Chase overdue invoices on a ladder anchored to the due date: reminder 1, reminder 2, the final notice, with the aging and the day's chase list. You register an unpaid invoice, client, reference, amount in whole minor units, currency, due date, and it returns a DUN-YYYY-NNNN id with the three escalation dates: reminder 1 at due plus 7 days, reminder 2 at due plus 14, the final notice at due plus 21, configurable per invoice. The ladder is anchored to the due date, not to the last letter, so a reminder that goes out twelve days late does not push the final notice back: the client's obligation was fixed by the due date. Letters go out strictly in order, and the late fee is simple interest, pro-rata on a 30-day month, on what is outstanding the day the letter is written, rounded once to the minor unit. letter_render produces the letter as Markdown or a self-contained printable HTML page, letter_sent records that it actually went out, and payment_record lowers what the next letter asks for, with a payment that covers the balance closing the ladder. Nothing is emailed or sent anywhere: the server produces the letter text, and sending it is your act.
overdue_list, aging_summary, chase_today, invoice_status and letter_render are reads and safe to auto-approve. Keep letter_sent behind a click, because it records a fact about what a client was sent and on what day, and keep invoice_register behind one, because it spends one of the three free chase slots. Nothing here is emailed: the server produces the text and the sending is yours.
| You say | Tool |
|---|---|
| Register INV-1042 to Acme Ltd, USD 1,250.00, due 2026-06-01, late fees at 2% a month. | invoice_register |
| What do I need to send today? | chase_today |
| They paid 500 on the 20th; record it and show me the final notice when it falls due. | payment_record then letter_render |
On the worked chase, USD 125,000 minor units due 2026-06-01 with the default gaps falls due on 06-08, 06-15 and 06-22 whether or not anything was sent, and on 2026-07-01 the fee at 2% per month is exactly 2,500. After a 50,000 part payment the fee on the remainder is 1,500, so the final notice asks for 76,500 and no invented figure more. The unit suite recomputes every one of those by hand.
The file is mcp.json, and the key inside it is mcpServers.
| Scope | Path |
|---|---|
| Cline CLI | ~/.cline/mcp.json |
| The editor extension | opened from the Cline panel, not by path; the documentation deliberately calls it the MCP settings JSON used by the extension |
If you also run Claude Desktop, the shortest path there is one click: dunning-letters.mcpb
from the latest release opens as an extension, with no JSON and no terminal.
Cline reads its own config, so here it is:
The config block:
{
"mcpServers": {
"dunning-letters": {
"command": "node",
"args": ["/absolute/path/to/mcp-servers/servers/dunning-letters/dist/index.js"],
"disabled": false,
"autoApprove": []
}
}
}The node command above wants a built file. From a clone, once:
git clone https://github.com/theluckystrike/mcp-servers.git
cd mcp-servers && npm install
npm run build -w packages/mcp-license -w servers/dunning-lettersThat writes servers/dunning-letters/dist/index.js, and its absolute path is the one argument
the config needs.
The npm packages are not published yet, so the form below returns a 404 today. It is here because it is what the entry becomes the day the publish lands, with nothing else changed:
{
"mcpServers": {
"dunning-letters": {
"command": "npx",
"args": ["-y", "@theluckystrike/mcp-dunning-letters"]
}
}
}No full-app restart. The MCP settings actions include restarting an unresponsive server if its tools do not appear.
Nothing is published to npm yet, so the working install paths are the ones above: the .mcpb bundle from the latest release, a clone and build, or the hosted URL.
There is no hosted endpoint for this one yet. MCP Dunning Letters runs locally over stdio with the config above, which is also the only form in which it reads and writes files on your own disk. Thirty of the servers in this collection are served at https://mcp.zovo.one/mcp/<name> over MCP streamable HTTP; https://mcp.zovo.one/mcp/connect lists them and prints a ready URL for each.
Cline is the one client here with an unsafe transport default. `type` selects it, and omitting `type` falls back to the legacy sse transport, so a streamable HTTP endpoint needs it written in or you will debug a server that is fine. Local entries carry "disabled" and an "autoApprove" array.
Free: Three unpaid invoices chased at once, with all three letters in both formats, the aging summary, the day's chase list and payment recording free on every tier. An invoice that gets paid frees its slot, because the cap is on how many chases run at once, never on the letters or the aging. Pro is $19 once, verified offline.
The CLI reads ~/.cline/mcp.json. For the extension, do not hunt for a path: MCP Servers icon, Configure tab, Configure MCP Servers. cline mcp opens a wizard, and cline config mcp --json is the non-interactive form.
Set the transport explicitly. Omitting type falls back to the legacy sse transport, so streamable HTTP needs "type": "streamableHttp" written in. It is the one default here that sends you debugging a server that works.
Approve the read-only ones and leave the writing ones behind a click: each entry carries an autoApprove array and a disabled flag.
MCP Dunning Letters in detail · The same server in Windsurf and Claude.ai and Claude Desktop connectors · Every server in Cline · Guides · Cline docs · Buy Pro