0.3.0 package and tool migration: Install industriagents-dnp3-mcp from npm (requires uv) or PyPI; the command remains dnp3-mcp. The advertised catalog now contains 5 tools. Older tool names in the examples below remain compatibility calls. See the architecture and canonical tool guide and release guide.

dnp3-python

Python MCP server for DNP3. Built with uv, mcp[cli] (FastMCP) and the pure-Python dnp3py stack, it exposes the dnp3-mcp CLI, which lets MCP-compatible clients read binary and analog inputs, operate binary outputs and poll event classes on DNP3 outstations over TCP. Responses include the outstation's IIN flags.

Controls are refused unless DNP3_WRITES_ENABLED=true. See Status and known limitations in the repository README.

Requirements

• Python 3.11+
• uv
• TCP access to the outstation (or to a serial-to-TCP gateway). No native libraries are needed.

Quick Start

uv sync
DNP3_HOST=127.0.0.1 DNP3_PORT=20000 uv run dnp3-mcp

Set the connection settings in the real environment, in the env block of your MCP client config, or in dnp3-python/.env (see .env.example). That file is found next to the package source in a checkout, whatever directory the server is started from; a .env in the working directory or a parent is never read, and an installed package has no implicit .env. It may set only DNP3_* and POINT_MAP_FILE, never DNP3_WRITES_ENABLED, and real environment variables take precedence. Put the write switch in the real environment or in a file you pass explicitly with uv run dnp3-mcp --env-file PATH. See Configuration for every setting.

Tests and checks

uv sync --locked
uv run --locked ruff check .
uv run --locked ruff format --check .
uv run --locked pytest

The tests include end-to-end runs that start ../dnp3-mock-outstation with this project's interpreter and drive the dnp3-mcp console script over stdio. tests/interop (opendnp3 via yadnp3, Linux x86_64 only) runs with uv sync --locked --group interop and REQUIRE_OPENDNP3=1 uv run --locked --group interop pytest tests/interop.

Layout

dnp3-python/
├── README.md
├── pyproject.toml
├── uv.lock
├── .python-version
├── .env.example
├── src/dnp3_mcp
│   ├── __init__.py
│   ├── cli.py           # entry point: --env-file, or dnp3-python/.env (DNP3_* only, no gates)
│   ├── config.py        # environment parsing, read when the server is built
│   ├── server.py        # FastMCP wiring, envelope for argument errors, version
│   ├── tools.py         # the MCP tools and the point map
│   └── dnp3_master.py   # DNP3 master on dnp3py (TCP, own CROB encoding, guarded confirms)
└── tests/               # unit, protocol, stdio end-to-end; tests/interop needs yadnp3