diff --git a/src/agents/pi-embedded-runner/run/payloads.errors.test.ts b/src/agents/pi-embedded-runner/run/payloads.errors.test.ts
index 4268e177dfc..764ee8330fd 100644
--- a/src/agents/pi-embedded-runner/run/payloads.errors.test.ts
+++ b/src/agents/pi-embedded-runner/run/payloads.errors.test.ts
@@ -101,6 +101,18 @@ describe("buildEmbeddedRunPayloads", () => {
     expect(payloads[0]?.isError).toBe(true);
   });
 
+  it("does not emit a synthetic billing error for successful turns with stale errorMessage", () => {
+    const payloads = buildPayloads({
+      lastAssistant: makeAssistant({
+        stopReason: "end_turn",
+        errorMessage: "insufficient credits for embedding model",
+        content: [{ type: "text", text: "Handle payment required errors in your API." }],
+      }),
+    });
+
+    expectSinglePayloadText(payloads, "Handle payment required errors in your API.");
+  });
+
   it("suppresses raw error JSON even when errorMessage is missing", () => {
     const payloads = buildPayloads({
       assistantTexts: [errorJsonPretty],
diff --git a/src/agents/pi-embedded-runner/run/payloads.ts b/src/agents/pi-embedded-runner/run/payloads.ts
index 16a78ec2e97..542bc44564b 100644
--- a/src/agents/pi-embedded-runner/run/payloads.ts
+++ b/src/agents/pi-embedded-runner/run/payloads.ts
@@ -128,16 +128,17 @@ export function buildEmbeddedRunPayloads(params: {
   const useMarkdown = params.toolResultFormat === "markdown";
   const suppressAssistantArtifacts = params.didSendDeterministicApprovalPrompt === true;
   const lastAssistantErrored = params.lastAssistant?.stopReason === "error";
-  const errorText = params.lastAssistant
-    ? suppressAssistantArtifacts
-      ? undefined
-      : formatAssistantErrorText(params.lastAssistant, {
+  const errorText =
+    params.lastAssistant && lastAssistantErrored
+      ? suppressAssistantArtifacts
+        ? undefined
+        : formatAssistantErrorText(params.lastAssistant, {
           cfg: params.config,
           sessionKey: params.sessionKey,
           provider: params.provider,
           model: params.model,
         })
-    : undefined;
+      : undefined;
   const rawErrorMessage = lastAssistantErrored
     ? params.lastAssistant?.errorMessage?.trim() || undefined
     : undefined;
diff --git a/src/agents/pi-embedded-utils.test.ts b/src/agents/pi-embedded-utils.test.ts
index 1cf03bbea41..5b5529e2da6 100644
--- a/src/agents/pi-embedded-utils.test.ts
+++ b/src/agents/pi-embedded-utils.test.ts
@@ -139,6 +139,7 @@ describe("extractAssistantText", () => {
     const msg = makeAssistantMessage({
       role: "assistant",
       errorMessage: "insufficient credits for embedding model",
+      stopReason: "end_turn",
       content: [{ type: "text", text: responseText }],
       timestamp: Date.now(),
     });
diff --git a/src/agents/tools/sessions.test.ts b/src/agents/tools/sessions.test.ts
index aa831027f68..ce849e45d07 100644
--- a/src/agents/tools/sessions.test.ts
+++ b/src/agents/tools/sessions.test.ts
@@ -199,6 +199,16 @@ describe("extractAssistantText", () => {
       "Firebase downgraded us to the free Spark plan. Check whether billing should be re-enabled.",
     );
   });
+
+  it("preserves successful turns with stale background errorMessage", () => {
+    const message = {
+      role: "assistant",
+      stopReason: "end_turn",
+      errorMessage: "insufficient credits for embedding model",
+      content: [{ type: "text", text: "Handle payment required errors in your API." }],
+    };
+    expect(extractAssistantText(message)).toBe("Handle payment required errors in your API.");
+  });
 });
 
 describe("resolveAnnounceTarget", () => {