{"name":"tengu_willow_tern","slug":"tengu-willow-tern","family":"flag","title":"Feature flags","noun":"feature flag","description":"A writing-style prompt block can be forced on with an environment variable; otherwise it stays off.","description_source":"entry","described_by":{"version":"2.1.247","anchor":"a-writing-for-the-user-prompt-block-off-unless-explicitly-tu"},"presence":{"first_seen":"2.1.248","removed_in":"2.1.295","in_current_build":false,"newest_mined":"2.1.308","builds":37,"mined_builds":149,"first_cited":{"version":"2.1.247","released_at":"2026-08-26 18:02:01","spans":1}},"aliases":[],"entries":[{"version":"2.1.247","anchor":"a-writing-for-the-user-prompt-block-off-unless-explicitly-tu","heading":"A \"Writing for the user\" prompt block, off unless explicitly turned on","line":"A writing-style prompt block can be forced on with an environment variable; otherwise it stays off.","released_at":"2026-08-26 18:02:01","reason":"gate cited by this entry, found in this entry's text"},{"version":"2.1.247","anchor":"a-model-capability-toggle-tengu-willow-tern","heading":"A model-capability toggle, tengu_willow_tern","line":"A new toggle applies only to models advertising an opus 5 prompt bundle capability.","released_at":"2026-08-26 18:02:01","reason":"named in this entry, gate cited by this entry, found in this entry's text"}],"entries_total":2,"docs":[],"docs_total":0,"gates":[{"version":"2.1.247","state":"off","account":false,"baseline":false,"code_default":null}],"related":[{"name":"tengu_willow_crate","slug":"tengu-willow-crate","description":"Opening the diff panel records one event with your terminal width bucket."},{"name":"tengu_willow_mode","slug":"tengu-willow-mode","description":null},{"name":"tengu_willow_prism","slug":"tengu-willow-prism","description":"Default `false`. Turns on the Agent tool's cost steer for `pro` subscribers when `CLAUDE_CODE_AGENT_COST_STEER` is neither a true nor a false value: the Agent tool prompt gains the paragraph `**Do not spawn agents unless the user asks.**` and drops the bullet about launching several agents in one message, and the initial agent listing omits its concurrency note."},{"name":"tengu_willow_tern_applied","slug":"tengu-willow-tern-applied","description":"A writing-style prompt block can be forced on with an environment variable; otherwise it stays off."}],"url":"https:\/\/changelogs.core-directive.com\/reference\/flag\/tengu-willow-tern","family_url":"https:\/\/changelogs.core-directive.com\/reference\/flag.json"}