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Week 39, 2026

Sep 21 to 27, 2026

Week 21 recap

Week 21: Opus 5.5 and GPT-6 Sol and Luna cut prices on the same day, Claude got a marketplace, and last week's Sunday launches took the board

Week 21 was a week where the ground moved under everyone building on AI. On Tuesday Anthropic shipped Claude Opus 5.5 at $4 in and $20 out per million tokens, 20% under Opus 5 and about 40% cheaper on real work, and OpenAI answered the same day with GPT-6 Sol and Luna at half the price of the GPT-5.6 line. On Wednesday Claude got a marketplace with more than 2,000 plugins and connectors, and a way for small builders to sell into enterprise budgets that already exist. By Friday all four new models, Grok 4.7 included, were in the GitHub Copilot picker, alongside local sandboxing for agents.

The bigger picture came from Vercel's gateway index: open-weight models ran 56% of all tokens in August for 14% of the spend, while Anthropic still took 64% of every dollar. If you budgeted against August's price list, re-run your evals this week.

Read the full week 21 recap

101 launches this week

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