Add or update a single custom property on a placed schematic symbol. This is a focused convenience wrapper around edit_schematic_component for the very common case of attaching one BOM / sourcing field at a time. The property is created if it does not already exist on the component. Typical custo...
AI agents use set_schematic_component_property 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 metadata properties on schematic components reversibly. It does not execute code, delete data irreversibly, or move money. The severity is medium because modifying schematic component properties could introduce errors in BOM generation, sourcing, or design intent, but changes are non-destructive and can be corrected.
From the tool's definition Add or update a single custom property on a placed schematic symbol. The property is created if it does not already exist on the component.
Documented attack patterns abuse exactly the kind of access set_schematic_component_property 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 set_schematic_component_property:
{
"version": "1",
"default": "deny",
"tools": {
"set_schematic_component_property": {
"limits": [
{
"counter": "set_schematic_component_property_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}set_schematic_component_property 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.
Add or update a single custom property on a placed schematic symbol. This is a focused convenience wrapper around edit_schematic_component for the very common case of attaching one BOM / sourcing field at a time. The property is created if it does not already exist on the component. Typical custom properties: • MPN, Manufacturer, Manufacturer_PN — manufacturer part number metadata • DigiKey, DigiKey_PN, Mouser_PN, LCSC, JLCPCB_PN — distributor part numbers • Voltage, Tolerance, Power, Dielectric, Temperature_Coefficient — passive parameters • Description, Notes — free-form documentation • Any custom field your BOM exporter expects. These properties are written into the .kicad_sch file as standard KiCad property records, are exported by export_bom, and are picked up by the JLCPCB and Digi-Key sourcing tools. Newly-created properties default to hidden — set hide=false to display the value on the schematic canvas. For batch updates of multiple properties at once, use edit_schematic_component with the \. 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 set_schematic_component_property: 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.
set_schematic_component_property 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 set_schematic_component_property 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 set_schematic_component_property. 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.
set_schematic_component_property 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.