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Pay3 gives your AI assistant a secure, policy-controlled wallet on Stellar — so it can check balances, send payments, and interact with DeFi on your behalf without ever touching your private key. This guide walks you through everything from wallet setup to your first AI-initiated transfer.
This guide uses the Stellar testnet. No real funds are required. When you’re ready to move to mainnet, repeat the same steps using a funded mainnet account and switch the network in Freighter.
1

Set up prerequisites

Before you begin, make sure you have the following ready.Freighter walletFreighter is the official Stellar browser extension wallet. Install it from the Freighter website and create or import a Stellar account.A funded Stellar testnet accountYour testnet account needs two assets:
  • XLM — to pay Stellar network transaction fees (a small amount is enough)
  • USDC — the stablecoin Pay3 uses for payments
Use the Stellar Laboratory Friendbot to fund your testnet account with XLM. Then add a USDC trustline and claim testnet USDC from a faucet.
The Stellar testnet USDC issuer is GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5. Add this as a trustline in Freighter before trying to receive testnet USDC.
2

Sign in to the Pay3 dashboard

Pay3 authenticates you using a cryptographic challenge — your private key never leaves Freighter.
  1. Navigate to app.pay3.finance and click Connect Freighter.
  2. Freighter will prompt you to approve the connection — click Connect.
  3. Pay3 issues a one-time challenge message. Freighter will ask you to sign it — click Sign.
  4. You’re redirected to the dashboard.
If Freighter shows a “connection not secure” warning on localhost, go to Settings → Security → Advanced in Freighter and enable insecure domains, then retry.
3

Link a smart account

A smart account is a Soroban vault contract deployed on Stellar. It holds the USDC your AI is allowed to spend, and it enforces hard on-chain limits that the AI cannot bypass — even if the off-chain policy is misconfigured.
  1. In the dashboard sidebar, go to Sessions.
  2. Under Link smart account, paste your Soroban contract ID (a string starting with C).
  3. Click Link contract.
Your linked contract ID appears in the list below the form once confirmed.
Don’t have a Soroban vault contract yet? You can deploy the open-source Pay3 vault contract from the contracts/smart-account directory, or contact the Pay3 team for a testnet deployment.
4

Create a spending policy

A policy defines exactly what your AI session is allowed to do: how much it can spend per day, how much per transaction, which assets it can use, and at what amount it must ask for your manual approval.
  1. In the dashboard sidebar, go to Policies.
  2. Give your policy a name (e.g. My first policy).
  3. Choose a preset from the table below, or select Custom to set your own values.
  4. Click Create policy.
Start with CONSERVATIVE for your first session. You can always create a more permissive policy later once you’re comfortable with how the approval flow works.
5

Create an AI session and configure your client

A session connects your smart account and policy to a specific AI client, and produces an MCP auth token your AI uses to authenticate every tool call.Create the session
  1. Still in Sessions, scroll to Create session.
  2. Select your linked smart account and the policy you just created.
  3. Choose your AI client: Cursor, Claude, ChatGPT, Gemini, or Other.
  4. Click Create AI session.
A panel appears with your MCP auth token and a ready-to-use mcpConfig JSON block. Copy both — the token is shown only once.Add the config to your AI clientPaste the mcpConfig into your client’s settings file. The JSON looks like this:
Where to put the file

Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json on macOS, or %APPDATA%\Claude\claude_desktop_config.json on Windows. Restart Claude Desktop after saving.

Cursor

Open Cursor → Settings → MCP and paste the mcpServers block, or edit ~/.cursor/mcp.json directly. Reload the window after saving.
Treat your MCP auth token like a password. Anyone who has it can initiate payments up to your policy limits. If you believe a token is compromised, go to Sessions in the dashboard and click Revoke immediately.
6

Make your first AI payment

With the MCP server connected, ask your AI assistant to check your balance:
Prompt
Your AI calls the get_balance tool through Pay3 and returns your current USDC balance from the linked smart account. If that works, try a small test transfer:
Prompt
Because the amount is below the approval threshold on a CONSERVATIVE policy, Pay3 auto-executes the transaction and returns a Stellar transaction hash as proof. You can verify it instantly on Stellar Expert.
If the transfer amount is above your policy’s approval threshold, Pay3 queues it for manual approval in the dashboard instead of executing immediately. Head to Sessions to approve or reject it. Approval requests expire after 2 minutes.

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What’s next?

How It Works

Understand the full payment flow, session key security model, and the three-level execution engine.

Policy Reference

Learn every field available in a custom policy and how the budget accounting works across sessions.

MCP Tools

Browse all tools your AI can call: get_balance, transfer, get_transaction_history, and more.

Session Key Security

Deep dive into how Pay3 keeps your private key safe while giving your AI delegated permissions.