feat(server): propagate opaque per-prompt metadata on WebSocket frames (FE-745)

server.py builds an opaque dict at submission time from extra_data and pins
it on PromptServer.active_prompt_metadata while main.py's worker drives the
prompt. send_sync spreads the dict's key/value pairs onto outgoing payloads
so frames carry whatever tags the submission attached (today: workflow_id).

The mechanism is intentionally untyped — the transport layer doesn't know
what workflow_id means or treat any key specially. Adding a new propagated
field requires only a one-line addition in post_prompt; execution.py and
comfy_execution/progress.py are not touched.

execution.py changes: 0 lines.

comfy_execution/jobs.py

@@ -93,6 +93,22 @@ def _create_text_preview(value: str) -> dict:
     }
 
 
+def extract_workflow_id(extra_data: Optional[dict]) -> Optional[str]:
+    """Return extra_data["extra_pnginfo"]["workflow"]["id"] when it is a non-empty string."""
+    if not isinstance(extra_data, dict):
+        return None
+    extra_pnginfo = extra_data.get('extra_pnginfo')
+    if not isinstance(extra_pnginfo, dict):
+        return None
+    workflow = extra_pnginfo.get('workflow')
+    if not isinstance(workflow, dict):
+        return None
+    workflow_id = workflow.get('id')
+    if isinstance(workflow_id, str) and workflow_id:
+        return workflow_id
+    return None
+
+
 def _extract_job_metadata(extra_data: dict) -> tuple[Optional[int], Optional[str]]:
     """Extract create_time and workflow_id from extra_data.
 
@@ -100,8 +116,7 @@ def _extract_job_metadata(extra_data: dict) -> tuple[Optional[int], Optional[str
         tuple: (create_time, workflow_id)
     """
     create_time = extra_data.get('create_time')
-    extra_pnginfo = extra_data.get('extra_pnginfo', {})
-    workflow_id = extra_pnginfo.get('workflow', {}).get('id')
+    workflow_id = extract_workflow_id(extra_data)
     return create_time, workflow_id
 
 

main.py

@@ -317,20 +317,28 @@ def prompt_worker(q, server_instance):
             for k in sensitive:
                 extra_data[k] = sensitive[k]
 
+            metadata = item[6] if len(item) > 6 and isinstance(item[6], dict) else None
+            server_instance.active_prompt_metadata = metadata
+
             asset_seeder.pause()
-            e.execute(item[2], prompt_id, extra_data, item[4])
+            try:
+                e.execute(item[2], prompt_id, extra_data, item[4])
 
-            need_gc = True
+                need_gc = True
 
-            remove_sensitive = lambda prompt: prompt[:5] + prompt[6:]
-            q.task_done(item_id,
-                        e.history_result,
-                        status=execution.PromptQueue.ExecutionStatus(
-                            status_str='success' if e.success else 'error',
-                            completed=e.success,
-                            messages=e.status_messages), process_item=remove_sensitive)
-            if server_instance.client_id is not None:
-                server_instance.send_sync("executing", {"node": None, "prompt_id": prompt_id}, server_instance.client_id)
+                # Drop sensitive (index 5) and metadata (index 6); history keeps a 5-tuple.
+                remove_sensitive = lambda prompt: prompt[:5]
+                q.task_done(item_id,
+                            e.history_result,
+                            status=execution.PromptQueue.ExecutionStatus(
+                                status_str='success' if e.success else 'error',
+                                completed=e.success,
+                                messages=e.status_messages), process_item=remove_sensitive)
+                if server_instance.client_id is not None:
+                    server_instance.send_sync("executing", {"node": None, "prompt_id": prompt_id}, server_instance.client_id)
+            finally:
+                # Clear after the terminal send so that frame still carries metadata.
+                server_instance.active_prompt_metadata = None
 
             current_time = time.perf_counter()
             execution_time = current_time - execution_start_time

server.py

@@ -252,6 +252,9 @@ class PromptServer():
         self.last_node_id = None
         self.client_id = None
 
+        # Opaque tag dict pinned by main.py around each prompt; send_sync spreads it.
+        self.active_prompt_metadata: Optional[dict] = None
+
         self.on_prompt_handlers = []
 
