feat: v0.6.1 — RETRACT operation for memory correction

New executor operation that marks memory facts as wrong with a visible
strikethrough tombstone. Fact IDs are preserved so readers know what was
retracted and why. Maps to IETF KU retract lifecycle state (#17).

- _retract_fact() in executor.py with [RETRACTED date — reason] annotation
- History file records retraction provenance
- Compaction + update prompts updated with RETRACT guidance
- 4 new tests (121 total)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Paul Kyle

docs/CHANGELOG.md

@@ -2,6 +2,22 @@
 
 All notable changes to Palinode. Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
+## [0.6.1] — 2026-04-12
+
+### Added
+
+**RETRACT operation**
+- New executor operation: `RETRACT` — marks a memory fact as wrong with a visible tombstone
+- Strikethrough formatting with `[RETRACTED date — reason]` annotation
+- Fact ID preserved (not deleted) so readers know what was retracted and why
+- History file records retraction provenance
+- Compaction and update prompts updated with RETRACT guidance
+- 4 new tests (121 total)
+
+Maps to IETF Knowledge Unit `retract` lifecycle state — see Paul-Kyle/palinode#17 for the interop discussion.
+
+---
+
 ## [0.6.0] — 2026-04-11
 
 ### Added

palinode/consolidation/executor.py

@@ -1,7 +1,7 @@
 """
 Compaction Executor
 
-Applies structured operations (KEEP/UPDATE/MERGE/SUPERSEDE/ARCHIVE)
+Applies structured operations (KEEP/UPDATE/MERGE/SUPERSEDE/ARCHIVE/RETRACT)
 to markdown memory files. The LLM decides what to do; the executor
 does it deterministically.
 
@@ -50,7 +50,7 @@ def apply_operations(file_path: str, operations: list[dict]) -> dict:
     with open(file_path) as f:
         content = f.read()
 
-    stats = {"kept": 0, "updated": 0, "merged": 0, "superseded": 0, "archived": 0}
+    stats = {"kept": 0, "updated": 0, "merged": 0, "superseded": 0, "archived": 0, "retracted": 0}
 
     for op in operations:
         if not isinstance(op, dict):
@@ -99,7 +99,16 @@ def apply_operations(file_path: str, operations: list[dict]) -> dict:
                 if archived_content != content:
                     content = archived_content
                     stats["archived"] += 1
-    
+
+        elif op_type == "RETRACT":
+            fact_id = op.get("id")
+            reason = op.get("reason", op.get("rationale", ""))
+            if fact_id:
+                retracted_content = _retract_fact(content, fact_id, reason, file_path)
+                if retracted_content != content:
+                    content = retracted_content
+                    stats["retracted"] += 1
+
     # Write back
     with open(file_path, 'w') as f:
         f.write(content)
@@ -191,6 +200,34 @@ def _archive_fact(content: str, fact_id: str, reason: str, file_path: str) -> st
     return content
 
 
+def _retract_fact(content: str, fact_id: str, reason: str, file_path: str) -> str:
+    """Mark a fact as retracted — explicitly wrong, not just stale.
+
+    Unlike ARCHIVE (removes silently), RETRACT leaves a visible tombstone
+    with strikethrough and reason so readers know the fact was wrong and why.
+    Aligns with IETF Knowledge Unit lifecycle (retract = known-incorrect).
+    """
+    now = _utc_now().strftime("%Y-%m-%d")
+    reason_text = f" — {reason}" if reason else ""
+
+    pattern = re.compile(
+        r'^([\s]*[-*]\s+)(.*?)(<!-- fact:' + re.escape(fact_id) + r' -->)',
+        re.MULTILINE
+    )
+
+    def replacer(m):
+        old_text = m.group(2).strip()
+        return f"{m.group(1)}~~{old_text}~~ [RETRACTED {now}{reason_text}] {m.group(3)}"
+
+    updated_content, substitutions = pattern.subn(replacer, content, count=1)
+    if substitutions == 0:
+        return content
+
+    _append_to_history(file_path, fact_id, f"Retracted ({now}): {reason}")
+
+    return updated_content
+
+
 def _append_to_history(file_path: str, fact_id: str, text: str) -> None:
     """Append an entry to the corresponding history file."""
     base = re.sub(r'-status\.md$', '', file_path)

