feat(memory): seed query_history with canonical NL-SQL pairs on index

wren/src/wren/memory/__init__.py

@@ -28,9 +28,20 @@ def __init__(self, path: str | Path | None = None):
 
         self._store = MemoryStore(path=path)
 
-    def index_manifest(self, manifest: dict, *, replace: bool = True) -> int:
-        """Index MDL schema into LanceDB.  Returns record count."""
-        return self._store.index_schema(manifest, replace=replace)
+    def index_manifest(
+        self,
+        manifest: dict,
+        *,
+        replace: bool = True,
+        seed_queries: bool = True,
+    ) -> dict:
+        """Index MDL schema into LanceDB.
+
+        Returns {"schema_items": int, "seed_queries": int}.
+        """
+        return self._store.index_schema(
+            manifest, replace=replace, seed_queries=seed_queries
+        )
 
     @staticmethod
     def describe_schema(manifest: dict) -> str:

wren/src/wren/memory/cli.py

@@ -125,12 +125,20 @@ def _print_results(results: list[dict], output: str) -> None:
 def index(
     mdl: MdlOpt = None,
     path: PathOpt = None,
+    no_seed: Annotated[
+        bool,
+        typer.Option("--no-seed", help="Skip generating seed NL-SQL examples."),
+    ] = False,
 ) -> None:
-    """Index MDL schema into LanceDB for semantic search."""
+    """Index MDL schema into LanceDB (and optionally seed example queries)."""
     manifest = _load_manifest(mdl)
     store = _get_store(path)
-    count = store.index_schema(manifest)
-    typer.echo(f"Indexed {count} schema items.")
+    result = store.index_schema(manifest, seed_queries=not no_seed)
+    typer.echo(
+        f"Indexed {result['schema_items']} schema items"
+        + (f", {result['seed_queries']} seed queries" if result["seed_queries"] else "")
+        + "."
+    )
 
 
 @memory_app.command()

wren/src/wren/memory/seed_queries.py

@@ -0,0 +1,104 @@
+"""Generate canonical NL-SQL seed pairs from an MDL manifest.
+
+Pure functions — no LanceDB or embedding dependency.
+"""
+
+from __future__ import annotations
+
+_NUMERIC_TYPES = {
+    "int",
+    "integer",
+    "bigint",
+    "smallint",
+    "tinyint",
+    "float",
+    "double",
+    "decimal",
+    "numeric",
+    "real",
+    "number",
+}
+
+SEED_TAG = "source:seed"
+
+
+def generate_seed_queries(manifest: dict) -> list[dict]:
+    """Return a list of {"nl": ..., "sql": ...} seed pairs."""
+    pairs: list[dict] = []
+
+    for model in manifest.get("models", []):
+        pairs.extend(_model_seeds(model))
+
+    for rel in manifest.get("relationships", []):
+        pair = _relationship_seed(rel)
+        if pair:
+            pairs.append(pair)
+
+    return pairs
+
+
+def _model_seeds(model: dict) -> list[dict]:
+    name = model["name"]
+    columns = model.get("columns", [])
+    pairs = []
+
+    # Template 1: basic listing
+    pairs.append(
+        {
+            "nl": f"List all {name}",
+            "sql": f"SELECT * FROM {name} LIMIT 100",
+        }
+    )
+
+    # Find first numeric column (non-calculated) and first groupable column
+    numeric_col = None
+    group_col = None
+    for col in columns:
+        col_type = (col.get("type") or "").split("(")[0].lower().strip()
+        is_calc = col.get("isCalculated", False)
+        is_pk = col["name"] == model.get("primaryKey")
+
+        if col_type in _NUMERIC_TYPES and not is_calc and numeric_col is None:
+            numeric_col = col["name"]
+        elif (
+            col_type not in _NUMERIC_TYPES
+            and not is_pk
+            and not is_calc
+            and group_col is None
+        ):
+            group_col = col["name"]
+
+    # Template 2a: simple aggregation
+    if numeric_col:
+        pairs.append(
+            {
+                "nl": f"Total {numeric_col} in {name}",
+                "sql": f"SELECT SUM({numeric_col}) FROM {name}",
+            }
+        )
+
+    # Template 2b: grouped aggregation
+    if numeric_col and group_col:
+        pairs.append(
+            {
+                "nl": f"{numeric_col} by {group_col} in {name}",
+                "sql": f"SELECT {group_col}, SUM({numeric_col}) FROM {name} GROUP BY 1",
+            }
+        )
+
+    return pairs
+
+
+def _relationship_seed(rel: dict) -> dict | None:
+    models = rel.get("models", [])
+    condition = rel.get("condition", "")
+
+    if len(models) < 2 or not condition:
+        return None
+
+    left, right = models[0], models[1]
+
+    return {
+        "nl": f"{left} with {right} details",
+        "sql": f"SELECT * FROM {left} JOIN {right} ON {condition} LIMIT 100",
+    }

wren/src/wren/memory/store.py

@@ -100,45 +100,86 @@ def _query_table_schema(self) -> pa.Schema:
 
