{"name":"CLAUDE_CODE_EXTRA_METADATA","slug":"claude-code-extra-metadata","family":"env","title":"Environment variables","noun":"environment variable","description":"`tk` is now a reserved metadata name and stripped from your extra metadata or body.","description_source":"entry","described_by":{"version":"2.1.232","anchor":"per-turn-attribution-key-sent-as-tk-and-tk-is-now-a-reserved"},"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":"2.1.78","released_at":"2026-03-17 21:04:05","spans":1}},"aliases":[],"entries":[{"version":"2.1.232","anchor":"per-turn-attribution-key-sent-as-tk-and-tk-is-now-a-reserved","heading":"Per-turn attribution key sent as tk , and tk is now a reserved metadata name","line":"`tk` is now a reserved metadata name and stripped from your extra metadata or body.","released_at":"2026-08-13 21:30:53","reason":"named in this entry, found in this entry's text"},{"version":"2.1.78","anchor":"claude-code-extra-metadata-environment-variable","heading":"CLAUDE_CODE_EXTRA_METADATA Environment Variable","line":null,"released_at":"2026-03-17 21:04:05","reason":"found in this entry's text"}],"entries_total":2,"docs":[],"docs_total":0,"gates":[],"related":[{"name":"CLAUDE_CODE_EXTRA_BODY","slug":"claude-code-extra-body","description":"JSON object to merge into the top level of every API request body. Useful for passing provider-specific parameters that Claude Code doesn't expose directly. A value exported in your shell also applies to the [background sessions](\/docs\/en\/agent-view) you dispatch with `claude agents` or `--bg`. Before v2.1.206, background sessions ignored a shell-exported value and used whatever copy the background supervisor process inherited"}],"url":"https:\/\/changelogs.core-directive.com\/reference\/env\/claude-code-extra-metadata","family_url":"https:\/\/changelogs.core-directive.com\/reference\/env.json"}