Connect the books you already keep.

import { GrainVault } from '@grainvault/sdk'

const vault = new GrainVault({
  apiKey: process.env.VAULT_API_KEY
})

const payment = await vault.payments.create({
  supplier_id: 'sup_123',
  amount_grain: 10000,
  invoice_ref: 'INV-2025-001',
  due_date: '2025-02-15'
})