{"name":"CLAUDE_ASYNC_AGENT_STALL_TIMEOUT_MS","slug":"claude-async-agent-stall-timeout-ms","family":"env","title":"Environment variables","noun":"environment variable","description":"Stall timeout in milliseconds for subagents. Default `600000` (10 minutes); if you raise `CLAUDE_STREAM_IDLE_TIMEOUT_MS` while the stream watchdog is on, the default rises with it, as [Handle slow or stalled API responses](\/docs\/en\/agent-sdk\/typescript#handle-slow-or-stalled-api-responses) describes. The timer resets on each streaming progress event; if no progress arrives within the window, Claude Code aborts the subagent and reports the stall to the parent","description_source":"docs","described_by":{"doc":"claude-code\/env-vars","title":"Environment variables"},"presence":{"first_seen":"2.1.138","removed_in":null,"in_current_build":true,"newest_mined":"2.1.309","builds":150,"mined_builds":150,"first_cited":{"version":"2.1.248","released_at":"2026-08-27 20:35:36","spans":1}},"aliases":[],"entries":[{"version":"2.1.248","anchor":"three-new-environment-variables","heading":"Three new environment variables","line":"Three new env vars tune the read-only memory notice, async agent stall timeout and check-in interval.","released_at":"2026-08-27 20:35:36","reason":"named in this entry, found in this entry's text"}],"entries_total":1,"docs":[{"source":"claude-code","path":"env-vars","title":"Environment variables","documented":true},{"source":"claude-code","path":"agent-sdk\/hosting","title":"Hosting the Agent SDK","documented":false},{"source":"claude-code","path":"agent-sdk\/python","title":"Agent SDK reference - Python","documented":false},{"source":"claude-code","path":"agent-sdk\/typescript","title":"Agent SDK reference - TypeScript","documented":false},{"source":"claude-code","path":"workflows","title":"Orchestrate subagents at scale with dynamic workflows","documented":false}],"docs_total":5,"gates":[],"related":[],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/claude-async-agent-stall-timeout-ms","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}