ACM Server

An MCP (Model Context Protocol) server that automates Aspen Custom Modeler (ACM) via COM. Designed for use with Claude Code to open .acmf files, run simulations, and read/write variable values programmatically.

Features

• 15 MCP tools for full ACM automation: session management, steady-state and dynamic simulation, variable access, and task control
• Session-based — manage multiple ACM instances
• COM automation via comtypes (not win32com, which has known VARIANT issues with ACM)
• Comprehensive docs — includes condensed ACM V15 Help (2,227 pages distilled to 10 markdown files)

Requirements

• Windows (COM automation is Windows-only)
• Python 3.10+
• Aspen Custom Modeler V15 installed
• Claude Code (or any MCP-compatible client)

Installation

pip install "mcp[cli]>=1.0.0" "comtypes>=1.4.0"

Setup with Claude Code

Add this to your project's .mcp.json:

{
  "mcpServers": {
    "acm": {
      "command": "python",
      "args": ["<path-to>/acm-mcp/server.py"]
    }
  }
}

Restart Claude Code after first setup to pick up the server.

Tools

Session Tools

Tool	Description
open_acm	Open an .acmf file and create a session
connect_acm	Connect to an already-running ACM instance
close_acm	Close a session and quit ACM
list_acm_sessions	List all active sessions

Simulation Tools

Tool	Description
run_steady_state	Run steady-state simulation
run_dynamic	Run dynamic simulation to a specified end time
get_simulation_status	Get current status, DOF, convergence info
reset_simulation	Reset to initial conditions

Variable Tools

Tool	Description
get_variable	Get a variable by dot-notation path (e.g. B1.Tank.h)
set_variable	Set a variable's value
get_variables_bulk	Get multiple variables at once
find_variables	Find variables matching a wildcard pattern

Task Tools

Tool	Description
create_task	Create a task on the flowsheet
activate_task	Activate a task for dynamic simulation
deactivate_task	Deactivate a task

Quick Start

1. open_acm("path/to/model.acmf")
2. run_steady_state("model")
3. get_variable("model", "B1.Tank.h")  →  "B1.Tank.h = 40.0 [cm] (Free)"

Dynamic step change procedure

To observe transient dynamics after a step change:

1. run_steady_state at initial conditions
2. run_dynamic to a small time (e.g. 0.001) — locks state variables at old SS
3. set_variable to apply the step change
4. run_dynamic to successive times, reading variables at each point

Important: Do NOT set_variable before the first run_dynamic — ACM re-initializes state variables at the new conditions, producing an instant jump to new SS with no visible transient.

Documentation

Detailed documentation is in docs/:

• overview.md — Architecture and design decisions
• tools.md — Full tool reference with parameters and examples
• com-api.md — ACM COM API notes and gotchas
• Error_Logbook.txt — Known ACM errors and fixes
• acm_help/ — Condensed ACM V15 Help system (10 files covering modeling language, solver options, library reference, examples, etc.)

Architecture

server.py              # FastMCP entry point, 15 tool registrations
acm_manager.py         # COM lifecycle: subprocess launch, GetActiveObject, sessions
tools/
  session_tools.py     # open, connect, close, list
  simulation_tools.py  # run steady/dynamic, status, reset
  variable_tools.py    # get, set, bulk get, find
  task_tools.py        # create, activate, deactivate
docs/                  # Documentation and ACM Help reference

License

MIT