Seventeen distinct models were first listed on OpenRouter in September 2026, from thirteen vendors: Anthropic, DeepSeek, Google, Inception, InclusionAI, Inference.net, Meta, OpenAI, Prism ML, Qwen, Sakana, Unbiased and Z.ai.
That brings 2026 to 156 models across 34 vendors so far.
Monthly release counts
There is no steady cadence to read here. The spread runs from 9 to 25 models a month with no visible rhythm, which is worth saying plainly because a lot of coverage treats a busy fortnight as a trend.
What moved at the top
The Intelligence Index ceiling in our catalog rose from 51 to 53 during the month. Claude Fable 5.1 (1 September) and GPT-6 Astra (3 September) both sit at 53, above Claude Opus 5's 51 from July.
The rest of the September frontier cohort, by index score:
A two-point ceiling rise in a month is real but modest. The more consequential movement in September was underneath: several models landed in the 40-to-48 band at prices that band has not previously seen.
On "what is coming next"
Nothing. Not in the sense that nothing is coming — in the sense that no frontier lab publishes a forward roadmap, and we are not going to invent one.
What the record does support is narrower and more useful. Eight models appeared on OpenRouter after 10 September that carry no Artificial Analysis Intelligence Index score yet, including Z.ai's GLM-5.3 FlashX, Sakana's Fugu Ultra v2 and Fugu Max, and Inception's Mercury 2.5. A model without an independent score is not a model without merit; it is a model whose ordering we cannot defend yet, so it is not in this catalog. Several of them will be, once scored.
That is the whole mechanism: a release is news when someone outside the vendor has measured it. Until then it is an announcement.
Release counts are distinct non-variant model listings on OpenRouter by first-seen date. Index scores are from each model's Artificial Analysis page, which states the index version alongside the number. Every figure carries its source and date on the model pages.
