This server automates overdue-invoice dunning by registering unpaid invoices, running a due-date-anchored reminder ladder, generating chase letters, and tracking payments and aging.
Register unpaid invoices with client, reference, amount in integer cents, currency, and due date; get a DUN id and reminder 1/reminder 2/final-notice schedule.
Configure escalation gaps and optional late-fee interest; late fees accrue simply and pro-rata.
Record full or partial payments; part payments lower the outstanding balance and full payment closes the ladder.
Generate current-stage chase letters as Markdown or self-contained printable HTML; nothing is emailed or sent.
Record letters actually sent so the ladder advances in order.
List overdue invoices, produce aging summaries by currency, show today’s chase list, and inspect one invoice’s full status.
Delete wrongly entered invoices without reissuing their ids.
Check license status and activate a Pro key offline; free tier chases up to 3 unpaid invoices at once.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@dunning-letters show me all overdue invoices and which letters to send today"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
MCP server for dunning letters and overdue invoice payment reminders: reminder, final notice and aging. 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.
Works with Claude Desktop, Claude Code, Cursor and any Model Context Protocol client. Runs on your own machine, or hosted with no install.
Product page: https://mcp.zovo.one/s/dunning-letters - what it does, the tools it exposes, and a live token endpoint.
Hosted, nothing to install. Get a token from https://mcp.zovo.one/mcp/connect (the connect page) or https://mcp.zovo.one/mcp/token (the same token as JSON); a free anonymous one is issued on the spot and a Pro key works the same way. Then point an MCP client at https://mcp.zovo.one/mcp/dunning-letters over streamable-http and send the token as Authorization: Bearer <token>.
If your client cannot set headers, put the token in the path instead: https://mcp.zovo.one/mcp/dunning-letters/t/<token>. Both forms work. The bare URL with no token answers 401 on tools/call, so the token is not optional.
Claude Desktop, one click. Download dunning-letters.mcpb from the latest release and double-click it.
From source. The mirror is self-contained: every @theluckystrike/* dependency is vendored, so a fresh clone builds with no extra setup.
git clone https://github.com/theluckystrike/mcp-dunning-letters.git
cd mcp-dunning-letters
npm install && npm run buildThen point your client at the built entry point:
{
"mcpServers": {
"dunning-letters": {
"command": "node",
"args": ["/absolute/path/to/mcp-dunning-letters/dist/index.js"]
}
}
}
@theluckystrike/mcp-dunning-lettersis not published on npm yet, so annpx -y @theluckystrike/mcp-dunning-letterscommand will fail. The three paths above are the working ones and each is exercised by CI.
Read-only mirror of mcp-servers/servers/dunning-letters. See MIRROR.md.
In the official MCP Registry (io.github.theluckystrike/dunning-letters).
Chase overdue invoices without losing the thread. Register an unpaid invoice, client, invoice reference, amount in integer cents, currency, due date, and the server runs the escalation ladder: reminder 1 (polite, due + 7 days), reminder 2 (firm, with the late fees note, due + 14), and the final notice (before-action wording, due + 21; the gaps are configurable per invoice). For each stage it generates the letter, as Markdown or as a self-contained printable HTML page. It records what you sent and when, lists everything overdue with days late and stage, ages the whole register into current/30/60/90+ buckets, and answers "what do I need to send today". Nothing is emailed or sent anywhere: this server produces the letter text, and sending it is your act.
Built by theluckystrike.
npm publish for @theluckystrike/mcp-dunning-letters is pending, so npx -y @theluckystrike/mcp-dunning-letters returns 404 today. Until then, a clone+build is the working path.
Related MCP server: kelo-mcp
macOS ~/Library/Application Support/Claude/claude_desktop_config.json, Windows %APPDATA%\Claude\claude_desktop_config.json:
{
"mcpServers": {
"dunning-letters": {
"command": "npx",
"args": ["-y", "@theluckystrike/mcp-dunning-letters"]
}
}
}claude mcp add dunning-letters -- npx -y @theluckystrike/mcp-dunning-letters~/.cursor/mcp.json (global) or .cursor/mcp.json (project), same entry as Claude Desktop.
tool | what it does |
| Start chasing an unpaid invoice: client, reference, amount, currency, due date. Returns |
| Record money received, full or partial. A part payment lowers what the next letter asks for; covering the balance closes the ladder |
| Generate the chase letter for the current stage -- reminder 1, reminder 2 or the final notice -- as Markdown or self-contained printable HTML. Nothing is emailed: you send the text it produces |
| Record that a letter actually went out, with its date, so the ladder advances. Letters go out in order |
| Every unpaid invoice past its due date: days late, outstanding, letters sent, what is due next, worst first |
| The whole register in current/1-30/31-60/61-90/91+ buckets, counts and totals in integer cents, per currency |
| The day's chase list: which invoices cross an escalation threshold today, which letter to send each, what falls due next |
| One chased invoice in full: payments, letters, schedule, next action |
| Delete an invoice entered wrongly. The id is not reissued |
| Free or Pro, and the key |
Free | Pro | |
Unpaid invoices chased at once | 3 | Unlimited |
All three letters, both formats | Yes | Yes |
Aging summary and the day's chase list | Yes | Yes |
Late fee accrual in the letters | Yes | Yes |
Payment recording and history | Yes | Yes |
The cap is on how many chases run at once, never on the letters or the aging: three late payers taken from first reminder to final notice is a real chase list, and an invoice that gets paid frees its slot. What is metered is breadth, a fourth concurrent chase is a collections workload, not a freelancer's month.
Get Pro: https://mcp.zovo.one/buy/dunning-letters, $19 one-time for this server, or $39 for the bundle.
The ladder is anchored to the due date, not to the last letter, and the two drift apart exactly when chasing is going badly.
