{"version":"2.1.269","anchor":"model-parameter-allowlist-changed-from-array-to-set","canonical_anchor":"model-parameter-allowlist-changed-from-array-to-set","heading":"Model-parameter allowlist changed from array to Set","tier":"internal","area":"Elsewhere","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.269\/e\/model-parameter-allowlist-changed-from-array-to-set","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.269","markdown":"### Model-parameter allowlist changed from array to Set\n\nInternal list of allowed API request fields switched from an array to a Set\n\n**Unclear.** The finding does not say where this allowlist is used or what request handling it affects.\n\n**What**\n\nA behind-the-scenes list of top-level fields allowed in Claude API requests (things like `model`, `system`, and `tools`) was changed from a plain array to a `Set`, an internal data structure used for faster membership checks.\n\n**Why**\n\nThis is an internal efficiency change with no visible effect on how Claude Code behaves.\n\n- Area: Elsewhere\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 0\/5"}