Folios
Request a key
Fiscal infrastructure · CFDI 4.0

The CFDI engine
you embed.

Folios is the fiscal layer for Mexican commerce. Stamp sealed, verifiable CFDIs by API, CLI or MCP — multi-issuer, white-label, pay per folio. The seal of every transaction.

$ npx folios stamp ⧉ copy
folios — zsh
Why Folios

Not a facturación app. A fiscal engine.

The same plumbing others sell as a timbrado API — plus the seal, multi-issuer white-label, and a per-folio price.

⌘

CLI-first

Stamp from the terminal. folios stamp · verify · void.

◈

MCP-native

Let an agent issue and reconcile CFDIs safely through your MCP.

↯

REST API

One endpoint to stamp CFDI 4.0. Webhooks + SDK. Built to embed.

◫

Multi-issuer

White-label: each business emits under its own RFC. HostCasa runs on it.

✓

The seal

Every folio comes back sealed, verifiable, with its UUID — not just a PDF.

◎

Pay per folio

~20¢ per stamp. No monthly fee, no license. You bring your CSD.

CLI · MCP · API

One engine, three surfaces

Embed Folios however you build.

~/.folios/mcp.jsonMCP
// an agent stamps CFDIs through your MCP
{
  "mcpServers": {
    "folios": {
      "command": "npx",
      "args": ["folios", "mcp"],
      "env": { "FOLIOS_TOKEN": "fol_live_…" }
    }
  }
}
stamp a CFDI 4.0API
await fetch("https://api.folios.works/v1/cfdi", {
  method: "POST",
  headers: { Authorization: `Bearer ${token}` },
  body: JSON.stringify({ emisor, receptor, conceptos })
})
  .then(r => r.json())
  // → { uuid, pdf, xml, sello, status: "sellado" }
Others sell "make your invoice."
Folios is the seal every transaction earns.