{"version":"2.0.2","anchor":"tool-use-concurrency-error-handler","canonical_anchor":"tool-use-concurrency-error-handler","heading":"Tool Use Concurrency Error Handler","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.0.2\/e\/tool-use-concurrency-error-handler","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.0.2","markdown":"### Tool Use Concurrency Error Handler\n\n**What:** New error handler for API 400 errors caused by tool use concurrency issues\n\n**How to recover:** When you encounter this error, the system will display:\n\n`API Error: 400 due to tool use concurrency issues. Run \/rewind to recover the conversation.` **Details:**\n\n- Detects when `tool_use` IDs are found without immediately following `tool_result` blocks\n- Provides clear recovery instructions using the existing `\/rewind` command\n- The `\/rewind` command restores both code state and conversation to a previous checkpoint\n- **Evidence**: Error handler at `bk1() at line 385221`\n\n**Why this matters:** Provides users with actionable recovery steps instead of a generic API error message when tool execution gets out of sync."}