Proxus Industrial MCP Server

io.github.proxusiiotplatformPublished by GitHub account proxusiiotplatformv0.1.0-beta.7Updated Oct 31, 2026

Read-only Modbus TCP and OPC UA access to PLCs and industrial devices, with connection diagnostics

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Overview

AI-generated overview

Read-only Modbus TCP and OPC UA access to PLCs and industrial devices, with connection diagnostics and register maps.

What you can do
  • List configured devices with endpoint, ISA-95 path and connection state
  • Read raw Modbus registers and bits, and poll an address for 1–60 s to see how it moves
  • Decode up to 16 registers as int, uint, float32 or float64 in common byte orders
  • Browse OPC UA nodes and read or watch up to 50 variables with type, quality, status code and timestamp
  • Diagnose why a device is unreachable, step by step, with the next thing to try
  • Find, inspect and verify register maps, and read named engineering values with units
When to use it
Useful when an assistant needs to inspect live values from PLCs, meters, drives or inverters over Modbus TCP or OPC UA, or to troubleshoot an unreachable device, without any risk of writing to the plant.
Requirements
Runs as a local process: a platform binary from the releases page, or the published container image, started by the MCP client with a configuration file path. Needs a JSON configuration listing devices (host, protocol, optional map) and network reachability to those devices. OPC UA needs a PKI folder for certificates; passwords are supplied through an environment variable named by password_env.
Before you install
Read-only by design: nothing can write to a device. OPC UA trust is never automatic; confirm a server certificate thumbprint with its administrator before moving it to trusted. Passwords must not go in the configuration file, only in the environment variable named by password_env. Binaries are not code-signed, so macOS and Windows require a manual override on first run. Map verification prepares a report and a prefilled issue link that you submit yourself; nothing is sent automatically.

Installation

In SourceWeft

  1. Open Proxus Industrial MCP Server in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

[Image] Proxus Industrial MCP Server

Gives AI assistants such as Claude Desktop, Cursor and VS Code read-only access to industrial devices. Supports Modbus TCP and OPC UA (Basic256Sha256, Aes128_Sha256_RsaOaep or Aes256_Sha256_RsaPss with Sign or SignAndEncrypt, or unsecured; anonymous or user-name login).

[An AI assistant reads a PLC, decodes a meter value and diagnoses a device that does not answer]

Condensed from a real session against simulated devices (docs/demo.json). More at proxus.io/tools/industrial-mcp-server.

Tools

ToolWhat it does
list_devicesConfigured devices, endpoint, ISA-95 path, connection state
read_addressRaw registers or bits: hr:0, ir:10, coil:5, di:0 or 40001
watch_addressPolls a Modbus address for 1–60 s and summarises how it moved, decoded as uint16, int16, uint32, int32 or float32 in any byte order
decode_registersUp to 16 registers read every common way: int16/32, uint, float32 in ABCD/CDAB/BADC/DCBA, float64 in both word orders
browseChildren of an OPC UA node (default: Objects folder)
read_nodesUp to 50 OPC UA variables with data type, quality, status code and source timestamp
watch_nodesWatches up to 20 OPC UA variables for 1–60 s through a subscription: every change, plus first, last, min, max and average
diagnose_connectionWhy a device can't be reached: name, TCP, protocol handshake, security and certificates, login, a test read, identity and clock, step by step with the next thing to try
find_device_mapSearches the register map library by vendor, model or alias, e.g. PM5560
get_device_mapA map's registers (key, address, type, byte order, unit, scale), filtered by a search word
read_namedReads registers by key from the device's map and returns engineering values with units
verify_device_mapChecks the device's map against the real device and prepares a hardware verification report (read-only)

Nothing can write to a device.

Register maps

With a register map the assistant reads voltage_l1_n instead of guessing that hr:0-1 is a word-swapped float. A map lists every register of a device model: address, data type, byte order, scale (fixed, or a SunSpec scale-factor register), unit and the meaning of enumerated values, with the vendor document it comes from. The binaries include the open Modbus Register Maps collection (energy meters, power analysers, drives, inverters); each release also attaches it as register-maps.json.gz.

