{"version":"2.1.323","anchor":"model-wait-gate-and-claude-code-subagent-model-checks","canonical_anchor":"model-wait-gate-and-claude-code-subagent-model-checks","heading":"The server-sent model mix recipe can be awaited at startup and reused from cache","tier":"soon","area":"Models","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.323\/e\/model-wait-gate-and-claude-code-subagent-model-checks","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.323","markdown":"### The server-sent model mix recipe can be awaited at startup and reused from cache\n\nClaude Code can wait for the server's model mix recipe before its first request, and can reuse a previously served recipe when none is sent\n\n**Unclear.** How long this wait can hold up the first request is not stated.\n\n**What**\n\nAnthropic's server can send a model mix recipe. The recipe names a lead model for the main conversation and a worker model for subagents, which are helpers Claude starts to work on part of a task. Two changes affect how that recipe is obtained.\n\n- A new step can make Claude Code wait for a served recipe before sending its first request. It runs only when the lead and worker models match and neither `CLAUDE_CODE_SUBAGENT_MODEL` nor `CLAUDE_CODE_SUBAGENT_MODEL_FORCE` is set. It is controlled by the remote switch `tengu_zesty_horizon_wait`, which defaults to on.\n\n- When the downloaded client data has no `tengu_zesty_horizon` entry, Claude Code can now fall back to a cached recipe it was served before (`servedMixRecipe`). Before, it simply had no recipe.\n\n- The fallback is used only when the account epoch matches and the run is neither non-interactive nor an SDK run. The cached recipe's lead model must also equal the model it was served for.\n\n- Each recipe is tagged with its source, either \"served\" or \"document\".\n\nNothing has been read about the `tengu_zesty_horizon_wait` or `tengu_zesty_horizon` switches.\n\n**Why**\n\nThe model mix no longer disappears when the downloaded data happens to leave it out. Startup may pause briefly while the recipe is fetched, but only when you have not chosen subagent models yourself.\n\n- Flag `tengu_zesty_horizon_wait`: Not enough to say (read for one account on one subscription tier against v2.1.323; this account: no value returned, anonymous baseline: no value returned, compiled default: on) These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.\n- Area: Models\n- Tier: Nothing to try yet\n- Useful: 4\/5\n- Signal: 5\/5\n- Scope: individual\n- Heads-up: no\n- Present in the build but not switched on"}