Self-custody invoicing — by Bull Project
Invoices, payments and proof — for people and for AI agents.
Get paid in stablecoins to your own wallet with one link. Let your AI agent pay suppliers within limits you set. Hand your accountant the bills and the proof at month end. Nothing custodial. Nothing to sign up for.
KYT (Know Your Transaction): every payment is found on the blockchain and both sides are screened against sanctions lists. KYA (Know Your Agent): an agent can show which company it acts for with a Skyfire KYA token, and the company is named on the proof.
Works across
Start where you are
One service, three jobs. Pick yours and see what it does for you.
Get paid in stablecoins, straight to your wallet
Make an invoice, share one link, and your client pays from their own wallet. No account, no middleman, and we never hold your money.
- Professional PDF invoices with line items, tax and your logo
- Payment links and QR codes that any wallet can open
- Signed links: a changed amount or address is caught before anyone pays
- Every recipient screened against sanctions lists
- Optional encryption, so only your client can read the invoice
- A Telegram message the moment you are paid
How it works
- Build the invoice. Parties, items, network and token, with a live preview.
- Sign the link with your wallet, so nobody can alter it on the way.
- Get paid. Your client checks the details and pays in one tap.
Your AI agent invoices, checks and pays, within limits you set
Connect Claude, GPT or any agent framework over MCP. It issues signed invoices, decides whether an invoice is safe to pay, pays it, and confirms the payment on the blockchain. The agent’s own wallet holds the keys; StableInvoice never does.
- Free hosted tools over MCP and plain HTTP: no account, no API key
- One call answers “safe to pay?” with the reasons, and refuses an invoice from the wrong sender
- Pays USDC invoices with no gas, over x402
- A policy file decides who can be paid and how much, per payment and per day; a ledger stops double payment
- At month end: a statement, one bill per supplier, QuickBooks and Xero files
- StableInvoice’s signed proof of every payment, sent straight to the company’s console
MCP server address
https://www.stableinvoice.xyz/mcp
What an agent pays with: USDC on Base. Other tokens and networks work only through a direct transfer, which needs gas.
The tools that pay run on your own machine, next to the wallet. They are not public yet: write to us for access.
At month end, the bills and the proof are already waiting
When AI agents pay your suppliers, you still need books your auditor accepts. The Agent Console turns a month of agent payments into what your accounting system expects, and shows the proof behind every payment, in plain words.
- One bill per supplier, as a PDF and as a QuickBooks or Xero import file
- The supplier’s own invoice behind each payment, marked paid
- Every payment checked on the blockchain, matched to its invoice and screened against sanctions lists
- Proof that nobody can change or backdate, StableInvoice included
- Months delivered by the agent straight into your encrypted vault, with no files to send
- Your auditor can check any proof in a browser, with no account
How it works
- Connect your agent once from the Business page, with a code it shows you.
- The agent pays suppliers during the month and sends you each month when it closes.
- Open the console. Download the bills, import the file, keep the proof.
How it fits together
From the supplier’s invoice to your books. Every step leaves a record someone else can check.
The supplier
Sends an invoice as a signed StableInvoice link.
Your agent
Checks the invoice and pays it, only within your policy.
StableInvoice
Checks each payment on the blockchain and signs a proof.
Your finance team
Gets the bills, the import files and the proof.
Stay safe
Built so a forged invoice cannot pay itself. Payment links get forwarded; these are the checks that survive that.
Tamper-evident links
The address, amount, token and network are signed. Change one character and the payment page turns red and refuses to pay.
It remembers who you pay
If a familiar supplier suddenly asks for a different address, you are warned before you send.
Sanctions screening
Every recipient is checked against the sanctions list before money moves, and the result goes on the record.
Nothing held by us
Payments go wallet to wallet. We hold no keys and no money, and what you store with us is encrypted before it leaves your browser.
Pricing
Free to start, paid in stablecoins when you grow. No card, no payment processor.
