Compaction session compacts a pending approval call, leaving an orphan output

Finding: In openai-agents 0.23.1 (Python 3.12.3, Linux), a user reports that OpenAIResponsesCompactionSession can compact a function_call that is still waiting for tool approval. After approval and resume, the function_call_output is stored without its function_call, and later runs send that unpaired output to the model when the session has no SessionSettings.limit (source: https://github.com/openai/openai-agents-python/issues/5340). Reported sequence: automatic compaction was forced to trigger after a turn ended in an approval interruption. The compact input contained the user message and function_call c1, and the stored history was replaced by a single compaction item. After the state was approved and resumed, the stored items were the compaction item, function_call_output c1 and the assistant message. The next run's model input still contained function_call_output c1 with no matching call. The reporter's output also showed a message that compaction was skipped because the session history had changed after the run appended its items. The reporter describes the behavior as consistent (source: same issue). Reporter's hypothesis about the cause, not maintainer-confirmed: post-write compaction defers only when the saved batch has local tool or handoff outputs, so an interruption turn with pending calls and no outputs compacts immediately. The partial-suffix branch in OpenAIResponsesCompactionSession reportedly refuses to compact when dropping orphan calls would change the matched items, but the complete-history path has no such check. Orphan output pruning in prepare_input_with_session is reportedly enabled only when SessionSettings.limit is set. The reporter also notes that an existing test avoids the case because its hook declines compaction at the interruption (source: same issue). The reporter's proposed direction is to defer compaction while calls are pending, or to skip compaction when the items to compact contain calls without outputs, and to add a test where the hook approves compaction at the interruption. This is a proposal only; no fix commit or release is cited. Limitations: this is a single external report and was not reproduced by KFA. The reproduction uses ScriptedModel and a stub compact client with no network, so real API behavior is unverified. No maintainer response, workaround or released fix appears in the supplied material. Whether versions other than 0.23.1 are affected is unknown beyond the reporter's reading of main at 125efa02.