:",
     "@hono/node-server": "^1.19.9",
-    "@openai/codex": "0.140.0",
+    "@openai/codex": "0.144.0",
     "@opentelemetry/api-logs": "^0.208.0",
     "@opentelemetry/exporter-logs-otlp-http": "^0.208.0",
     "@opentelemetry/resources": "^2.0.0",

packages/agent/src/adapters/codex-app-server/codex-app-server-agent.test.ts

@@ -1636,6 +1636,32 @@ describe("CodexAppServerAgent", () => {
     );
   });
 
+  it("rejects the prompt with guidance when the gateway request is too large", async () => {
+    const stub = makeStubRpc({ "thread/start": { thread: { id: "t" } } });
+    const { client } = makeFakeClient();
+    const agent = new CodexAppServerAgent(client, {
+      processOptions: { binaryPath: "/x/codex" },
+      rpcFactory: stub.factory,
+    });
+
+    await agent.newSession({ cwd: "/r" } as unknown as NewSessionRequest);
+    const done = agent.prompt({
+      sessionId: "t",
+      prompt: [{ type: "text", text: "continue" }],
+    } as unknown as PromptRequest);
+    stub.emit("error", {
+      willRetry: false,
+      error: {
+        message:
+          "unexpected status 413 Payload Too Large: Request body too large",
+      },
+    });
+
+    await expect(done).rejects.toThrow(
+      "This conversation is too large to continue",
+    );
+  });
+
   it("ends the turn without turn/start when no prompt block is usable", async () => {
     const stub = makeStubRpc({ "thread/start": { thread: { id: "t" } } });
     const { client } = makeFakeClient();

packages/agent/src/adapters/codex-app-server/codex-app-server-agent.ts

@@ -1305,6 +1305,18 @@ export class CodexAppServerAgent extends BaseAcpAgent {
           this.turns.fail(RequestError.internalError(undefined, message));
           return;
         }
+        if (
+          message.includes("413") ||
+          message.toLowerCase().includes("request body too large")
+        ) {
+          this.turns.fail(
+            RequestError.internalError(
+              undefined,
+              "This conversation is too large to continue. Start a new task and carry over a text summary instead of image or tool output.",
+            ),
+          );
+          return;
+        }
         void this.finalizeTurn("refusal");
       }
     }