{"name":"tengu_amber_kestrel","slug":"tengu-amber-kestrel","family":"flag","title":"Feature flags","noun":"feature flag","description":"Subagent launching gets a nesting-depth cap, a bypassable concurrency cap, and new teammate\/model-inherit rules","description_source":"entry","described_by":{"version":"2.1.269","anchor":"subagenttask-launch-pipeline-agent-tool-substantially-rew"},"presence":{"first_seen":"2.1.217","removed_in":null,"in_current_build":true,"newest_mined":"2.1.308","builds":80,"mined_builds":149,"first_cited":null},"aliases":[],"entries":[{"version":"2.1.284","anchor":"ultracode-becomes-an-onoff-row-in-the-effort-picker-instea","heading":"Ultracode is now an on\/off switch that works with any effort level","line":"Ultracode is no longer an effort level that forces xhigh; you turn it on or off with `\/effort ultracode on` or `off`","released_at":"2026-09-28 17:11:59","reason":"gate cited by this entry"},{"version":"2.1.284","anchor":"subagent-concurrency-cap-is-now-bypassed-only-when-ultracode","heading":"Subagent limit is skipped based on the ultracode setting instead of model and effort","line":"Claude Code skips the concurrent subagent limit only when ultracode is on and the model qualifies; effort level no longer plays a part","released_at":"2026-09-28 17:11:59","reason":"gate cited by this entry"},{"version":"2.1.275","anchor":"subagent-concurrency-cap-enforced-by-default-with-a-kill-sw","heading":"Subagent concurrency cap enforced by default, with a kill switch and CLAUDE_CODE_MAX_CONCURRENT_SUBAGENTS env var","line":"Subagents now hit a default cap of 20 concurrent runs, adjustable via CLAUDE_CODE_MAX_CONCURRENT_SUBAGENTS","released_at":"2026-09-17 20:20:31","reason":"gate cited by this entry"},{"version":"2.1.269","anchor":"subagenttask-launch-pipeline-agent-tool-substantially-rew","heading":"Subagent\/Task launch pipeline (Agent tool) substantially reworked with new caps and teammate rules","line":"Subagent launching gets a nesting-depth cap, a bypassable concurrency cap, and new teammate\/model-inherit rules","released_at":"2026-09-11 18:12:49","reason":"gate cited by this entry"}],"entries_total":4,"docs":[],"docs_total":0,"gates":[{"version":"2.1.284","state":"unknown","account":null,"baseline":null,"code_default":false},{"version":"2.1.275","state":"unknown","account":null,"baseline":null,"code_default":false},{"version":"2.1.269","state":"unknown","account":null,"baseline":null,"code_default":false}],"related":[{"name":"tengu_amber_anchor","slug":"tengu-amber-anchor","description":"Default `false`. Enables installing the background daemon as a launchctl\/systemd service: when off, `claude daemon install`, `start` and `restart` fail as disabled in this version, the `claude daemon` usage text says the daemon runs on demand, and daemon messages call it `background service` in place of `daemon`. When on and the daemon cold-start mode is `ask` (`CLAUDE_CODE_DAEMON_COLD_START`, the `daemonColdStart` setting, or the `tengu_quiet_harbor` flag), starting a background session with no daemon running can offer `claude daemon install` instead of starting one on demand, unless that prompt was dismissed or `CLAUDE_CONFIG_DIR` is set."},{"name":"tengu_amber_astrolabe","slug":"tengu-amber-astrolabe","description":"Default `false`. One of the switches that add the `autonomy_append` system prompt section (\"You are operating autonomously...\": proceed with reversible actions without asking, report findings without applying a fix when the user is only asking, finish the work before ending the turn). The section is added when `tengu_amber_sextant` is on (default `true`) and either the current model's settings turn it on or this check passes; the check passes when `CLAUDE_CODE_AMBER_ASTROLABE` is set, the client data key of this name is `true`, or this flag is on."},{"name":"tengu_amber_creek","slug":"tengu-amber-creek","description":"Accepting fullscreen now runs as a trial, and two crashed launches disable it on that machine."},{"name":"tengu_amber_ferry","slug":"tengu-amber-ferry","description":"A new mode, off unless switched on remotely, lets remote sessions start preparing a message's attachments before its files finish downloading"},{"name":"tengu_amber_flint","slug":"tengu-amber-flint","description":"Default `true`. A kill switch for agent teams: teams are enabled only when `CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS` is set or `--agent-teams` is passed, and this flag is on. Turning it off disables teams even when they were requested."},{"name":"tengu_amber_heron","slug":"tengu-amber-heron","description":"Default `false`. When true, an `Agent` tool call that does not set `run_in_background` launches the subagent as a background task. An explicit `run_in_background: false`, an in-process teammate caller, or `CLAUDE_CODE_DISABLE_BACKGROUND_TASKS` keeps it synchronous."},{"name":"tengu_amber_larch","slug":"tengu-amber-larch","description":"Before running a Bash command, Claude Code now also checks shell scripts written inline in it, such as heredocs or code passed with -c"},{"name":"tengu_amber_lark","slug":"tengu-amber-lark","description":"The usage report's analysis now calculates the most sessions running at the same time, adds per-day and per-week detail, and blanks some recommendations"},{"name":"tengu_amber_lattice","slug":"tengu-amber-lattice","description":"Default `{}`. Its `plugins` field is a list of plugin names (without the `@marketplace` suffix) whose hook commands are given the user's Anthropic credential in their environment: `ANTHROPIC_AUTH_TOKEN` set to the claude.ai OAuth access token when logged in that way, otherwise `ANTHROPIC_API_KEY`. It applies only to a plugin installed from one of Anthropic's official marketplaces, never when `ANTHROPIC_UNIX_SOCKET` is set, and subject to further provider and account checks."},{"name":"tengu_amber_lynx","slug":"tengu-amber-lynx","description":"The feedback dialog still skips one extra request when a server-side flag is on, the same as in the previous build"}],"url":"https:\/\/changelogs.core-directive.com\/reference\/flag\/tengu-amber-kestrel","family_url":"https:\/\/changelogs.core-directive.com\/reference\/flag.json"}