passkey_register_verify · Run402 MCP: Risk & Policy

WHAT IT DOES

What passkey_register_verify does on Run402

AI agents use passkey_register_verify 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 passkey_register_verify needs a policy

This tool creates or modifies user authentication state by storing WebAuthn passkey registration data. While it does not delete data (Destructive) or move money (Financial), it irreversibly alters the security posture of a user account by adding a new authentication factor. Misuse could allow an attacker to register unauthorized passkeys for a victim account, gaining persistent access.

From the tool's definition The tool description explicitly states 'store the user' in relation to a WebAuthn registration response. This involves creating or modifying authentication credentials/user data in a persistent store.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

passkey_register_verify Rate-limited

passkey_register_verify 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": {
    "passkey_register_verify": {
      "limits": [
        {
          "counter": "passkey_register_verify_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 passkey_register_verify

What does the passkey_register_verify tool do? +

Verify a browser WebAuthn registration response and store the user. 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 passkey_register_verify? +

Register the Run402 MCP server in PolicyLayer and add a rule for passkey_register_verify: 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 passkey_register_verify? +

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

Can I rate-limit passkey_register_verify? +

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

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

passkey_register_verify 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.