GPT-5.6 Terra
openai/gpt-5.6-terraGPT-5.6 Terra is the middle tier of OpenAI's GPT-5.6 reasoning family, with text and image input, and is described by OpenAI as a balanced model for everyday work; it roughly corresponds to the mini tier of earlier GPT-5 families. It suits day-to-day coding, analysis and agentic tasks that need solid reasoning without flagship-level depth. Choose GPT-5.6 Sol for the most demanding work, GPT-5.6 Luna for the highest-volume tasks, or Terra Pro for hard individual requests.
- Input price
- $1.80
$2.00USD / 1M tokens - Output price
- $10.80
$12.00USD / 1M tokens - Context window
- 1.1M
- Max output
- 128K
Try the model
Playground
Try a prompt
Your response will appear here
Choose an example or write a prompt, then click Run.
Model card
Specifications
Pricing
- Input
- $1.80 / 1M tokens
- Output
- $10.80 / 1M tokens
- Cache read
- $0.18 / 1M tokens
- Cache write
- $2.25 / 1M tokens
Context & modalities
- Context window
- 1,050,000 tokens
- Max output
- 128,000 tokens
- Input
- Text, image
- Output
- Text
Capabilities
- Chat
- Supported
- Vision
- Supported
- Reasoning
- Supported
- Structured output
- Supported
- Function calling
- Supported
- Audio input
- Not supported
Access
- Provider
- OpenAI
- Model ID
- openai/gpt-5.6-terra
- Execution
- sync
- Base URL
- https://api.sandbase.ai
- API
- Responses API
- Endpoint
- /v1/responses
- API
- Chat Completions API
- Endpoint
- /v1/chat/completions
Independent evaluations
Benchmarks
Scores on standardized evaluations, compared with other models on SandBase.
Metrics sourced from Artificial Analysis · Intelligence Index v4.3
Start building
Send your first request
Choose either supported API with unified authentication and usage tracking.
# The quoted heredoc keeps Unicode and shell metacharacters unchanged.
result=$(curl --fail-with-body --silent \
-X POST "https://api.sandbase.ai/v1/responses" \
-H "Authorization: Bearer $SANDBASE_API_KEY" \
-H "Content-Type: application/json" \
--data-binary @- <<'SANDBASE_JSON'
{
"model": "openai/gpt-5.6-terra",
"input": "Hello",
"max_output_tokens": 2048
}
SANDBASE_JSON
)
printf '%s\n' "$result"Choose your model
Compare models
| Model | Context | Input / 1M | Output / 1M | Released |
|---|---|---|---|---|
GPT-5.6 TerraThis model OpenAI | 1.1M | $1.80 | $10.80 | Jul 9, 2026 |
OpenAI | 1.1M | $2.00 | $10.00 | Sep 29, 2026 |
OpenAI | 1.1M | $2.00 | $10.00 | Sep 29, 2026 |
OpenAI | 1.1M | $0.10 | $0.50 | Sep 22, 2026 |
OpenAI | 1.1M | $0.10 | $0.50 | Sep 22, 2026 |
OpenAI | 1.1M | $2.00 | $10.00 | Sep 22, 2026 |
Questions
FAQ
How do I call OpenAI GPT-5.6 Terra through SandBase?
Create a SandBase API key, then send requests with the model ID "openai/gpt-5.6-terra" to Responses API (/v1/responses) or Chat Completions API (/v1/chat/completions) at https://api.sandbase.ai. The request examples on this page show the exact payload.
How much does OpenAI GPT-5.6 Terra cost?
$1.80 per 1M input tokens and $10.80 per 1M output tokens with the current 10% discount (list price $2 / $12), billed per request from your SandBase balance.
What is the context window of OpenAI GPT-5.6 Terra?
1.1M tokens of context, with up to 128K output tokens per response.
How does OpenAI GPT-5.6 Terra score on benchmarks?
OpenAI GPT-5.6 Terra scores 42.1 on the Artificial Analysis Intelligence Index (v4.3), ranking #16 of 84 models on SandBase; Coding Index 76.7, Agentic Index 43.2. Source: Artificial Analysis, measured as GPT-5.6 Terra (Max).
Which features does OpenAI GPT-5.6 Terra support?
OpenAI GPT-5.6 Terra supports vision (image input), reasoning, function calling, structured output. See Specifications above for the full list.
Do I need a separate OpenAI account?
No. One SandBase API key and balance gives you access to OpenAI GPT-5.6 Terra and the other models in the catalog; you do not need to sign up with OpenAI separately.