GPT-6 Astra Release: Capabilities and API Limits
OpenAI released GPT-6 Astra on September 3, 2026. This model targets end-to-end tasks like coding and research but removes support for specific sampling…
Official Announcement and Scope
OpenAI announced the release of GPT-6 Astra on September 3, 2026. The official changelog identifies the model identifier as gpt-6-astra and lists compatibility with the v1/responses and v1/chat/completions APIs. The documentation characterizes the model as built for the hardest end-to-end work. It is intended for use in reasoning, coding, computer use, research, and document creation. The source states that the model combines these capabilities to carry complex tasks from an initial request to a finished result using provided context and tools.
- Model name: GPT 6 Astra
- Provider: OpenAI
- Input modality: text
- Output modality: text
Documented Parameter Constraints
The changelog specifies key changes engineers must consider when migrating workflows to this model. The source explicitly records that GPT-6 Astra does not support the 'none' reasoning effort level. Furthermore, the model does not support custom temperature or topp values. It also does not support log probabilities (logprobs). These constraints define the current parameter compatibility for this specific release. The source does not provide information regarding pricing, context window size, or maximum output tokens.
- Unsupported: 'none' reasoning effort level
- Unsupported: Custom temperature values
- Unsupported: Custom topp values
- Unsupported: Log probabilities (logprobs)
Evaluation Procedure and Evidence Limits
To evaluate GPT-6 Astra, engineers can design a controlled test suite. First, select a representative set of complex tasks involving coding or research. Second, measure the output quality and completion rate for each task using GPT-6 Astra. Third, compare these results with outputs from other models using identical prompts and contexts. Finally, validate whether the removal of custom temperature and topp settings impacts the consistency of generated code or documents in your specific use case. The source confirms the release date, supported APIs, and listed parameter limitations. It does not confirm performance rankings, cost savings, or local installation requirements. The record indicates open weights are not confirmed, which does not establish whether local installation is possible or impossible.
Artificial Analysis benchmark review
Benchmark review updated on . These scores apply to the linked artifact and recorded methodology; they do not establish the performance of a different runtime or quantized model.
| Measurement | Recorded result | Measured |
|---|---|---|
| Artificial Analysis Coding Index (v4.1) ↗ | 76.9 index_points | 2026-09-04 |
| Artificial Analysis Coding Index (v4.2) ↗ | 76.9 index_points | 2026-09-05 |
| Artificial Analysis Coding Index (v4.3) ↗ | 76.9 index_points | 2026-09-20 |
| Artificial Analysis Intelligence Index (v4.1) ↗ | 61.2 index_points | 2026-09-04 |
| Artificial Analysis Intelligence Index (v4.2) ↗ | 54.7 index_points | 2026-09-05 |
| Artificial Analysis Intelligence Index (v4.3) ↗ | 52.7 index_points | 2026-09-20 |
Review the full benchmark provenance and source methodology →
Primary sources
Frequently asked questions
What is the status of open weights for GPT-6 Astra?
The source records that open weights are not confirmed for GPT-6 Astra. This status does not establish that local installation is impossible, nor does it specify hosting arrangements beyond the documented API access.
Which specific parameters are unsupported by GPT-6 Astra?
According to the official changelog, GPT-6 Astra does not support the 'none' reasoning effort level, custom temperature values, custom topp values, or log probabilities (logprobs).