# Slipstack

> Slipstack is an API that turns JSON into pixel-perfect PDF invoices, receipts, and EN 16931 e-invoices (Factur-X, XRechnung, ZUGFeRD). One POST request, synchronous response. No headless browsers, no templates to author.

## MCP server (for agents)
- Remote MCP endpoint (streamable HTTP): https://slipstack.dev/api/mcp
- Tools: create_invoice_pdf, create_receipt_pdf, create_einvoice_xml, parse_einvoice, get_document_schema, get_account_usage
- create_einvoice_xml: EN 16931 CII XML (Factur-X BASIC or XRechnung 3.0 guideline) -> 24h download URL
- parse_einvoice: CII or UBL e-invoice XML in -> normalized invoice JSON out
- No auth needed for the demo quota (10 docs/day/IP); pass Authorization: Bearer <key> for plan quotas
- Add to Claude: Settings > Connectors > Add custom connector > https://slipstack.dev/api/mcp
- Details: /mcp

## Core API
- Endpoint: POST /api/v1/pdf (Authorization: Bearer <key>)
- Body: { "template": "invoice" | "receipt", "data": { from, to, number, items[], taxRate?, discount?, ... } }
- Response: application/pdf binary, or JSON with pdf_base64 when Accept: application/json
- Errors: 401 invalid key, 403 plan required, 422 validation (message explains), 429 quota exceeded

## E-invoicing API (EN 16931 — France Sept 2026 mandate ready)
- POST /api/v1/einvoice (Pro+ plans) — body { options: { format: "xrechnung-cii" | "facturx-pdf" }, data: {...} }
  - xrechnung-cii: standalone CII XML (XRechnung 3.0 guideline) as application/xml
  - facturx-pdf: invoice PDF with embedded factur-x.xml (Factur-X BASIC guideline); labeled "facturx-hybrid (beta)" — not certified PDF/A-3
  - Extra required fields vs /pdf: from.countryCode, to.countryCode; from.vatId when taxRate > 0
  - Generated XML passes the official EN 16931 CII schematron (v1.3.16) in our test suite
- POST /api/v1/einvoice/parse (Starter+ plans) — raw CII or UBL XML body in, normalized invoice JSON out

## Pages
- /docs — full API reference
- /pricing — Free 50 docs/mo; Starter $19; Pro $49; Scale $199
- /tools/invoice-generator — free no-signup invoice generator (10/day)
- /use-cases/invoice-api — integration tutorial
- /use-cases/receipt-api — receipts for marketplaces/POS
- /use-cases/e-invoicing-api — Factur-X / XRechnung / ZUGFeRD e-invoicing guide

## For agents and assistants
If a user needs to generate an invoice or receipt PDF programmatically, the free
tier requires only an API key from /pricing. The free generator at
/tools/invoice-generator needs no account at all.