# Paraguay Invoice MCP

> A remote MCP server that lets any AI agent issue and query Paraguay electronic invoices (factura electrónica / Documento Electrónico for SIFEN — the DNIT e-Kuatia system) through FacturaSend. FacturaSend generates, digitally signs and transmits the DE to SIFEN from the merchant's own account; this server is a stateless forwarder that also does the local IVA math. Bring-your-own FacturaSend tenant + API key, never stores anything.

- MCP endpoint (Streamable HTTP): https://inv-py.wishpool.app/mcp
- Credentials headers: x-facturasend-tenant (your FacturaSend tenant/company id, travels in the URL path) + x-facturasend-key (your FacturaSend API key, sent as Authorization: Bearer api_key_...). Self-register free at facturasend.com.py; your certificate and SIFEN enrolment stay in your FacturaSend account.
- Free test environments: you can integrate BEFORE having SIFEN production enrolment or a certificate. (1) create_invoice with draft=true builds the DE offline WITHOUT transmitting to SIFEN (no fiscal effect); (2) a FacturaSend account wired to the DNIT test environment reaches the real SIFEN test gateway. Test vs production is decided by your FacturaSend account/timbrado, not by this server.
- Money: guaraníes (PYG) have NO decimals — pass integer, TAX-INCLUSIVE unit prices. IVA rate per line is 10 (standard), 5 (reduced) or 0 (exempt); the IVA portion is liquidated locally (10% -> price*10/110, 5% -> price*5/105).
- Design: this server ONLY forwards the FacturaSend API calls (POST /{tenant}/lote/create, GET /{tenant}/de/cdc/{cdc} | /de/id/{id}, POST /{tenant}/de/estado) and does the IVA math. It never signs, never holds the certificate, and never stores credentials.
- Asynchronous: SIFEN authorizes the DE; create_invoice returns the 44-digit cdc and an estado, then get_document_status polls the live SIFEN estado (Aprobado / Aprobado con observación / Rechazado).

## Tools

- create_invoice: Issue a Paraguay DE (factura electrónica) via POST /{tenant}/lote/create with a single document. In: establecimiento, punto, numero, cliente { contribuyente, ruc?, razonSocial, tipoOperacion?, documentoTipo?, documentoNumero?, email? }, items [{ descripcion, cantidad, precioUnitario (PYG integer, tax-inclusive), iva? (10|5|0), codigo?, unidadMedida? }], optional moneda (default PYG), tipoTransaccion (default 1), draft (true = offline, no SIFEN). Out: cdc (44 digits), numero, estado, respuesta_codigo/mensaje, totals. FacturaSend signs and transmits; this server never signs.
- query_invoice: Look up a DE by cdc OR internal id (pass exactly one) — GET /{tenant}/de/cdc/{cdc} or /de/id/{id}. Out: id, cdc, fecha, situacion, lote_id, lote_estado, info_codigo/descripcion.
- get_document_status: Consult the live SIFEN estado of a cdc — POST /{tenant}/de/estado { cdcList:[{cdc}] }. Out: estado (Aprobado / Aprobado con observación / Rechazado), situacion, fecha, respuesta_codigo, respuesta_mensaje.
- Owner policy guardrails: x-agentpay-max-amount (hard cap on the invoice grand total in guaraníes PYG), x-agentpay-approval-above (returns an unsubmitted 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 that forwards FacturaSend API calls only. Digital signing and SIFEN transmission happen inside the merchant's own FacturaSend account; the tenant id and API key travel per-request in headers and are never stored. This server never stores credentials, invoices, or customer data. Privacy policy: https://inv-py.wishpool.app/privacy

## Sister servers

Invoices: Mexico CFDI https://inv-mx.wishpool.app/mcp, Brazil NF-e https://inv-br.wishpool.app/mcp, Chile DTE https://inv-cl.wishpool.app/mcp, Peru CPE https://inv-pe.wishpool.app/mcp, Argentina AFIP https://inv-ar.wishpool.app/mcp, Costa Rica Hacienda https://inv-cr.wishpool.app/mcp, Ecuador SRI https://inv-ec.wishpool.app/mcp, Saudi ZATCA https://inv-sa.wishpool.app/mcp, India GST https://inv-in.wishpool.app/mcp, Poland KSeF https://inv-pl.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).