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Harvey turns legal context into stronger drafts with GPT-6 Astra
GPT-6 Astra produces more structured, context-aware legal documents, freeing lawyers to focus on strategy.
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GPT-6
reference & signals.
GPT-6 reference: pricing, context window, API specifications, model family details and the latest primary-source updates tracked by SXF / AI.
15tracked signals
1primary sources
September 23, 2026latest tracked
MODEL REFERENCE
GPT-6 family at a glance.
GPT-6 is OpenAI’s current flagship model family, spanning Astra for the hardest end-to-end work, Sol for demanding coding and agentic workflows, and Luna for efficient high-volume tasks.
Text and image input · text output · Last verified 2026-09-26
FAMILY3flagship variants
CONTEXT WINDOW1,050,000tokens across family
MAX OUTPUT128,000tokens across family
INPUTText + image
OUTPUTText
PROVIDEROpenAI
FAMILY COMPARISON
Astra, Sol and Luna.
| Model | Positioning | Context | Max output | Input | Cached | Output |
|---|---|---|---|---|---|---|
| GPT-6 Astragpt-6-astra | Highest capability | 1,050,000 | 128,000 | $10.00 | $1.00 | $50.00 |
| GPT-6 Solgpt-6-sol | Capability / cost balance | 1,050,000 | 128,000 | $2.00 | $0.20 | $10.00 |
| GPT-6 Lunagpt-6-luna | Efficiency | 1,050,000 | 128,000 | $0.10 | $0.01 | $0.50 |
Standard API pricing per 1M text tokens for prompts up to 272K input tokens. Longer prompts use higher rates.
QUICK ANSWERS
What models are in the GPT-6 family?
OpenAI currently lists GPT-6 Astra, GPT-6 Sol and GPT-6 Luna as the flagship GPT-6 family.
What is the GPT-6 context window?
Astra, Sol and Luna each have a 1,050,000-token context window and support up to 128,000 output tokens.
How much does GPT-6 cost in the API?
For Standard API requests up to 272K input tokens, Astra is $10 input / $50 output per 1M tokens, Sol is $2 / $10, and Luna is $0.10 / $0.50. Cached-input rates are lower.
What is each GPT-6 model for?
OpenAI positions Astra for the hardest end-to-end work, Sol for complex coding and agentic workflows, and Luna for efficient high-volume tasks.