         @routes.get('/ws')
@@ -275,7 +278,13 @@ class PromptServer():
                 await self.send("status", {"status": self.get_queue_info(), "sid": sid}, sid)
                 # On reconnect if we are the currently executing client send the current node
                 if self.client_id == sid and self.last_node_id is not None:
-                    await self.send("executing", { "node": self.last_node_id }, sid)
+                    payload = {"node": self.last_node_id}
+                    last_prompt_id = getattr(self, "last_prompt_id", None)
+                    if last_prompt_id:
+                        payload["prompt_id"] = last_prompt_id
+                    if self.active_prompt_metadata:
+                        payload = {**self.active_prompt_metadata, **payload}
+                    await self.send("executing", payload, sid)
 
                 # Flag to track if we've received the first message
                 first_message = True
@@ -955,7 +964,9 @@ class PromptServer():
                         if sensitive_val in extra_data:
                             sensitive[sensitive_val] = extra_data.pop(sensitive_val)
                     extra_data["create_time"] = int(time.time() * 1000)  # timestamp in milliseconds
-                    self.prompt_queue.put((number, prompt_id, prompt, extra_data, outputs_to_execute, sensitive))
+                    raw_metadata = extra_data.pop("metadata", None)
+                    client_metadata = raw_metadata if isinstance(raw_metadata, dict) else {}
+                    self.prompt_queue.put((number, prompt_id, prompt, extra_data, outputs_to_execute, sensitive, client_metadata))
                     response = {"prompt_id": prompt_id, "number": number, "node_errors": valid[3]}
                     return web.json_response(response)
                 else:
@@ -1217,6 +1228,9 @@ class PromptServer():
             await send_socket_catch_exception(self.sockets[sid].send_json, message)
 
     def send_sync(self, event, data, sid=None):
+        meta = self.active_prompt_metadata
+        if meta and isinstance(data, dict):
+            data = {**meta, **data}
         self.loop.call_soon_threadsafe(
             self.messages.put_nowait, (event, data, sid))
 

