Highlights
- Base: Qwen3.5-4B (text + vision).
- Method: on-policy GRPO, 200-step MCP agentic RL (slime trainer + sglang rollout, 8×A100).
- Reward: final environment-state verifiers on real agent tasks (tool correctness + DB checks),
with penalties for degeneration/truncation.
- Training-set diversity: ~2.3k agent environments spanning 63% of industries and
76% of tools in the source corpus.
Benchmark results (improvement over the base model)
Only benchmarks where AgentMercury improves over the Qwen3.5-4B base are listed,
with the absolute gain (Δ) over base. Evaluated with an OpenAI-compatible endpoint
(sglang, 32k context), N repeats per cell.
Table with columns: Benchmark, Base, AgentMercury, Δ| Benchmark | Base | AgentMercury | Δ |
|---|
| BFCL | 30.35 | 31.93 | +1.58 |
| τ³-bench | 0.706 | 0.747 | +0.041 |
| τ²-bench | 0.448 | 0.457 | +0.009 |
Math & reasoning
Table with columns: Benchmark, Base, AgentMercury, Δ| Benchmark | Base | AgentMercury | Δ |
|---|
| AIME 2026 | 0.459 | 0.553 | +0.094 |
| HMMT 2026-02 | 0.285 | 0.356 | +0.071 |
| GPQA-Diamond | 0.765 | 0.770 | +0.005 |
| Finance-Reasoning | 0.563 | 0.571 |
Code
Table with columns: Benchmark, Base, AgentMercury, Δ| Benchmark | Base | AgentMercury | Δ |
|---|
| LiveCodeBench (v5+v6) | 0.366 | 0.435 | +0.069 |
| SciCode | 0.226 | 0.260 | +0.034 |
Writing
Table with columns: Benchmark, Base, AgentMercury, Δ| Benchmark | Base | AgentMercury | Δ |
|---|
| WritingBench | 6.232 | 6.307 | +0.075 |
Metrics use each benchmark's native scale (fractions 0–1, or the benchmark's own points).
The largest, most consistent gains are on agentic tool-use (BFCL, τ-bench) and
competition math / code (AIME, HMMT, LiveCodeBench).
Usage
Serving (sglang, recommended — matches evaluation)
python3 -m sglang.launch_server \
--model-path Minbyul/AgentMercury-Qwen3.5-4B \
--served-model-name agentmercury-qwen3.5-4b \
--host 0.0.0.0 --port 30000 --tp 1 \
--context-length 32768 \
--reasoning-parser qwen3 --tool-call-parser qwen3_coder \
--trust-remote-code
Then call the OpenAI-compatible endpoint at http://localhost:30000/v1 (supports tool calls).
from transformers import AutoModelForCausalLM, AutoProcessor
model = AutoModelForCausalLM.from_pretrained(
"Minbyul/AgentMercury-Qwen3.5-4B",
torch_dtype="bfloat16", device_map="auto", trust_remote_code=True,
)
processor = AutoProcessor.from_pretrained(
"Minbyul/AgentMercury-Qwen3.5-4B", trust_remote_code=True,
)
Training notes
The reward peaks around this checkpoint while the model stays clean
(no repetition collapse, no context truncation). Continuing RL past this point raised
response length and reintroduced degeneration/truncation without adding capability —
so this clean-minimum checkpoint is released as the recommended weights.
License
Released under the Apache-2.0 license (see LICENSE).