Give a Modbus device its map in the configuration, by id or as the path of a map's JSON file:

json
"meter-1": { "protocol": "modbus-tcp", "host": "192.168.10.40", "map": "schneider-electric/pm5500-pm5600-pm5700" }

maps_dir adds maps (or replaces built-in ones with the same id) from a folder of JSON files, as python3 tools/maps.py build in the collection writes them. A map that does not exist stops the server at start-up with the reason. Maps tell the assistant how to read a register, never to write one: read_named only reads.

Verify a map on your device

Most maps are transcribed from vendor documents. Ask your assistant to verify the device's map: verify_device_map reads every register once (read-only), checks that the values are plausible (floats, frequency, voltage, power factor, energy counters, model) and asks you to compare two values with the device's display. The result is a report and a link that opens a prefilled issue in the map collection; you submit it under your own GitHub account, and a bot adds you to the map's verified list. Nothing is sent without you, and the report holds check results only, no addresses, host names or serial numbers.

OPC UA security

Set security_mode (sign_and_encrypt, sign or none) and security_policy (Basic256Sha256, Aes128_Sha256_RsaOaep or Aes256_Sha256_RsaPss) per device. Certificates live in pki_dir (default pki/ next to the configuration file), in the layout most OPC UA tools use:

FolderHolds
own/This server's application certificate, created on first use (private key readable only by you)
trusted/Server certificates you approved
rejected/Server certificates seen but not approved

Trust is never automatic, in either direction:

  1. On the first connection the server's certificate lands in rejected/ and the tool answers with its SHA-256 thumbprint. Confirm the thumbprint with the server's administrator, then move the file to trusted/.
  2. If the server answers BadCertificateUntrusted or BadSecurityChecksFailed, it has not trusted this client yet. proxus-mcp certificate --config <file> prints this server's certificate file and thumbprint to trust on the server.

Passwords never go in the configuration file: password_env names the environment variable that holds them. Errors carry the OPC UA StatusCode name, the specification's description and a suggested next step.

Install

Download the archive for your platform from the releases page, unpack it, and point your MCP client at the proxus-mcp binary (see Claude Desktop below). Each archive has a .sha256 file next to it. The binaries are not code-signed yet: on macOS run xattr -d com.apple.quarantine proxus-mcp once after unpacking, and on Windows choose "More info, Run anyway" the first time.

proxus-mcp --version prints the version.

Docker

bash
docker run -i --rm -v "$PWD:/config" ghcr.io/proxus-io/proxus-mcp:<version>

The image reads /config/proxus-mcp.json and speaks MCP over stdin/stdout, so an MCP client starts it with docker as the command and run -i --rm -v <folder>:/config ghcr.io/proxus-io/proxus-mcp:<version> as the arguments. Devices on the host are reachable as host.docker.internal; on Linux add --network host to reach the plant network directly. Images are published for linux/amd64 and linux/arm64.

Build

Needs the .NET 10 SDK. The protocol drivers come from the Proxus.Drivers NuGet packages (Apache-2.0).

bash
dotnet publish src/Proxus.Mcp.Server -c Release -r osx-arm64 -o artifacts/osx-arm64

The result is one native file, artifacts/osx-arm64/proxus-mcp (about 10 MB).

Claude Desktop

Add to claude_desktop_config.json:

json
{  "mcpServers": {    "proxus": {      "command": "/absolute/path/to/proxus-mcp",      "args": ["--config", "/absolute/path/to/proxus-mcp.json"]    }  }}

Copy proxus-mcp.example.json as a starting configuration.

Tests

  • dotnet test tests/Proxus.Mcp.Tests: unit tests, no devices needed.
  • tests/smoke/run_all.sh: the published binary against Modbus and OPC UA simulators (see tests/smoke/README.md).
  • CI (.github/workflows/ci.yml) runs both and publishes Native AOT binaries for linux-x64, linux-arm64, win-x64 and osx-arm64.

Licence

Apache-2.0, see LICENSE.

Source: README.md at commit 362a7a4

Tools

0
SourceWeft started this package once in an isolated sandbox, without credentials, to list its tools. That failed: the package type cannot run in the sandbox.

Version history

2
  1. v0.1.0-beta.7LatestOct 31, 2026
  2. v0.1.0-beta.5Oct 30, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts