DSPy ReActV2 gets async execution and stops returning half-finished Predictions

GitHub·medium signalXBlueskyLinkedInCopy link

PRs #10355 and #10356 in 3.4.0b1 add `await agent.acall(...)` to the experimental `dspy.ReActV2`, covering async prediction, async tools and forced final submission, and letting async MCP tools run through the agent's structured tool-call history with call IDs and results preserved across turns. Tools execute sequentially on the async path; this adds no parallel tool execution and does not offload blocking sync tools. ReActV2 also now raises `ValueError` on missing or invalid final submission instead of returning an incomplete `Prediction`, and rejects signatures with output fields named `history` or `termination_reason`.