{"name":"CLAUDE_CODE_ATTRIBUTION_ANNOUNCEMENT","slug":"claude-code-attribution-announcement","family":"env","title":"Environment variables","noun":"environment variable","description":null,"description_source":"none","described_by":null,"presence":{"first_seen":"2.1.268","removed_in":null,"in_current_build":true,"newest_mined":"2.1.280","builds":12,"mined_builds":123,"first_cited":null},"aliases":[],"entries":[],"entries_total":0,"docs":[],"docs_total":0,"gates":[],"related":[{"name":"CLAUDE_CODE_ATTRIBUTION_HEADER","slug":"claude-code-attribution-header","description":"Set to `0` to omit the [attribution block](\/docs\/en\/llm-gateway-protocol#system-prompt-attribution-block), which carries the client version and a prompt fingerprint, from the start of the system prompt. Caching on a direct connection to the Anthropic API is unaffected either way. In some direct-connection setups, Claude Code keeps the block on [auto mode](\/docs\/en\/permission-modes#eliminate-prompts-with-auto-mode) classifier requests even when you set `0`. In [System prompt attribution block](\/docs\/en\/llm-gateway-protocol#system-prompt-attribution-block), check which connections and credentials this covers. Before v2.1.181 the block included a per-request token on custom base URLs and Microsoft Foundry connections, so on those versions set it to `0` when your LLM gateway caches on the request body or forwards requests to a third-party provider, or when you connect to Microsoft Foundry directly"},{"name":"CLAUDE_CODE_ATTRIBUTION_STATUS_TIMEOUT_MS","slug":"claude-code-attribution-status-timeout-ms","description":"Four more environment variables are now recognized and passed through by Claude Code"}],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/claude-code-attribution-announcement","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}