zero_auth

THE RISK

Critical Risk

Why zero_auth needs a policy

Although no actual charge is made, this tool performs a financial authorization against a payment card or token, which is a financial operation that touches payment infrastructure. Misuse could be used to validate stolen card credentials at scale, constituting a high-severity financial risk. The presence of sibling tools like activate_subscription and add_cart further confirms a financial/commerce context.

From the tool's definition Zero-dollar authorization to validate a card without charging (card or CardToken)

Documented attack patterns abuse exactly the kind of access zero_auth gives an agent:

POLICY

How to control zero_auth

PolicyLayer is an MCP gateway — it sits between your AI agents and Mcp Afip, and nothing reaches the server without passing your rules. This is the rule we recommend for zero_auth:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "zero_auth": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

Any call to zero_auth is blocked until a human approves it. The rest of the server keeps working.

Create a free account and register Mcp Afip — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

GATE THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Mcp Afip tools

Financial authorize_transaction Authorize a transaction (reserve funds without capturing) via Braintree GraphQL authorizeP Financial cancel_collection Cancel a scheduled collection request Financial cancel_credit Cancel an authorized-but-uncaptured credit payment. Financial cancel_payment Attempt to cancel a payment that has not yet settled. Iniciador endpoint: POST /payments/{ Financial cancel_payment_intent Cancel a payment intent that has not yet been captured. Fails on already-captured intents; Financial cancel_recurrence Cancel an active recurrence. Future charges will stop; already-charged cycles are untouche Financial cancel_subscription Cancel a subscription by ID Financial revoke_token Revoke an issued access_token or refresh_token at POST /v1/token/revoke. Use to terminate

All 1300 Mcp Afip tools →

Financial tools on other servers

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Go deeper

Critical-risk tools in Mcp Afip → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Human-in-the-loop → When a tool call should wait for a person — and when policy can decide alone.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
How to Add Spending Controls to Any MCP Agent →
Rate Limiting MCP Tool Calls: A Practical Guide →

FAQ

Questions about zero_auth

What does the zero_auth tool do? +

Zero-dollar authorization to validate a card without charging (card or CardToken). It is categorised as a Financial tool in the Mcp Afip MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on zero_auth? +

Register the Mcp Afip MCP server in PolicyLayer and add a rule for zero_auth: 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 Afip. Nothing to install.

What risk level is zero_auth? +

zero_auth is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit zero_auth? +

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

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

zero_auth is provided by the Mcp Afip MCP server (codespar/mcp-dev-latam). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Mcp Afip tool call.

Start from Mcp Afip, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →