AI agents use claim_subdomain 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.
This tool creates a new subdomain mapping and associates it with a deployment. It's a reversible write operation (subdomain can be released/unclaimed). Misuse could allow an agent to claim subdomains on the shared run402.com domain, potentially for phishing or brand confusion, giving it medium severity.
From the tool's definition Claim a custom subdomain... and point it at an existing deployment
Attacks that exploit this kind of access
Claim a custom subdomain (e.g. myapp.run402.com) and point it at an existing deployment. Free, requires service_key auth. 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.
Register the Run402 MCP server in PolicyLayer and add a rule for claim_subdomain: 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.
claim_subdomain 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 claim_subdomain 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 claim_subdomain. 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.
claim_subdomain 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.
claim_subdomain 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.
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