palinode/core/config.py

@@ -285,8 +285,8 @@ class ContextConfig:
 class CompactionConfig:
     """Operations controls algorithms parameters logic models layouts mapping endpoints."""
     # Which operations are allowed
-    allowed_ops: list[str] = field(default_factory=lambda: 
-        ["KEEP", "UPDATE", "MERGE", "SUPERSEDE", "ARCHIVE"])
+    allowed_ops: list[str] = field(default_factory=lambda:
+        ["KEEP", "UPDATE", "MERGE", "SUPERSEDE", "ARCHIVE", "RETRACT"])
     # How aggressive: conservative = mostly KEEP, aggressive = more MERGE/ARCHIVE
     aggressiveness: str = "moderate"  # "conservative" | "moderate" | "aggressive"
     # Layer split heuristics

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "palinode"
-version = "0.6.0"
+version = "0.6.1"
 description = "Persistent memory that makes AI agents smarter over time."
 authors = [
   {name = "Paul Kyle"}

specs/prompts/compaction.md

@@ -16,15 +16,17 @@ Your job: decide what happens to each fact.
 | MERGE | Two+ facts say the same thing differently |
 | SUPERSEDE | A decision or fact has been explicitly changed |
 | ARCHIVE | Fact is stale (>60 days, never referenced), or no longer relevant |
+| RETRACT | Fact is **known to be wrong** — not just outdated, but incorrect. Leaves a visible tombstone. |
 
 ## Rules
 
 1. **Default to KEEP.** Most facts are fine. Only modify what's clearly outdated.
 2. **SUPERSEDE requires evidence.** Don't supersede unless recent notes show an explicit change.
 3. **MERGE only when redundant.** Two facts about different aspects of the same topic are NOT redundant.
 4. **ARCHIVE aggressively for status, conservatively for decisions.** Old milestones → archive. Old decisions → keep unless superseded.
-5. **Preserve specificity.** "Switched to BGE-M3 on March 20" is better than "changed embedding model."
-6. **Include rationale.** Every UPDATE/MERGE/SUPERSEDE/ARCHIVE must explain why.
+5. **RETRACT only when provably wrong.** A fact that was true but is now outdated → SUPERSEDE. A fact that was never true → RETRACT.
+6. **Preserve specificity.** "Switched to BGE-M3 on March 20" is better than "changed embedding model."
+7. **Include rationale.** Every UPDATE/MERGE/SUPERSEDE/ARCHIVE/RETRACT must explain why.
 
 ## Output Format
 
@@ -36,6 +38,7 @@ Return ONLY a JSON array:
   {"op": "UPDATE", "id": "fact_id", "new_text": "updated text", "rationale": "why"},
   {"op": "MERGE", "ids": ["id1", "id2"], "new_text": "merged text", "rationale": "why"},
   {"op": "SUPERSEDE", "id": "old_id", "new_text": "new text", "reason": "what changed"},
-  {"op": "ARCHIVE", "id": "fact_id", "rationale": "why archive"}
+  {"op": "ARCHIVE", "id": "fact_id", "rationale": "why archive"},
+  {"op": "RETRACT", "id": "fact_id", "reason": "why this fact is wrong"}
 ]
 ```

specs/prompts/update.md

@@ -20,7 +20,7 @@ Return a single JSON object:
 
 ```json
 {
-  "operation": "ADD | UPDATE | NOOP | SUPERSEDE | ARCHIVE",
+  "operation": "ADD | UPDATE | NOOP | SUPERSEDE | ARCHIVE | RETRACT",
   "target_id": "id-of-existing-item-to-modify",
   "updated_content": "the new content if UPDATE",
   "reason": "brief explanation of why this operation"
@@ -34,11 +34,13 @@ Return a single JSON object:
 3. **Existing says similar thing but candidate has new/updated info** → `UPDATE` (modify the existing file, update `last_updated`)
 4. **Existing directly contradicts candidate (same topic, opposite conclusion)** → `SUPERSEDE` (mark existing as superseded, add new)
 5. **Existing is clearly outdated/wrong** → `ARCHIVE` (mark as archived)
+6. **Existing is provably incorrect (was never true)** → `RETRACT` (leave visible tombstone with reason)
 
