Strands 1.57.1 fixes guardrail redactions that came back from disk after a retried prompt
GitHub·medium signal
When a message-list prompt was retried after a model error, the same message ended up in two session records. A guardrail redaction fixed both in memory but rewrote only the latest record on disk, so restoring the session in a new process brought the flagged text back (#4606). The release also adds an a2a_client tool, Agent.shutdown() for scope-based cleanup, and moves the TypeScript MCP integration to @modelcontextprotocol/client 2.0. The repo now lives at strands-agents/harness-sdk.