fix: tighten compaction memory candidate prompt

src/plugin.ts

@@ -108,45 +108,37 @@ function buildCompactionPrompt(privateContext: string): string {
     "",
     "## Relevant Files",
     "",
-    "At the end of the summary, extract durable memory entries for future sessions.",
+    "At the end of the summary, include a Memory candidates section only if there are durable facts that will change future behavior.",
     "",
-    "Memory quality bar:",
-    "Extract only durable facts that will change future behavior: user preferences, decisions with rationale, stable constraints, or hard-to-rediscover references.",
-    "",
-    "Do not extract trivia: transient IDs/revisions, task progress, test/file counts, bare status updates, local UI details, or facts easily rediscovered from the repo.",
-    "",
-    "When unsure, skip it. Fewer high-signal memories are better than many low-value ones.",
+    "CRITICAL MEMORY RULES:",
+    "- Most compactions should produce ZERO memories. Empty is correct when nothing durable changed.",
+    "- NO completion or progress statements: do not extract completed work, passing tests, commits, PR status, wave/task/phase completion, or current state.",
+    "- NO session-internal implementation notes: do not extract what files were edited, what bug was just fixed, what command just ran, or what the assistant reviewed.",
+    "- feedback ONLY means stable user preferences or user instructions, written in imperative/future-facing form.",
+    "- decision ONLY means rules that apply to FUTURE work, not decisions already implemented in this session.",
+    "- project/reference ONLY when the fact is stable across sessions and hard to rediscover from the repository.",
+    "- If unsure, skip it.",
     "",
     "Good memory examples:",
     "- [feedback] User prefers architecture reviews in Traditional Chinese.",
-    "- [decision] Use frozen workspace memory snapshots plus ephemeral hot state for cache stability.",
-    "- [project] The plugin should piggyback memory extraction on OpenCode compaction and avoid extra LLM calls.",
-    "- [reference] Workspace memory appears in frozen system[1]; pending memories appear in hot session state until compaction.",
+    "- [decision] Do not add semantic merge to memory dedupe.",
+    "- [project] This repository is an OpenCode plugin using local JSON stores.",
+    "- [reference] Workspace memory is rendered as frozen system[1]; pending memories remain in hot state until compaction.",
     "",
     "Bad memory examples to skip:",
-    "- 42 tests passed.",
     "- Wave 2 completed successfully.",
-    "- Modified 5 files.",
-    "- commit 4309cb8 contains the latest fix.",
-    "- TypeError: Cannot read properties of undefined.",
-    "- Currently running npm test.",
-    "",
-    "A memory should still be useful if a new agent opens this workspace next week.",
-    "",
-    "Only extract facts that are likely to stay true across sessions.",
-    "Do not extract session-specific progress like exact test counts, file counts, or phase numbers.",
-    "For progress, extract the stable goal or durable milestone, not the current number.",
-    "For references, extract configuration values that do not usually change between sessions.",
-    "For feedback, extract unresolved issues or user preferences that future sessions need to know.",
-    "Use exactly this candidate format, including square brackets around the type:",
+    "- 180 tests passed and CI is green.",
+    "- Implemented owner-aware cleanup in plugin.ts.",
+    "- The assistant reviewed code reviewer feedback and updated the plan.",
+    "- Commit a762e86 contains the owner scope fix.",
     "",
+    "Format when there ARE durable memories:",
     "Memory candidates:",
-    "- [feedback] content",
-    "- [project] content",
-    "- [decision] content",
-    "- [reference] content",
+    "- [feedback|decision|project|reference] future-facing durable fact",
     "",
-    "Do not write '- project content'; write '- [project] content'.",
+    "Format when there are NO durable memories:",
+    "Memory candidates:",
+    "(none)",
     "",
     "Background context, use this to inform the summary above.",
     "Do not output this context verbatim:",

tests/plugin.test.ts

@@ -297,9 +297,9 @@ test("compaction hook sets output.prompt with ---free template", async () => {
       "Prompt should include concrete positive memory examples");
     assert.equal(prompt!.includes("Bad memory examples to skip:"), true,
       "Prompt should include concrete negative memory examples");
-    assert.equal(prompt!.includes("42 tests passed"), true,
+    assert.equal(prompt!.includes("180 tests passed"), true,
       "Prompt should explicitly reject test-count snapshots");
-    assert.equal(prompt!.includes("commit 4309cb8"), true,
+    assert.equal(prompt!.includes("Commit a762e86"), true,
       "Prompt should explicitly reject commit-hash snapshots");
 
     // Should contain our context data (hot session state)
@@ -317,6 +317,27 @@ test("compaction hook sets output.prompt with ---free template", async () => {
   }
 });
 
+test("compaction prompt forbids progress and session-internal memory candidates", async () => {
+  const tmpDir = await mkdtemp(join(tmpdir(), "memory-plugin-prompt-"));
+  try {
+    const plugin = await MemoryV2Plugin({ directory: tmpDir, client: mockRootClient() });
+    const output = { prompt: "", context: [] as string[] };
+
+    await (plugin as Record<string, Function>)["experimental.session.compacting"](
+      { sessionID: "prompt-session", model: {} },
+      output,
+    );
+
+    assert.match(output.prompt, /CRITICAL MEMORY RULES/);
+    assert.match(output.prompt, /NO completion or progress statements/i);
+    assert.match(output.prompt, /NO session-internal implementation notes/i);
+    assert.match(output.prompt, /feedback ONLY/i);
+    assert.match(output.prompt, /Most compactions should produce ZERO memories/i);
+  } finally {
+    await rm(tmpDir, { recursive: true, force: true });
+  }
+});
+
 test("compaction hook merges existing output.context from other plugins", async () => {
   const tmpDir = await mkdtemp(join(tmpdir(), "memory-plugin-test-"));