Auto-recover when the provider rejects a view_image output

When view_image lands an image content block in the agent session and the
next model call fails because the provider rejects the format (SVG on
Anthropic, anything on a text-only model, etc.), the agent used to die
once the general failsafe parked it and there was no way back.

Recovery flow when _run_cycle catches an input-rejection error
(BadRequestError/NotFoundError/422, by status_code) and the latest
session item is an image-bearing function_call_output:

- pop_item() the offending output (single SDK-public primitive)
- add_items() a replacement function_call_output paired by the original
  call_id, with text content telling the model "view_image is
  unsupported on this scan; do not call it again"
- retry the cycle once with empty input_data

Gated by status_code so unrelated failures (timeouts, 5xx, 429, auth,
network blips) leave session content intact — no false-trigger that
would destroy a valid image during a transient hiccup on a
vision-capable model. Hard cap of 3 strips per cycle so a model that
keeps re-calling view_image despite the instruction text still
terminates.

strip_latest_image_from_session lives in core.sessions next to
open_agent_session — both are session helpers operating only through
the SDK's public Session protocol.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

strix/core/execution.py

@@ -14,7 +14,7 @@ from agents.exceptions import AgentsException, MaxTurnsExceeded, UserError
 from openai import APIError
 
 from strix.core.inputs import child_initial_input
-from strix.core.sessions import open_agent_session
+from strix.core.sessions import open_agent_session, strip_latest_image_from_session
 
 
 if TYPE_CHECKING:
@@ -32,6 +32,8 @@ logger = logging.getLogger(__name__)
 
 StreamEventSink = Callable[[str, Any], None]
 
+_INPUT_REJECTION_CODES = frozenset({400, 404, 422})
+
 
 async def run_agent_loop(
     *,
@@ -321,7 +323,7 @@ async def _run_noninteractive_until_lifecycle(
         )
 
 
-async def _run_cycle(
+async def _run_cycle(  # noqa: PLR0912
     agent: Any,
     coordinator: AgentCoordinator,
     agent_id: str,
@@ -335,6 +337,8 @@ async def _run_cycle(
     event_sink: StreamEventSink | None,
     hooks: RunHooks[dict[str, Any]] | None,
 ) -> RunResultBase | None:
+    image_strips = 0
+    while True:
         try:
             await coordinator.mark_running(agent_id)
             stream = Runner.run_streamed(
@@ -359,6 +363,25 @@ async def _run_cycle(
             finally:
                 await coordinator.detach_stream(agent_id, stream)
         except Exception as exc:
+            if (
+                image_strips < 3
+                and session is not None
+                and getattr(exc, "status_code", None) in _INPUT_REJECTION_CODES
+            ):
+                try:
+                    stripped = await strip_latest_image_from_session(session)
+                except Exception:
+                    logger.exception("image-strip recovery failed for %s", agent_id)
+                    stripped = False
+                if stripped:
+                    image_strips += 1
+                    logger.info(
+                        "Stripped latest image from %s session after rejection; retrying (%d)",
+                        agent_id,
+                        image_strips,
+                    )
+                    input_data = []
+                    continue
             if not interactive:
                 raise
             if isinstance(exc, MaxTurnsExceeded):

strix/core/sessions.py

@@ -1,10 +1,53 @@
 """SDK session helpers for Strix agents."""
 
-from pathlib import Path
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, cast
 
 from agents.memory import SQLiteSession
 
 
+if TYPE_CHECKING:
+    from pathlib import Path
+
+    from agents.items import TResponseInputItem
+    from agents.memory import Session
+
+
 def open_agent_session(agent_id: str, path: Path) -> SQLiteSession:
     path.parent.mkdir(parents=True, exist_ok=True)
     return SQLiteSession(session_id=agent_id, db_path=path)
+
+
+_IMAGE_REJECTED_TEXT = (
+    "[image rejected by the model — view_image is unsupported on this scan; "
+    "do not call it again, continue without visual inspection]"
+)
+
+
+async def strip_latest_image_from_session(session: Session) -> bool:
+    items = await session.get_items()
+    if not items:
+        return False
+    latest = items[-1]
+    if not isinstance(latest, dict) or latest.get("type") != "function_call_output":
+        return False
+    output = latest.get("output")
+    if not isinstance(output, list):
+        return False
+    if not any(isinstance(b, dict) and b.get("type") == "input_image" for b in output):
+        return False
+    await session.pop_item()
+    await session.add_items(
+        cast(
+            "list[TResponseInputItem]",
+            [
+                {
+                    "type": "function_call_output",
+                    "call_id": latest.get("call_id"),
+                    "output": [{"type": "input_text", "text": _IMAGE_REJECTED_TEXT}],
+                },
+            ],
+        ),
+    )
+    return True