# gpt-5.6-terra — API, Pricing & Context Window

gpt-5.6-terra on Vivgrid: OpenAI's balanced gpt-5.6 model with a 1.05M-token context window, strong coding performance, 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.

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 |
| **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, matching the provider's rates.

| Input | Cached input | Output |
| --- | --- | --- |
| $2.50 | $0.25 | $15.00 |

## Quick start

Call `gpt-5.6-terra` through Vivgrid's unified, OpenAI-compatible endpoint. Get an API key from the [Vivgrid Console](https://console.vivgrid.com/).

```
    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
      }'
    ```

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.

## 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-5.6-sol](/content/docs/models/gpt-5.6-sol/index.html) — the flagship gpt-5.6 model
- [gpt-5.6-luna](/content/docs/models/gpt-5.6-luna/index.html) — the fast, low-cost gpt-5.6 model
- [gpt-5.4](/content/docs/models/gpt-5.4) — the prior-generation model at this tier