add_custom_domain · Run402 MCP: Risk & Policy

WHAT IT DOES

What add_custom_domain does on Run402

AI agents use add_custom_domain to create or update resources in Run402 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Run402 environment.

WHY IT NEEDS A POLICY

Why add_custom_domain needs a policy

This tool creates a new domain registration and modifies routing/DNS configuration, which is a reversible write operation. It does not execute arbitrary code, delete data, move funds, or trigger external operations with unpredictable effects.

From the tool's definition Tool 'add_custom_domain' registers/creates a custom domain configuration that modifies DNS records and domain routing settings.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_custom_domain Rate-limited

add_custom_domain 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_custom_domain": {
      "limits": [
        {
          "counter": "add_custom_domain_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Run402, so you can run agents against it safely.

FAQ

Questions about add_custom_domain

What does the add_custom_domain tool do? +

Register a custom domain (e.g. example.com) to point at a Run402 subdomain. Returns DNS instructions for the human to configure. It is categorised as a Write tool in the Run402 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_custom_domain? +

Register the Run402 MCP server in PolicyLayer and add a rule for add_custom_domain: 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 Run402. Nothing to install.

What risk level is add_custom_domain? +

add_custom_domain is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_custom_domain? +

Yes. Add a rate_limit block to the add_custom_domain 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 add_custom_domain completely? +

Set action: deny in the PolicyLayer policy for add_custom_domain. 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 add_custom_domain? +

add_custom_domain is provided by the Run402 MCP server (kychee-com/run402). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

add_custom_domain is one line of Run402's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

Teams ship this data inside their own products. See what a licence covers →