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Invoice numbers that advance in order, issued from chat

An invoice needs a number that has not been used before, and next month it needs a number that still has not been used. MCP Invoice issues invoices with a sequence that advances once, and MCP Recurring Invoices keeps the repeat billing on the same orderly track, so the numbering on your side is the numbering a client sees.

One number per invoice

"Invoice Acme for the retainer, next number" issues the invoice and advances the counter, so you never risk a duplicate or a gap by hand-typing the next figure. Because the sequence lives in the server and not in your head, the number on a revised or credited invoice stays consistent with every other document.

The same track for recurring work

Monthly retainers are where numbering quietly breaks, because a template re-issued by hand tends to repeat a number or skip one. The recurring server invoices on the schedule and numbers each issue in the sequence, so a year of monthly billing is a numbered spine an accountant can trace. Every numbered document stays in the chat for the audit trail.

One click, with no JSON. Download invoice.mcpb from the latest release and open it in Claude Desktop. It runs on the Node runtime Claude Desktop ships with, so your own PATH and node version never come into it.

Or a URL, with nothing installed. /mcp/connect mints a free anonymous token and prints the ready line:

claude mcp add --transport http invoice https://mcp.zovo.one/mcp/invoice/t/<token>

Or from a clone, for a client with no bundle installer. Build once, then point the client at the built file:

git clone https://github.com/theluckystrike/mcp-servers.git
cd mcp-servers && npm install
npm run build -w packages/mcp-license -w servers/invoice

claude mcp add --scope user invoice -- node /absolute/path/to/mcp-servers/servers/invoice/dist/index.js

Claude Desktop, Cursor, Windsurf and Cline take the same two strings as JSON, in claude_desktop_config.json or the client's own MCP config file:

{
  "mcpServers": {
    "invoice": {
      "command": "node",
      "args": ["/absolute/path/to/mcp-servers/servers/invoice/dist/index.js"]
    }
  }
}

The npm packages are not published yet, so the npx form below returns a 404 today. It is kept because it is what that config becomes the day the publish lands, with nothing else changed; installing these servers when npx does not work yet has the whole picture.

claude mcp add invoice -- npx -y @theluckystrike/mcp-invoice

Questions

Will the sequence ever reuse a number?

No. Issuing an invoice advances the counter once, so the next number has not been produced before. Reversals reference the original without reusing its number.

Can I start the sequence at my own number?

Yes. Set the starting point to match your existing books, and every invoice after continues from there in order.

Do recurring invoices keep numbering consistent?

Yes. Each scheduled issue is numbered in the same sequence, so monthly billing stays traceable rather than repeating a template number.

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