diff --git a/codex-rs/app-server-protocol/schema/json/v2/RawResponseCompletedNotification.json b/codex-rs/app-server-protocol/schema/json/v2/RawResponseCompletedNotification.json
index d0caf5f26b..77f9fbb057 100644
--- a/codex-rs/app-server-protocol/schema/json/v2/RawResponseCompletedNotification.json
+++ b/codex-rs/app-server-protocol/schema/json/v2/RawResponseCompletedNotification.json
@@ -3,6 +3,11 @@
   "definitions": {
     "TokenUsageBreakdown": {
       "properties": {
+        "cacheWriteInputTokens": {
+          "default": 0,
+          "format": "int64",
+          "type": "integer"
+        },
         "cachedInputTokens": {
           "format": "int64",
           "type": "integer"
diff --git a/codex-rs/app-server/tests/suite/v2/compaction.rs b/codex-rs/app-server/tests/suite/v2/compaction.rs
index d4e5891538..494c8b8944 100644
--- a/codex-rs/app-server/tests/suite/v2/compaction.rs
+++ b/codex-rs/app-server/tests/suite/v2/compaction.rs
@@ -345,6 +345,7 @@ async fn thread_compact_start_triggers_compaction_and_returns_empty_response() -
                 total_tokens: 200,
                 input_tokens: 200,
                 cached_input_tokens: 0,
+                cache_write_input_tokens: 0,
                 output_tokens: 0,
                 reasoning_output_tokens: 0,
             }),
diff --git a/codex-rs/app-server/tests/suite/v2/turn_start.rs b/codex-rs/app-server/tests/suite/v2/turn_start.rs
index 1938db2adf..bbf92c37c0 100644
--- a/codex-rs/app-server/tests/suite/v2/turn_start.rs
+++ b/codex-rs/app-server/tests/suite/v2/turn_start.rs
@@ -856,6 +856,7 @@ async fn turn_start_emits_raw_response_completed_with_upstream_usage() -> Result
                 total_tokens: 37,
                 input_tokens: 30,
                 cached_input_tokens: 11,
+                cache_write_input_tokens: 0,
                 output_tokens: 7,
                 reasoning_output_tokens: 3,
             }),