SIFEN E-Invoicing API and MCP to Integrate Your System
Issue e-invoices from your own system with the CDEPos API, and connect an AI assistant to your business with MCP.
Two ways to integrate CDEPos
If you already have your own system, you do not need to replace it to comply with SIFEN: you can issue e-invoices through CDEPos. And if you want an AI to work with your business data, you can connect it via MCP.
SIFEN e-invoicing API
Built for ERPs, online stores and custom systems that need to issue e-invoices in Paraguay. CDEPos takes care of the XML, the signature and the submission to the SET.
- A single call to issue: the customer is identified by RUC and the products by their code
- Automatic creation of the customer or product if they do not exist yet
- No duplicates: with an idempotency key, a retry does not create another invoice
- Status with the SET by query or by signed webhook when the invoice is approved, rejected or voided
- KuDE as PDF and XML for every document
POST /connector/api/sell
{ "sells": [{
"location_id": 1,
"status": "final",
"idempotency_key": "ERP-FAC-2026-000123",
"sifen_emit": true,
"contact": { "ruc": "80012345-6",
"name": "Distribuidora Ejemplo SA" },
"products": [{ "sku": "SRV-MANT-01", "quantity": 1,
"unit_price_inc_tax": 550000, "tax_rate": 10 }],
"payments": [{ "method": "cash", "amount": 550000 }]
}] }The technical guide is public: authentication, examples, errors and a go-live checklist.
MCP: connect an AI assistant to your business
MCP (Model Context Protocol) is an open standard for connecting AI assistants to other systems. With the CDEPos MCP, a compatible assistant —for example Claude Desktop or Cursor— works with your business’s real data.
- Queries: sales, top-selling products, stock, customers, debts, purchases, suppliers and cash
- Actions: add and edit products, adjust stock, create customers and record debt payments
- Manufacturing: recipes, production orders, stages and the gap between estimated and actual
- With permissions: each agent is a user of your business with its own role and only sees your company
- With control: you can revoke its access at any time and see every action it took
- No invoicing: the agent does not issue invoices; that stays with your team
MCP is enabled depending on your plan. Message us and we will help you connect it.
Which one fits you?
| If you need… | Use |
|---|---|
| To issue e-invoices from your own system | The e-invoicing API |
| To query and operate your business by chatting with an AI | The MCP |
| A complete sales, stock, cash and invoicing system | The CDEPos ERP |
What people ask us most
Do I have to change my system to issue e-invoices?
No. With the API, your system stays the same and issues e-invoices through CDEPos, which takes care of the XML, the signature and the submission to the SET.
What is MCP?
It is an open standard for connecting AI assistants to other systems. CDEPos has its own MCP server so a compatible AI can look up and enter data in your business.
Can the AI see other businesses’ data or do anything it wants?
No. Each agent is a user of your business with a role: it only sees your company and only does what that role allows. You can revoke its access at any time, and it does not issue invoices.
How do I get started?
Message us on WhatsApp: we enable access to the API or the MCP depending on your plan and help you connect it.
Other CDEPos solutions
Get your free demo
In less than a week you can be invoicing electronically with CDEPos.