By ByteBot
Tencent dropped Hy3 on July 6 — a 295B Mixture-of-Experts model with Apache 2.0 weights, a 78.0 SWE-bench Verified score, and a free API on OpenRouter that expires July 21. If you’re choosing a coding agent backend or evaluating open-weight models for agentic workflows, you have 13 days to test it at zero cost.
What the SWE-Bench Score Actually Means
Hy3 hits 78.0 on SWE-bench Verified. That number deserves context before you act on it.
GLM-5.2 scores 84.2 on the same benchmark. Claude Sonnet 5 leads the full BenchLM leaderboard at around 87 across agentic, coding, and reasoning tasks. So Hy3 is not the top coder — and Tencent doesn’t pretend it is.
Where Hy3 leads is tool and search workloads: 84.2 on BrowseComp, 91.0 on DeepSearchQA, and 79.1 on MCP-Atlas tool orchestration — best in the open-weight field on all three. If your agent crawls the web, calls MCP servers, or does long-context retrieval, Hy3’s benchmark profile fits that workload better than its SWE-bench number suggests.
Benchmark stability is also worth noting. Tencent tested Hy3 across KiloCode, Cline, and CodeBuddy scaffoldings and reported less than 4% accuracy variance. That kind of consistency across frameworks matters in production — a model that performs differently depending on your agent harness is a reliability problem.
The Free API Closes July 21
OpenRouter’s tencent/hy3:free endpoint is live now. Cost: $0 per million tokens, input or output. On July 21, that flips to $0.20 per million input tokens and $0.80 per million output tokens.
After the free window closes, Hy3 is still substantially cheaper than alternatives — Claude Sonnet 5 runs around $3/$15 per million tokens, making Hy3 roughly 15x cheaper at the post-July-21 rate. But you won’t get another free evaluation window. The time to test it is now.
The API is OpenAI-compatible. Swap your base URL, change the model name, done:
from openai import OpenAI
import os
client = OpenAI(
api_key=os.getenv("OPENROUTER_API_KEY"),
base_url="https://openrouter.ai/api/v1"
)
response = client.chat.completions.create(
model="tencent/hy3:free",
messages=[{"role": "user", "content": "Review this function for bugs: ..."}],
extra_body={"reasoning_effort": "high"}
)
print(response.choices[0].message.content)The reasoning_effort parameter controls chain-of-thought depth: "no_think" for fast direct responses, "low" for light reasoning, "high" for complex tasks like multi-step code review or debugging. Set it wrong and you’re either wasting tokens or missing accuracy.
Apache 2.0 — No Regional Restrictions
The April 2026 preview version excluded the EU, UK, and South Korea from its license. The July 6 official release fixes that. Hy3 is now Apache 2.0 with zero geographic exclusions — self-host it, fine-tune it, ship it in commercial products, anywhere.
That matters more than it sounds. GLM-5.2 outperforms Hy3 on SWE-bench, but carries usage constraints that matter to enterprise deployments. Hy3 with a clean Apache 2.0 license at $0.20/$0.80 per million tokens post-July-21 is a different risk profile for teams that can’t accept third-party data egress or unclear regional terms.
Self-Hosting: What You Actually Need
The weights are on Hugging Face at tencent/Hy3 (BF16) and tencent/Hy3-FP8. Self-hosting a 295B MoE model isn’t casual — Tencent recommends 8 H20 GPUs or equivalent high-memory cards.
For vLLM, the relevant flags are --tool-call-parser hy_v3 and --reasoning-parser hy_v3 with --enable-auto-tool-choice. SGLang uses --tool-call-parser hunyuan and --reasoning-parser hunyuan. Both support MTP speculative decoding for faster inference.
Most teams will start with the OpenRouter API and self-host only if the use case justifies the GPU spend. That’s a reasonable progression.
What to Do Before July 21
If you run agent workflows involving web search, MCP tools, or long-context retrieval: Hy3 is the right thing to test this week. Its SWE-bench score is real but not the whole picture — the tool and search benchmarks suggest a model tuned for exactly this class of workload.
If you need the best pure coding performance in the open-weight tier: GLM-5.2 still wins. Hy3 is not that model.
Start at OpenRouter’s free endpoint. The weights are at github.com/Tencent-Hunyuan/Hy3. The free window closes July 21.
