From edde928736cf92ef44009f22df2301d2c26c214c Mon Sep 17 00:00:00 2001
From: Paul Bakaus <paul.bakaus@gmail.com>
Date: Sun, 12 Jul 2026 20:47:01 -0700
Subject: [PATCH] Capture Codex worker token usage

Record per-turn app-server token notifications so Live architecture benchmarks can compare context and cache costs.\n\nAI-assisted: OpenAI Codex.
---
 skill/scripts/live/codex-app-server-client.mjs |  5 +++++
 tests/live-codex-app-server-client.test.mjs    | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/skill/scripts/live/codex-app-server-client.mjs b/skill/scripts/live/codex-app-server-client.mjs
index de16395be..a75f7ca70 100644
--- a/skill/scripts/live/codex-app-server-client.mjs
+++ b/skill/scripts/live/codex-app-server-client.mjs
@@ -384,6 +384,7 @@ export class CodexAppServerClient {
     let turnId = null;
     let started = null;
     let completed = null;
+    let tokenUsage = null;
     const agentMessages = [];
     const agentMessageCallbacks = [];
     let firstAgentMessageAt = null;
@@ -407,6 +408,9 @@ export class CodexAppServerClient {
       }
       if (notificationTurnId !== turnId) return;
       if (notification.method === 'turn/started') started = notification;
+      if (notification.method === 'thread/tokenUsage/updated') {
+        tokenUsage = notification.params?.tokenUsage || tokenUsage;
+      }
       if (notification.method === 'item/completed'
         && notification.params?.item?.type === 'agentMessage'
         && typeof notification.params.item.text === 'string') {
@@ -456,6 +460,7 @@ export class CodexAppServerClient {
         startResponse: result,
         started,
         completed,
+        tokenUsage,
         status: completed?.params?.turn?.status || result.turn?.status || null,
         agentMessages,
         message: agentMessages.at(-1) || null,
diff --git a/tests/live-codex-app-server-client.test.mjs b/tests/live-codex-app-server-client.test.mjs
index d9729674a..d0547ddc5 100644
--- a/tests/live-codex-app-server-client.test.mjs
+++ b/tests/live-codex-app-server-client.test.mjs
@@ -294,6 +294,16 @@ describe('dedicated Codex worker threads', () => {
             method: 'item/completed',
             params: { ...common, item: { type: 'agentMessage', text: 'final answer' } },
           });
+          process.send({
+            method: 'thread/tokenUsage/updated',
+            params: {
+              ...common,
+              tokenUsage: {
+                last: { inputTokens: 100, cachedInputTokens: 60, outputTokens: 20, reasoningOutputTokens: 4, totalTokens: 124 },
+                total: { inputTokens: 100, cachedInputTokens: 60, outputTokens: 20, reasoningOutputTokens: 4, totalTokens: 124 },
+              },
+            },
+          });
           process.send({
             method: 'turn/completed',
             params: { threadId: 'worker', turn: { id: 'turn-1', status: 'completed' } },
@@ -321,6 +331,7 @@ describe('dedicated Codex worker threads', () => {
     assert.deepEqual(deliveredMessages, ['first fragment', 'final answer']);
     assert.equal(result.message, 'final answer');
     assert.equal(result.firstAgentMessageMs >= 0, true);
+    assert.equal(result.tokenUsage.last.inputTokens, 100);
     assert.equal(result.started.method, 'turn/started');
     assert.equal(result.durationMs > 0, true);
     await client.close();