This week's AI launch calendar turned into a street fight. Anthropic shipped Claude Opus 5.5 on September 22, pricing it around $4/$20 per million input/output tokens — roughly 20% cheaper than Opus 5, and reportedly about 40% cheaper on typical real workloads. Roughly 90 minutes later, OpenAI answered with not one but two models: GPT-6 Sol at $2/$10 per million tokens and GPT-6 Luna at just $0.10/$0.50 — about half of GPT-5.6's promotional pricing.

Both labs are aiming their price guns at the same target: coding and agent workloads, where API volume is highest and margins thinnest. Anthropic has owned the coding-agent narrative all year, and OpenAI's Sol/Luna pricing is a direct bid to undercut it. For builders, the practical upshot is hard to argue with: frontier-class intelligence keeps getting dramatically cheaper. A year ago these token prices would have been unthinkable; today the battle is being fought over fractions of a cent per million tokens.

The question worth watching is who feels the squeeze first. A price war between the two best-funded labs is great news for developers and agent startups — and a rough environment for every model company that has to raise capital at old-economy margins. If you're building on top of these models, keep your provider abstraction clean: this war has a long way to run. Compare the chatbots themselves in our Claude vs Gemini comparison and the free ChatGPT alternatives roundup.

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