kyb_lookup_cnpj

THE RISK

Low Risk

Why kyb_lookup_cnpj needs a policy

This tool retrieves and queries public company profile information from AFIP (Argentine tax authority) based on a CNPJ number. It performs no data modification, deletion, or financial transaction. The operation is read-only lookup of existing company registration data, which is the archetypal 'Read' category use case. Severity is low because unauthorized access to public company information poses minimal direct risk.

From the tool's definition Tool performs CNPJ validation and returns company profile data (corporate name, fantasia, address, partners, CNAE, share capital, regularity status).

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

POLICY

How to control kyb_lookup_cnpj

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 kyb_lookup_cnpj:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "kyb_lookup_cnpj": {}
  }
}

kyb_lookup_cnpj is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

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.

CAP 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 →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about kyb_lookup_cnpj

What does the kyb_lookup_cnpj tool do? +

Validate a CNPJ and return company profile — corporate name, fantasia, address, partners (QSA), CNAE, share capital, regularity status. POST /v1/kyb/cnpj. It is categorised as a Read tool in the Mcp Afip MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on kyb_lookup_cnpj? +

Register the Mcp Afip MCP server in PolicyLayer and add a rule for kyb_lookup_cnpj: 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 kyb_lookup_cnpj? +

kyb_lookup_cnpj is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit kyb_lookup_cnpj? +

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

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

kyb_lookup_cnpj 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 →