fix: tighten reply payload typing and safe text coercion

src/agents/pi-embedded-helpers/errors.ts

@@ -545,7 +545,28 @@ export function classifyFailoverReasonFromHttpStatus(
 }
 
 function coerceText(value: unknown): string {
-  return typeof value === "string" ? value : value == null ? "" : String(value);
+  if (typeof value === "string") {
+    return value;
+  }
+  if (value == null) {
+    return "";
+  }
+  if (
+    typeof value === "number" ||
+    typeof value === "boolean" ||
+    typeof value === "bigint" ||
+    typeof value === "symbol"
+  ) {
+    return String(value);
+  }
+  if (typeof value === "object") {
+    try {
+      return JSON.stringify(value) ?? "";
+    } catch {
+      return "";
+    }
+  }
+  return "";
 }
 
 function stripFinalTagsFromText(text: unknown): string {

src/agents/pi-embedded-subscribe.handlers.messages.ts

@@ -38,8 +38,30 @@ const stripTrailingDirective = (text: string): string => {
   return text.slice(0, openIndex);
 };
 
-const coerceText = (value: unknown): string =>
-  typeof value === "string" ? value : value == null ? "" : String(value);
+const coerceText = (value: unknown): string => {
+  if (typeof value === "string") {
+    return value;
+  }
+  if (value == null) {
+    return "";
+  }
+  if (
+    typeof value === "number" ||
+    typeof value === "boolean" ||
+    typeof value === "bigint" ||
+    typeof value === "symbol"
+  ) {
+    return String(value);
+  }
+  if (typeof value === "object") {
+    try {
+      return JSON.stringify(value) ?? "";
+    } catch {
+      return "";
+    }
+  }
+  return "";
+};
 
 function isTranscriptOnlyOpenClawAssistantMessage(message: AgentMessage | undefined): boolean {
   if (!message || message.role !== "assistant") {

src/plugin-sdk/approval-renderers.test.ts

@@ -145,7 +145,10 @@ describe("plugin-sdk/approval-renderers", () => {
       },
     },
   ])("$name", ({ payload, textExpected, interactiveExpected, channelDataExpected }) => {
-    textExpected(payload.text);
+    expect(payload.text).toBeDefined();
+    if (payload.text !== undefined) {
+      textExpected(payload.text);
+    }
     if (interactiveExpected) {
       expect(payload.interactive).toEqual(interactiveExpected);
     }

src/shared/chat-content.ts

@@ -8,8 +8,30 @@ export function extractTextFromChatContent(
 ): string | null {
   const normalizeText = opts?.normalizeText ?? ((text: string) => text.replace(/\s+/g, " ").trim());
   const joinWith = opts?.joinWith ?? " ";
-  const coerceText = (value: unknown): string =>
-    typeof value === "string" ? value : value == null ? "" : String(value);
+  const coerceText = (value: unknown): string => {
+    if (typeof value === "string") {
+      return value;
+    }
+    if (value == null) {
+      return "";
+    }
+    if (
+      typeof value === "number" ||
+      typeof value === "boolean" ||
+      typeof value === "bigint" ||
+      typeof value === "symbol"
+    ) {
+      return String(value);
+    }
+    if (typeof value === "object") {
+      try {
+        return JSON.stringify(value) ?? "";
+      } catch {
+        return "";
+      }
+    }
+    return "";
+  };
   const sanitize = (text: unknown): string => {
     const raw = coerceText(text);
     const sanitized = opts?.sanitizeText ? opts.sanitizeText(raw) : raw;