Ensemble Agent

An agentic system for generating, running, and iteratively fixing simulation scripts. Currently supports libEnsemble, designed to extend to other ensemble tools.

Uses LangChain ReAct agents with tools exposed via MCP and local Python functions.

Installation

Dependencies (no package installer yet):

pip install langchain langchain-openai langchain-anthropic mcp

For the web UI:

pip install gradio fastapi uvicorn[standard] websockets

MCP Server Setup (Script Generation)

The script generator runs as an MCP server from a separate repository. It is required for --interactive and --prompt modes but not for --scripts (fix-only) mode.

git clone https://github.com/Libensemble/script-creator.git
export GENERATOR_MCP_SERVER=/path/to/script-creator/mcp_server.mjs

Or pass it directly:

python ensemble_agent.py --mcp-server /path/to/script-creator/mcp_server.mjs

The MCP server requires Node.js (node on PATH).

Usage

# Fix existing scripts
python ensemble_agent.py --scripts tests/scripts_with_errors/

# Generate scripts interactively via MCP
python ensemble_agent.py --interactive

# Generate from a prompt
python ensemble_agent.py --prompt "Create APOSMM scripts..."

# Enable debug logging
python ensemble_agent.py --debug

Environment Variables

Variable	Description
OPENAI_API_KEY	OpenAI API key
ANTHROPIC_API_KEY	Anthropic API key
ANTHROPIC_AUTH_TOKEN	Argo gateway token (auto-mapped to ANTHROPIC_API_KEY)
OPENAI_BASE_URL	Custom OpenAI-compatible endpoint
ANTHROPIC_BASE_URL	Custom Anthropic endpoint
LLM_MODEL	Override default model
GENERATOR_MCP_SERVER	Path to mcp_server.mjs
AGENT_DEBUG	Enable debug logging

Web UI

A Gradio web interface is available in web_ui/. See web_ui/README.md for details.

cd web_ui
python gradio_ui.py