Serbia Invoice MCP 🇷🇸 — How can my AI agent issue a SEF eFaktura elektronska faktura in Serbia?

Remote MCP server that lets any AI agent issue Serbia SEF eFaktura electronic invoices (elektronska faktura) into the national Ministry of Finance system. It builds UBL 2.1 SRB-CIUS XML (Serbia's CIUS of EN 16931) and uploads it under the merchant's own SEF API key. Stateless, bring-your-own credential, never stores anything.

Live endpoint: https://inv-rs.wishpool.app/mcp · Registry: app.wishpool/serbia-invoice-mcp

Quick start

{
  "mcpServers": {
    "serbia-invoice": {
      "type": "http",
      "url": "https://inv-rs.wishpool.app/mcp",
      "headers": {
        "x-sef-api-key": "<your SEF API key>"
      }
    }
  }
}

You generate the SEF API key yourself in the SEF portal under Settings → API management (Podešavanja → Upravljanje API). Requests default to the SEF demo rail (no fiscal effect); add x-sef-mode: prod for the live rail. Your key never reaches storage — it is forwarded per-request to SEF as the official ApiKey header.

Tools

Tool	What it does
`create_invoice`	Build a UBL 2.1 SRB-CIUS invoice from seller PIB + name, buyer PIB + name + address + lines (name, qty, net unit price, VAT rate 20/10/0) and upload to SEF eFaktura. Returns `sales_invoice_id` + computed VAT totals. Optional `send_to_cir` for budget/public-sector buyers.
`query_invoice`	Check SEF status by `sales_invoice_id`: `NEW`, `SENDING`, `SENT`, `SEEN`, `APPROVED`, `APPROVED_WITH_RESERVATION`, `REJECTED`, `CANCELLED`, `STORNO`, `MISTAKE`, `OVERDUE`, `REMINDED`, `DELETED`.
`cancel_invoice`	Cancel (Otkazivanje) a sales invoice you sent, by `sales_invoice_id` + `cancel_comment`, before the buyer accepts it.

Amounts are in RSD. You supply your own seller identity (supplier_pib + supplier_name) — SEF validates it against your API-key account. After the buyer APPROVES, cancellation is closed — corrections require a storno (credit) document (out of scope in v1).

Owner policy guardrails ride optional headers (x-agentpay-max-amount, x-agentpay-approval-above, x-agentpay-allowed-tools) — set by the human owner in client config; the agent cannot relax them.

Endpoints wrapped (SEF eFaktura publicApi REST)

Base: DEMO https://demoefaktura.mfin.gov.rs · PROD https://efaktura.mfin.gov.rs (prefix /api/publicApi)
Upload: POST /sales-invoice/ubl?requestId={unique}&sendToCir={true|false} (Content-Type application/xml, raw UBL body) → { InvoiceId, PurchaseInvoiceId }
Status: GET /sales-invoice?invoiceId={id} → invoice record incl. Status
Cancel: POST /sales-invoice/cancel?invoiceId={id}&cancelComment={text}
Auth: header ApiKey (forwarded from x-sef-api-key)

Develop

node test/serve.js   # local server on :3238
node test/e2e.js     # protocol + validation + VAT math + UBL structure + fake-key live probes

Safety

Pure stateless translation layer over the national SEF eFaktura API. The API key stays with the merchant and travels per-request in a header; nothing is stored. Privacy policy.

Sister servers

Local invoices, one family: Romania e-Factura (inv-ro) · Mexico CFDI (inv-mx) · Brazil NF-e (inv-br) · Chile DTE (inv-cl) · Peru CPE (inv-pe) · India GST (inv-in). Local payments in 81 countries: mcp.wishpool.app.

MIT licensed.