passkey_register_options · Run402 MCP: Risk & Policy

WHAT IT DOES

What passkey_register_options does on Run402

AI agents use passkey_register_options 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_options needs a policy

This tool creates new authentication credentials for a user. While the creation itself is not destructive and reversible, it has side effects that persist (new passkey becomes available for future authentication).

From the tool's definition The tool creates registration options (not merely retrieving existing data), explicitly stated as 'Create WebAuthn passkey registration options'. This is a write operation that modifies the user's authentication state by initiating passkey registration.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

passkey_register_options Rate-limited

passkey_register_options 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_options": {
      "limits": [
        {
          "counter": "passkey_register_options_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_options

What does the passkey_register_options tool do? +

Create WebAuthn passkey registration options for the authenticated 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_options? +

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

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

Can I rate-limit passkey_register_options? +

Yes. Add a rate_limit block to the passkey_register_options 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_options completely? +

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

passkey_register_options 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.