feat: form-input library with schema parsing and endpoint

backend/app/flows/api.py

@@ -18,6 +18,7 @@ from app.settings import settings
 from app.auth.deps import get_optional_user, resolve_tenant
 
 from . import runner, store
+from . import input_schema as form_schema
 from .deploy import import_from_langflow
 from .sync import lfx_id_for, sync_from_directory
 from .langflow_client import (
@@ -46,6 +47,7 @@ from .schemas import (
     FlowImportRequest,
     FlowVersionCreate,
     FlowVersionRead,
+    InputSchemaRead,
     RunRead,
     RunRequest,
     SyncReport,
@@ -91,6 +93,7 @@ def _read_version(v) -> FlowVersionRead:
         deployed_at=v.deployed_at,
         author=v.author,
         created_at=v.created_at,
+        input_schema=v.input_schema,
     )
 
 
@@ -386,6 +389,28 @@ async def import_flow(
     )
 
 
+@flows_router.get("/{flow_id}/input-schema", response_model=InputSchemaRead)
+def get_input_schema(
+    flow_id: UUID,
+    session: Session = Depends(get_db),
+):
+    """Form schema of the latest deployed version (404 when none)."""
+    try:
+        version = store.get_latest_deployed_version(session, flow_id)
+    except (store.NotFoundError, store.InvalidError) as exc:
+        raise HTTPException(status_code=404, detail=str(exc)) from exc
+    cached = version.input_schema or form_schema.extract_form_schema(
+        version.langflow_json
+    )
+    return InputSchemaRead(
+        flow_id=flow_id,
+        version_no=version.version_no,
+        json_schema=cached.get("json_schema", {}),
+        ui_schema=cached.get("ui_schema", {}),
+        fallback=cached.get("fallback"),
+    )
+
+
 @flows_router.get("/runs/{run_id}", response_model=RunRead)
 def get_run(
     run_id: UUID,