SAYBOOKS · solo

Invoices, kept by conversation.

A free invoice generator for freelancers who work with Claude. You talk; it asks for exactly what it needs, one question at a time; you get back a clean, immutable invoice with a link to send your client. Ahead of the work, partial, or after — your agreement, your call.

Start free with Google → See it working first
The demo is a live sandbox with a freelancer's books already in it — no account needed. No credit card, no trial clock; export or delete everything, any time.
You: let's create an invoice
Claude: Happy to. You haven't set your company details yet — what's your company (or trading) name?
You: Crankk Inc
Claude: And the address, as it should appear on the invoice?
· · ·
Claude: Saved. Now the client — who are we invoicing, and what terms did you two agree on?
· · ·
Claude: Here's the draft: 17 h consulting × $250 + workshop day $1,200 = $5,450.00, due Oct 2 (net 30). Issue it? Once issued it's immutable — mistakes become void-and-reissue, on the record.
You: go
Claude: Issued — INV-0001. Your document: saybooks.io/doc/… — save as PDF and send it over. I'll keep an eye on what's outstanding.

Why these invoices are worth keeping

Issued means issued

An issued invoice is immutable. Fixing a mistake is a void with a reason and a fresh invoice — the number stays burned, the history stays honest. Exactly what your accountant wishes you did.

Your details, frozen in time

The seller block — your name, address, payment instructions — freezes onto each invoice at issue. Change banks next year; last year's invoices still say what they said.

An agent that can't make things up

It never invents an amount, a rate, or a date — it asks you. And everything it does lands in an audit trail you can read, refusals included.

Who owes what, honestly

Payments are recorded as they arrive — unapplied money is a real, visible state, never silently matched. Outstanding shows the truth, oldest first.

How it works — three steps

1
Sign in above.

You get your own private space for invoices. Nothing to install.

2
Add Saybooks to Claude.

In the Claude app: Customize → Connectors → Add (or open claude.ai/customize/connectors), paste the address below, Continue. Claude sends you to sign in with Google and asks which books to open and what the agent may do; you pick, and you're connected. Revoke it any time under Share this space….

Name
books
Remote MCP server URL
https://saybooks.io/mcp/invoices
3
Open a new session and say: let's create an invoice

That's genuinely all. The agent knows this space's rules and guides you from there — company details, client, the work, every number shown before anything is issued. Prefer forms? The same books are in your browser, and each side picks up what the other did.

Your data, actually yours
Built on Saybooks — the open-source platform where AI agents and humans share one set of rules and one audit trail. Solo is its fourth module: no orders, no credit gates — just invoices, done properly. Also free: the job-hunt tracker.