GPT-5.6 Terra
Overview
GPT-5.6 Terra is OpenAI's balanced GPT-5.6 tier, made generally available on July 9, 2026. In the API, its model ID is gpt-5.6-terra, and OpenAI positions it for workloads that balance capability and cost.
Key Features
- Balanced GPT-5.6 Tier: Positioned between Sol and Luna for production workflows that need strong reasoning at lower cost than Sol.
- Expanded Reasoning Controls: Supports
none,low,medium,high,xhigh, andmaxreasoning effort; GPT-5.6 also supports Pro mode throughreasoning.mode: "pro". - Agentic Tooling: Supports Responses API workflows, functions, web search, file search, computer use, Programmatic Tool Calling, persisted reasoning, and multi-agent beta.
- Large Working Context: Supports a 1.05M-token context window and up to 128K output tokens, with a February 16, 2026 knowledge cutoff.
Best Use Cases
- Production Knowledge Work: Drafting, analysis, document processing, structured research, and multi-step business workflows.
- Software Engineering Assistance: Debugging, test planning, code review, repository navigation, and implementation support where cost control matters.
- Scaled Professional Automation: Tool-heavy workflows that need strong quality but do not require Sol for every request.
Capabilities and Limitations
| Capability | Description |
|---|---|
| Reasoning | Supports none, low, medium, high, xhigh, and max; API Pro mode is enabled with reasoning.mode: "pro" rather than a separate Pro model slug. |
| Coding | Official benchmark examples include SWE-Bench Pro 63.4%, DeepSWE v1.1 69.6%, and Terminal-Bench 2.1 87.4%. |
| Creative Writing | General text generation is supported. |
| Multimodal | Text and image input with text output; GPT-5.6 preserves original image dimensions for original or auto detail. |
| Response Speed | Public API latency depends on reasoning effort, tools, and processing tier; Terra is positioned as the balanced tier for intelligence and cost. |
| Context Window | 1.05M tokens. |
| Max Output | 128K tokens. |
| Tool Use | Functions, web search, file search, computer use, Programmatic Tool Calling, persisted reasoning, and multi-agent beta. |
| Multilingual | OpenAI API model documentation lists multilingual support across current models. |
Known Limitations
- Terra is positioned below Sol for capability, so the hardest quality-first workflows may need Sol, Pro mode, or higher reasoning effort.
- Higher reasoning efforts, Pro mode, multi-agent runs, and long-context use can increase latency and cost.
- Cyber and biology safeguards may refuse, block, or pause sensitive requests, including some legitimate dual-use work.
- Prompt cache writes are billed on GPT-5.6 models, so cache breakpoints should be monitored with
cache_write_tokensandcached_tokens.
Standard Pricing
The token prices below are shown in USD per 1 million tokens; web search is billed in USD per use.
| Context | Input (USD / 1M Tokens) | Cache Write (USD / 1M Tokens) | Cache Read (USD / 1M Tokens) | Output (USD / 1M Tokens) | Web Search (USD / use) | Billing Notes |
|---|---|---|---|---|---|---|
| Short context | $2.00 | $2.50 | $0.20 | $12.00 | $0.01 | Standard GPT-5.6 Terra pricing |
Credits settlement: B.AI converts charges at 1 USD = 1,000,000 Credits and deducts Credits from the account balance.
Pricing note
Prices shown in the documentation are B.AI standard reference prices for base billing purposes. B.AI may provide lower actual usage costs through top-up bonuses and account benefits. Specific prices, bonus Credits, and account benefits are subject to the platform display and final billing records.
- For GPT-5.6 models, cache writes are billed at 1.25x the uncached input rate; cache reads remain discounted at 0.1x input.