September 23, 2026
Agent coding got cheaper: GPT-6 Sol and Luna API prices are down 50%
On September 22, OpenAI cut GPT-6 Sol and Luna API prices by 50% compared with GPT-5.6 promotional pricing. GPT-6 Sol costs $2 per million input tokens and $10 per million output tokens. GPT-6 Luna costs $0,10 and $0,50.
OpenAI
@openai
Meet GPT-6 Sol and GPT-6 Luna in the GPT-6 universe. GPT-6 Sol and Luna build on the advances that underpin GPT-6 Astra, bringing many of its strengths to faster, more affordable models for work at scale. We also made caching and inference more efficient and are passing those savings on to you: API pricing for Sol and Luna is 50% below GPT-5.6 promotional pricing.
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Previously, 1 million GPT-5.6 Sol input tokens cost $4. OpenAI now charges $2. Luna's input price fell from $0,20 to $0,10, while output fell from $1,20 to $0,50.
For agent work. Sol is designed for complex coding and agentic scenarios. Both models have a 1 050 000-token context window and support up to 128 000 output tokens. The API uses the identifiers `gpt-6-sol` and `gpt-6-luna`.
Where they are available. Sol and Luna are already available in ChatGPT Work and Codex for Plus, Pro, Business, Enterprise, and Edu. Free and Go users get Luna in the desktop app.
OpenAI says cached input reads for GPT-6 receive a 90% discount.
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