VercelEngineering PostOfficial Source

AI Gateway adds unified fast mode support

AI Gateway now exposes one beta fast-mode option across models, letting coding agents request lower latency while retaining standard-speed fallback when no fast tier exists.

Vercel · Jul 31, 2026

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Source Summary

AI Gateway’s **unified fast mode is in beta**. Setting speed to fast requests a model’s fast serving tier and falls back to standard speed when unavailable; a fast-specific slug addresses that variant directly.

Practical Implication

Keep the base model ID plus the speed option when graceful fallback matters. Use a fast slug in explicit routing or fallback lists; Claude Code users can toggle supported Anthropic Opus models with **/fast** after setup.

Agent-Ready Context

AI Gateway’s **unified fast mode is in beta**. Setting speed to fast requests a model’s fast serving tier and falls back to standard speed when unavailable; a fast-specific slug addresses that variant directly.

Keep the base model ID plus the speed option when graceful fallback matters. Use a fast slug in explicit routing or fallback lists; Claude Code users can toggle supported Anthropic Opus models with **/fast** after setup.

Fast tiers usually have a **higher per-token cost**, and model coverage is still growing. Requesting fast mode where no tier exists has no effect, so inspect returned routing metadata and pricing before assuming latency changed.

Connected Context · Feed7 Judgment

This makes fast serving a common gateway control instead of a collection of model-specific choices, while preserving standard-speed fallback when latency is preferred rather than mandatory. It sharpens routing policy rather than proving a universal speedup: coverage is incomplete, fast tiers usually cost more, and clients must inspect routing metadata to confirm that a request actually used one.

Claude Opus 5 now available on AI GatewayClaude Opus 5 is a concrete supported route where the unified control can combine fast serving with reasoning settings and provider fallbacks.Kimi K3 and Kimi K3 Fast with ZDR and US-based providers now on AI GatewayKimi’s separate standard and fast endpoints illustrate the model-specific tiering that the unified speed option abstracts, while its residency and retention properties remain separate routing concerns.AI Gateway: GPT-5.6 pricing and speed updatesSol’s fast-mode improvement changes the performance of one supported tier, while unified fast mode supplies the common request mechanism; the accompanying price changes reinforce the need to evaluate cost and latency together.TRACE-ROUTER: Task-Consistent and Adaptive Online Routing for Agentic AIUnified fast mode adds a serving-speed preference, whereas TRACE-Router chooses a backend from task-level outcomes; fast-tier availability alone is therefore insufficient evidence for model selection.

Context Map

infracoding#gateways#coding-agents#model-selection

Uncertainty

Fast tiers usually have a **higher per-token cost**, and model coverage is still growing. Requesting fast mode where no tier exists has no effect, so inspect returned routing metadata and pricing before assuming latency changed.