refill_zones

Refill all copper zones on the board. WARNING: SWIG path has known segfault risk (see KNOWN_ISSUES.md). Prefer using IPC backend (KiCAD open) or triggering zone fill via KiCAD UI instead.

SERVERKiCAD-MCP-Server SOURCEmixelpixx/kicad-mcp-server

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/mixelpixx-kicad-mcp-server/refill-zones.md

WHAT IT DOES

What refill_zones does on KiCAD-MCP-Server

AI agents invoke refill_zones to trigger actions in KiCAD-MCP-Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

RISK

Why refill_zones is rated High

This tool triggers a board-level operation (refilling copper zones) which modifies the PCB design state. It is an Execute-class action as it runs an external operation with side effects on the KiCAD board file. The severity is high because misuse or crashes (noted segfault risk) could corrupt the board design, and the operation affects all copper zones globally across the board.

From the tool's definition 'Refill all copper zones on the board' and 'WARNING: SWIG path has known segfault risk (see KNOWN_ISSUES.md)'

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs refill_zones safely

PolicyLayer is an MCP gateway: it sits between your AI agents and KiCAD-MCP-Server, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For refill_zones, this is the rule to start with:

refill_zones Rate-limited

refill_zones stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "refill_zones": {
      "limits": [
        {
          "counter": "refill_zones_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect KiCAD-MCP-Server, apply this rule, and every refill_zones call is checked against it from then on.

FAQ

Questions about refill_zones

What does the refill_zones tool do? +

Refill all copper zones on the board. WARNING: SWIG path has known segfault risk (see KNOWN_ISSUES.md). Prefer using IPC backend (KiCAD open) or triggering zone fill via KiCAD UI instead. It is categorised as a Execute tool in the KiCAD-MCP-Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on refill_zones? +

Register the KiCAD-MCP-Server MCP server in PolicyLayer and add a rule for refill_zones: 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.

What risk level is refill_zones? +

refill_zones is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit refill_zones? +

Yes. Add a rate_limit block to the refill_zones 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.

How do I block refill_zones completely? +

Set action: deny in the PolicyLayer policy for refill_zones. 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.

What MCP server provides refill_zones? +

refill_zones 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.

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