<img width="3840" height="1920" alt="A3 _ MCP server" src="https://github.com/user-attachments/assets/21e2cf1e-69c0-414c-9cee-180a60c17f51" />

Scribo MCP Server

Free, AI-native e-invoicing — for any MCP client.

Contents

• What is Scribo?
• What is the Scribo MCP server?
  • Demo
• Getting started
  • Quickstart
  • Setup & prerequisites
• Usage
  • How it works
  • Examples
• Compliance
• FAQ
• Resources
• License

What is Scribo?

Scribo is a free, conversational e-invoicing tool. Describe an invoice in plain language — "bill Acme GmbH €2,400 for May design work" — and it drafts a structured invoice for you to review, download and send directly.

Just ask your AI agent about Scribo: it ships as an MCP server, a CLI, and a Claude/Codex skill, alongside a public HTTP API and a web app. Free forever — no credit card. You just need a sender email.

Built by Causa Prima — Scribo is built by Causa Prima, a company building agentic AI for the CFO office. It's our first freely available skill — an early glimpse of what we're building.

What is the Scribo MCP server?

The Scribo MCP server gives your AI assistant the ability to create invoices for you. It's a hosted Model Context Protocol endpoint — add its URL to your assistant once, then just ask for an invoice and it gathers the details and hands back a finished, compliant invoice in the chat, ready to download and send.

Because it's hosted, there's nothing to install or run locally. It works with any MCP-aware client — Claude Desktop, Claude.ai, Cursor, Cline, ChatGPT App, the OpenAI Codex CLI, and others. Free, no signup — your email is all you need.

Demo

https://github.com/user-attachments/assets/3e1fcca8-580b-448f-bb1c-bee5ee016b54

Getting started

Quickstart

Scribo's MCP server is hosted — there's nothing to install. Point your client at:

https://scribo.causaprima.ai/mcp

In Claude Desktop or Claude.ai: Customize → Connectors → Add custom connector, name it Scribo, paste the URL, and save. Then just ask:

Draft an invoice for 3 days of consulting at €1,200/day to Acme GmbH.

Scribo collects the missing details, verifies your sender email once, and returns a download link.

Using a different client? See the per-client setup below.

Setup & prerequisites

The server speaks MCP over Streamable HTTP (JSON-RPC 2.0, MCP spec ≥ 2025-03-26) with no auth. Any MCP-aware client connects with one setting — the URL https://scribo.causaprima.ai/mcp.

Claude Desktop / Claude.ai — Customize → Connectors → Add custom connector → name Scribo, paste the URL. On Team/Enterprise plans an org owner may need to add it once under Organization settings → Connectors.

Cursor — add to ~/.cursor/mcp.json (or workspace .cursor/mcp.json):

{ "mcpServers": { "scribo": { "url": "https://scribo.causaprima.ai/mcp" } } }

Cline — add to cline_mcp_settings.json:

{ "mcpServers": { "scribo": { "transport": "streamable-http", "url": "https://scribo.causaprima.ai/mcp" } } }

OpenAI Codex CLI — add to ~/.codex/config.toml, then restart Codex:

[mcp_servers.scribo]
url = "https://scribo.causaprima.ai/mcp"

Any other MCP client — configure a remote server at the URL above, transport Streamable HTTP, no auth.

Prefer a plain-bash setup with no connector in the loop? The Scribo skill covers Claude Code, Claude.ai, Claude Desktop, and Codex via simple helper scripts.

Verify. Ask your assistant: "list the jurisdictions Scribo supports."

Usage

How it works

You describe the invoice in plain language; your assistant calls Scribo's tools to build it. The server exposes four tools:

Tool	What it does
create_invoice	Generates a compliant invoice from the sender, recipient, and line-item details, and returns a durable download link.
verify_email_code	Confirms ownership of the sender email using the 6-digit code Scribo emails on the first invoice.
get_invoice	Re-fetches a previously generated invoice and a fresh download link.
list_supported_jurisdictions	Lists which countries and formats are available.

A typical flow: you ask for an invoice → your assistant calls create_invoice and collects anything missing → on your first invoice from a new sender email, Scribo asks you to paste a 6-digit code (confirmed via verify_email_code) → your assistant retries and hands back a download link — a PDF with the matching EN 16931 XML embedded. On clients that render widgets (e.g. the ChatGPT App), the invoice appears as a card with a download button.

The server also registers five workflow prompts (generate_invoice, german_b2b_invoice, german_b2g_xrechnung, us_plain_pdf_invoice, redownload_invoice) — clients that surface prompts show them as slash-command-style starters.

Full tool schemas and sample payloads are in schemas/ and examples/, and in the MCP docs.

