Open-weight models carry a majority of tokens on Vercel's AI Gateway for the first time (56% in August 2026)
Vercel's AI Gateway Production Index for September 2026 (published Sept 17) reported that open-weight models processed 56% of all tokens routed through its gateway in August 2026, up from 13% in April and under 10% in December 2025. It was the first month with an open-weight majority. Open models took only 14% of spend, however, and Anthropic took 64% of gateway spend.
Key facts
- Open-weight share of gateway tokens: under 10% (Dec 2025) → 13% (Apr 2026) → 56% (Aug 2026); CEO Guillermo Rauch said the daily share peaked at 62% on Aug 22 (per press)
- Spend vs volume: open-weight models were 56% of tokens but 14% of spend in August
- Anthropic: 64% of gateway spend in August; Claude Opus 5 rose to 22.5% of spend
- DeepSeek became the second-largest source of tokens, at about a quarter of the total, more than twice Google's ~11% (press summaries of the index)
- Average price per token fell 23.2% in August, the third straight monthly drop; the median team paid 7.6% less per token
- Launch comparison: in their first 12 days at identical prices, GPT-6 Astra took 7.7% of gateway spend vs 3.7% for Claude Fable 5.1, and was adopted by twice as many teams
- Method: anonymized AI Gateway traffic through August 2026; counts input, output, reasoning, cached-input and cache-creation tokens; spend estimated at list prices
- Caveat: one gateway's customer mix (largely developers building apps on Vercel), not the whole market
What happened
Vercel publishes a monthly index of anonymized traffic through its AI Gateway, which routes production apps' requests to model providers. The September 2026 edition (by Amelia Charles and Eric Dodds) found that open-weight models, led by Chinese models such as DeepSeek, handled most tokens in August. The Financial Times and others reported the figure in late September. Closed models still captured most of the money: Anthropic alone took 64% of spend. The report also compared the first 12 days of GPT-6 Astra and Claude Fable 5.1, which launched at the same price.
Why it matters
This is one of the few public measurements of what production apps actually run. High-volume, cost-sensitive work is shifting to cheap open-weight models, while premium closed models keep revenue on harder tasks, a "barbell" pattern. Because the data comes from one gateway, it shows a trend rather than overall market share.
Changelog
- 2026-10-04: created (resolves a leads.md data-point line; FT coverage Sept 27)
Related events
- OpenAI releases GPT-6 Astra, its first GPT-6 model ★★★★★
- Anthropic releases Claude Fable 5.1 and Claude Mythos 5.1 ★★★★★
- Anthropic releases Claude Opus 5 — near-Fable-5 intelligence at half the price ★★★★
- Anthropic says it has never advocated a ban on open-weights models, after Jensen Huang's industry letter ★★★
Sources (4)
- officialVercel: AI Gateway Production Index, September 2026 (open-weight models take 56% of token volume)
- pressIT Brief: Open-weight AI models take majority of Vercel traffic
- pressTechstrong.ai: Open-weight AI models seize token lead, but proprietary systems still make the money
- pressTrending Topics: Open-weight models from China are capturing a growing share of AI usage
id: 2026-09-17-vercel-open-weight-models-majority-tokens · updated 2026-10-04 · open in the interactive timeline