The worked chase in test/_client.mjs: USD 1,250.00 due 2026-06-01, gaps 7/14/21, so the letters fall due on 06-08, 06-15 and 06-22 whether or not anything was sent. If reminder 1 actually goes out late, say 06-20, twelve days after its date, a previous-letter-anchored ladder would push the final notice to 07-11. This one does not: 06-22 stands, because the client's obligation was fixed by the due date, not by when you got around to writing. Recording a sending moves only which stage is next; it never moves the schedule. The letters are also strictly sequential: an invoice 60 days late with nothing sent is still owed reminder 1, because a final notice that no polite letter preceded reads as a threat, not a chase.
The late fee is measured the same way, once: simple interest, pro-rata on a 30-day month, on the amount outstanding on the day the letter is written, rounded once to the minor unit. On the worked chase that is 125,000 minor units at 2% over 30 days late, 2,500 exactly, and after a 50,000 part payment it is 1,500 on the 75,000 that remains, so the final notice asks for 76,500 and no invented figure more.
All data stays local, in ${XDG_DATA_HOME:-~/.local/share}/mcp-servers/dunning-letters/. Two files: invoices.json, counter.json. Nothing is sent anywhere, no account, no API key, no network call in this server at all, and the letters are rendered to text for you to send yourself; this server holds no mail credentials and wants none. License keys are verified offline.
Built by theluckystrike. https://github.com/theluckystrike
Yes. The dunning-letters server at mcp.zovo.one automates accounts-receivable follow-up: tiered reminder sequences (friendly, firm, final), printable PDF letters, per-customer aging. Free tier, hosted remote endpoint.
Connect https://mcp.zovo.one/mcp/dunning-letters and say: 'List overdue invoices and draft a firm reminder for Acme.' The letter follows the standard tier sequence and exports as PDF.
Any MCP client (Claude, Cursor, Windsurf, VS Code) can read this repository's documentation directly via GitMCP - no install:
Docs MCP URL: https://gitmcp.io/theluckystrike/mcp-dunning-letters
The aging summary across every unpaid invoice: current, 1-30, 31-60, 61-90 and 91+ day buckets, with counts and totals in integer cents, per currency. This is the answer to "how much am I owed, and how stale is it".
Inputs: on.
The day's chase list: which invoices cross an escalation threshold today, which letter to send each and how long it has been waiting, what falls due in the next few days, and which invoices have had all three letters and need a decision outside this server.
Inputs: on, within_days.
Delete an invoice entered wrongly, by id or reference: the record, its payments and its letter history. The id is not reissued, so a gap in the DUN series is the record that a deletion happened.
Inputs: invoice (required).
Start chasing an unpaid invoice: register the client, the invoice reference, the amount in integer cents, the currency and the due date, and get the three-letter escalation schedule (reminder 1, reminder 2, final notice) with the date each falls due. Free tier: 3 unpaid invoices chased at once.
Inputs: due (required), client (required), currency (required), reference (required), +6 more.
One chased invoice in full: what was billed, what has been paid and what is still owed, every letter sent with its date, the escalation schedule with each stage's state, and what happens next and when.
Inputs: invoice (required), on.
Chase an unpaid invoice: generate the letter for the current stage of the ladder -- reminder 1 (polite), reminder 2 (firm, with the late fees note) or the final notice (before-action wording) -- as Markdown or as self-contained printable HTML. Nothing is emailed or sent anywhere: this server produces the letter text, and sending it is your act. Record the sending with letter_sent so the ladder advances.
Inputs: invoice (required), on, stage, format.
Record that a chase letter was actually sent, with its date, so the ladder advances to the next stage. Letters go out in order: reminder 2 cannot be recorded before reminder 1. Returns what is due next and when.
Inputs: invoice (required), sent, stage.
Activate a Pro key (MCPL1.xxx.yyy) from checkout: verified offline against a built-in public key, saved to your config file. A wrong, malformed or expired key is refused, unsaved. license_status reads it back.
Inputs: key (required).
Report this server's licence state: product, tier free or pro, licence id, expiry, the key source and the upgrade URL. No arguments, no network. Explains a free-tier refusal; license_activate installs a key.
Inputs: no named parameters.
Every unpaid invoice past its due date: how many days late, what is still owed, which letters have gone out, and what is due next and when. Sorted by days late, worst first.
Inputs: on, limit.
Record money received against a chased invoice, in whole MINOR units: a part payment lowers what is still chased, a payment that covers the balance closes the ladder and frees the free-tier slot. Returns the outstanding amount.
Inputs: invoice (required), amount_minor (required), date, note.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
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Scored across 11 tools
Each tool has a clearly distinct purpose: registration, payments, letter generation, recording sent letters, status queries, reporting, and license management. Even the reporting tools (overdue_list, aging_summary, chase_today) target different views (detailed list, summary buckets, today's actions) with descriptions that prevent confusion.
All tool names use snake_case and mostly follow a noun-verb or verb-noun pattern, but the order is inconsistent (e.g., invoice_register vs. payment_record). Some names are noun-noun (license_status, aging_summary) or ambiguous (chase_today). Despite this, the pattern is readable and predictable enough.
With 11 tools, the set is well-scoped for the domain. It covers the core invoice lifecycle (register, status, delete), payment handling, letter generation and sending, comprehensive reporting (overdue, aging, daily chase), and license management. Each tool earns its place.
The tool surface is complete for dunning letter management: starting chases, recording payments, generating and tracking letters, querying invoice state, and producing aggregated reports. The license tools are separate but necessary. No obvious gaps in the lifecycle are apparent.
Chase unpaid invoices: reminder, firm reminder and final notice letters, and a daily chase list.
Client statements of account, ageing of open invoices and payment chasers as text or PDF.
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