Tencent dropped Hy4 on November 4 — a 770-billion-parameter mixture-of-experts model that now sees images and operates computers. At roughly $0.42 per million input tokens on OpenRouter, it undercuts Claude Opus 5.5 by around ten times. The marketing says “open source” and “#1 open-weight model.” The reality is more nuanced, and developers deserve the unvarnished version.
Computer Use Is the Headline Feature #
The August 2026 Hy4 preview was text-only. This release adds something different: the model reads on-screen text, clicks UI elements, runs CLI commands, and chains tasks across multiple applications. Tencent demonstrated booking appointments, extracting spreadsheet data, and managing email workflows. For agentic work, Hy4 hit 78.9 on OSWorld 2.1 — Claude Opus 5.5 leads at 81.8, but that gap is small enough to matter when you factor in cost.
The model was specifically post-trained for professional tooling: Blender, CAD applications, Unreal Engine, Unity, and Godot. If you’re building agents that need to operate real software rather than just generate code, that targeted training is worth noting.
How to Access Hy4 Today #
You don’t need to wait for weights. Hy4 is live right now across several platforms:
- OpenRouter — model ID
tencent/hy4, available immediately - CodeBuddy and WorkBuddy — free through November 15, 2026
- Tencent Cloud TokenHub — 50% off through December 31, 2026
- Hermes and OpenCode — rolling out now
The OpenRouter integration means you can drop it into any OpenAI-compatible client. Change the base URL to https://openrouter.ai/api/v1 and set the model to tencent/hy4 — that’s the full migration.
The Price Math (With a Catch) #
List price is $0.834/$2.501 per million input/output tokens. OpenRouter’s promotional rate brings that down to roughly $0.42/$1.25 — about ten times cheaper than Grok 4.7 and thirteen times cheaper than Qwen3.8 Max at comparable capability levels.
The catch: Hy4 is verbose. Third-party analysis found it averaging 160 million output tokens against a 75 million median for similar models. That doubling of output volume can quietly eat the per-token savings. If you’re running high-volume pipelines, benchmark your actual token usage before committing.
Benchmarks: The Honest Picture #
All twelve benchmarks in Tencent’s launch materials are Tencent-reported. No independent verification exists yet for the full November model. Keep that in mind:
- Finance workflows: Ranked first among open-weight models in an evaluation with 213 experts on 579 real-world tasks (3.04 vs. DeepSeek-V4.1-Flash’s 2.97)
- SWE-bench Multilingual: 82.9% resolved — a solid result for multi-language code repair
- Coding agents: 30.0 on ProgramBench versus Claude Opus 5.5’s 56.5 — a meaningful gap
- Terminal automation: 44.4 on Terminal Bench 4.0 versus Kimi K3.1 Pro’s 66.8 — not ideal for pure CLI work
- Math: 13.0 on Frontier Math versus GPT-6.1 Sol’s 97.5 — do not use this for quantitative reasoning
Third-party hallucination testing also surfaced an 89% rate — a stark contrast to Tencent’s claimed 5.45%. Different evaluation sets likely explain the discrepancy, but the variance is wide enough to treat both numbers as directional, not authoritative.
“Open Source” Is Still a Pledge #
This needs saying plainly: Tencent is calling Hy4 open source, but the model weights are not publicly available as of November 6. The Hugging Face repository for tencent/hy4 returns a 401 error. The GitHub repo returns a 404. The August 2026 preview shipped with Apache 2.0, but that license does not automatically extend to the full release. Tencent says weights and a system card are coming “in the coming days.” Until then, you’re using a hosted API, not open-source software.
When to Use Hy4 vs. the Alternatives #
Hy4 earns its place for finance and document workflows, long-context tasks that fill the 1M-token window, and computer-use agents where cost pressure is real. For coding accuracy and terminal automation, Claude Opus 5.5 and Kimi K3.1 Pro still lead on the available numbers. Once weights drop, the self-hosting story changes — Hy4 becomes a compelling option for teams with data-residency requirements that can’t use hosted APIs.
Use it free in CodeBuddy through November 15 and form your own opinion before the promotional window closes.