     # ── Schema indexing ───────────────────────────────────────────────────
 
-    def index_schema(self, manifest: dict, *, replace: bool = True) -> int:
+    def index_schema(
+        self,
+        manifest: dict,
+        *,
+        replace: bool = True,
+        seed_queries: bool = True,
+    ) -> dict:
         """Extract schema items from *manifest*, embed, and store.
 
-        Returns the number of records indexed.
+        If *seed_queries* is True, also generates canonical NL-SQL pairs
+        and inserts them into query_history (tagged 'source:seed').
+        Old seed entries are replaced; user-confirmed entries are preserved.
+
+        Returns {"schema_items": int, "seed_queries": int}.
         """
         items = extract_schema_items(manifest)
         table_exists = _SCHEMA_TABLE in _table_names(self._db)
 
         if not items:
             if replace and table_exists:
                 self._db.drop_table(_SCHEMA_TABLE)
-            return 0
-
-        texts = [item["text"] for item in items]
-        vectors = self._embed_fn.compute_source_embeddings(texts)
+            schema_count = 0
+        else:
+            texts = [item["text"] for item in items]
+            vectors = self._embed_fn.compute_source_embeddings(texts)
 
-        for item, vec in zip(items, vectors):
-            item["vector"] = vec
+            for item, vec in zip(items, vectors):
+                item["vector"] = vec
 
-        if replace:
-            if table_exists:
-                self._db.drop_table(_SCHEMA_TABLE)
-            self._db.create_table(
-                _SCHEMA_TABLE,
-                items,
-                schema=self._schema_table_schema(),
-            )
-        else:
-            if table_exists:
-                tbl = self._db.open_table(_SCHEMA_TABLE)
-                tbl.add(items)
-            else:
+            if replace:
+                if table_exists:
+                    self._db.drop_table(_SCHEMA_TABLE)
                 self._db.create_table(
                     _SCHEMA_TABLE,
                     items,
                     schema=self._schema_table_schema(),
                 )
+            else:
+                if table_exists:
+                    tbl = self._db.open_table(_SCHEMA_TABLE)
+                    tbl.add(items)
+                else:
+                    self._db.create_table(
+                        _SCHEMA_TABLE,
+                        items,
+                        schema=self._schema_table_schema(),
+                    )
+            schema_count = len(items)
+
+        seed_count = 0
+        if seed_queries:
+            seed_count = self._upsert_seed_queries(manifest)
+
+        return {"schema_items": schema_count, "seed_queries": seed_count}
+
+    def _upsert_seed_queries(self, manifest: dict) -> int:
+        """Replace seed query entries, preserving user-confirmed ones."""
+        from wren.memory.seed_queries import (  # noqa: PLC0415
+            SEED_TAG,
+            generate_seed_queries,
+        )
+
+        pairs = generate_seed_queries(manifest)
+        if not pairs:
+            return 0
+
+        # Remove old seeds (tagged 'source:seed') but keep user entries
+        if _QUERY_TABLE in _table_names(self._db):
+            table = self._db.open_table(_QUERY_TABLE)
+            table.delete(f"tags = '{SEED_TAG}'")
+
+        # Insert new seeds via the existing store_query() method
+        for pair in pairs:
+            self.store_query(
+                nl_query=pair["nl"],
+                sql_query=pair["sql"],
+                tags=SEED_TAG,
+            )
 
-        return len(items)
+        return len(pairs)
 
     def schema_is_current(self, manifest: dict) -> bool:
         """Check whether the indexed schema matches *manifest*.

wren/tests/unit/test_memory.py

@@ -236,13 +236,13 @@ def memory_store(tmp_path):
 @pytest.mark.unit
 class TestMemoryStore:
     def test_index_and_context(self, memory_store):
-        count = memory_store.index_schema(_MANIFEST)
-        assert count == 10
+        result = memory_store.index_schema(_MANIFEST)
+        assert result["schema_items"] == 10
 
