gpt-5.6-terra — API, Pricing & Context Window | Vivgrid
gpt-5.6-terra on Vivgrid: OpenAI's balanced gpt-5.6 model with a 1.05M-token context window, strong coding, and geo-distributed acceleration.
gpt-5.6-terra is the balanced model in OpenAI's gpt-5.6 family and the successor to gpt-5.4, delivering most of gpt-5.6-sol's coding and reasoning quality at half the price. Its 1.05M-token context window makes it a strong default for production agents. For new projects, gpt-6.1-terra is the latest terra release, at under half the input and output price.
On Vivgrid, gpt-5.6-terra is served through a single OpenAI-compatible endpoint with geo-distributed acceleration across AMER and EMEA, reachable with the same unified key as the rest of the catalog.
Specifications
| Provider | OpenAI |
| Model ID | gpt-5.6-terra |
| Best for | Coding |
| Available on | Chat Completions, Vibe coding |
| Context window | 1,050,000 tokens |
| Max output | 128,000 tokens |
| Modalities | Text, Image |
| Tool / function calling | Yes |
| Knowledge cutoff | 2026-03 |
| Acceleration | ⚡ Geo-Distributed — AMER, EMEA |
Pricing
Pricing in USD per 1M tokens.
| Input | Cached input | Output |
|---|---|---|
| $2.50 | $0.25 | $15.00 |
What one request costs
The rates above applied to a 20K-token prompt with a 2K-token reply — a typical single agent turn, small enough that every request is billed at the base rate.
| Request | Cost |
|---|---|
| Cold prompt, nothing cached | $0.0800 |
| Warm prompt, 90% of the input served from cache | $0.0395 |
Requests beyond 272K input tokens are billed at the long-context rate: $5.00 input / $0.50 cached input / $22.50 output per 1M tokens.
API surfaces
The Vivgrid Console catalogs gpt-5.6-terra on 2 surfaces, all behind the same API key. The endpoint shown is the one the Console previews for that surface.
| Surface | Primary endpoint | Use it for |
|---|---|---|
| Chat Completions | /chat/completions | Agent projects, where Vivgrid injects the model, system prompt and tools server-side, and Model API calls that name the model per request. |
| Vibe coding | /chat/completions | Coding CLIs and IDE agents that drive the model themselves — point the tool at Vivgrid and keep your own loop. |
Quick start
Get an API key from the Vivgrid Console, then call gpt-5.6-terra directly.
curl https://api.vivgrid.com/v1/chat/completions \
-H "Authorization: Bearer $VIVGRID_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-5.6-terra",
"messages": [
{ "role": "user", "content": "Say hello in English, Chinese and Spanish." }
],
"stream": true
}'Ideal use cases
- Production coding agents balancing quality, speed, and cost
- Whole-repository analysis within a 1.05M-token context
- High-volume tool-calling workflows on Chat Completions
- Teams standardizing on one model across coding and agent tasks
Related models
- gpt-6.1-terra — the next terra release, on the gpt-6 generation at under half the input and output price
- gpt-5.6-sol — the flagship gpt-5.6 model
- gpt-5.6-luna — the fast, low-cost gpt-5.6 model