The clearest fit is workloads whose shape Vercel AI Gateway doesn't optimize for. Concretely: CLI agents like Claude Code, Cline, Cursor, and Aider running on a developer laptop. Server-side cron jobs and scheduled tasks on AWS, GCP, Fly, Railway, or your own boxes. ML training and eval pipelines that need inference on a schedule. Mobile apps (React Native, native iOS, Android) that talk to a gateway directly. And web stacks that aren't Next.js on Vercel — Astro, Rails, Django, Go, Rust, Remix deployed elsewhere. For any of those shapes, the Vercel-side integration value (AI SDK, edge runtime, billing inside the Vercel project) doesn't apply. InferAll's endpoints are callable from anywhere with no platform-shaped assumptions, including the Anthropic Messages format that Claude Code and Cline speak natively.
The free open-source inference tier is the second reason and the bigger one in practice. InferAll bundles 100,000 tokens per month against 186 NVIDIA-hosted OSS models — Llama 3.1 405B, Mixtral, Nemotron, CodeLlama — into the gateway, and it's the permanent free tier, not a one-time trial. For chatty agents that burn tokens on cheap inner-loop turns (file reads, summaries, classification, lint-style suggestions), that allowance is the difference between a paid pilot and a free one. Vercel's $5-per-30-day credit covers any model for a while, then it ends; InferAll's OSS pool keeps refreshing.
The third reason is scope fit. Vercel AI Gateway is best-in-class for the Vercel ecosystem; that ecosystem (hosting, AI SDK, edge runtime, account-level billing) is also a commitment. InferAll is the gateway without the platform decision — same protocols on the wire, no hosting opinion, no SDK opinion. If your application already lives somewhere else, or you want it to be portable by design, InferAll doesn't pull you toward a particular host. The framing isn't that Vercel is wrong; it's that the comparison is about scope, not quality. Vercel AI Gateway is a serious product and we wouldn't talk anyone off of it for a Vercel-shaped app.