Register an AI agent as a trusted payer in the AP2 network. Defines the agent
AI agents use register_agent to create or update resources in Mcp Ap2 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mcp Ap2 environment.
This tool creates a new registration entry (Write), but the consequences are elevated because registering an agent as a 'trusted payer' in a payment protocol grants financial authorization capabilities to that agent. Misuse could allow unauthorized agents to gain payment privileges, making this high severity despite being a Write operation rather than a direct Financial action.
From the tool's definition 'Register an AI agent as a trusted payer in the AP2 network' — creates a new trusted entity record in the AP2 payment/authorization network
Documented attack patterns abuse exactly the kind of access register_agent gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Ap2, and nothing reaches the server without passing your rules. This is the rule we recommend for register_agent:
{
"version": "1",
"default": "deny",
"tools": {
"register_agent": {
"limits": [
{
"counter": "register_agent_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}register_agent 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.
Free to start. No card required.
Register an AI agent as a trusted payer in the AP2 network. Defines the agent. It is categorised as a Write tool in the Mcp Ap2 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mcp Ap2 MCP server in PolicyLayer and add a rule for register_agent: 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 Mcp Ap2. Nothing to install.
register_agent 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 register_agent 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 register_agent. 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.
register_agent is provided by the Mcp Ap2 MCP server (@codespar/mcp-ap2). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mcp Ap2, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
1300 Mcp Ap2 tools catalogued and risk-classified — across an index of 43,000+ MCP servers.