Compare a selfie against a document photo (RG / CNH front). Returns match_score (0..1) and liveness verdict. POST /v1/biometrics/face-match.
AI agents call biometrics_face_match to retrieve information from Mcp Ap2 without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Despite the biometric context and integration with a payment protocol server, the tool's function is fundamentally a read operation—it compares two images and returns a verdict without altering any data. Severity is medium rather than low because biometric matching failure could block legitimate users or false positives could enable account takeover in the payment context, posing moderate risk if misused by an agent.
From the tool's definition Tool performs comparison and returns match_score and liveness verdict with no modification of data. Description states 'Compare' and 'Returns' indicating a query-like operation. No creation, deletion, or financial transaction occurs.
Documented attack patterns abuse exactly the kind of access biometrics_face_match 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 biometrics_face_match:
{
"version": "1",
"default": "deny",
"tools": {
"biometrics_face_match": {}
}
} biometrics_face_match is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Compare a selfie against a document photo (RG / CNH front). Returns match_score (0..1) and liveness verdict. POST /v1/biometrics/face-match. It is categorised as a Read tool in the Mcp Ap2 MCP Server, which means it retrieves data without modifying state.
Register the Mcp Ap2 MCP server in PolicyLayer and add a rule for biometrics_face_match: 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.
biometrics_face_match is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the biometrics_face_match 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 biometrics_face_match. 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.
biometrics_face_match 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.
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1300 Mcp Ap2 tools catalogued and risk-classified — across an index of 43,000+ MCP servers.