{"version":"2.1.36","anchor":"fast-mode","canonical_anchor":"fast-mode","heading":"Fast Mode","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.36\/e\/fast-mode","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.36","markdown":"### Fast Mode\n\n**What**\n\nHigh-speed output mode for Claude Opus 4.6 that provides faster token generation without switching to a different model. Currently available as a research preview.\n\n**Usage**\n\n`# Toggle fast mode from the prompt \/fast # Or configure in settings.json { \"fastMode\": true }` **Details** - Uses the same Opus 4.6 model with accelerated output generation - Billed as extra usage at a premium rate with separate rate limits - Interactive toggle shows current status: \"Fast mode ON\" or \"Fast mode OFF\" - When enabled, displays with the penguin icon (\u21af) and orange color theming - Has its own rate limits; when reached, enters a cooldown period and automatically re-enables when reset - Model automatically switches to Opus 4.6 if not already selected **Availability**:\n\n- Requires a paid subscription\n- Requires extra usage billing to be enabled (`\/extra-usage`)\n- Requires the native binary (not available via npm install)\n- Not available on Bedrock, Vertex, Foundry, or in the Agent SDK\n- Organizations can disable fast mode for their accounts\n\n**Rate Limiting**:\n\n- Displays \"Fast limit reached and temporarily disabled \u00b7 resets in X\" when hitting limits\n- Shows \"Fast limit reset \u00b7 now using fast mode\" when cooldown expires\n- Tracks remaining time to reset in the UI\n\n**Promotions**:\n\n- May show discount percentages for extra usage (e.g., \"50% off through [date]\")\n\n**Evidence**\n\nFast mode system (search for `\"Fast mode\"`, `\"tengu_penguins_enabled\"`, `\"\/fast\"`)\n\n- Flag `tengu_penguins_enabled`: On for this account, and not off by default (read for one account on one subscription tier against v2.1.36; this account: on, anonymous baseline: on, compiled default: no gate table built for this version) 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."}