fix: avoid no reply prompt in message tool mode (#75779)

CHANGELOG.md

@@ -6,6 +6,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Agents/Codex: stop prompting message-tool-only source turns to finish with `NO_REPLY`, so quiet turns are represented by not calling the visible message tool instead of conflicting final-text instructions. Thanks @pashpashpash.
 - Gateway/config: report failed backup restores as failed in logs and config observe audit records instead of marking them valid. (#70515) Thanks @davidangularme.
 - Compaction: use the active session model fallback chain for implicit summarization failures without persisting fallback model selection, so Azure content-filter 400s can recover. Fixes #64960. (#74470) Thanks @jalehman and @OpenCodeEngineer.
 

src/agents/system-prompt.test.ts

@@ -803,6 +803,8 @@ describe("buildAgentSystemPrompt", () => {
     expect(prompt).toContain("use `message(action=send)` for visible channel output");
     expect(prompt).toContain("The target defaults to the current source channel");
     expect(prompt).toContain("final answers are private in this mode");
+    expect(prompt).not.toContain("## Silent Replies");
+    expect(prompt).not.toContain(SILENT_REPLY_TOKEN);
     expect(prompt).not.toContain(
       `respond with ONLY: ${SILENT_REPLY_TOKEN} (avoid duplicate replies)`,
     );

src/agents/system-prompt.ts

@@ -351,6 +351,9 @@ function buildMessagingSection(params: {
   const showGenericInlineButtonHint = params.runtimeChannel !== "slack";
   const hasSessionsSpawn = params.availableTools.has("sessions_spawn");
   const hasSubagents = params.availableTools.has("subagents");
+  const completionEventGuidance = messageToolOnly
+    ? "- Runtime-generated completion events may ask for a user update. Rewrite those in your normal assistant voice and send the update (do not forward raw internal metadata or default to a silent placeholder)."
+    : `- Runtime-generated completion events may ask for a user update. Rewrite those in your normal assistant voice and send the update (do not forward raw internal metadata or default to ${SILENT_REPLY_TOKEN}).`;
   const subagentOrchestrationGuidance = hasSessionsSpawn
     ? hasSubagents
       ? '- Sub-agent orchestration → use `sessions_spawn(...)` to start delegated work; omit `context` for isolated children, set `context:"fork"` only when the child needs the current transcript; use `subagents(action=list|steer|kill)` to manage already-spawned children.'
@@ -365,7 +368,7 @@ function buildMessagingSection(params: {
       : "- Reply in current session → automatically routes to the source channel (Signal, Telegram, etc.)",
     "- Cross-session messaging → use sessions_send(sessionKey, message)",
     subagentOrchestrationGuidance,
-    `- Runtime-generated completion events may ask for a user update. Rewrite those in your normal assistant voice and send the update (do not forward raw internal metadata or default to ${SILENT_REPLY_TOKEN}).`,
+    completionEventGuidance,
     "- Never use exec/curl for provider messaging; OpenClaw handles all routing internally.",
     params.availableTools.has("message")
       ? [
@@ -665,7 +668,10 @@ export function buildAgentSystemPrompt(params: {
   const messageChannelOptions = listDeliverableMessageChannels().join("|");
   const promptMode = params.promptMode ?? "full";
   const isMinimal = promptMode === "minimal" || promptMode === "none";
-  const silentReplyPromptMode = params.silentReplyPromptMode ?? "generic";
+  const sourceMessageToolOnly = params.sourceReplyDeliveryMode === "message_tool_only";
+  const silentReplyPromptMode = sourceMessageToolOnly
+    ? "none"
+    : (params.silentReplyPromptMode ?? "generic");
   const sandboxContainerWorkspace = params.sandboxInfo?.containerWorkspaceDir?.trim();
   const sanitizedWorkspaceDir = sanitizeForPromptLiteral(params.workspaceDir);
   const sanitizedSandboxContainerWorkspace = sandboxContainerWorkspace

src/auto-reply/reply/get-reply-run.ts

@@ -450,6 +450,7 @@ export async function runPreparedReply(
   const directChatContext = isDirectChat
     ? buildDirectChatContext({
         sessionCtx: promptSessionCtx,
+        sourceReplyDeliveryMode: opts?.sourceReplyDeliveryMode,
         silentReplyPolicy: silentReplySettings.policy,
         silentReplyRewrite: silentReplySettings.rewrite,
         silentToken: SILENT_REPLY_TOKEN,

src/auto-reply/reply/groups.test.ts

@@ -87,6 +87,19 @@ describe("group runtime loading", () => {
         silentToken: "NO_REPLY",
       }),
     ).toContain('reply with exactly "NO_REPLY"');
+
+    const toolOnlyContext = groups.buildDirectChatContext({
+      sessionCtx: { ChatType: "direct", Provider: "telegram" },
+      sourceReplyDeliveryMode: "message_tool_only",
+      silentReplyPolicy: "allow",
+      silentReplyRewrite: true,
+      silentToken: "NO_REPLY",
+    });
+    expect(toolOnlyContext).toContain("Normal final replies are private");
+    expect(toolOnlyContext).toContain("message tool with action=send");
+    expect(toolOnlyContext).toContain("do not call message(action=send)");
+    expect(toolOnlyContext).not.toContain("NO_REPLY");
+    expect(toolOnlyContext).not.toContain("Your replies are automatically sent");
   });
 
   it("gates group silent-token instructions on the resolved silent reply policy", async () => {

src/auto-reply/reply/groups.ts

@@ -283,13 +283,24 @@ export function buildGroupChatContext(params: {
 
 export function buildDirectChatContext(params: {
   sessionCtx: TemplateContext;
+  sourceReplyDeliveryMode?: SourceReplyDeliveryMode;
   silentReplyPolicy?: SilentReplyPolicy;
   silentReplyRewrite?: boolean;
   silentToken: string;
 }): string {
   const providerLabel = resolveProviderLabel(params.sessionCtx.Provider);
+  const messageToolOnly = params.sourceReplyDeliveryMode === "message_tool_only";
   const lines: string[] = [];
   lines.push(`You are in a ${providerLabel} direct conversation.`);
+  if (messageToolOnly) {
+    lines.push(
+      "Normal final replies are private and are not automatically sent to this conversation. To post visible output here, use the message tool with action=send; the target defaults to this conversation.",
+    );
+    lines.push(
+      "If no visible direct response is needed, do not call message(action=send). Your normal final answer stays private and will not be posted to the conversation.",
+    );
+    return lines.join(" ");
+  }
   lines.push("Your replies are automatically sent to this conversation.");
   if (params.silentReplyPolicy === "allow") {
     lines.push(