Checkpoint Overview
This repository contains the initial research release of JIT-Agent-27B. The
checkpoint builds on the Stage-I harness-customization model and is further
trained through distillation from the final research checkpoint.
Model Details
Table with columns: Property, Value| Property | Value |
|---|
| Base model | Qwen/Qwen3.6-27B |
| Parameters | 27.36B |
| Weight precision | BF16 |
| Architecture context length | 262,144 tokens |
| Recommended serving context | 163,840 tokens |
| Primary input | Task, tools, protocol, and reference-harness descriptions |
| Primary output | Four Python modules and one YAML prompt configuration |
JIT-Agent generates harnesses under a fixed four-module protocol:
memory.py: constructs and updates the agent's working context;
planning.py: forms directives and manages plan state;
action.py: implements the task-execution loop;
tool_policy.py: controls tool and skill exposure;
prompt.yaml: defines the prompts consumed by the generated modules.
The model emits these files using the following tagged format:
<<<PYTHON_MEMORY>>>
...
<<<END_PYTHON_MEMORY>>>
<<<PYTHON_PLANNING>>>
...
<<<END_PYTHON_PLANNING>>>
<<<PYTHON_ACTION>>>
...
<<<END_PYTHON_ACTION>>>
<<<PYTHON_TOOL_POLICY>>>
...
<<<END_PYTHON_TOOL_POLICY>>>
<<<YAML>>>
...
<<<END_YAML>>>
Recommended Usage
The checkpoint is designed to be used with the
JIT-Agent runtime, which constructs the full
generation prompt, validates the structured output, installs the resulting
harness, and executes it against an off-the-shelf agentic model.
1. Set up the runtime
git clone https://github.com/bingreeky/JIT.git
cd JIT
conda env create -f environment.yml
conda activate jit
2. Serve the checkpoint
The repository provides a vLLM launcher with the recommended serving settings:
MODEL=JIT-Agent/jit-27b \
TP=4 \
bash scripts/serve_meta_model.sh
This exposes an OpenAI-compatible endpoint at http://localhost:8000/v1.
3. Generate and execute a task-conditioned harness
python -m scripts.run_jit \
--bench xbench \
--meta-model jit \
--meta-base http://localhost:8000/v1 \
--harness-refs desc \
--max-samples 5
The released checkpoint should be used with description references:
In this mode, the model receives natural-language design descriptions of the
reference harnesses rather than their source code. This is also the default mode
of the released runtime.
For best-of-N inference, the runtime generates three candidate harnesses at
temperature 1.0 and selects one before task execution.
Intended Use
JIT-Agent-27B is intended for research on:
- task-adaptive agent architecture generation;
- model–harness co-design;
- modular agent runtimes;
- memory, planning, action, and tool-policy composition;
- best-of-N harness synthesis;
- harness transfer across executor models and task domains.
It is a harness generator rather than a general-purpose chat model. Direct
chat-style prompting without the accompanying protocol and runtime context is
unlikely to produce valid executable harnesses. Also see here.
License
The checkpoint is released under the Apache License 2.0. It is derived from
Qwen/Qwen3.6-27B, which is also
released under Apache 2.0.