Merge pull request #2765 from Molecule-AI/fix/isolate-adapter-failures-from-card

fix(runtime): isolate card-skill enrichment + transcript handler from adapter shape mismatch

scripts/build_runtime_package.py

@@ -58,6 +58,7 @@ TOP_LEVEL_MODULES = {
     "adapter_base",
     "agent",
     "agents_md",
+    "card_helpers",
     "config",
     "configs_dir",
     "consolidation",

workspace/card_helpers.py

@@ -0,0 +1,57 @@
+"""Helpers for building / mutating the workspace ``AgentCard``.
+
+Kept as their own module so the behavior is unit-testable without booting
+the whole runtime (``main.py`` is ``# pragma: no cover``).
+"""
+from __future__ import annotations
+
+from typing import Iterable
+
+from a2a.types import AgentCard, AgentSkill
+
+
+def enrich_card_skills(card: AgentCard, loaded_skills: Iterable | None) -> bool:
+    """Replace ``card.skills`` with rich metadata from the adapter's loaded
+    skills, in place. Pairs with PR #2756: the card was built up front from
+    static ``config.skills`` names so /.well-known/agent-card.json could
+    serve before ``adapter.setup()`` finishes; this swaps in the richer
+    descriptions/tags/examples that ``setup()``'s skill loader produces.
+
+    Returns ``True`` on swap, ``False`` when the swap was skipped or
+    failed. Failure cases:
+    * ``loaded_skills`` is None / empty — caller didn't load any.
+    * Any element doesn't expose ``.metadata.{id,name,description,tags,examples}``
+      (a future adapter that doesn't follow the canonical shape).
+
+    Failures DO NOT raise — a malformed ``loaded_skills`` shape would
+    otherwise propagate to ``main.py``'s outer ``except Exception``,
+    silently degrading an OK boot to the not-configured state. Static
+    stubs from ``config.skills`` stay in place; setup() already
+    succeeded, the agent works, only the card's skill enrichment is
+    degraded. Operator sees a clear log line; tests assert this
+    distinction.
+    """
+    if not loaded_skills:
+        return False
+
+    try:
+        rich = [
+            AgentSkill(
+                id=skill.metadata.id,
+                name=skill.metadata.name,
+                description=skill.metadata.description,
+                tags=skill.metadata.tags,
+                examples=skill.metadata.examples,
+            )
+            for skill in loaded_skills
+        ]
+    except Exception as enrich_err:  # noqa: BLE001
+        print(
+            f"Warning: skill metadata enrichment failed (keeping static "
+            f"stubs from config.skills): {type(enrich_err).__name__}: {enrich_err}",
+            flush=True,
+        )
+        return False
+
+    card.skills = rich
+    return True

workspace/main.py

@@ -245,18 +245,13 @@ async def main():  # pragma: no cover
         # 6c. Swap rich skill metadata into the card now that setup() loaded
         # them. In-place mutation: a2a-sdk's create_agent_card_routes serialises
         # the card on each request, so the route mounted below sees the update.
-        loaded_skills = getattr(adapter, "loaded_skills", None)
+        # Isolated via card_helpers.enrich_card_skills — a malformed
-        if loaded_skills:
+        # loaded_skills shape (e.g., a future adapter that doesn't follow
-            agent_card.skills = [
+        # the .metadata convention) is logged + swallowed instead of
-                AgentSkill(
+        # propagating up to the outer except, where it would silently
-                    id=skill.metadata.id,
+        # degrade an OK boot to the not-configured state.
-                    name=skill.metadata.name,
+        from card_helpers import enrich_card_skills
-                    description=skill.metadata.description,
+        enrich_card_skills(agent_card, getattr(adapter, "loaded_skills", None))
-                    tags=skill.metadata.tags,
-                    examples=skill.metadata.examples,
-                )
-                for skill in loaded_skills
-            ]
         adapter_ready = True
     except SystemExit:
         # Smoke-mode exit signal — propagate untouched.
@@ -497,7 +492,24 @@ async def main():  # pragma: no cover
             limit = int(request.query_params.get("limit", "100"))
         except (TypeError, ValueError):
             return JSONResponse({"error": "since and limit must be integers"}, status_code=400)
-        result = await adapter.transcript_lines(since=since, limit=limit)
+        # Isolate adapter call: misconfigured boots leave the adapter
+        # partially-initialised, and a future adapter override of
+        # transcript_lines might assume setup() ran. Surface a 503 with
+        # a clear reason instead of letting the exception propagate to
+        # Starlette's 500 handler — same pattern as the not-configured
+        # JSON-RPC route (PR #2756). BaseAdapter.transcript_lines's
+        # default returns {"supported": false} so today's 4 adapters
+        # never trigger this branch; this is the safety net.
+        try:
+            result = await adapter.transcript_lines(since=since, limit=limit)
+        except Exception as transcript_err:  # noqa: BLE001
+            return JSONResponse(
+                {
+                    "error": "transcript unavailable",
+                    "detail": f"{type(transcript_err).__name__}: {transcript_err}",
+                },
+                status_code=503,
+            )
         return JSONResponse(result)
 
