AgentFlow: In-the-Flow Agentic System Optimization

📣 News

• [2026.01.26] 🚀 Our paper has been accepted by ICLR 2026! See you in Rio de Janeiro!
• [2025.10.26] 📚 Our project introduction has been featured on DeepWiki!
• [2025.10.16] 🏆 Our paper has been accepted by NeurIPS 2025 Efficient Reasoning Workshop!
• [2025.10.13] 📸 Excited to have a tutorial video for AgentFlow covered by Discover AI on YouTube!
• [2025.10.10] 🚀 Our X post received 1K+ likes! Feel free to check out the post and join the discussion! 💬
• [2025.10.08] 🔥 We are honored to be featured as 🤗 HuggingFace Daily Paper #2.

🌟 Why AgentFlow?

AgentFlow is a trainable, tool-integrated agentic framework designed to overcome the scalability and generalization limits of today’s tool-augmented reasoning approaches.

Unlike prevailing approaches such as Search-R1 which train a single LLM to interleave reasoning steps with tool calls, AgentFlow introduces a modular agentic system with four specialized modules: 🧭 Planner, 🛠 Executor, ✅ Verifier, and ✍️ Generator.

For effective planning and tool use, the framework directly optimizes planner agent within the system in an online fashion using Flow-based Group Refined Policy Optimization (Flow-GRPO), achieving superior performance across diverse domains with improved tool-calling reliability and long-horizon reasoning capabilities.

📺 YouTube Tutorial

Excited to have a tutorial video for AgentFlow covered by Discover AI on YouTube!

🚀 Key Features

• 🧩 Modular Agentic System – Four specialized agent modules (Planner, Executor, Verifier, Generator) that coordinate via evolving memory and integrated tools across multiple turns.
• 🔗 Multi-Tool Integration – Seamlessly connect with diverse tool ecosystems, including base_generator, python_coder, google_search, wikipedia_search, web_search, and more.
• 🎯 Flow-GRPO Algorithm – Enables in-the-flow agent optimization for long-horizon reasoning tasks with sparse rewards.
• 📈 Proven Results – AgentFlow (7B Backbone) beats top baselines on 10 benchmarks, with +14.9% search, +14.0% agentic, +14.5% math, +4.1% science, even outperforming ~200B-parameter GPT-4o.

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📑 Table of Contents

• ⚙️ Setup
  • Installation
  • Setup Environment Variables
• ⚡ Quick Start on AgentFlow Inference
• 💥 Quick Start on AgentFlow Flow-GRPO Training
  • (Optional) Test Your Environment
  • Dataset Preparation
  • Flow-GRPO Training
• 🎯 AgentFlow Benchmark
• 🧩 Use Your Own Model in AgentFlow
• 🤝 Core Contributors
• 🎓 Advisors
• 🙏 Acknowledgements
• 🚀 Contributing

⚙️ Setup

Prerequisites

• Python 3.11 (recommended)

Installation

bash setup.sh
source .venv/bin/activate
# (Optional) Install `parallel` for running benchmark experiments in parallel:
sudo apt-get update
sudo apt-get install parallel

Setup Environment Variables

Copy the .env.template file from agentflow/.env.template and rename it to .env, then place it in the agentflow/ folder. Update the following variables with your own API keys:

• OPENAI_API_KEY (for judging reasponse)
• GOOGLE_API_KEY (for Google Search tool)
• DASHSCOPE_API_KEY ([optional] for calling Qwen-2.5-7B-Instruct as engine for agents and tools)
• TOGETHER_API_KEY ([optional] alternative for calling Qwen-2.5-7B-Instruct as engine for agents and tools - recommended for international users)
• More ways: serve Qwen2.5-7B-instruct model with vLLM (details refer to serve_vllm_local.md).

Please check API Key Setup Guide for detailed instructions on how to obtain these keys.

cp agentflow/.env.template agentflow/.env
# Then edit agentflow/.env with your API keys

🔍 Check Before You Run (Recommended)

Before running inference or training, we recommend verifying that your API keys and environment are properly configured.

🛠️ Test Tools

Run the following command to test all integrated tools:

cd agentflow/agentflow
bash ./tools/test_all_tools.sh

Example output:

Testing all tools...
✅ base_generator passed
✅ google_search passed
✅ python_coder passed
✅ wikipedia_search passed
...
✅ All tests passed

🧠 Test LLM Engines

Verify that your LLM engines (OpenAI, DashScope, Gemini, etc.) are correctly initialized and responding:

python agentflow/scripts/test_llm_engine.py

Example output:

🚀 Starting fault-tolerant test for 11 engines...
✅ Passed: 4
   • gpt-4o → ChatOpenAI
   • dashscope-qwen2.5-3b-instruct → ChatDashScope
   • gemini-1.5-flash → ChatGemini
   • deepseek-chat → ChatDeepseek
...
🎉 All engines initialized successfully!

⚡ Quick Start on AgentFlow Inference

AgentFlow provides a modular agentic system with four specialized modules (planner, executor, verifier, generator) that coordinate through evolving memory and a toolkit over multiple turns to solve complex reasoning tasks.

