{"name":"CLAUDE_STREAM_FIRST_BYTE_TIMEOUT_MS","slug":"claude-stream-first-byte-timeout-ms","family":"env","title":"Environment variables","noun":"environment variable","description":"Hung requests are aborted when headers never arrive, and you can tune the window.","description_source":"entry","described_by":{"version":"2.1.242","anchor":"api-requests-that-never-send-response-headers-are-now-aborte"},"presence":{"first_seen":"2.1.242","removed_in":null,"in_current_build":true,"newest_mined":"2.1.309","builds":57,"mined_builds":150,"first_cited":{"version":"2.1.261","released_at":"2026-09-04 17:49:34","spans":4}},"aliases":[],"entries":[{"version":"2.1.261","anchor":"more-detailed-stream-timeout-error-message-with-tunable-env","heading":"More detailed stream-timeout error message with tunable env vars","line":"Stream-timeout errors now suggest raising API_TIMEOUT_MS or CLAUDE_STREAM_FIRST_BYTE_TIMEOUT_MS.","released_at":"2026-09-04 17:49:34","reason":"found in this entry's text, named in this entry"},{"version":"2.1.261","anchor":"new-distinct-ui-for-no-response-from-api-retry-state-sepa","heading":"New distinct UI for 'no response from API' retry state, separate from rate-limit retries","line":"A 'no response from API' retry message now appears separately from rate-limit retries, with a tunable timeout hint.","released_at":"2026-09-04 17:49:34","reason":"found in this entry's text, named in this entry"},{"version":"2.1.261","anchor":"new-env-var-claude-stream-first-byte-timeout-ms","heading":"New env var CLAUDE_STREAM_FIRST_BYTE_TIMEOUT_MS","line":"A new env var controls how long Claude Code waits for the first byte of a streamed response.","released_at":"2026-09-04 17:49:34","reason":"found in this entry's text, named in this entry"},{"version":"2.1.261","anchor":"new-no-response-diagnostic-field-for-stream-timeouts","heading":"New no_response diagnostic field for stream timeouts","line":"Telemetry schema now records how long a no-response stream timeout waited.","released_at":"2026-09-04 17:49:34","reason":"found in this entry's text"},{"version":"2.1.242","anchor":"api-requests-that-never-send-response-headers-are-now-aborte","heading":"API requests that never send response headers are now aborted","line":"Hung requests are aborted when headers never arrive, and you can tune the window.","released_at":"2026-08-24 19:16:14","reason":"named in this entry, found in this entry's text"}],"entries_total":5,"docs":[{"source":"claude-code","path":"changelog","title":"Claude Code changelog","documented":false},{"source":"claude-code","path":"env-vars","title":"Environment variables","documented":false},{"source":"claude-code","path":"errors","title":"Error reference","documented":false},{"source":"claude-code","path":"network-config","title":"Enterprise network configuration","documented":false}],"docs_total":4,"gates":[],"related":[{"name":"CLAUDE_STREAM_IDLE_TIMEOUT_MS","slug":"claude-stream-idle-timeout-ms","description":"A new admin key, `inferenceStreamIdleTimeoutSec`, sets Claude Code's stream idle timeout (300 to 1800 seconds) for sessions the app starts"}],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/claude-stream-first-byte-timeout-ms","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}