This guide explains what the Notabene Flow MCP server is, how to connect it to Claude and Codex clients—claude.ai in the browser, Claude Desktop, Claude Code, Codex desktop, and Codex CLI—and how to use its tools once connected.

What is the Notabene Flow MCP server?

MCP (Model Context Protocol) is the open standard that lets AI assistants such as Claude and Codex call tools on external services. Notabene Flow provides a hosted MCP server that brings compliant stablecoin payment link generation directly into your AI assistant.

In practice, that means you can hand your assistant an invoice—a PDF, an image, pasted text, or just a description—and ask it to “create a payment link for this.” The assistant extracts the invoice data, helps you choose where the funds should settle, and creates a payment link you can share with your customer, with Notabene handling Travel Rule compliance behind the scenes.

Key properties:

• The assistant acts for the merchant—the business getting paid. Your identity is your verified login email; it is never something the assistant or an uploaded invoice can override.
• Login is simple. Connecting from any supported client opens a login page where you enter your email and a one-time code sent to it. Sessions last up to 7 days, then you sign in again.
• Interactive previews. On ChatGPT, claude.ai and Claude Desktop, previewing or creating an invoice renders a live invoice preview in the conversation. CLI clients return equivalent text summaries instead.

Endpoint

https://flow.link/mcp

Authentication endpoints are discovered automatically—this is the only URL you enter.

Connecting

Claude (web)

1. Click your initials in the lower-left corner, then select Customize → Connectors.
2. Click Add → Add custom connector.
3. Enter https://flow.link/mcp and click Add. No OAuth client ID or secret is needed.
4. Click Connect. Enter your email in the Notabene Flow login, then the one-time code sent to it.
5. In a chat, click the + button, open Connectors, and make sure the connector is enabled.

On Team and Enterprise plans, an organization admin adds the connector first under Admin settings → Connectors. Members then connect with their own email from Customize → Connectors.

Claude Desktop app

Open Customize → Connectors → Add → Add custom connector, enter https://flow.link/mcp, then click Connect and complete the email login. Enable it in a conversation through the + → Connectors menu.

Claude Desktop supports the interactive invoice preview, so previews and created payment links render inline in the conversation.

Claude Code (CLI)

Add the server over HTTP transport:

claude mcp add --transport http notabene-flow https://flow.link/mcp

Use --scope user to make it available in all your projects, or --scope project to write it to a shareable .mcp.jsonfor your team.

Inside a session, run /mcp, select the server, and choose Authenticate. Your browser opens the Notabene Flow login. claude mcp list shows the connection status.

Claude Code does not render the interactive preview; the tools return text summaries instead.

ChatGPT/Codex desktop app

1. Open the Plugins page.
2. Click Add in the upper-right corner, then select Add MCP server.
3. Enter notabene-flow as the name and https://flow.link/mcp as the server URL.
4. Complete the form to add the server.
5. When prompted, complete the Notabene Flow login using your email and the one-time code sent to it.
6. Open the MCPs tab on the Plugins page to check that Notabene Flow is connected.

Once connected, try: “Use Notabene Flow to list the supported settlement assets and chains.” Then provide an invoice and ask Codex to validate and preview it before creating a payment link.

Codex CLI

Register the server and sign in from your terminal:

codex mcp add notabene-flow --url https://flow.link/mcp
codex mcp login notabene-flow

Complete the Notabene Flow email login in your browser. Run codex mcp list to inspect the configuration, then start Codex and run /mcp to check the active connection.

Codex desktop and Codex CLI share MCP configuration on the same host, so setup in either client is sufficient. Restart an already-running client after adding the server.

Codex CLI does not render the interactive invoice preview. Ask it to use preview_invoice_text, then review the invoice and settlement destination before requesting the payment link.

Using the tools

Available tools

• update_profile — Sets your merchant display name and optional tax ID or address shown on every payment link.
• get_invoice_extraction_guide — Gives the assistant the extraction guide to follow when you upload or paste an invoice.
• validate_invoice — Normalizes and validates an invoice without creating anything.
• preview_invoice / preview_invoice_text — Shows the invoice before committing, as an interactive preview in supported clients or as text in CLI clients.
• list_supported_assets — Lists the stablecoin assets and chains a payment link can settle in.
• find_provider — Looks up an exchange or custodian such as Kraken, Coinbase, or Fireblocks.
• request_wallet_proof — Creates a single-use, 24-hour signing link for proving ownership of a self-hosted wallet. No funds move.
• get_wallet_proof_status — Checks a wallet-proof request and returns the settlement address once signed.
• create_invoice_payment_link — Issues the payment link.

Typical flow

1. Set your profile once: the assistant calls update_profile with your business display name.
2. Get the invoice in: upload or paste an invoice, or describe it. Your customer’s email is required so the payer is identifiable.
3. Preview: the assistant validates and previews the invoice so you can confirm it before committing.
4. Choose the settlement wallet where funds land. Use a wallet from a previous invoice, an account at an exchange or custodian found with find_provider, or a new self-hosted wallet verified through request_wallet_proof.
5. Create the link: create_invoice_payment_link returns the payment link URL. Share it with your customer, who opens it, picks an asset and chain, and pays. You are shown as the beneficiary.

Example prompts once connected:

“Here’s an invoice PDF—create a payment link for it. Settle to my Kraken account.”

“Create a $500 payment link for consulting services for [email protected], settled to the wallet I used last time.”

Good to know

• After you sign a wallet proof, it can take up to a minute for the signature to appear. The assistant will wait and re-check.
• Wallet ownership proofs are per wallet, not per invoice: sign once, and later invoices skip the step.
• An optional bank account adds a fiat payment fallback to the link.
• Payment links are valid for 60 days by default. If the invoice has a due date, the link stays payable until 60 days after it, capped at 2 years from creation. Wallet-proof signing links are single-use and expire after 24 hours.
• Travel Rule compliance is handled by Notabene. A new self-hosted wallet needs a signed ownership proof before it can receive a link.