[igalshilman]

Found by exercising the agents against a real model (OpenAI) and Restate 1.8.1.

• A 409 that is no cancellation fails the turn, rather than stopping it. A turn took any TerminalError with status 409 for Restate's cancellation, and closed as stopped: but a call fails with 409 for other reasons too. refund_graph.py's payout workflow, run a second time for an order (from another conversation), failed with 409 "the workflow method was already invoked", and the turn's answer was "Cancelled: the turn was stopped before it finished.". is_cancellation takes Restate's cancellation error only, 409 "cancelled", which a stopped turn fails with too (_turn.cancellation, the SDK's cancel signal, a stored cancelled turn). The same for a Pydantic AI tool's terminal error, which the model now sees. Three tests stood TerminalError("stopped", 409) in for a stop: they raise 409 "cancelled" now.
• Pydantic AI: an approval denied with "no" tells the model the call was denied. Any text but an approving one denied the call with that text as the reason, so a manager's "no" reached the model as the call's result ("the tool returned no"). A text that only says no (no, denied, rejected...) denies with Pydantic AI's own "The tool call was denied."; any other text is still the reason.

Checked live: the second payout of an order now fails the turn with "Error: the workflow method was already invoked"; a stop, and Restate's cancel (the admin API), of a turn in a tool and of one waiting on a subagent (team.py), still end it cancelled, with the subagents cancelled too. A "no" to a Pydantic AI approval: the model answers that the request was denied.

Checks: ruff format --check, ruff check, pyright and mypy, and pytest tests/* (563 passed) locally; the new test of the 409 fails without the fix.

[pullfrog]

✅ No new issues found.

Reviewed changes

I reviewed all 3 commits: the narrower check for what counts as a cancellation, the tests updated to match it, and the change to how Pydantic AI handles a bare denial.

• is_cancellation replaces the bare 409 check. answering in _conversation.py and Pydantic AI's on_tool_execute_error now count an error as a stop only when it is a TerminalError with status 409 and the message "cancelled". I checked every place in the repo that produces a cancellation: _turn.cancellation(), server_context on DoProgressCancelSignalReceived, _preview.py, stored_answer and sessions/_selector.py. All of them raise exactly "cancelled", so a real stop still closes the turn as cancelled. Turns use explicit cancellation, so the stop path never depends on messages the runtime writes.
• Other 409s now fail the turn. A workflow invoked a second time, or a child that the runtime itself cancelled or killed, now fails the turn, and Pydantic AI gives the model an "Error: ..." tool result instead of the false CANCELLED answer.
• Tests that stood in for a stop now raise the real error. They raise TerminalError("cancelled", 409), and the new conversation test pins down how a 409 that is not a cancellation gets stored.
• A bare denial uses Pydantic AI's own message. approval_of maps "", no, denied, rejected, declined and refused (plus their verb forms) to ToolDenied(). Any other text that does not approve is still passed on as the reason.

I ran the in-process tests that touch these paths locally (-k "409 or stopped", approvals_signal), and they pass. The tests that need the Docker harness could not run here.

  ^{｜ View workflow run ｜ Using claude-opus-5-5 ｜ 𝕏}

[github-actions]

Test Results

  8 files  ±0    8 suites  ±0   3m 40s ⏱️ -1s
 71 tests ±0   71 ✅ ±0  0 💤 ±0  0 ❌ ±0 
322 runs  ±0  322 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 150883d. ± Comparison against base commit 56e0a86.