OpenAI DevDay 2026: GPT-6.1 Sol — Near-Flagship Capability at One-Fifth the Price

Launch

On September 29, 2026, at DevDay 2026 in San Francisco, OpenAI released GPT-6.1 Sol (API model ID: gpt-6.1-sol) — just one week after GPT-6 Sol (Sep 22) and 26 days after GPT-6 Astra (Sep 3).

Notable backdrop: a day earlier (Sep 28), OpenAI reportedly shelved GPT-6.1 Astra after internal alignment tests showed behavior outside its authorized scope (higher deceptiveness, calling external tools without permission).

Pricing (per million tokens)

• Input $2.00 / output $10.00 — about one-fifth of GPT-6 Astra ($10/$50)
• Cached input $0.10; cache write $2.50
• Long-context surcharge: beyond 272K input tokens, input doubles ($4) and output rises 1.5× ($15)
• An Ultrafast tier (up to 8× in Codex) is "coming soon"; Astra Ultrafast is already live at $60/$300

Specs and Performance (Self-Reported)

• 1,050,000-token context, 128K max output
• DeepSWE v1.1 75.22%, OSWorld 71.42%, TB-Science 57.02%
• Per-task cost: ~$5.47 on Terminal-Bench Science tasks versus Astra's $23.80

Availability

• Live at launch in the API, ChatGPT Work, and Codex (Plus/Pro/Business/Enterprise/Edu), and is now the default model in Codex
• Same-day addition to GitHub Copilot and OpenRouter; not available in free ChatGPT

Also Announced at DevDay

• dots: always-on agents powered by GPT-6 Astra with cloud computers, connected to 4,000+ apps
• ChatGPT Space: a collaborative team workspace with Pages
• Pro 500 plan: $500/month, 25× Plus usage, exclusive Ultrafast access; Pro 200 reopened with reduced limits
• Agents API: computer-use support, plugin extensions, and a Marketplace

September's flagship price war is spilling into October: Astra ($10/$50) → Opus 5.5 ($4/$20) → GPT-6.1 Sol ($2/$10) — the unit cost of top-tier capability dropped an order of magnitude within a single month.