diff --git a/tests/engineering/test_prompt_history.py b/tests/engineering/test_prompt_history.py
index 5d584372..5988853a 100644
--- a/tests/engineering/test_prompt_history.py
+++ b/tests/engineering/test_prompt_history.py
@@ -35,6 +35,33 @@ def test_projects_persisted_submission_and_execution_context_snapshot(self) -> N
             self.assertEqual(entry["producer_submission_contract_version"], "1.0")
             self.assertEqual(entry["execution_context_version"], "1.0")
             self.assertEqual(entry["execution_context"], {"context_version": "1.0", "mission_title": "Aurora"})
+
+    def test_imports_legacy_dismissal_evidence_once_into_canonical_storage(self) -> None:
+        with tempfile.TemporaryDirectory() as temporary:
+            root = Path(temporary)
+            record_prompt_execution(
+                root, run_id="inbox-legacy-dismissal", terminal_state="BLOCKED",
+                prompt_title="Previously dismissed execution", executed_at="2026-08-08T10:00:00Z",
+            )
+            audit = root / ".engineering" / "status" / "execution_dismissals.json"
+            audit.parent.mkdir(parents=True, exist_ok=True)
+            audit.write_text(
+                '[{"run_id":"inbox-legacy-dismissal","terminal_state":"BLOCKED",'
+                '"dismissed":true,"dismissed_at":"2026-08-08T10:01:00Z",'
+                '"dismissed_by":"dashboard_operator"}]',
+                encoding="utf-8",
+            )
+
+            imported = prompt_history(root)[0]
+            self.assertTrue(imported["dismissed"])
+            self.assertEqual(imported["handling_state"], "DISMISSED")
+            self.assertFalse(imported["can_retry"])
+
+            audit.unlink()
+            persisted = prompt_history(root)[0]
+            self.assertTrue(persisted["dismissed"])
+            self.assertEqual(persisted["dismissed_at"], "2026-08-08T10:01:00Z")
+
     def test_records_terminal_run_and_serves_only_its_local_report(self) -> None:
         with tempfile.TemporaryDirectory() as temporary:
             root = Path(temporary)
diff --git a/tools/engineering/ENGINEERING_INBOX_PROTOCOL.md b/tools/engineering/ENGINEERING_INBOX_PROTOCOL.md
index 759a4fde..f3942244 100644
--- a/tools/engineering/ENGINEERING_INBOX_PROTOCOL.md
+++ b/tools/engineering/ENGINEERING_INBOX_PROTOCOL.md
@@ -223,6 +223,7 @@ remain immutable. A dismissed terminal execution is read-only: Retry, Resume,
 Dismiss and every other lifecycle-mutating action are unavailable and rejected
 server-side, including requests from a stale client. Queue Recovery remains the
 separate explicit operation for dependent Inbox work. Dismiss never resumes
-that queue.
+that queue. Existing records from the former JSON audit are imported
+idempotently into SQLite; thereafter SQLite remains authoritative.
 
 Commands: `python3 -m tools.engineering.inbox_watcher once|run|status|install|uninstall|doctor|migrate-icloud-archives`.
diff --git a/tools/engineering/storage.py b/tools/engineering/storage.py
index e526fdfd..6a5b1ca3 100644
--- a/tools/engineering/storage.py
+++ b/tools/engineering/storage.py
@@ -20,6 +20,7 @@
 DATABASE_FILENAME = "engineering.db"
 ENGINEERING_STORAGE_SCHEMA_VERSION = 18
 JOURNAL_MODES = frozenset({"DELETE", "MEMORY"})
+LEGACY_DISMISSALS_PATH = Path(".engineering/status/execution_dismissals.json")
 
 
 class EngineeringStorageError(RuntimeError):
@@ -577,6 +578,52 @@ def _schema_v18(connection: sqlite3.Connection) -> None:
     )
 
 
+def _import_legacy_execution_dismissals(root: Path, connection: sqlite3.Connection) -> None:
+    """Copy valid legacy dismissal evidence into the canonical datastore.
+
+    The former JSON audit is retained as source evidence, but never consulted
+    by projections after its records have been copied to SQLite. Repeating the
+    import is safe: the canonical run key makes it idempotent and permits a
+    record whose history was backfilled later to be imported on a later open.
+    """
+    path = root / LEGACY_DISMISSALS_PATH
+    try:
+        payload = json.loads(path.read_text(encoding="utf-8"))
+    except FileNotFoundError:
+        return
+    except (OSError, json.JSONDecodeError):
+        return
+    if not isinstance(payload, list):
+        return
+    for record in payload:
+        if not isinstance(record, dict) or record.get("dismissed") is not True:
+            continue
+        run_id = record.get("run_id")
+        terminal_state = record.get("terminal_state")
+        dismissed_at = record.get("dismissed_at")
+        dismissed_by = record.get("dismissed_by")
+        if (
+            not isinstance(run_id, str)
+            or not re.fullmatch(r"[a-z0-9][a-z0-9-]{0,63}", run_id)
+            or terminal_state not in {"COMPLETE", "BLOCKED", "FAILED"}
+            or not isinstance(dismissed_at, str)
+            or not dismissed_at.strip()
+            or not isinstance(dismissed_by, str)
+            or not dismissed_by.strip()
+        ):
+            continue
+        history_exists = connection.execute(
+            "SELECT 1 FROM prompt_execution_history WHERE run_id=?", (run_id,)
+        ).fetchone()
+        if history_exists is None:
+            continue
+        connection.execute(
+            "INSERT OR IGNORE INTO execution_dismissals(run_id,terminal_state,handling_state,dismissed_at,dismissed_by) "
+            "VALUES(?,?,?,?,?)",
+            (run_id, terminal_state, "DISMISSED", dismissed_at.strip(), dismissed_by.strip()),
+        )
+
+
 MIGRATIONS: dict[int, Migration] = {
     1: _schema_v1,
     2: _schema_v2,
@@ -954,6 +1001,7 @@ def open_storage(
             connection.execute(
                 "INSERT INTO engineering_schema_migrations(version) VALUES(?)", (version,)
             )
+        _import_legacy_execution_dismissals(root, connection)
         connection.execute("COMMIT")
         path.chmod(0o600)
     except (OSError, sqlite3.DatabaseError, EngineeringStorageError) as error: