# gpt-5.5 — API, Pricing & Context Window | Vivgrid

> Source: https://vivgrid.com/docs/models/gpt-5.5

Run OpenAI's gpt-5.5 on Vivgrid: a 1.05M-token flagship coding model for agents and CLIs, with geo-distributed acceleration and a unified API.

`gpt-5.5` is OpenAI's flagship model and Vivgrid's top recommendation for coding agents. It pairs a **1.05M-token context window** with strong multi-step reasoning, making it well suited for whole-repository refactors, long agent traces, and complex tool-calling workflows.

On Vivgrid, `gpt-5.5` is served through a single OpenAI-compatible endpoint with **geo-distributed acceleration across AMER and EMEA**, so requests are routed to the nearest compute region for lower latency. You can switch your agent to `gpt-5.5` from the Console without changing a line of application code.

## Specifications

| Field | Value |
| --- | --- |
| Provider | OpenAI |
| Model ID | `gpt-5.5` |
| Best for | Coding |
| Available on | Vibe coding |
| Context window | 1,050,000 tokens |
| Max output | 128,000 tokens |
| Modalities | Text, Image |
| Tool / function calling | Yes |
| Knowledge cutoff | 2025-12 |
| Acceleration | Geo-distributed — AMER, EMEA |

## Pricing

Pricing in USD per 1M tokens.

| Input | Cached input | Output |
| --- | --- | --- |
| $5.00 | $0.50 | $30.00 |

### 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 | $0.1600 |
| Warm prompt, 90% of the input served from cache | $0.0790 |


## API surfaces

The Vivgrid Console catalogs `gpt-5.5` on one surface, all behind the same API key. The endpoint shown is the one the Console previews for that surface.

| Surface | Primary endpoint | Use it for |
| --- | --- | --- |
| 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 (https://console.vivgrid.com), then call `gpt-5.5` directly.

```bash
curl https://api.vivgrid.com/v1/chat/completions \
  -H "Authorization: Bearer $VIVGRID_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.5",
    "messages": [
      { "role": "user", "content": "Say hello in English, Chinese and Spanish." }
    ],
    "stream": true
  }'
```


## Ideal use cases

- Autonomous coding agents and CLI tools (Codex, OpenCode, Claude Code-style flows)
- Large-context tasks: reading and editing entire codebases in one pass
- High-stakes reasoning where output quality outweighs token cost
- Multi-tool agents that chain function calls across long sessions

## Related models

- [gpt-6-astra](/docs/models/gpt-6-astra) — the gpt-6 generation flagship
- [gpt-6.1-sol](/docs/models/gpt-6.1-sol) — the balanced gpt-6 model at a lower price
- [gpt-5.3-codex](/docs/models/gpt-5.3-codex) — Codex-tuned variant on the Responses API