Invoicing
- Invoices, payment links, QR codes and PDFs
- Signed and encrypted links
- Sanctions screening
- The Telegram bot
Business
- An encrypted vault we cannot read
- Several wallets on one account
- Treasury view across every network
- One AI agent’s months, delivered to you
Proof for AI agents
- $0.10 minimum, up to 50 payments per check
- Cheaper with volume: $0.002 after 1,000 a month, $0.0005 after 10,000
- Checked on the blockchain, matched to the invoice
- Signed, and recorded so it cannot be backdated
- Paid in USDC on Base, or with Skyfire
Enterprise
For companies running several AI agents, with a finance team looking after the money.
Price on request
- Several AI agents on one company account, each named and paused or removed at any time
- 10,000 proven payments a month included, then volume prices
- Far more space for your records: 10 GB
- Coming next: rules for each agent, same-day alerts, team members with roles
The proof service is in test mode for now: it is paid with test USDC on Base Sepolia while we finish testing.
Or get paid from a chat message
@StableInvoice_Bot builds the same payment links where your client already is. Store your wallet once, then ask in plain English. It reads the amount, token and network out of the sentence, and it messages you the moment a link is paid. Your details are stored encrypted, and a link is forgotten once it is paid.
Open @StableInvoice_BotQuestions
Do I need an account?
No. Every payment link, invoice PDF and QR code works with no account at all, and that will not change. The optional Business account adds an encrypted vault that keeps your invoices. It is opened by a wallet signature, and we cannot read what it stores.
Is StableInvoice free?
For individuals, yes. Invoices, payment links, QR codes, PDF export, encryption and sanctions screening are free, with no signup and no limits. Business costs $14.99 a year, paid in stablecoins. AI agents pay $0.005 per payment for StableInvoice’s proof, with a $0.10 minimum.
Which networks and tokens can I use?
USDT, USDC, EURC, DOC, FDUSD, USDRIF and USDT0 across Ethereum, Polygon, Base, Arbitrum, Avalanche, BNB Chain and Rootstock, wherever each token genuinely exists. If a token is not deployed on the network you picked, the app refuses to build a link rather than quietly using a different asset.
Do you hold my funds or my keys?
No. Payments go wallet to wallet. We hold no money and no keys, and the invoice itself lives in the link, in the part of the address browsers never send to a server.
What stops someone editing a payment link?
Signing it. A signed link ties the recipient address, amount, token, network and expiry to your wallet. The payment page checks that before it enables the pay button, so an altered link is caught rather than paid.
Can an AI agent use StableInvoice?
Yes. Seven free tools are available over MCP at www.stableinvoice.xyz/mcp
and as a plain HTTP API, with no account: create a link, sign it, read and check a
link, confirm a payment, check an address, list the supported tokens, and check a
proof. The tools hold no keys and move no money; the agent’s own wallet signs
and pays. The agent guide explains the rest.
What can an AI agent pay with?
USDC on Base. That is what pays invoices with no gas and what pays for StableInvoice’s proof. Other tokens and networks work only through a direct transfer, which needs gas.
What does StableInvoice’s proof prove?
That StableInvoice found each payment on the blockchain on the date shown, matched it to the supplier’s signed invoice where there was one, and screened both sides against sanctions lists. The proof is signed and recorded on the blockchain, so nobody can change or backdate it. It is a record of checks, not an audit opinion.
What are KYT and KYA?
KYT, Know Your Transaction: before StableInvoice signs anything, it finds every payment on the blockchain, confirms the amount reached the right recipient, and screens both the payer and the recipient against sanctions lists (OFAC). KYA, Know Your Agent: an AI agent can send a Skyfire KYA token, which proves which company it acts for. StableInvoice checks the token and names that company on the proof. It copies company details only, never personal data, and does not keep the token.
Can my client pay without a browser extension?
Yes. Every link carries a QR code and a wallet link, so a mobile wallet can scan it or open a pre-filled transfer.
Pick your way in
No signup. Nothing held by us. Paid in stablecoins, straight to the wallet, with a record someone else can check.