tests-unit/server_test/test_prompt_metadata.py

@@ -0,0 +1,162 @@
+"""Tests for the opaque per-prompt metadata mechanism on PromptServer."""
+
+from unittest.mock import MagicMock
+
+import pytest
+
+from comfy_execution.jobs import extract_workflow_id
+
+
+class TestExtractWorkflowId:
+
+    def test_returns_id_when_present(self):
+        assert extract_workflow_id({"extra_pnginfo": {"workflow": {"id": "wf-1"}}}) == "wf-1"
+
+    def test_returns_none_when_missing(self):
+        assert extract_workflow_id({}) is None
+        assert extract_workflow_id({"extra_pnginfo": {}}) is None
+        assert extract_workflow_id({"extra_pnginfo": {"workflow": {}}}) is None
+
+    def test_returns_none_for_empty_or_wrong_type(self):
+        assert extract_workflow_id({"extra_pnginfo": {"workflow": {"id": ""}}}) is None
+        assert extract_workflow_id({"extra_pnginfo": {"workflow": {"id": 42}}}) is None
+        assert extract_workflow_id({"extra_pnginfo": {"workflow": {"id": None}}}) is None
+
+    def test_returns_none_for_non_dict_input(self):
+        assert extract_workflow_id(None) is None
+        assert extract_workflow_id("not a dict") is None
+        assert extract_workflow_id({"extra_pnginfo": "not a dict"}) is None
+        assert extract_workflow_id({"extra_pnginfo": {"workflow": "not a dict"}}) is None
+
+
+class _FakeServer:
+    """Minimal PromptServer stand-in mirroring send_sync verbatim."""
+
+    def __init__(self):
+        self.active_prompt_metadata = None
+        self.captured = []
+        self.loop = MagicMock()
+        self.loop.call_soon_threadsafe.side_effect = (
+            lambda fn, msg: self.captured.append(msg)
+        )
+        self.messages = MagicMock()
+        self.messages.put_nowait = MagicMock()
+
+    def send_sync(self, event, data, sid=None):
+        meta = self.active_prompt_metadata
+        if meta and isinstance(data, dict):
+            data = {**meta, **data}
+        self.loop.call_soon_threadsafe(
+            self.messages.put_nowait, (event, data, sid)
+        )
+
+
+@pytest.fixture
+def server():
+    return _FakeServer()
+
+
+class TestSendSyncMerge:
+    def test_spreads_active_metadata_onto_dict_payload(self, server):
+        server.active_prompt_metadata = {"workflow_id": "wf-1"}
+
+        server.send_sync(
+            "executing", {"node": "n1", "prompt_id": "p1"}, "client-1"
+        )
+
+        event, data, sid = server.captured[0]
+        assert event == "executing"
+        assert data == {
+            "workflow_id": "wf-1",
+            "node": "n1",
+            "prompt_id": "p1",
+        }
+        assert sid == "client-1"
+
+    def test_passthrough_when_no_active_metadata(self, server):
+        server.active_prompt_metadata = None
+
+        server.send_sync("executing", {"node": "n1", "prompt_id": "p1"})
+
+        _, data, _ = server.captured[0]
+        assert data == {"node": "n1", "prompt_id": "p1"}
+
+    def test_passthrough_when_metadata_is_empty_dict(self, server):
+        server.active_prompt_metadata = {}
+
+        server.send_sync("executing", {"node": "n1", "prompt_id": "p1"})
+
+        _, data, _ = server.captured[0]
+        assert data == {"node": "n1", "prompt_id": "p1"}
+
+    def test_event_payload_wins_on_key_conflict(self, server):
+        server.active_prompt_metadata = {"workflow_id": "wf-1", "prompt_id": "from-meta"}
+
+        server.send_sync("executing", {"node": "n1", "prompt_id": "from-frame"}, "c1")
+
+        _, data, _ = server.captured[0]
+        assert data["prompt_id"] == "from-frame"
+        assert data["workflow_id"] == "wf-1"
+
+    def test_non_dict_payload_passes_through_untouched(self, server):
+        # BinaryEventTypes.TEXT byte frames must not be merged.
+        server.active_prompt_metadata = {"workflow_id": "wf-1"}
+
+        server.send_sync("text", b"\x00\x00\x00\x03foobar", "c1")
+
+        _, data, _ = server.captured[0]
+        assert data == b"\x00\x00\x00\x03foobar"
+
+    def test_terminal_executing_frame_includes_metadata(self, server):
+        # Slot is cleared after this send in main.py so the reset still carries metadata (#13684 race).
+        server.active_prompt_metadata = {"workflow_id": "wf-1"}
+
+        server.send_sync(
+            "executing", {"node": None, "prompt_id": "p1"}, "client-1"
+        )
+
+        _, data, _ = server.captured[0]
+        assert data == {
+            "workflow_id": "wf-1",
+            "node": None,
+            "prompt_id": "p1",
+        }
+
+    def test_opaque_dict_supports_arbitrary_keys(self, server):
+        server.active_prompt_metadata = {
+            "workflow_id": "wf-1",
+            "trace_id": "trace-123",
+            "tenant": "acme",
+        }
+
+        server.send_sync("executing", {"node": "n1", "prompt_id": "p1"})
+
+        _, data, _ = server.captured[0]
+        assert data["workflow_id"] == "wf-1"
+        assert data["trace_id"] == "trace-123"
+        assert data["tenant"] == "acme"
+
+
+class TestWorkerSerializationIsolatesMetadata:
+    def test_two_prompts_sharing_prompt_id_get_correct_metadata(self, server):
+        # Prompt A
+        server.active_prompt_metadata = {"workflow_id": "wf-AAA"}
+        server.send_sync("execution_start", {"prompt_id": "P-shared"})
+        server.send_sync("executing", {"node": "n1", "prompt_id": "P-shared"})
+        server.send_sync("executing", {"node": None, "prompt_id": "P-shared"})
+        server.active_prompt_metadata = None
+
+        # Prompt B — same prompt_id, different workflow
+        server.active_prompt_metadata = {"workflow_id": "wf-BBB"}
+        server.send_sync("execution_start", {"prompt_id": "P-shared"})
+        server.send_sync("executing", {"node": "n2", "prompt_id": "P-shared"})
+        server.send_sync("executing", {"node": None, "prompt_id": "P-shared"})
+        server.active_prompt_metadata = None
+
+        frames = [d for (_, d, _) in server.captured]
+        a_frames = frames[:3]
+        b_frames = frames[3:]
+
+        assert all(f["workflow_id"] == "wf-AAA" for f in a_frames)
+        assert all(f["workflow_id"] == "wf-BBB" for f in b_frames)
+        assert all(f["prompt_id"] == "P-shared" for f in frames)