Haystack 3.1.1 stops a discarded malformed tool call from killing the next LLM call

GitHub·medium signalXBlueskyLinkedInCopy link

Released 2026-09-03T09:27Z, Haystack 3.1.1 fixes the OpenAI Chat Completions and Responses converters raising on an assistant message with no content parts, which is exactly what a Chat Generator returns when it discards a malformed tool call. The message is now sent with empty content, which both APIs accept, so the run continues instead of failing; `ChatMessage.from_openai_dict_format` accepts the same empty content so such a message round-trips, and the Hugging Face converter got the matching fix. This is the failure mode where one bad tool call from the model ends an otherwise healthy multi-turn agent run.