gpt-5.6-sol — API, Pricing & Context Window | Vivgrid

gpt-5.6-sol is the flagship of OpenAI's gpt-5.6 family and the successor to gpt-5.5. It pairs a 1.05M-token context window with frontier multi-step reasoning, built for whole-repository refactors, long agent traces, and complex tool-calling workflows.

On Vivgrid, gpt-5.6-sol 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-5.6-sol from the Console without changing a line of application code.

Specifications

Pricing

Pricing in USD per 1M tokens, matching the provider's rates.

Quick start

Call gpt-5.6-sol through Vivgrid's unified, OpenAI-compatible endpoint. Get an API key from the Vivgrid Console.

curl https://api.vivgrid.com/v1/chat/completions \
  -H "Authorization: Bearer $VIVGRID_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.6-sol",
    "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: $10.00 input / $1.00 cached input / $45.00 output per 1M tokens.

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-5.6-terra — the balanced gpt-5.6 model at half the price
• gpt-5.6-luna — the fast, low-cost gpt-5.6 model
• claude-opus-4-8 — Anthropic's frontier coding model