GPT-5.6 Luna

Claims and evidence

• Announced 26 June 2026Announced with GPT-5.6 Sol and GPT-5.6 Terra as a limited preview for a small group of trusted partners. ● Primary source[6]first paragraph [7]Published June 26, 2026; 1. Introduction
• Released 9 July 2026 ● Primary source[3]first paragraph; Availability and pricing [8]July, 2026: Jul 9 [1]Published July 9, 2026

• Status AvailableListed in the API model catalog and not deprecated on the deprecations page as read on 2026-10-01. ● Primary source[2]Snapshots [9]Upcoming deprecations (gpt-5.6-luna appears only as a recommended replacement)

• Successor of GPT-5.4 miniThe docs say GPT-5.6 Luna roughly corresponds to the nano model tier of earlier GPT-5 families and compare it with GPT-5.4 nano, an inline variant of the GPT-5.4 mini record; the Codex notice of 2026-07-31 names gpt-5.6-luna as the replacement for gpt-5.4-mini. ● Primary source[2]description; Quick comparison [10]2026-07-31: GPT-5.4 and GPT-5.4 mini retire from Codex on August 31

• Change · Context length Context window of 1,050,000 tokens, up from 400,000 in GPT-5.4 nano, the model of the nano tier that Luna corresponds to.Compared with GPT-5.4 mini ● Primary source[2]Model details [11]Model details
• Change · Training data Knowledge cutoff of 16 February 2026, against 31 August 2025 for GPT-5.4 nano.Compared with GPT-5.4 mini ● Primary source[2]Model details [11]Model details
• Change · Tool use Gains the API features added with GPT-5.6, including Programmatic Tool Calling and multi-agent orchestration in beta.Compared with GPT-5.4 mini ● Primary source[8]July, 2026: Jul 9

• Input text, image ● Primary source[2]Model details
• Output text ● Primary source[2]Model details
• Feature Reasoning mode ● Primary source[2]description (reasoning.effort); Model details (reasoning token support) [1]2. Model Data and Training
• Feature Function calling ● Primary source[2]Supported features
• Feature Computer use ● Primary source[2]Supported tools
• Context window 1,050,000 tokensThe docs give 922,000 maximum input tokens and 128,000 maximum output tokens. ● Primary source[2]Model details
• Parameters Not disclosedNot disclosed by OpenAI. No claim madeNo source
• Access API, consumer app, cloud partner ● Primary source[3]Availability and pricing [8]July, 2026: Jul 9 [4]July 13–17, 2026: Use GPT-5.6 through Amazon Bedrock [5]Safety and availability

Lineage

Variants

No variants recorded in this record.

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