Import the schematic netlist into the PCB board — equivalent to pressing F8 in KiCAD (Tools → Update PCB from Schematic). MUST be called after the schematic is complete and before placing or routing components on the PCB. Without this step, the board has no footprints and no net assignments — pla...
AI agents use sync_schematic_to_board to create or update resources in KiCAD-MCP-Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your KiCAD-MCP-Server environment.
This tool creates or modifies PCB board data (footprints, net assignments) in a reversible manner. While the effects are significant (the tool notes that without it 'the board has no footprints and no net assignments'), the operation is not destructive—the netlist can be re-imported or the board state can be reset. It does not execute arbitrary code, delete data irreversibly, or move money.
From the tool's definition Tool description explicitly states it "Import[s] the schematic netlist into the PCB board" and performs an update operation equivalent to 'Update PCB from Schematic'. This modifies the PCB board state by adding footprints and net assignments.
Documented attack patterns abuse exactly the kind of access sync_schematic_to_board gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and KiCAD-MCP-Server, and nothing reaches the server without passing your rules. This is the rule we recommend for sync_schematic_to_board:
{
"version": "1",
"default": "deny",
"tools": {
"sync_schematic_to_board": {
"limits": [
{
"counter": "sync_schematic_to_board_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}sync_schematic_to_board stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Import the schematic netlist into the PCB board — equivalent to pressing F8 in KiCAD (Tools → Update PCB from Schematic). MUST be called after the schematic is complete and before placing or routing components on the PCB. Without this step, the board has no footprints and no net assignments — place_component and route_pad_to_pad will produce an empty, unroutable board. It is categorised as a Write tool in the KiCAD-MCP-Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the KiCAD-MCP-Server MCP server in PolicyLayer and add a rule for sync_schematic_to_board: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches KiCAD-MCP-Server. Nothing to install.
sync_schematic_to_board is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the sync_schematic_to_board rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for sync_schematic_to_board. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
sync_schematic_to_board is provided by the KiCAD-MCP-Server MCP server (mixelpixx/kicad-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from KiCAD-MCP-Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
157 KiCAD-MCP-Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.