fix(intake): accept ATIF observation on all step types

services/intake/src/nmp/intake/spans/ingest/atif_domain.py

@@ -155,6 +155,7 @@ class AtifStepBase(BaseModel):
     is_copied_context: bool | None = None
     extra: dict[str, Any] | None = None
     llm_call_count: int | None = Field(default=None, ge=0)
+    observation: AtifObservation | None = None
 
     model_config = ConfigDict(extra="forbid")
 
@@ -184,7 +185,6 @@ class AtifStepAgent(AtifStepBase):
     reasoning_effort: str | float | None = None
     reasoning_content: str | None = None
     tool_calls: list[AtifToolCall] | None = None
-    observation: AtifObservation | None = None
     metrics: AtifMetrics | None = None
 
 
@@ -209,10 +209,9 @@ def validate_atif_step_ids(steps: list[AtifStep]) -> None:
 def validate_atif_tool_call_references(steps: list[AtifStep]) -> None:
     """Require unique calls and resolvable observation call references."""
     for step in steps:
-        if not isinstance(step, AtifStepAgent):
-            continue
         tool_call_ids: set[str] = set()
-        for tool_call in step.tool_calls or []:
+        tool_calls = step.tool_calls if isinstance(step, AtifStepAgent) else None
+        for tool_call in tool_calls or []:
             if tool_call.tool_call_id in tool_call_ids:
                 raise ValueError(f"Duplicate tool_call_id '{tool_call.tool_call_id}' in step {step.step_id}")
             tool_call_ids.add(tool_call.tool_call_id)
@@ -229,7 +228,7 @@ def validate_atif_tool_call_references(steps: list[AtifStep]) -> None:
 def validate_atif_v17_subagent_ref_resolution_keys(steps: list[AtifStep]) -> None:
     """Require v1.7 subagent references to include a resolvable key."""
     for step in steps:
-        if not isinstance(step, AtifStepAgent) or step.observation is None:
+        if step.observation is None:
             continue
         for result in step.observation.results:
             for subagent_ref in result.subagent_trajectory_ref or []:

services/intake/src/nmp/intake/spans/ingest/atif_mapping.py

@@ -844,8 +844,8 @@ def _step_tool_calls(step: AtifStep) -> list[AtifToolCall]:
 
 
 def _step_observation(step: AtifStep) -> AtifObservation | None:
-    """Return the observation attached to an agent step."""
-    return step.observation if isinstance(step, AtifStepAgent) else None
+    """Return the observation attached to any step."""
+    return step.observation
 
 
 def _observation_result_for_tool_call(step: AtifStep, tool_call_id: str) -> AtifObservationResult | None:

services/intake/tests/test_atif_v17.py

@@ -1040,3 +1040,61 @@ def test_atif_mapping_end_time_none_when_no_timing_exists_at_all() -> None:
         for span in spans
         if span.name in {"user-1", "bash"} or (span.name == "sample-agent" and span.kind == SpanKind.LLM)
     )
+
+
+def test_atif_v17_observation_on_nested_system_step() -> None:
+    """Regression: DeepAgents emits an observation on a nested *system* step.
+
+    ``observation`` previously lived only on ``AtifStepAgent``, so a system step
+    carrying one was rejected as an extra field and Intake returned HTTP 422,
+    storing nothing. It now lives on ``AtifStepBase``; every step type accepts it,
+    validators run on all step types, and the mapper reads observations anywhere.
+    """
+    trajectory = AtifTrajectory.model_validate(
+        {
+            "schema_version": "ATIF-v1.7",
+            "session_id": "deepagents-session",
+            "trajectory_id": "root",
+            "agent": {"name": "orchestrator", "version": "1.0"},
+            "steps": [
+                {"step_id": 1, "source": "user", "message": "classify this email"},
+                {
+                    "step_id": 2,
+                    "source": "agent",
+                    "message": "delegating to phishing-analyzer",
+                    "tool_calls": [{"tool_call_id": "task-1", "function_name": "task"}],
+                    "observation": {
+                        "results": [{"source_call_id": "task-1", "subagent_trajectory_ref": [{"trajectory_id": "sub"}]}]
+                    },
+                },
+            ],
+            "subagent_trajectories": [
+                {
+                    "schema_version": "ATIF-v1.7",
+                    "trajectory_id": "sub",
+                    "agent": {"name": "phishing-analyzer", "version": "1.0"},
+                    "steps": [
+                        {
+                            "step_id": 1,
+                            "source": "system",
+                            "message": "You are a careful email phishing analyzer.",
+                            "observation": {"results": [{"content": "is_likely_phishing: true"}]},
+                        }
+                    ],
+                }
+            ],
+        }
+    )
+
+    system_step = trajectory.subagent_trajectories[0].steps[0]
+    assert system_step.source == "system"
+    assert system_step.observation is not None
+    assert system_step.observation.results[0].content == "is_likely_phishing: true"
+
+    # The non-agent observation maps without error and produces spans.
+    spans = trajectory_to_spans(
+        workspace="default",
+        trajectory=trajectory,
+        ingested_at=datetime(2026, 1, 1, tzinfo=timezone.utc),
+    )
+    assert spans