 ## Rules
 
 - Prefer `NOOP` when in doubt. Not creating a duplicate is always better than creating a bad memory.
 - Prefer `UPDATE` over `ADD` when the same entity already has a file. Append to the existing file rather than creating a new one.
-- Never hard-delete. `ARCHIVE` sets `status: archived`. The file stays for audit.
+- Never hard-delete. `ARCHIVE` sets `status: archived`. `RETRACT` leaves a strikethrough tombstone. Both stay for audit.
+- Use `RETRACT` only when you can prove the fact was wrong, not just outdated. Outdated → SUPERSEDE. Wrong → RETRACT.
 - When superseding a decision: the new decision gets `supersedes: [old_id]`, the old gets `superseded_by: new_id` and `status: superseded`.
 - Explain your reasoning in `reason` — this gets logged for the audit trail.

tests/test_executor.py

@@ -94,7 +94,7 @@ def test_missing_fields_are_skipped(temp_memory_file):
         {"op": "SUPERSEDE", "new_text": "Replacement"},
         {"op": "ARCHIVE"},
     ])
-    assert stats == {"kept": 0, "updated": 0, "merged": 0, "superseded": 0, "archived": 0}
+    assert stats == {"kept": 0, "updated": 0, "merged": 0, "superseded": 0, "archived": 0, "retracted": 0}
 
 def test_missing_fact_id_is_noop(temp_memory_file):
     stats = apply_operations(temp_memory_file, [{"op": "SUPERSEDE", "id": "missing", "new_text": "Replacement"}])
@@ -108,4 +108,59 @@ def test_empty_operations_leave_file_unchanged(temp_memory_file):
     with open(temp_memory_file) as f:
         after = f.read()
     assert before == after
-    assert stats == {"kept": 0, "updated": 0, "merged": 0, "superseded": 0, "archived": 0}
+    assert stats == {"kept": 0, "updated": 0, "merged": 0, "superseded": 0, "archived": 0, "retracted": 0}
+
+
+def test_retract_operation(temp_memory_file):
+    """RETRACT leaves a visible tombstone with strikethrough and reason."""
+    ops = [{"op": "RETRACT", "id": "f2", "reason": "This was never true"}]
+    stats = apply_operations(temp_memory_file, ops)
+    assert stats["retracted"] == 1
+    with open(temp_memory_file) as f:
+        content = f.read()
+    # Fact should be struck through with RETRACTED label
+    assert "~~[2024-01-02] An update occurred~~" in content
+    assert "[RETRACTED" in content
+    assert "This was never true" in content
+    # Fact ID should still be present (tombstone, not deleted)
+    assert "<!-- fact:f2 -->" in content
+
+    # Check history file
+    history_file = temp_memory_file.replace(".md", "-history.md")
+    assert os.path.exists(history_file)
+    with open(history_file) as f:
+        hist = f.read()
+    assert "Retracted" in hist
+    assert "This was never true" in hist
+    os.remove(history_file)
+
+
+def test_retract_without_reason(temp_memory_file):
+    """RETRACT should work even without a reason."""
+    ops = [{"op": "RETRACT", "id": "f1"}]
+    stats = apply_operations(temp_memory_file, ops)
+    assert stats["retracted"] == 1
+    with open(temp_memory_file) as f:
+        content = f.read()
+    assert "~~[2024-01-01] The project started today~~" in content
+    assert "[RETRACTED" in content
+    # No reason text after the date
+    assert "— " not in content.split("RETRACTED")[1].split("]")[0]
+
+    history_file = temp_memory_file.replace(".md", "-history.md")
+    if os.path.exists(history_file):
+        os.remove(history_file)
+
+
+def test_retract_missing_fact_is_noop(temp_memory_file):
+    """RETRACT on a non-existent fact ID should be a no-op."""
+    ops = [{"op": "RETRACT", "id": "nonexistent", "reason": "test"}]
+    stats = apply_operations(temp_memory_file, ops)
+    assert stats["retracted"] == 0
+
+
+def test_retract_missing_id_is_skipped(temp_memory_file):
+    """RETRACT without an ID field should be skipped."""
+    ops = [{"op": "RETRACT", "reason": "no id"}]
+    stats = apply_operations(temp_memory_file, ops)
+    assert stats["retracted"] == 0