Wave MCP Server

A complete Model Context Protocol (MCP) server for Wave Accounting, providing comprehensive access to invoicing, customers, products, transactions, bills, estimates, taxes, and financial reporting.

Features

🔧 45+ Tools across 10 categories:

Invoices (10 tools)

• List, get, create, update, delete invoices
• Send invoices via email
• Approve and mark invoices as sent
• List and record invoice payments

Customers (6 tools)

• List, get, create, update, delete customers
• Search customers by name or email

Products (5 tools)

• List, get, create, update, archive products and services
• Filter by sold/bought status

Accounts (4 tools)

• List, get, create, update chart of accounts
• Filter by account type (ASSET, LIABILITY, EQUITY, INCOME, EXPENSE)

Transactions (6 tools)

• List, get, create, update transactions
• Categorize transactions to accounts
• List transaction attachments

Bills (7 tools)

• List, get, create, update bills (accounts payable)
• List and record bill payments

Estimates (6 tools)

• List, get, create, update, send estimates
• Convert estimates to invoices

Taxes (3 tools)

• List, get, create sales taxes

Businesses (3 tools)

• List businesses
• Get current or specific business details

Reporting (5 tools)

• Profit & Loss (Income Statement)
• Balance Sheet
• Aged Receivables (A/R Aging)
• Tax Summary
• Cashflow Statement

📱 17 MCP Apps - Pre-built UI workflows:

1. invoice-dashboard - Overview of invoices with status breakdown
2. invoice-detail - Detailed invoice view with payments and actions
3. invoice-builder - Create/edit invoices with line items
4. customer-detail - Customer profile with invoice history
5. customer-grid - Searchable customer grid
6. product-catalog - Product/service management
7. chart-of-accounts - Account tree view
8. transaction-feed - Real-time transaction stream
9. transaction-categorizer - Bulk transaction categorization
10. bill-manager - Track and pay bills
11. estimate-builder - Create and manage quotes
12. tax-overview - Tax configuration and summary
13. profit-loss - P&L report with visualization
14. balance-sheet - Balance sheet report
15. cashflow-chart - Cashflow waterfall chart
16. aging-report - Aged receivables report
17. business-overview - Business dashboard with quick actions

Installation

cd servers/wave
npm install
npm run build

Configuration

Prerequisites

1. Wave Account: You need a Wave account at waveapps.com
2. API Access Token: Get an OAuth2 access token from Wave Developer Portal

Environment Variables

# Required
WAVE_ACCESS_TOKEN=your_oauth2_access_token

# Optional - set a default business ID
WAVE_BUSINESS_ID=your_business_id

Usage

As MCP Server

Run the server:

WAVE_ACCESS_TOKEN=your_token npm run dev

With Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "wave": {
      "command": "node",
      "args": ["/path/to/mcpengine-repo/servers/wave/build/main.js"],
      "env": {
        "WAVE_ACCESS_TOKEN": "your_access_token",
        "WAVE_BUSINESS_ID": "optional_business_id"
      }
    }
  }
}

With NPX

npx @mcpengine/wave-server

Tool Examples

List Invoices

// List all invoices
wave_list_invoices({ businessId: "business_123" })

// Filter by status
wave_list_invoices({ 
  businessId: "business_123",
  status: "OVERDUE"
})

// Filter by customer
wave_list_invoices({
  businessId: "business_123", 
  customerId: "customer_456"
})

Create Invoice

wave_create_invoice({
  businessId: "business_123",
  customerId: "customer_456",
  invoiceDate: "2025-01-15",
  dueDate: "2025-02-15",
  title: "January Services",
  items: [
    {
      description: "Consulting Services",
      quantity: 10,
      unitPrice: "150.00",
      taxIds: ["tax_789"]
    },
    {
      productId: "product_101",
      description: "Software License",
      quantity: 1,
      unitPrice: "500.00"
    }
  ]
})

Create Customer

wave_create_customer({
  businessId: "business_123",
  name: "Acme Corporation",
  email: "billing@acme.com",
  addressLine1: "123 Main Street",
  city: "San Francisco",
  provinceCode: "CA",
  countryCode: "US",
  postalCode: "94105"
})

Generate Reports

// Profit & Loss
wave_profit_and_loss({
  businessId: "business_123",
  startDate: "2025-01-01",
  endDate: "2025-01-31"
})

// Balance Sheet
wave_balance_sheet({
  businessId: "business_123",
  asOfDate: "2025-01-31"
})

// Aged Receivables
wave_aged_receivables({
  businessId: "business_123",
  asOfDate: "2025-01-31"
})

API Architecture

GraphQL-Based

Wave uses a GraphQL API, not REST. The server handles:

• Authentication: OAuth2 Bearer token
• Error Handling: GraphQL error parsing and network error detection
• Type Safety: Full TypeScript types for all Wave entities
• Pagination: Automatic page handling for large result sets

Client Implementation

// client.ts
import { GraphQLClient } from 'graphql-request';

const client = new GraphQLClient('https://gql.waveapps.com/graphql/public', {
  headers: {
    Authorization: `Bearer ${accessToken}`
  }
});

Tool Organization

src/tools/
├── invoices-tools.ts      # 10 tools for invoice management
├── customers-tools.ts     # 6 tools for customer management
├── products-tools.ts      # 5 tools for product/service catalog
├── accounts-tools.ts      # 4 tools for chart of accounts
├── transactions-tools.ts  # 6 tools for transaction management
├── bills-tools.ts         # 7 tools for bills payable
├── estimates-tools.ts     # 6 tools for estimates/quotes
├── taxes-tools.ts         # 3 tools for sales tax management
├── businesses-tools.ts    # 3 tools for business info
└── reporting-tools.ts     # 5 tools for financial reports

Type System

Complete TypeScript types for all Wave entities:

// types/index.ts
export interface Invoice {
  id: string;
  invoiceNumber: string;
  customer: Customer;
  status: 'DRAFT' | 'SENT' | 'VIEWED' | 'PAID' | 'PARTIAL' | 'OVERDUE' | 'APPROVED';
  items: InvoiceItem[];
  total: Money;
  amountDue: Money;
  amountPaid: Money;
  // ... full type definitions
}

Error Handling

The server provides comprehensive error handling:

try {
  const invoice = await wave_get_invoice({ invoiceId: "inv_123" });
} catch (error) {
  // GraphQL errors
  if (error.graphQLErrors) {
    console.error('GraphQL errors:', error.graphQLErrors);
  }
  
  // Network errors
  if (error.networkError) {
    console.error('Network error:', error.networkError);
  }
  
  // HTTP status codes
  if (error.statusCode) {
    console.error('HTTP status:', error.statusCode);
  }
}

MCP Apps

Apps are accessed via resources:

// List all apps
const apps = await readResource({ uri: "wave://apps" });

// Load specific app
const invoiceDashboard = await readResource({ 
  uri: "wave://apps/invoice-dashboard" 
});

Each app includes:

• Display name and description
• Default tools to load
• Layout configuration for UI rendering
• Workflow steps (for process-driven apps)

Development

Build

npm run build

Watch Mode

npm run watch

Type Checking

npx tsc --noEmit

License

MIT

Links

• Wave Developer Portal
• Wave GraphQL API Docs
• MCP Protocol Specification
• MCPEngine Repository

Contributing

Contributions welcome! Please see the main MCPEngine repository for guidelines.

Support

For issues or questions:

• Wave API issues: Wave Developer Support
• MCP Server issues: GitHub Issues