fix(compaction): share real-conversation predicate and ignore tool-call-only assistant blocks

src/agents/compaction-real-conversation.ts

@@ -0,0 +1,77 @@
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
+import { stripHeartbeatToken } from "../auto-reply/heartbeat.js";
+import { isSilentReplyText } from "../auto-reply/tokens.js";
+
+export const TOOL_RESULT_REAL_CONVERSATION_LOOKBACK = 20;
+const TOOL_ONLY_BLOCK_TYPES = new Set(["toolCall", "toolUse", "functionCall"]);
+
+function hasMeaningfulText(text: string): boolean {
+  const trimmed = text.trim();
+  if (!trimmed) {
+    return false;
+  }
+  if (isSilentReplyText(trimmed)) {
+    return false;
+  }
+  const heartbeat = stripHeartbeatToken(trimmed, { mode: "message" });
+  if (heartbeat.didStrip) {
+    return heartbeat.text.trim().length > 0;
+  }
+  return true;
+}
+
+export function hasMeaningfulConversationContent(message: AgentMessage): boolean {
+  const content = (message as { content?: unknown }).content;
+  if (typeof content === "string") {
+    return hasMeaningfulText(content);
+  }
+  if (!Array.isArray(content)) {
+    return false;
+  }
+  let sawMeaningfulNonTextBlock = false;
+  for (const block of content) {
+    if (!block || typeof block !== "object") {
+      continue;
+    }
+    const type = (block as { type?: unknown }).type;
+    if (type !== "text") {
+      if (typeof type === "string" && TOOL_ONLY_BLOCK_TYPES.has(type)) {
+        continue;
+      }
+      sawMeaningfulNonTextBlock = true;
+      continue;
+    }
+    const text = (block as { text?: unknown }).text;
+    if (typeof text !== "string") {
+      continue;
+    }
+    if (hasMeaningfulText(text)) {
+      return true;
+    }
+  }
+  return sawMeaningfulNonTextBlock;
+}
+
+export function isRealConversationMessage(
+  message: AgentMessage,
+  messages: AgentMessage[],
+  index: number,
+): boolean {
+  if (message.role === "user" || message.role === "assistant") {
+    return hasMeaningfulConversationContent(message);
+  }
+  if (message.role !== "toolResult") {
+    return false;
+  }
+  const start = Math.max(0, index - TOOL_RESULT_REAL_CONVERSATION_LOOKBACK);
+  for (let i = index - 1; i >= start; i -= 1) {
+    const candidate = messages[i];
+    if (!candidate || candidate.role !== "user") {
+      continue;
+    }
+    if (hasMeaningfulConversationContent(candidate)) {
+      return true;
+    }
+  }
+  return false;
+}

src/agents/pi-embedded-runner/compact.hooks.test.ts

@@ -1,3 +1,4 @@
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { getApiProvider, unregisterApiProviders } from "@mariozechner/pi-ai";
 import { beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
 import { getCustomApiRegistrySourceId } from "../custom-api-registry.js";
@@ -23,6 +24,7 @@ import {
 
 let compactEmbeddedPiSessionDirect: typeof import("./compact.js").compactEmbeddedPiSessionDirect;
 let compactEmbeddedPiSession: typeof import("./compact.js").compactEmbeddedPiSession;
+let compactTesting: typeof import("./compact.js").__testing;
 let onSessionTranscriptUpdate: typeof import("../../sessions/transcript-events.js").onSessionTranscriptUpdate;
 
 const TEST_SESSION_ID = "session-1";
@@ -109,6 +111,7 @@ beforeAll(async () => {
   const loaded = await loadCompactHooksHarness();
   compactEmbeddedPiSessionDirect = loaded.compactEmbeddedPiSessionDirect;
   compactEmbeddedPiSession = loaded.compactEmbeddedPiSession;
+  compactTesting = loaded.__testing;
   onSessionTranscriptUpdate = loaded.onSessionTranscriptUpdate;
 });
 
@@ -509,7 +512,7 @@ describe("compactEmbeddedPiSessionDirect hooks", () => {
     sessionMessages.splice(
       0,
       sessionMessages.length,
-      { role: "user", content: "HEARTBEAT_OK", timestamp: 1 },
+      { role: "user", content: "<b>HEARTBEAT_OK</b>", timestamp: 1 },
       {
         role: "toolResult",
         toolCallId: "t1",
@@ -536,31 +539,50 @@ describe("compactEmbeddedPiSessionDirect hooks", () => {
     expect(sessionCompactImpl).not.toHaveBeenCalled();
   });
 
