[eric] workflows: a stalled label lane can no longer hold a step edit open, which is what bricked the editor

backend/apps/workflows/workflows.py

@@ -448,6 +448,10 @@ async def p_generate_metadata_for_steps(
 
 _PLACEHOLDER_TITLES = {"", "New workflow", "Untitled workflow", "Scheduled workflow"}
 
+# Ceiling on the cosmetic label/title aux call, which runs INSIDE the step-edit request. The SDK's own
+# stream timeout is minutes, long enough that a stalled lane reads as the editor being dead.
+AUX_LABEL_TIMEOUT_S = 20.0
+
 
 def p_fallback_title_for_steps(steps: list[WorkflowStep]) -> str:
     """Deterministic title derived from the steps, used when the aux model is
@@ -510,9 +514,16 @@ async def p_relabel_steps(
     if not regen_idxs and not need_autoname:
         return
     try:
-        title, description, labels = await p_generate_metadata_for_steps(steps, model)
+        title, description, labels = await asyncio.wait_for(
+            p_generate_metadata_for_steps(steps, model), timeout=AUX_LABEL_TIMEOUT_S,
+        )
     except Exception:
-        return
+        # Every caller awaits this INSIDE the PATCH request, so an aux lane that stalls used to hold
+        # the whole edit open and the editor just span: an agent editing a step bricked the app. This
+        # is decoration with deterministic fallbacks right below, so failing here must cost a nicer
+        # label, never the edit itself.
+        logger.info("workflow meta gen unavailable; using deterministic labels", exc_info=True)
+        title, description, labels = "", "", []
     # One aux call covers labels AND auto-naming. A manual rename sets auto_named=False, so the title/description below are left untouched then.
     if need_autoname:
         if title:

backend/tests/test_step_edit_survives_dead_aux.py

@@ -0,0 +1,86 @@
+"""Editing a workflow step must finish even when the aux label lane is dead.
+
+`p_relabel_steps` is awaited INSIDE the PATCH request, and its aux call had no timeout at all (the
+Anthropic SDK's own stream ceiling is minutes). A stalled lane therefore held the whole edit open:
+the agent's EditWorkflowStep tool never returned and the editor just span, which is the
+"agent edits a workflow and the app bricks" report. The labels are decoration with deterministic
+fallbacks, so a dead lane must cost a nicer label, never the edit.
+"""
+
+import asyncio
+
+import pytest
+
+from backend.apps.workflows import workflows as wf_mod
+from backend.apps.workflows.models import Workflow, WorkflowStep
+
+
+def p_wf() -> Workflow:
+    return Workflow(title="Untitled workflow", auto_named=True, steps=[WorkflowStep(text="do the first thing")])
+
+
+def test_a_hung_aux_lane_cannot_hold_the_edit_open(monkeypatch):
+    async def never_returns(*_a, **_k):
+        await asyncio.sleep(3600)
+
+    monkeypatch.setattr(wf_mod, "p_generate_metadata_for_steps", never_returns)
+    monkeypatch.setattr(wf_mod, "AUX_LABEL_TIMEOUT_S", 0.05)
+
+    wf = p_wf()
+    steps = [WorkflowStep(text="a brand new instruction")]
+
+    async def run():
+        await asyncio.wait_for(
+            wf_mod.p_relabel_steps(wf, [], steps, None),
+            timeout=5.0,  # the assertion IS that we return well inside this
+        )
+
+    asyncio.run(run())
+
+
+def test_a_hung_lane_still_leaves_a_usable_label_and_title(monkeypatch):
+    """Falling through to the deterministic path matters: the old code returned early on any aux
+    failure, which left the step showing its raw prompt as its own title."""
+    async def never_returns(*_a, **_k):
+        await asyncio.sleep(3600)
+
+    monkeypatch.setattr(wf_mod, "p_generate_metadata_for_steps", never_returns)
+    monkeypatch.setattr(wf_mod, "AUX_LABEL_TIMEOUT_S", 0.05)
+
+    wf = p_wf()
+    steps = [WorkflowStep(text="summarize my unread email and text me the digest")]
+    asyncio.run(wf_mod.p_relabel_steps(wf, [], steps, None))
+
+    assert steps[0].label, "a dead aux lane must still leave a label"
+    assert steps[0].label != steps[0].text, "the label must not be the raw prompt"
+    assert wf.title not in wf_mod._PLACEHOLDER_TITLES, "auto-name must fall back, not stay Untitled"
+
+
+def test_an_erroring_aux_lane_behaves_the_same_as_a_hung_one(monkeypatch):
+    async def blows_up(*_a, **_k):
+        raise RuntimeError("provider 500")
+
+    monkeypatch.setattr(wf_mod, "p_generate_metadata_for_steps", blows_up)
+    wf = p_wf()
+    steps = [WorkflowStep(text="pull the calendar and write a brief")]
+    asyncio.run(wf_mod.p_relabel_steps(wf, [], steps, None))
+    assert steps[0].label
+    assert wf.title not in wf_mod._PLACEHOLDER_TITLES
+
+
+def test_a_healthy_lane_still_wins(monkeypatch):
+    """The timeout must not quietly replace good aux output with the fallback."""
+    async def good(*_a, **_k):
+        return "Summarize Daily Email", "Reads unread mail and texts a digest.", ["Summarize unread email"]
+
+    monkeypatch.setattr(wf_mod, "p_generate_metadata_for_steps", good)
+    wf = p_wf()
+    steps = [WorkflowStep(text="summarize my unread email")]
+    asyncio.run(wf_mod.p_relabel_steps(wf, [], steps, None))
+    assert wf.title == "Summarize Daily Email"
+    assert steps[0].label == "Summarize unread email"
+
+
+@pytest.mark.parametrize("budget", [20.0])
+def test_the_ceiling_is_bounded_and_sane(budget):
+    assert 0 < wf_mod.AUX_LABEL_TIMEOUT_S <= budget