     starlette_app.add_route("/transcript", _transcript_handler, methods=["GET"])

workspace/tests/conftest.py

@@ -145,6 +145,42 @@ def _make_a2a_mocks():
     types_mod.TaskStatus = TaskStatus
     types_mod.TaskState = _TaskStateEnum
 
+    # v1 AgentCard / AgentSkill / AgentCapabilities / AgentInterface — used
+    # by main.py's static-card construction (PR #2756) and by
+    # card_helpers.enrich_card_skills's swap path. Stubs preserve kwargs so
+    # tests can assert on card.skills[i].name etc., and let card.skills be
+    # reassigned in place (the production code's enrichment pattern).
+    class AgentSkill:
+        def __init__(self, id="", name="", description="", tags=None, examples=None, **kwargs):
+            self.id = id
+            self.name = name
+            self.description = description
+            self.tags = list(tags) if tags is not None else []
+            self.examples = list(examples) if examples is not None else []
+            for k, v in kwargs.items():
+                setattr(self, k, v)
+
+    class AgentCapabilities:
+        def __init__(self, **kwargs):
+            for k, v in kwargs.items():
+                setattr(self, k, v)
+
+    class AgentInterface:
+        def __init__(self, **kwargs):
+            for k, v in kwargs.items():
+                setattr(self, k, v)
+
+    class AgentCard:
+        def __init__(self, **kwargs):
+            self.skills = []
+            for k, v in kwargs.items():
+                setattr(self, k, v)
+
+    types_mod.AgentSkill = AgentSkill
+    types_mod.AgentCapabilities = AgentCapabilities
+    types_mod.AgentInterface = AgentInterface
+    types_mod.AgentCard = AgentCard
+
     # a2a.helpers (v1: moved from a2a.utils, renamed new_agent_text_message
     # → new_text_message). Mock both names — production code only calls
     # new_text_message, but if any test still references the old name it

