OpenAI spending on OpenRouter topped Anthropic last week, with Astra model taking 19% share

OpenRouter’s latest data shows that user spending on OpenAI models exceeded spending on Anthropic last week, marking the first time this has happened since February 2024. That shift ended Anthropic’s two-and-a-half-year lead on the platform. The biggest change came from Astra, whose model captured about 19% of combined spending across OpenAI and Anthropic models, ahead of Opus 5 at 16%. GPT-5.6 Sol and Luna each accounted for roughly 10%. The rebound in OpenAI’s share did not start last week alone. According to the data cited by ChainCatcher, usage on OpenRouter climbed quickly after Terra and Luna saw major price cuts this summer, and some users kept using the models even after the discounts ended. After Astra launched, OpenAI’s spending share eventually moved above 50%. OpenRouter’s figures only reflect relative spending between OpenAI and Anthropic on its own platform. The data should not be treated as a direct measure of the broader API market or either company’s total revenue.