To quickly experience the system in action, run the command below (don’t forget to set up your API key):

python quick_start.py

Example output of python quick_start.py:

==> Initializing agentflow...
==> Setting up tools...
==> 🎯 Reasoning Steps from AgentFlow (Deep Thinking...)
==> 🔍 Step 0: Query Analysis
==> 🎯 Step 1: Action Prediction (Google_Search_Tool)
==> 🛠️ Step 1: Command Execution (Google_Search_Tool)
...
**Answer:** The capital of France is Paris.
==> ✅ Query Solved!

**Process Summary:**
1. **Query Analysis:** Identified as a factual question about the capital of France.
2. **Tool Selection:** Used Google Search for accurate information.
3. **Execution:** Confirmed Paris as the capital.
4. **Verification:** Cross-referenced sources for reliability.

**Answer:** The capital of France is Paris.

💥 Quick Start on AgentFlow Flow-GRPO Training

For effective planning and tool use, the framework directly optimizes the planner agent within the system in an online fashion using Flow-GRPO. Below is a quick start for training.

(Optional) Test Your Environment

Before diving in, we recommend verifying that AgentFlow's tools, LLM engines, and network configuration are properly set up. See test_env.md for detailed testing instructions.

Dataset Preparation

We mix two datasets for training: NQ (Natural Questions) for agentic search and DeepMath-103K for mathematical reasoning.

# train data
python data/get_train_data.py
# validation data
python data/aime24_data.py

After that, data dir should be:

data/
├── train/
│   └── combined_train.parquet (182,190 samples)
├── val/
│   └── aime24.parquet (30 samples)
├── aime24_data.py
└── get_train_data.py

Flow-GRPO Training

Start agentflow training using Flow-GRPO with tmux:

# Create tmux session and start agentflow service (Window 0)
tmux new-session -s agentflow
bash train/serve_with_logs.sh

# Create new window (Ctrl+B then C) and start training (Window 1)
bash train/train_with_logs.sh

Configuration: All training hyperparameters are in train/config.yaml (model settings, tools, RL parameters, resources, etc.)

Logging: We provide a comprehensive logging to monitor training. See logs.md for more details.

🎯 AgentFlow Benchmark

Serve the trained planner model with VLLM (here we deploy our 7B Flow-GRPO planner model):

bash scripts/serve_vllm.sh

Run inference on specific benchmark tasks:

cd test
# Run Bamboogle benchmark
bash bamboogle/run.sh

After running, each task folder (e.g., test/bamboogle/) will contain:

• data/: Contains the evaluation dataset (e.g., data.json).
• logs/: Contains detailed execution logs for each problem index (organized by model label).
• results/: Contains the model's generated answers (output_i.json) and final evaluation scores (finalscore_*.log).

You can find more benchmarking details in benchmark.md.

🧩 Use Your Own Model in AgentFlow

AgentFlow supports different LLM engines for each agent module. See llm_engine.md for supported models and factory.py for the corresponding model_string configuration:

Planner Agent:

• Modify the llm_engine_name parameter in the corresponding run.sh script (e.g., test/bamboogle/run.sh)

Other Agents (Executor, Verifier, Generator):

• By default, these agents use a fixed LLM engine (Qwen-2.5-7B-Instruct via DashScope)
• To use your own model, modify self.llm_engine_fixed in agentflow/agentflow/models/planner.py:19:

self.llm_engine_fixed = create_llm_engine(model_string="your-engine", is_multimodal=False, temperature=temperature)

and

• Modify the llm_engine_name parameter in the Executor instantiation from agentflow/agentflow/solver.py:232:

# Instantiate Executor
executor = Executor(
    # llm_engine_name=llm_engine_name,
    llm_engine_name="dashscope",
    root_cache_dir=root_cache_dir,
    verbose=verbose,
    # base_url=base_url,
    temperature=temperature
)

• For detailed information on supported engines and model_string formats, see llm_engine.md

🏆 Experiments

📊 Main Results

AgentFlow (Qwen-2.5-7B-Instruct Backbone) outperforms top baselines on 10 benchmarks:

• +14.9% on search
• +14.0% on agentic reasoning
• +14.5% on math
• +4.1% on science

💡 Even surpasses larger proprietary models like GPT-4o (~200B).

🔍 In-Depth Analysis

• Improved planning and decision-making
• Enhanced tool-calling reliability
• Positive scaling trends with model size & reasoning turns

Explore more in our paper or project page.

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🤝 Core Contributors

🎓 Advisors

🙏 Acknowledgements

We thank the following open-source projects:

• verl for the excellent RL framework design.
• vLLM for fast LLM inference support.
• Verl-Tool and agent-lightning for their early-stage exploration in agentic RL Training.

We thank Lambda for GPU support!

🚀 Contributing

We are truly looking forward to open-source contributions to AgentFlow! If you’re interested in contributing, collaborating, or reporting issues, please feel free to open an issue or submit a pull request (PR). You can also reach us at [email protected], [email protected], [email protected] or join our Slack community: AgentFlow.

We are also looking forward to your feedback and suggestions!

📚 Citation

@inproceedings{li2026flow,
    title = {In-the-Flow Agentic System Optimization for Effective Planning and Tool Use},
    author = {Li, Zhuofeng and Zhang, Haoxiang and Han, Seungju and Liu, Sheng and Xie, Jianwen and Zhang, Yu and Choi, Yejin and Zou, James and Lu, Pan},
    booktitle = {International Conference on Learning Representations (ICLR)},
    year = {2026}
}

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