Vercel AI Gateway index: open-weight models handled 71.5% of tokens and ~23% of spend in September; DeepSeek-V4.1-Flash ran nearly half of all tokens, and Anthropic's spend share fell below half

Why it matters

【Key points】

Vercel's October AI Gateway Production Index (Oct 15), based on anonymized production traffic through its gateway to end-September:

· Open-weight models handled 71.5% of tokens in September (56% in August) and ~23% of spend, up more than fourfold from ~5% in June;

· DeepSeek-V4.1-Flash alone processed nearly half of September tokens for 2.6% of spend; Kimi K3 drove nearly half the rise in open-weight spend;

· Gateway spend was ~13x December's while average price per token fell 47%; almost one in three teams changed their most-used lab, an index record;

· Nearly 70% of spend on Chinese models went through US-based providers (under 10% in December);

· Anthropic's share of spend fell below half for the first time (63.7% → 43.9%); Opus 5.5 took 11% of spend in its first two weeks, the top September launch; decision model Jev reached 35% of paid teams in two weeks, the fastest ever, but only 0.27% of spend.

【Verifiable】

Report: https://vercel.com/blog/ai-gateway-production-index-october-2026

September report: https://vercel.com/blog/ai-gateway-production-index-september-2026

【Our read】

1. The sample is teams that chose a multi-model gateway, priced at list rates; it undercounts direct enterprise contracts with OpenAI and Anthropic.

2. Still, the direction is clear: cheap open weights are taking token volume and money is starting to follow.

3. Chinese open models increasingly earn revenue for US hosts, which blurs "Chinese model" vs "US revenue" in export-control debates.