S Flagship capability
Sol
gpt-5.6-sol
Complex production work where quality, coding, knowledge work, and difficult multi-step execution matter most.
OpenAI model family / GPT-5.6 Generally available · July 9, 2026
Sol Terra Luna
GPT-5.6 has three tiers, not one default answer.
OpenAI positions Sol for flagship capability, Terra for balanced everyday work, and Luna for efficient throughput. Provider availability is confirmed; Flowith availability must be checked separately.
Family map
Choose by operating role
The tier names are durable roles. Exact limits, pricing, and features should always be checked in the live OpenAI docs.
T Balanced everyday work
Terra
gpt-5.6-terra
Strong general performance when a workflow needs a lower-cost role than the flagship tier.
L Fast, efficient throughput
Luna
gpt-5.6-luna
High-volume or latency-sensitive work where efficiency is the primary model-selection constraint.
Availability boundary
Provider access is not Flowith access
OpenAI's announcement establishes availability on its own surfaces. It does not establish a Flowith launch, account entitlement, free-credit offer, or model mapping.
Surface What official evidence supports Flowith interpretation
ChatGPT
OpenAI says GPT-5.6 is available, with tier and effort access depending on the user's plan.
Not evidence of Flowith access.
Codex
OpenAI says the GPT-5.6 family is available in Codex, with plan-dependent model choices.
Separate OpenAI product surface.
OpenAI API
OpenAI documents Sol, Terra, and Luna model IDs for API use.
Does not confirm a Flowith model mapping.
Flowith
No internal launch evidence was found for GPT-5.6 during this route review.
Verify in the live workspace model selector.
Selection protocol
Three checks before you switch
Choose the tier by role
Start with Sol for frontier capability, Terra for balanced work, or Luna for efficient throughput. Do not collapse a multi-model workflow into one tier without evaluation.
Confirm the product surface
ChatGPT, Codex, the OpenAI API, and Flowith have separate access and entitlement boundaries. Verify the surface you will actually use.
Test the real contract
Measure task success, output completeness, latency, token use, tools, and structured-output behavior on representative work before switching.
Primary sources
Read the live OpenAI record
Use the announcement for the availability event and the model guide for current implementation details.
Related model routes
GPT-5.2 Review the former flagship's documented variants and a safe migration handoff to the current family. DeepSeek V4 Compare another coding and long-context route while keeping provider and Flowith access boundaries separate. Gemini 3.1 Compare a Google model route when the task depends on a different multimodal or provider boundary. Grok 4 Review another reasoning route when live-answer style analysis is a core workflow requirement.
GPT-5.6 questions, answered
GPT-5.6 is OpenAI's model family launched for general availability on July 9, 2026. The family includes Sol, Terra, and Luna tiers for different capability, cost, and throughput roles.
Sol is the flagship tier, Terra is the balanced lower-cost tier, and Luna is the fastest and most affordable tier. Choose by workload requirements rather than treating the family as one interchangeable model.
OpenAI documents gpt-5.6-sol, gpt-5.6-terra, and gpt-5.6-luna. The gpt-5.6 alias routes to gpt-5.6-sol according to the current model guidance.
OpenAI says GPT-5.6 is available across ChatGPT, Codex, and the OpenAI API, with plan-dependent access. Those provider surfaces do not automatically establish availability inside Flowith.
This page does not claim that GPT-5.6 is currently available on Flowith. Check the live Flowith workspace model selector and account entitlements before planning a workflow.
Test a migration on representative tasks first. Preserve the endpoint, tools, output contract, reasoning behavior, latency role, and cost role before adopting new GPT-5.6 features.
Start with Sol when quality is the priority, Terra for a balanced everyday role, and Luna for efficient high-volume work. Validate the choice against your own task-success, latency, and cost requirements.