Claude Code for PLC programming
If you came here looking for Claude Code for PLC, you're in the right place. PLC Assist is an AI coding agent built specifically for industrial automation — same idea as Claude Code, but for the IDE your PLC actually runs in: CODESYS or Beckhoff TwinCAT.
Like Claude Code, PLC Assist accepts natural-language prompts, reads your project for context, and writes code in your editor. Unlike Claude Code, it knows IEC 61131-3, compiles your code in your PLC IDE, and fixes errors on its own.
Under the hood, PLC Assist runs on frontier models — DeepSeek by default, or Anthropic's Claude, the family that powers Claude Code — tuned for the patterns and pitfalls of industrial automation. You pick, per chat.
Why a separate AI tool exists for PLC
- Claude Code can't see your PLC project. CODESYS and TwinCAT are not VS Code or JetBrains — they have proprietary IDEs with no extension API the way software editors do. PLC Assist runs as a local bridge inside your IDE so it has live access to your POUs, GVLs, DUTs, and the compile output.
- Industrial code has different rules. Real-time constraints, graphical languages (FBD/LD/SFC/CFC), vendor library quirks, and Structured Text idioms that don't map cleanly to general-purpose languages. The agent is trained on PLC-specific patterns, not retrofitted.
- Compile loop, not just suggestion. PLC Assist doesn't just write code — it compiles, reads the actual error messages from your PLC IDE, and fixes them autonomously. That's the workflow that makes industrial code tractable for AI.
Supported platforms
- CODESYS V3 — all CODESYS-based PLCs (Schneider Electric, WAGO, Festo, Lenze, Bosch Rexroth, and more)
- Beckhoff TwinCAT 3 — full project read/write via TwinCAT COM interop
One agent across CODESYS and Beckhoff TwinCAT — same prompts, same compile-and-fix loop on every platform. Read how the multiplatform agent works for system integrators, OEMs, and engineering services firms.
Frequently asked questions
Does PLC Assist actually use Claude?
Yes, if you pick it. Claude Sonnet, Haiku and Opus are all in the model picker, and a Claude chat is also summarized on Claude (Haiku). New chats now default to DeepSeek V4.1 Flash instead, because it handles most PLC work for a fraction of the quota — switch to Claude in one click. The agent is tuned for IEC 61131-3 and the quirks of CODESYS and TwinCAT.
Can I use Claude Code directly to write PLC code?
Claude Code is excellent for software development, but it can't see inside CODESYS or Beckhoff TwinCAT — those IDEs don't expose a terminal or filesystem the way software projects do. PLC Assist runs the same Claude models with a small bridge that sits inside your PLC IDE so the agent has live project access.
Which Claude models does PLC Assist use?
Claude Sonnet is the strongest all-round choice for multi-step tasks and is one click away in the picker; Claude Opus is there for the subtle ones. New chats default to DeepSeek V4.1 Flash, not Claude. Long chats are summarized by the same provider: Claude Haiku for Claude chats, DeepSeek for DeepSeek chats. You'll see the model name in your usage dashboard.
Is my PLC code sent to Anthropic?
Only the context the agent needs to answer your prompt is sent, and only to the model provider serving that chat — never to anyone else. On the default model that provider is DeepSeek, whose inference runs outside the EU; pick a Claude model and it goes to Anthropic instead. Your full project stays on your local machine. We don't train on your code.
Looking for the original Claude Code instead? It's a great tool — for software development. For PLC code, you need a tool that talks to your PLC IDE — and PLC Assist runs on the same Claude models you already trust.
Looking for Claude Code for PLC? Try PLC Assist free.
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