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What the AI can do

Reading and understanding — always allowed

These actions the assistant can always perform without enabling anything:

  • Project overview — name, POU count, variable count
  • List POUs — all programs + function blocks + functions
  • Read a POU — view the ST code of a single POU
  • List variables — all pool variables with addresses + types, filtered by scope (globals, POU locals, Bellows export, …)
  • Bus configuration — segments, devices, variable mapping
  • Aliases — all defined variable names + addresses
  • Library — all standard FB blocks (TON, CTU, R_TRIG, …) with parameters and ST examples

With this the assistant can get to know your codebase before making suggestions.

Live observation — always allowed

When the PLC is running, the assistant can query live values:

  • Live snapshot — read all watched variables at once
  • Single value — query a specific address
  • PLC status — is it running, how much watch traffic, last upload
  • Cycle statistics — task time, jitter, min/max/average
  • PLC code state — Run / Pause / Stop
  • Start/stop recording — live values for later analysis
  • Oscilloscope capture — time series of one or more addresses, with optional trigger (edge, threshold)

With this the assistant can do diagnostics: “Why does Motor_Ready not switch? Look at the last 5 seconds on the oscilloscope.”

Changes — only in the unlocked version

The following actions change your project or the PLC. They are switched off in the default build from the internet and require a special version with MCP_OVERRIDE_SECURITIES=ON. Every action asks back first:

Project changes

  • Create variable — new pool variable with address + type
  • Move variable — between POU-local, globals, Bellows export
  • Delete variable — carefully
  • Create POU — new program, function block or function
  • Rename POU — AST-based via tree-sitter-st (identifier sites
    • comment mentions; no regex over the code body)
  • Delete POU — carefully, task bindings may become dangling
  • Set POU body — replace the ST code
  • Set flag — Bellows export, retain, constant, monitor-enable

Refactoring (REF-1)

Tree-sitter-based rename and find-references actions, always with a preview + apply workflow:

  • refactor.find_references — find every occurrence of a variable / POU / Anvil group / Bellows group / GVL namespace in the project
  • refactor.preview — prepare a rename or move; the response carries a tx_id + the list of planned changes with before/after + confidence (exact / ambiguous)
  • refactor.apply — execute the transaction, optionally with individual changes unchecked (each row in the preview has its own checkbox in the output panel)
  • refactor.cancel — discard an open transaction
  • refactor.list_transactions — see all open transactions

Compile + deploy

  • Pre-compile check (codegen.lint) — fast syntax pass over every ST POU. Returns FStCompiler errors plus tree-sitter parse_diagnostics[] (ERROR/MISSING nodes with byte ranges for editor highlighting)
  • Full compile — like the build button in the toolbar; since 2026-05 it runs through the C++-codegen path (FCxxProjectEmitter). The old matiec / C path is deprecated.
  • Generate code (codegen.generate) — inspect the emitted C++ files (Gen<POU>.h/.cpp + AnvilGen.h + BellowsGen.h + GvlGen.h + runtime_main.cpp + CMakeLists.txt) without deploying. Default target cxx; calling with target='c' returns FORGE_ERR_DEPRECATED.
  • Deploy — upload to the PLC, build there via cmake -B build && cmake --build build, then start the new binary
  • Deploy status — phases + build output of the last deploy

PLC control

  • Start — PLC run command
  • Stop — PLC stop command, outputs go to safe state
  • Pause / Resume — halt cycle without complete stop
  • Force — pin a variable (ONLY via the GUI, not via the AI; see Security model)

Tasks + task management

The assistant can also change the task setup:

  • List resources + list tasks in a resource
  • Read program instances of a task
  • Create new task with cycle time + priority
  • Place program instance on task
  • Cycle overview across all tasks

Assistant queries itself

When the AI does not know what a certain tool does, it can query its own help:

  • forge.help — cheat sheet of all available actions with short descriptions, grouped by family
  • forge.help_for(name) — detailed manual for a specific tool, with examples and error classes

With this a fresh model after a restart can reorient itself without you having to explain how ForgeIEC works.

Anvil / Bellows / HMI connection

The assistant can also address the HMI bridge (Bellows) and the SHM IPC layer (Anvil):

  • List Bellows groups + variables and read them
  • List Anvil topics + read them
  • Anvil plugin status + health check
  • Modbus bridge status (tongs-modbustcp)

This is diagnostic material when the HMI sees something different from the PLC.

Editor operation

A handful of editor actions are also reachable via the AI:

  • Quit ForgeIEC Studio — clean stop without kill -9
  • Recent ForgeIEC Studio logs — what ForgeIEC Studio itself logged
  • Fetch / answer confirmations
  • List pending confirmations

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