# Hy4 Preview: AI model fact sheet

- **Provider:** tencent
- **Released:** 2026-08-28
- **Context window:** 1,048,576 tokens
- **Parameters:** 770B total / 49B active
- **API pricing:** $0.83 / 1M input, $2.50 / 1M output
- **OpenRouter ID:** tencent/hy4-preview
- **Capabilities:** conversation, reasoning, code-generation, analysis, planning, agentic-tool-use, tool-use, function-calling

Tencent's 770B-parameter mixture-of-experts model activates 49B parameters per token. It is built for coding agents and tool-heavy workflows that need planning, context continuity and sustained execution across a 1M-token window.

Source: real side-by-side outputs, pricing and specs at https://rival.tips/models/hy4-preview