# Hungary Invoice MCP

> A remote MCP server that lets any AI agent report Hungary invoice data to NAV Online Számla 3.0 (számla adatszolgáltatás) — the Hungarian tax authority's national invoice-data reporting API. Submit invoice data and query the processing status by transactionId. This is REPORTING, not issuing: the merchant issues the actual invoice to the buyer; this tool reports the data to NAV as required by law. Stateless, bring-your-own credentials, never stores anything.

- MCP endpoint (Streamable HTTP): https://inv-hu.wishpool.app/mcp
- Credentials headers (technical user, all five self-minted in the Online Számla portal, onlineszamla.nav.gov.hu -> Technical users): x-nav-login, x-nav-password (plaintext; hashed SHA-512 server-side), x-nav-signkey (signature key; SHA3-512 request signing), x-nav-exchangekey (16-byte exchange key; AES-128 decrypts the exchange token), x-nav-taxnumber (your 8-digit tax number). Your keys stay with you.
- Mode header: x-nav-mode: prod reports real invoices to NAV; omitted = TEST env (no legal effect, the safe default).
- Flow: submit_invoice exchanges a token, builds the InvoiceData XML, signs the request (SHA3-512), submits a CREATE operation, and returns a transactionId -> query_transaction with that transaction_id reads the NAV processing status.
- Amounts in HUF. Each line item has a NET unit price + a Hungarian ÁFA (VAT) rate (27, 18, 5, or 0). Per-rate net/VAT and the invoice gross total (invoiceGrossAmount) are computed for you. The supplier tax number comes from the x-nav-taxnumber header (not the body).
- Scope: v0.1 ships CREATE reporting + status query. Correcting or cancelling a reported invoice (MODIFY/STORNO) is a separate operation not covered here.

## Tools

- submit_invoice: Report an invoice to NAV — supplier_name, customer_name (+ optional customer_tax_number for B2B), invoice_number, items (name, quantity, unit_net_price, vat_rate) in, transactionId out. Omit customer_tax_number for a private person (customerVatStatus PRIVATE_PERSON).
- query_transaction: Read the NAV processing status of a submission by its transactionId — RECEIVED / PROCESSING / SAVED / DONE (success terminal) / ABORTED (rejected; validation_messages explain why).
- Owner policy guardrails: x-agentpay-max-amount (hard cap on invoice gross total, HUF), x-agentpay-approval-above (returns an unsigned draft for human review), x-agentpay-allowed-tools (tool allow-list) — set by the human owner in the MCP client config; the agent cannot relax them.

## Safety

Stateless translation layer straight to the government NAV Online Számla API. The merchant's technical-user keys travel per-request in headers; the password is hashed, the request is signed and the exchange token is decrypted in memory only, then discarded. This server never stores credentials, invoices, or customer data. Privacy policy: https://inv-hu.wishpool.app/privacy

## Sister servers

National e-invoices: Poland KSeF 2.0 https://inv-pl.wishpool.app/mcp, Mexico CFDI 4.0 https://inv-mx.wishpool.app/mcp, Chile DTE https://inv-cl.wishpool.app/mcp, Brazil NF-e https://inv-br.wishpool.app/mcp. Same stateless BYO pattern, local payments in 81 countries — full list: https://mcp.wishpool.app/llms.txt (Taiwan e-invoice 電子發票 lives in https://mcp.wishpool.app/mcp).