         # Small schema → full strategy
-        result = memory_store.get_context(_MANIFEST, "customer order price")
-        assert result["strategy"] == "full"
-        assert "### Model: orders" in result["schema"]
+        ctx = memory_store.get_context(_MANIFEST, "customer order price")
+        assert ctx["strategy"] == "full"
+        assert "### Model: orders" in ctx["schema"]
 
     def test_context_search_strategy(self, memory_store):
         memory_store.index_schema(_MANIFEST)
@@ -316,8 +316,8 @@ def test_describe_schema_static(self, memory_store):
 
     def test_index_replace(self, memory_store):
         memory_store.index_schema(_MANIFEST)
-        count = memory_store.index_schema(_MANIFEST, replace=True)
-        assert count == 10
+        result = memory_store.index_schema(_MANIFEST, replace=True)
+        assert result["schema_items"] == 10
         info = memory_store.status()
         assert info["tables"]["schema_items"] == 10
 
@@ -339,8 +339,8 @@ def wren_memory(tmp_path):
 @pytest.mark.unit
 class TestWrenMemory:
     def test_full_lifecycle(self, wren_memory):
-        count = wren_memory.index_manifest(_MANIFEST)
-        assert count == 10
+        result = wren_memory.index_manifest(_MANIFEST)
+        assert result["schema_items"] == 10
 
         ctx = wren_memory.get_context(_MANIFEST, "customer")
         assert ctx["strategy"] == "full"
@@ -357,7 +357,83 @@ def test_full_lifecycle(self, wren_memory):
 
         status = wren_memory.status()
         assert status["tables"]["schema_items"] == 10
-        assert status["tables"]["query_history"] == 1
+        # query_history has 1 user query + seed queries
+        assert status["tables"]["query_history"] >= 1
 
         wren_memory.reset()
         assert wren_memory.status()["tables"] == {}
+
+
+# ── MemoryStore seed lifecycle tests ─────────────────────────────────────
+
+
+@pytest.mark.unit
+class TestMemoryStoreSeedLifecycle:
+    def test_index_schema_seeds_query_history(self, memory_store):
+        from wren.memory.seed_queries import SEED_TAG  # noqa: PLC0415
+
+        result = memory_store.index_schema(_MANIFEST, seed_queries=True)
+        assert result["seed_queries"] > 0
+
+        import pandas as pd  # noqa: PLC0415
+
+        table = memory_store._db.open_table("query_history")
+        df = table.to_pandas()
+        seeds = df[df["tags"] == SEED_TAG]
+        assert len(seeds) == result["seed_queries"]
+
+    def test_index_schema_no_seed_flag(self, memory_store):
+        result = memory_store.index_schema(_MANIFEST, seed_queries=False)
+        assert result["seed_queries"] == 0
+        from wren.memory.store import _table_names  # noqa: PLC0415
+
+        assert "query_history" not in _table_names(memory_store._db)
+
+    def test_reindex_replaces_seeds_preserves_user_queries(self, memory_store):
+        from wren.memory.seed_queries import SEED_TAG  # noqa: PLC0415
+
+        # Index once to create seeds
+        first = memory_store.index_schema(_MANIFEST, seed_queries=True)
+        seed_count = first["seed_queries"]
+        assert seed_count > 0
+
+        # Store a user-confirmed query (no seed tag)
+        memory_store.store_query(
+            nl_query="show me the most expensive orders",
+            sql_query="SELECT * FROM orders ORDER BY o_totalprice DESC LIMIT 10",
+        )
+
+        import pandas as pd  # noqa: PLC0415
+
+        table = memory_store._db.open_table("query_history")
+        total_before = table.count_rows()
+        assert total_before == seed_count + 1
+
+        # Re-index — seeds should be replaced, user entry preserved
+        second = memory_store.index_schema(_MANIFEST, seed_queries=True)
+        assert second["seed_queries"] == seed_count
+
+        table = memory_store._db.open_table("query_history")
+        df = table.to_pandas()
+        seeds = df[df["tags"] == SEED_TAG]
+        user_rows = df[df["tags"] != SEED_TAG]
+        assert len(seeds) == seed_count
+        assert len(user_rows) == 1
+        assert "expensive orders" in user_rows.iloc[0]["nl_query"]
+
+    def test_recall_returns_seed_entries(self, memory_store):
+        from wren.memory.seed_queries import SEED_TAG  # noqa: PLC0415
+
+        memory_store.index_schema(_MANIFEST, seed_queries=True)
+        results = memory_store.recall_queries("list all orders", limit=5)
+        assert len(results) > 0
+        # At least one result should be a seed entry
+        tags = [r.get("tags", "") for r in results]
+        assert any(t == SEED_TAG for t in tags)
+
+    def test_index_schema_returns_dict(self, memory_store):
+        result = memory_store.index_schema(_MANIFEST)
+        assert isinstance(result, dict)
+        assert "schema_items" in result
+        assert "seed_queries" in result
+        assert result["schema_items"] == 10