workspace/tests/test_card_helpers.py

@@ -0,0 +1,163 @@
+"""Tests for ``card_helpers.enrich_card_skills`` — the defensive swap that
+replaces ``AgentCard.skills`` with rich metadata from the adapter's
+loaded skills, falling back to the static stubs on shape mismatch.
+
+The whole point of the helper (vs inline in main.py) is that a future
+adapter author who returns a non-standard ``loaded_skills`` shape
+should NOT silently downgrade their workspace boot to not-configured —
+``setup()`` succeeded, the agent works, only the card's skill metadata
+enrichment is degraded.
+"""
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+WORKSPACE_DIR = Path(__file__).resolve().parents[1]
+if str(WORKSPACE_DIR) not in sys.path:
+    sys.path.insert(0, str(WORKSPACE_DIR))
+
+from a2a.types import AgentCard, AgentCapabilities, AgentInterface, AgentSkill
+
+from card_helpers import enrich_card_skills
+
+
+def _make_card(static_skill_names):
+    return AgentCard(
+        name="test-agent",
+        description="test",
+        version="0.0.0",
+        supported_interfaces=[
+            AgentInterface(protocol_binding="https://a2a.g/v1", url="http://x:8000")
+        ],
+        capabilities=AgentCapabilities(streaming=True, push_notifications=False),
+        skills=[
+            AgentSkill(id=n, name=n, description=n, tags=[], examples=[])
+            for n in static_skill_names
+        ],
+        default_input_modes=["text/plain"],
+        default_output_modes=["text/plain"],
+    )
+
+
+class _SkillMetadata:
+    """Mimics the adapter-side Skill.metadata shape."""
+    def __init__(self, id, name, description, tags, examples):
+        self.id = id
+        self.name = name
+        self.description = description
+        self.tags = tags
+        self.examples = examples
+
+
+class _Skill:
+    def __init__(self, **kwargs):
+        self.metadata = _SkillMetadata(**kwargs)
+
+
+def test_returns_false_on_none():
+    """No loaded_skills → caller didn't load any → no swap, no log spam."""
+    card = _make_card(["a", "b"])
+    assert enrich_card_skills(card, None) is False
+    # Static stubs preserved.
+    assert [s.id for s in card.skills] == ["a", "b"]
+
+
+def test_returns_false_on_empty_list():
+    """Empty list → same treatment as None: nothing to enrich."""
+    card = _make_card(["a"])
+    assert enrich_card_skills(card, []) is False
+    assert [s.id for s in card.skills] == ["a"]
+
+
+def test_swaps_in_rich_metadata_on_canonical_shape():
+    """The happy path: adapter returns Skill objects with the canonical
+    .metadata shape, card gets the richer descriptions/tags/examples."""
+    card = _make_card(["search"])  # static stub
+    rich = [
+        _Skill(
+            id="search",
+            name="Web Search",
+            description="Search the web for the user's question",
+            tags=["web", "io"],
+            examples=["who won the world cup in 2022?"],
+        ),
+    ]
+    assert enrich_card_skills(card, rich) is True
+    assert len(card.skills) == 1
+    assert card.skills[0].id == "search"
+    assert card.skills[0].name == "Web Search"
+    assert "web" in card.skills[0].tags
+    assert card.skills[0].examples == ["who won the world cup in 2022?"]
+
+
+def test_returns_false_and_keeps_stubs_when_metadata_attr_missing(capsys):
+    """Defensive: a future adapter that returns objects without
+    ``.metadata`` would otherwise raise AttributeError and propagate to
+    main.py's outer except — silently degrading an OK boot to
+    not-configured. Helper logs + returns False instead, static stubs
+    stay in place.
+
+    This is the reason the helper exists at all; without it the
+    inline swap in main.py at PR #2756 was a coupling between adapter
+    discipline and tenant-facing readiness."""
+    card = _make_card(["a"])
+
+    class NoMetadata:
+        id = "x"  # has id but no .metadata.id (the canonical path)
+
+    assert enrich_card_skills(card, [NoMetadata()]) is False
+    # Static stub preserved.
+    assert [s.id for s in card.skills] == ["a"]
+    # Operator gets a log line.
+    captured = capsys.readouterr()
+    assert "skill metadata enrichment failed" in captured.out
+
+
+def test_returns_false_when_metadata_is_partial(capsys):
+    """Partial shape — has .metadata but the .metadata object lacks one
+    of the canonical attrs (here: ``examples``). The list comprehension
+    raises AttributeError on ``skill.metadata.examples`` access, which
+    the helper swallows. (In production, a2a.types.AgentSkill is a
+    Pydantic model that ALSO raises on missing required fields — both
+    failure modes route through the same except branch.)"""
+    card = _make_card(["a"])
+
+    class PartialMeta:
+        def __init__(self):
+            self.id = "x"
+            self.name = "x"
+            self.description = "x"
+            self.tags = []
+            # examples missing
+
+    class PartialSkill:
+        def __init__(self):
+            self.metadata = PartialMeta()
+
+    result = enrich_card_skills(card, [PartialSkill()])
+    assert result is False
+    assert [s.id for s in card.skills] == ["a"]
+    captured = capsys.readouterr()
+    assert "skill metadata enrichment failed" in captured.out
+
+
+def test_failure_is_atomic_no_partial_swap(capsys):
+    """If the second skill is malformed, the FIRST skill's swap must NOT
+    leak into card.skills. We use a list-comprehension which builds the
+    full list before assignment; verify that property holds.
+
+    Without this property, a misbehaving adapter could half-corrupt the
+    card — operators would see "1 skill listed" when 3 were declared,
+    no log line if the inline swap was partial."""
+    card = _make_card(["a", "b"])
+
+    valid = _Skill(id="x", name="x", description="x", tags=[], examples=[])
+
+    class BadSkill:
+        # No .metadata at all.
+        pass
+
+    assert enrich_card_skills(card, [valid, BadSkill()]) is False
+    # Original two static stubs intact — card.skills was never reassigned.
+    assert [s.id for s in card.skills] == ["a", "b"]