Examples

Things you can say to your assistant once Scribo is connected:

German B2B invoice (ZUGFeRD)

Invoice Beispiel GmbH for 12 hours of web development at €110/hour, 19% VAT. I'm Example GmbH, VAT ID DE123456789.

Returns a ZUGFeRD invoice — a PDF a human can read, with EN 16931 XML embedded for the recipient's accounting system.

German public-sector invoice (XRechnung)

Same client, but it's for the City of Munich — the Leitweg-ID is 04011000-1234512345-06.

A Leitweg-ID tells Scribo this is a B2G invoice, so it produces XRechnung, the format German public authorities require.

US invoice (plain PDF)

Bill Acme Inc. $4,000 for a brand strategy workshop.

A clean PDF invoice — no e-invoice XML, since the US has no e-invoicing mandate.

Re-download a past invoice

Send me the download link for the invoice I made for Beispiel GmbH last week.

Scribo returns a fresh download link for an invoice you've already generated.

Compliance

Scribo emits invoices conforming to EN 16931, the European e-invoicing standard, with the relevant national CIUS. Every EN 16931 output (ZUGFeRD, XRechnung) is validated against the Invopop-hosted validator at generate-time — output that fails the rule set never reaches the user. US plain PDFs carry no EN 16931 XML and are rendered directly.

Supported formats

Jurisdiction	Format	Status
Germany (B2B)	ZUGFeRD COMFORT (PDF/A-3 hybrid + CII XML)	✅ Live
Germany (B2G)	XRechnung (UBL / CII)	✅ Live
United States	Plain PDF (no XML, no e-invoice claim)	✅ Live
France	Factur-X EN 16931	🔜 Coming soon
Spain	Facturae	🔜 Coming soon
Belgium / NL / LU / AT	Peppol BIS 3.0 UBL	🔜 Coming soon

Disclaimer: Scribo generates and validates compliant invoice documents. It is not tax or legal advice — Scribo does not determine your tax obligations, VAT treatment, or filing requirements.

FAQ

<details> <summary><strong>Is Scribo really free?</strong></summary>

Yes — free forever. No credit card, no subscription, no paywall before your first invoice. You just need a sender email.

</details>

<details> <summary><strong>Do I need an account or signup?</strong></summary>

No signup form. On your first invoice, Scribo verifies the sender email — a 6-digit code (or one-click link) arrives at that address; one verification covers ~30 minutes of invoicing. The same email doubles as your magic-link login for re-downloads later.

</details>

<details> <summary><strong>Which countries and formats are supported?</strong></summary>

Live today: Germany — ZUGFeRD (B2B) and XRechnung (B2G) — and the United States (plain PDF). Coming next: France (Factur-X), Spain (Facturae), and Belgium / NL / LU / AT (Peppol BIS 3.0).

</details>

<details> <summary><strong>What does "EN 16931-compliant" actually mean here?</strong></summary>

Every EN 16931 output (ZUGFeRD, XRechnung) is validated against the EN 16931-1:2017 rule set (via the Invopop-hosted validator) before it's returned. Output that fails validation never reaches you. US plain PDFs carry no EN 16931 XML, so no schematron validation applies.

</details>

<details> <summary><strong>Is the US version compliant?</strong></summary>

Yes. There is no US e-invoicing mandate, so Scribo produces a fully compliant plain PDF.

</details>

<details> <summary><strong>Does Scribo give tax or legal advice?</strong></summary>

No. Scribo generates and validates compliant invoice documents. It does not determine your tax obligations, VAT treatment, or filing requirements.

</details>

<details> <summary><strong>How do AI agents / LLMs use Scribo?</strong></summary>

Scribo is built to be operated by an agent. It ships as an MCP server, a CLI, and a Claude/Codex skill, plus a public HTTP API and a web app — all on the same backend. An agent can discover Scribo, create an invoice, and return the file on a user's behalf.

</details>

<details> <summary><strong>Who builds Scribo?</strong></summary>

Causa Prima — a company building agentic AI for the CFO office. Operated by Causa Prima Germany GmbH, Munich.

</details>

Resources

• Web app — scribo.causaprima.ai
• Documentation — scribo.causaprima.ai/docs
• Compliance & trust — scribo.causaprima.ai/compliance
• Causa Prima — causaprima.ai

Other Scribo surfaces

• Skill (Claude / Codex) — scribo-skill · docs
• MCP server — scribo-mcp · docs
• CLI — scribo-cli · docs
• HTTP API — scribo-api-docs · docs
• Brand hub — scribo

License

Proprietary — UNLICENSED. © Causa Prima Germany GmbH. All rights reserved. Distributed for use against the public Scribo API; not open-source. See LICENSE.