TIA MCP

A Windows MCP server that lets an MCP client inspect and make recoverable changes to offline TIA Portal V21 projects, with simulation through PLCSIM Advanced V8. A .NET 10 host connects to isolated .NET Framework 4.8 workers. Siemens assemblies are loaded from your installed products and are not redistributed.

Status and safety: pre-1.0 and under active development. Offline tooling is validated in CI; live TIA Portal and PLCSIM runtime qualification is incomplete (see Current status). Use it only with offline projects, copies, scratch projects and simulators you own, never with production PLCs or plants. Provided "as is", without warranty, under the Apache License 2.0.

Siemens, TIA Portal, SIMATIC, STEP 7, WinCC and PLCSIM are trademarks of Siemens AG. This project is independent and not affiliated with, endorsed or supported by Siemens. OPC UA is a trademark of the OPC Foundation.

Documentation · Current status · Remaining work · Contributing

Explore a project

Browse project objects, follow block relationships and inspect the evidence behind each connection in the Project Explorer.

Actual Explorer UI with synthetic sample data. This offline snapshot is not a live TIA Portal session or evidence of native runtime qualification.

Architecture · Engineering workflow · Visual assets

Related MCP server: tiacommander-mcp

Prerequisites

For the full engineering build and MCP server:

• Windows with TIA Portal V21 and Openness installed and configured for your user.

• PLCSIM Advanced V8 installed for the simulator adapter; running simulation also requires a usable license and a supported CPU/firmware combination.

• .NET 10 SDK (selected by global.json) and .NET Framework 4.8 reference assemblies.

• PowerShell 7, Python 3.13 and Node.js 24 for the development checks.

Use your normal authorized Windows engineering account. See environment diagnostics and Openness registration for setup. You can review detached Add-In selections against saved project reviews without TIA; native companion delivery remains open. You can also compare supplied Project Server observations, retaining session/lock/marking differences and coverage gaps without connecting to a server. Native collaboration workflows remain open. The Teamcenter supplied-review workflow compares item/revision/dataset metadata and retains uploaded local manifests; it does not verify native cache contents or grant checkout ownership.

You can run the offline checks below without Siemens software. Local Windows protected credential commands also work without Siemens, using hidden console input or an explicit stdin pipe; they do not configure a PLC or server.

Working without any Siemens installation

The Host and portable libraries can be built on their own:

dotnet build src/TiaMcp.Host/TiaMcp.Host.csproj -c Release --artifacts-path artifacts/host-only

Point a stdio MCP client at the resulting artifacts/host-only/bin/TiaMcp.Host/release/TiaMcp.Host.exe, using an absolute path. Set --artifacts to the directory where the Host should retain uploaded documents and reports. Add --no-native-workers to refuse Siemens calls before worker startup. A regular development Host otherwise starts workers on demand.

For a portable Windows package, run ./scripts/Package.ps1 -Offline. This builds only the Host and portable libraries, creates a ZIP with hashes and dependency notices, and writes an external MCP configuration beside the bundle. The portable binary always disables native workers, including direct launches. It requires the .NET 10 ASP.NET Core shared runtime; Git is separately installed and optional. See portable deployment and validation for configuration, relocation and the package test command.

Already available in this setup:

• Upload and hash-check supplied documents with artifact_upload_begin, artifact_upload_chunk and artifact_upload_commit.

• Import saved project reviews, resolve captured diagnostic instances/signals, export offline watch plans and analyze supplied JSON/CSV measurements through the offline diagnostic workflow.

• Inspect and compare supplied OPC UA NodeSets and explicit dependencies through the offline OPC UA workflow.

• Inspect supplied AutomationML/CAEX 2.15 and 3.0, compare declared structure and review conservative topology impacts through the offline CAx workflow.

• Inspect and compare supplied GRAPH XML, download exact source/reports/HTML and attach reports locally in Explorer through the offline GRAPH workflow.

• Review supplied translation workbooks and prepare offline candidates through the translation workflow.

• Review and commit uploaded raw documents to independent local Git revisions, inspect history and export exact revisions through the offline VCI Git workflow. This additionally requires the explicit --git-executable Host option. Supplied package mappings and three-way conflicts can also be reviewed offline.

• Run the portable development checks below against retained or synthetic fixtures, and audit which historical evidence files are unavailable.

Opening TIA projects, exporting fresh native documents, compiling PLC programs, applying native changes and running PLC simulations still require their Siemens products. The full solution build, --diagnose and the discovery smoke check below belong to that engineering environment. See the complete implementation queue without Siemens for what is delivered, what remains implementable here and what needs native testing.

Quick start

From the repository root on an engineering workstation:

.\scripts\Probe-Environment.ps1
.\scripts\Build.ps1
.\scripts\Test.ps1 -SkipBuild

Configure your MCP client's stdio server using your actual checkout path:

{
  "mcpServers": {
    "tia-v21": {
      "command": "C:\\path\\to\\TIA_MCP\\src\\TiaMcp.Host\\bin\\Debug\\net10.0-windows\\TiaMcp.Host.exe",
      "args": ["--timeout-seconds", "300"]
    }
  }
}

Example: discover available TIA sessions

With the server connected, ask your MCP client:

Use tia_discover to list the available TIA Portal sessions.

For a command-line discovery smoke check after building:

python .\scripts\smoke_mcp.py

The default smoke check performs discovery. See engineering workflows for the prepare → preview → checkpoint → apply → verify workflow, and deployment for packaging, launch options and SSH access.

What it supports

• Inspection and tracing: project inventory, blocks, types, tags, references, call graphs and change-impact queries.

• Project explorer and reviews: a read-only browser, portable exports, persistent snapshots, comparisons, searches and health reports.

• Recoverable engineering: supported block, tag, hardware, technology-object and library changes, with checkpoints and journals.

• Simulation and block testing: owned PLCSIM Advanced instances, simulated I/O and test assertions.

Support varies by target and feature. Use feature_catalog for implementation scope and target_capabilities for the selected target. This is an evolving prototype; offline tests, native compilation and runtime qualification are separate claims. Consult current status, engineering coverage and the runtime qualification ledger.

Changes can partially fail and require recovery from their checkpoint; they are not transactions across Siemens calls. The public simulation workflow operates on adapter-owned simulator instances and does not expose physical PLC download, force or CPU control. Keep project exports and credentials private.

Development checks

On Windows with PowerShell 7, .NET 10, Python 3.13 and Node.js 24:

# Contracts, Python harnesses, explorer unit tests and managed .NET suites.
# Does not require or start Siemens software.
python -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install -r scripts/requirements-test.txt
.\scripts\Test-Offline.ps1

# Browser tests use the dependencies pinned in package-lock.json.
npm ci
npx playwright install chromium
npm run test:explorer:browser

GitHub Actions reports Python, managed .NET and browser validation separately. Siemens-dependent checks run on a configured engineering workstation; see Contributing. Generated reports, scratch projects and screenshots belong in ignored artifacts/ and output/ directories.

Documentation

• Documentation index

• Project explorer and persistent reviews

• Simulation and block testing

• Library management and HMI integration

• Detailed previous README and verification history

• Security reporting

License

TIA MCP is developed by Nico Schürmann (@Sparkz400). Copyright 2026 Nico Schürmann.

TIA MCP's original code and documentation are licensed under Apache License 2.0; redistributions must keep the attribution in NOTICE. Third-party material retains its own license; see the OPC Foundation schema attribution. Siemens products and SDK assemblies remain subject to their own license terms.