-  it("keeps compaction enabled when tool output follows a meaningful user request", async () => {
-    sessionMessages.splice(
-      0,
-      sessionMessages.length,
-      { role: "user", content: "please inspect the failing PR", timestamp: 1 },
+  it("does not treat assistant-only tool-call blocks as meaningful conversation", () => {
+    expect(
+      compactTesting.hasMeaningfulConversationContent({
+        role: "assistant",
+        content: [{ type: "toolCall", id: "call_1", name: "exec", arguments: {} }],
+      } as AgentMessage),
+    ).toBe(false);
+  });
+
+  it("counts tool output as real only when a meaningful user ask exists in the lookback window", () => {
+    const heartbeatToolResultWindow = [
+      { role: "user", content: "<b>HEARTBEAT_OK</b>" },
       {
         role: "toolResult",
         toolCallId: "t1",
         toolName: "exec",
         content: [{ type: "text", text: "checked" }],
-        isError: false,
-        timestamp: 2,
       },
-    );
+    ] as AgentMessage[];
+    expect(
+      compactTesting.hasRealConversationContent(
+        heartbeatToolResultWindow[1],
+        heartbeatToolResultWindow,
+        1,
+      ),
+    ).toBe(false);
 
-    const result = await compactEmbeddedPiSessionDirect({
-      sessionId: "session-1",
-      sessionKey: "agent:main:session-1",
-      sessionFile: "/tmp/session.jsonl",
-      workspaceDir: "/tmp",
-      customInstructions: "focus on decisions",
-    });
-
-    expect(result.ok).toBe(true);
-    expect(sessionCompactImpl).toHaveBeenCalled();
+    const realAskToolResultWindow = [
+      { role: "assistant", content: "NO_REPLY" },
+      { role: "user", content: "please inspect the failing PR" },
+      {
+        role: "toolResult",
+        toolCallId: "t2",
+        toolName: "exec",
+        content: [{ type: "text", text: "checked" }],
+      },
+    ] as AgentMessage[];
+    expect(
+      compactTesting.hasRealConversationContent(
+        realAskToolResultWindow[2],
+        realAskToolResultWindow,
+        2,
+      ),
+    ).toBe(true);
   });
 
   it("registers the Ollama api provider before compaction", async () => {

src/agents/pi-embedded-runner/compact.ts

@@ -38,6 +38,10 @@ import { resolveSessionAgentId, resolveSessionAgentIds } from "../agent-scope.js
 import type { ExecElevatedDefaults } from "../bash-tools.js";
 import { makeBootstrapWarn, resolveBootstrapContextForRun } from "../bootstrap-files.js";
 import { listChannelSupportedActions, resolveChannelMessageToolHints } from "../channel-tools.js";
+import {
+  hasMeaningfulConversationContent,
+  isRealConversationMessage,
+} from "../compaction-real-conversation.js";
 import { resolveContextWindowInfo } from "../context-window-guard.js";
 import { ensureCustomApiRegistered } from "../custom-api-registry.js";
 import { formatUserTime, resolveUserTimeFormat, resolveUserTimezone } from "../date-time.js";
@@ -167,68 +171,12 @@ type CompactionMessageMetrics = {
   contributors: Array<{ role: string; chars: number; tool?: string }>;
 };
 
-const BOILERPLATE_REPLY_TEXT = new Set(["HEARTBEAT_OK", "NO_REPLY"]);
-const TOOL_RESULT_REAL_CONVERSATION_LOOKBACK = 20;
-
-function hasMeaningfulConversationContent(msg: AgentMessage): boolean {
-  const content = (msg as { content?: unknown }).content;
-  if (typeof content === "string") {
-    const trimmed = content.trim();
-    if (!trimmed) {
-      return false;
-    }
-    return !BOILERPLATE_REPLY_TEXT.has(trimmed);
-  }
-  if (!Array.isArray(content)) {
-    return false;
-  }
-  let sawNonTextBlock = false;
-  for (const block of content) {
-    if (!block || typeof block !== "object") {
-      continue;
-    }
-    const type = (block as { type?: unknown }).type;
-    if (type !== "text") {
-      sawNonTextBlock = true;
-      continue;
-    }
-    const text = (block as { text?: unknown }).text;
-    if (typeof text !== "string") {
-      continue;
-    }
-    const trimmed = text.trim();
-    if (!trimmed) {
-      continue;
-    }
-    if (!BOILERPLATE_REPLY_TEXT.has(trimmed)) {
-      return true;
-    }
-  }
-  return sawNonTextBlock;
-}
-
 function hasRealConversationContent(
   msg: AgentMessage,
   messages: AgentMessage[],
   index: number,
 ): boolean {
-  if (msg.role === "user" || msg.role === "assistant") {
-    return hasMeaningfulConversationContent(msg);
-  }
-  if (msg.role !== "toolResult") {
-    return false;
-  }
-  const start = Math.max(0, index - TOOL_RESULT_REAL_CONVERSATION_LOOKBACK);
-  for (let i = index - 1; i >= start; i -= 1) {
-    const candidate = messages[i];
-    if (!candidate || candidate.role !== "user") {
-      continue;
-    }
-    if (hasMeaningfulConversationContent(candidate)) {
-      return true;
-    }
-  }
-  return false;
+  return isRealConversationMessage(msg, messages, index);
 }
 
 function createCompactionDiagId(): string {
@@ -1314,3 +1262,8 @@ export async function compactEmbeddedPiSession(
     }),
   );
 }
+
+export const __testing = {
+  hasRealConversationContent,
+  hasMeaningfulConversationContent,
+} as const;

src/agents/pi-extensions/compaction-safeguard.test.ts

@@ -1684,7 +1684,7 @@ describe("compaction-safeguard double-compaction guard", () => {
           content: [{ type: "text", text: "done" }],
         } as AgentMessage,
         [
-          { role: "user", content: "HEARTBEAT_OK" } as AgentMessage,
+          { role: "user", content: "<b>HEARTBEAT_OK</b>" } as AgentMessage,
           {
             role: "toolResult",
             toolCallId: "t1",
@@ -1717,6 +1717,24 @@ describe("compaction-safeguard double-compaction guard", () => {
       ),
     ).toBe(true);
   });
+
+  it("does not treat assistant-only tool calls as meaningful conversation", () => {
+    expect(
+      __testing.hasMeaningfulConversationContent({
+        role: "assistant",
+        content: [{ type: "toolCall", id: "call_1", name: "exec", arguments: {} }],
+      } as AgentMessage),
+    ).toBe(false);
+  });
+
+  it("treats markup-wrapped heartbeat tokens as boilerplate", () => {
+    expect(
+      __testing.hasMeaningfulConversationContent({
+        role: "assistant",
+        content: "<b>HEARTBEAT_OK</b>",
+      } as AgentMessage),
+    ).toBe(false);
+  });
 });
 
 async function expectWorkspaceSummaryEmptyForAgentsAlias(

src/agents/pi-extensions/compaction-safeguard.ts

@@ -6,6 +6,10 @@ import { extractSections } from "../../auto-reply/reply/post-compaction-context.
 import { openBoundaryFile } from "../../infra/boundary-file-read.js";
 import { createSubsystemLogger } from "../../logging/subsystem.js";
 import { extractKeywords, isQueryStopWordToken } from "../../memory/query-expansion.js";
+import {
+  hasMeaningfulConversationContent,
+  isRealConversationMessage,
+} from "../compaction-real-conversation.js";
 import {
   BASE_CHUNK_RATIO,
   type CompactionSummarizationInstructions,
@@ -179,70 +183,6 @@ function formatToolFailuresSection(failures: ToolFailure[]): string {
   return `\n\n## Tool Failures\n${lines.join("\n")}`;
 }
 
-const BOILERPLATE_REPLY_TEXT = new Set(["HEARTBEAT_OK", "NO_REPLY"]);
-const TOOL_RESULT_REAL_CONVERSATION_LOOKBACK = 20;
-
-function hasMeaningfulConversationContent(message: AgentMessage): boolean {
-  const content = (message as { content?: unknown }).content;
-  if (typeof content === "string") {
-    const trimmed = content.trim();
-    if (!trimmed) {
-      return false;
-    }
-    return !BOILERPLATE_REPLY_TEXT.has(trimmed);
-  }
-  if (!Array.isArray(content)) {
-    return false;
-  }
-  let sawNonTextBlock = false;
-  for (const block of content) {
-    if (!block || typeof block !== "object") {
-      continue;
-    }
-    const type = (block as { type?: unknown }).type;
-    if (type !== "text") {
-      sawNonTextBlock = true;
-      continue;
-    }
-    const text = (block as { text?: unknown }).text;
-    if (typeof text !== "string") {
-      continue;
-    }
-    const trimmed = text.trim();
-    if (!trimmed) {
-      continue;
-    }
-    if (!BOILERPLATE_REPLY_TEXT.has(trimmed)) {
-      return true;
-    }
-  }
-  return sawNonTextBlock;
-}
-
-function isRealConversationMessage(
-  message: AgentMessage,
-  messages: AgentMessage[],
-  index: number,
-): boolean {
-  if (message.role === "user" || message.role === "assistant") {
-    return hasMeaningfulConversationContent(message);
-  }
-  if (message.role !== "toolResult") {
-    return false;
-  }
-  const start = Math.max(0, index - TOOL_RESULT_REAL_CONVERSATION_LOOKBACK);
-  for (let i = index - 1; i >= start; i -= 1) {
-    const candidate = messages[i];
-    if (!candidate || candidate.role !== "user") {
-      continue;
-    }
-    if (hasMeaningfulConversationContent(candidate)) {
-      return true;
-    }
-  }
-  return false;
-}
-
 function computeFileLists(fileOps: FileOperations): {
   readFiles: string[];
   modifiedFiles: string[];