AI Agents Integration

thelawin.dev works well with AI agents. The API is stateless and JSON-based, so any agent that can make HTTP requests can generate invoices.

3 Ways to Integrate

Method	Best for	Setup
MCP Server	Claude Code, MCP-capable clients	Clone from GitHub
REST API + curl	Any agent with HTTP access	No setup, start immediately
SDKs	Agents in Python, TypeScript, etc.	Install SDK

MCP Server (recommended for Claude)

The Model Context Protocol server gives Claude Code (and other MCP clients) two tools: thelawin_generate and thelawin_validate.

Installation

git clone https://github.com/steviee/thelawin.dev.git
cd thelawin.dev/mcp-server
npm install && npm run build

Configuration for Claude Code

Add to your Claude Code MCP config:

{
  "mcpServers": {
    "thelawin": {
      "command": "node",
      "args": ["/path/to/thelawin.dev/mcp-server/dist/index.js"],
      "env": {
        "THELAWIN_API_KEY": "env_sandbox_demo"
      }
    }
  }
}

Without MCP Server

You can also use thelawin.dev without the MCP server, directly via REST API (curl) or SDKs.

Natural Language → Invoice

After setup, Claude Code can generate invoices from natural language:

"Create a ZUGFeRD invoice for 8 hours of consulting at 150 EUR from Acme GmbH to Customer AG"

Claude automatically uses the thelawin_generate tool and returns the PDF.

REST API with curl

Any agent that can execute HTTP requests can use thelawin.dev. The demo key env_sandbox_demo works immediately without an account.

Minimal Invoice

curl -s -X POST https://api.thelawin.dev/v1/generate \
  -H "Content-Type: application/json" \
  -H "X-API-Key: env_sandbox_demo" \
  -d '{
    "format": "zugferd",
    "template": "minimal",
    "invoice": {
      "number": "RE-2026-001",
      "date": "2026-01-15",
      "seller": {"name": "Acme GmbH", "country": "DE", "vat_id": "DE123456789"},
      "buyer": {"name": "Customer AG", "country": "DE"},
      "items": [{"description": "Beratung", "quantity": 8, "unit": "HUR", "unit_price": 150}]
    }
  }'

Save PDF

curl -s -X POST https://api.thelawin.dev/v1/generate \
  -H "Content-Type: application/json" \
  -H "X-API-Key: env_sandbox_demo" \
  -d '{"invoice":{"number":"001","date":"2026-01-15","seller":{"name":"Test GmbH"},"buyer":{"name":"Kunde AG"},"items":[{"description":"Service","quantity":1,"unit_price":100}]}}' \
  | jq -r '.pdf_base64' | base64 -d > rechnung.pdf

Pre-validation (free)

curl -s -X POST https://api.thelawin.dev/v1/validate \
  -H "Content-Type: application/json" \
  -H "X-API-Key: env_sandbox_demo" \
  -d '{"format":"xrechnung","invoice":{"number":"XR-001","date":"2026-01-15","leitweg_id":"04011000-12345-67","seller":{"name":"GmbH","vat_id":"DE123"},"buyer":{"name":"Amt"},"items":[{"description":"Lizenz","quantity":1,"unit_price":1000}]}}' \
  | jq '.valid, .format'

Extract Data from PDF

PDF_BASE64=$(base64 < rechnung.pdf)
curl -s -X POST https://api.thelawin.dev/v1/retrieve \
  -H "Content-Type: application/json" \
  -H "X-API-Key: env_sandbox_demo" \
  -d "{\"data_base64\": \"$PDF_BASE64\"}" \
  | jq '.invoice'

SDKs for Agent Frameworks

Python (LangChain, CrewAI, AutoGen)

from thelawin import ThelawinClient

client = ThelawinClient("env_sandbox_demo")

result = (
    client.invoice()
    .number("RE-2026-001")
    .date("2026-01-15")
    .format("zugferd")
    .seller("Acme GmbH", vat_id="DE123456789", city="Berlin", country="DE")
    .buyer("Customer AG", city="Muenchen", country="DE")
    .add_item("Beratung", quantity=8, unit_price=150, unit="HUR")
    .generate()
)

if result.success:
    result.save_pdf("rechnung.pdf")

pip install git+https://github.com/steviee/thelawin-clients.git#subdirectory=python

TypeScript (Vercel AI SDK, LlamaIndex)

import { ThelawinClient } from '@thelawin/sdk';

const client = new ThelawinClient('env_sandbox_demo');

const result = await client.invoice()
  .number('RE-2026-001')
  .date('2026-01-15')
  .format('zugferd')
  .seller({ name: 'Acme GmbH', vatId: 'DE123456789', city: 'Berlin', country: 'DE' })
  .buyer({ name: 'Customer AG', city: 'Munich', country: 'DE' })
  .addItem({ description: 'Consulting', quantity: 8, unit: 'HUR', unitPrice: 150 })
  .generate();

npm install github:steviee/thelawin-clients#path:typescript

Supported Formats

Format	Description	Region
zugferd	PDF/A-3 + CII XML	Germany
facturx	PDF/A-3 + CII XML	France
xrechnung	PDF/A-3 + UBL XML	Germany B2G
peppol	XML (UBL-based)	EU/international
fatturapa	XML	Italy
ubl	XML	OASIS standard
cii	XML	UN/CEFACT
pdf	Plain PDF	Universal
auto	Auto-detect	EU

API Key for Production

The demo key (env_sandbox_demo) adds a SANDBOX watermark. For production use:

1. Sign up (free)
2. Dashboard → API Keys → Create key
3. Sandbox keys (env_sandbox_*): 0 credits included, free (buy credit packs for clean PDFs)
4. Live keys (env_live_*): From 9.50 EUR/month, no watermark

Next Steps

• MCP Server Docs | Detailed MCP documentation
• API Reference | Full request/response fields
• SDKs | All 8 official SDKs
• n8n Guide | Workflow automation with n8n