Complete a 3-D Secure challenge. Call after the payer finishes the issuer challenge (redirected back to return_url) with the authenticator response (cres / PaRes). Returns the authenticated charge state so capture or authorization can proceed.
AI agents use authenticate_3ds to commit financial operations through Mcp Ap2 — usually the final step of a payment, billing, or trading workflow. A call moves real money.
This tool completes a 3DS payment authentication flow, directly enabling financial transactions (charge capture or authorization) to proceed. Misuse could allow unauthorized payment authorization, making it Financial category with critical severity due to the direct financial impact.
From the tool's definition Complete a 3-D Secure challenge... Returns the authenticated charge state so capture or authorization can proceed
Documented attack patterns abuse exactly the kind of access authenticate_3ds 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 authenticate_3ds:
{
"version": "1",
"default": "deny",
"tools": {
"authenticate_3ds": {
"deny_if": [
{
"conditions": [],
"on_deny": "Requires human approval."
}
]
}
}
}Any call to authenticate_3ds is blocked until a human approves it. The rest of the server keeps working.
Free to start. No card required.
Complete a 3-D Secure challenge. Call after the payer finishes the issuer challenge (redirected back to return_url) with the authenticator response (cres / PaRes). Returns the authenticated charge state so capture or authorization can proceed. It is categorised as a Financial tool in the Mcp Ap2 MCP Server, which means it involves financial transactions. Block by default and require explicit approval.
Register the Mcp Ap2 MCP server in PolicyLayer and add a rule for authenticate_3ds: 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.
authenticate_3ds is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the authenticate_3ds 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 authenticate_3ds. 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.
authenticate_3ds 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.