LLM Wallet - x402 stabelcoin payments on Polygon

Manage crypto wallets and make x402 micropayments with USDC stablecoins on Polygon

LLM Wallet - Crypto Wallet & x402 Micropayments

Use llm-wallet commands to manage crypto wallets and make micropayments to paid APIs using USDC stablecoins on Polygon blockchain.

Default Network: Polygon Testnet (polygon-amoy) - safe for testing Facilitator: https://x402-amoy.polygon.technology

Quick Start

bash

# Create wallet
llm-wallet create

# Check balance
llm-wallet balance

# Set spending limits (recommended)
llm-wallet set-limit --per-tx 0.10 --daily 5.00

# View transaction history
llm-wallet history

Wallet Management

Create Wallet

bash

llm-wallet create [--label <name>]

Creates a new HD wallet with encryption. Returns wallet address.

Example:

bash

llm-wallet create --label "agent-wallet"

Import Wallet

bash

llm-wallet import --private-key <key> [--label <name>]

Import existing wallet from private key.

Check Balance

bash

llm-wallet balance

Shows USDC balance and native token balance on current network.

Transaction History

bash

llm-wallet history

View all transactions and payments made from this wallet.

Spending Limits

Set Limits

bash

llm-wallet set-limit --per-tx <amount> --daily <amount>

Set per-transaction and daily spending caps in USDC.

Example:

bash

llm-wallet set-limit --per-tx 0.10 --daily 5.00

Check Limits

bash

llm-wallet get-limits

View current spending limits and daily usage.

x402 Payments

Make Payment

bash

llm-wallet pay <url> [--method GET|POST] [--body <json>]

Make x402 micropayment to a paid API endpoint.

⚠️ IMPORTANT: Always ask user for approval before making payments!

Example:

bash

# Ask user: "I need to make a payment to https://api.example.com/weather. Cost: $0.001 USDC. Approve?"
llm-wallet pay "https://api.example.com/weather?location=London"

Workflow:

1. Check if payment is needed: llm-wallet check-payment <url>
2. Show user: URL, estimated cost, current limits
3. Wait for user approval
4. Execute: llm-wallet pay <url>
5. Confirm completion and show transaction ID

Check Payment (Pre-flight)

bash

llm-wallet check-payment <url>

Checks if wallet can afford payment without executing it.

Dynamic API Registration

Register API

bash

llm-wallet register-api <url> --name <tool_name>

Register a paid API endpoint as a reusable tool.

Example:

bash

llm-wallet register-api "https://api.example.com/weather" --name weather_api

List Registered APIs

bash

llm-wallet list-apis

Show all registered API tools.

Call Registered API

bash

llm-wallet call-api <tool_name> [--params <json>]

Execute a registered API tool. Requires approval if payment needed.

Example:

bash

# Ask user for approval first if cost > 0
llm-wallet call-api weather_api --params '{"location": "London"}'

Unregister API

bash

llm-wallet unregister-api <tool_name>

Remove a registered API tool.

Seller Tools (Advanced)

Verify Payment

bash

llm-wallet verify-payment --header <x-payment-header> --requirements <json>

Verify incoming payment from a buyer (seller-side).

Create Payment Requirements

bash

llm-wallet create-requirements --price <amount> --pay-to <address> --url <resource-url>

Generate payment requirements for a protected resource.

Safety Rules

1. Network Default: Always uses polygon-amoy (testnet) unless configured otherwise
2. Approval Required: Always ask user before making payments
3. Spending Limits: Check limits before payment attempts
4. Transaction Logging: All payments are logged with timestamps
5. Encryption: Wallets are encrypted with AES-256-GCM

Configuration

Environment Variables

• WALLET_ENCRYPTION_KEY - Wallet encryption key (32+ chars, auto-generated if missing)
• WALLET_NETWORK - Network selection (default: polygon-amoy | polygon)
• FACILITATOR_URL - Custom facilitator URL (auto-configured)
• WALLET_MAX_TX_AMOUNT - Per-transaction limit override
• WALLET_DAILY_LIMIT - Daily limit override

Network Info

• Polygon Testnet (Amoy): Chain ID 80002, Facilitator: https://x402-amoy.polygon.technology
• Polygon Mainnet: Chain ID 137, Facilitator: https://x402.polygon.technology

Common Workflows

First Time Setup

bash

# 1. Create wallet
llm-wallet create --label "my-agent"

# 2. Set spending limits
llm-wallet set-limit --per-tx 0.10 --daily 5.00

# 3. Check balance (will be 0 initially)
llm-wallet balance

# 4. Fund wallet with testnet USDC
# User needs to: visit https://faucet.polygon.technology/

Making a Payment

bash

# 1. Pre-check payment
llm-wallet check-payment "https://api.example.com/weather?location=London"

# 2. Show user: URL, cost estimate, current limits
# 3. Ask user: "Approve payment of $0.001 USDC to https://api.example.com/weather?"

# 4. If approved, execute payment
llm-wallet pay "https://api.example.com/weather?location=London"

# 5. Confirm and show transaction ID
llm-wallet history

Registering a Paid API

bash

# 1. Register the API
llm-wallet register-api "https://api.example.com/translate" --name translate_api

# 2. List available APIs
llm-wallet list-apis

# 3. Call the API (with approval)
llm-wallet call-api translate_api --params '{"text": "hello", "to": "es"}'

# 4. View payment in history
llm-wallet history

Error Handling

• Insufficient Balance: Show error and guide user to faucet (testnet) or funding instructions (mainnet)
• Payment Rejected: Transaction reverted, check error message for details
• Limit Exceeded: Show current limits and daily usage, suggest increasing limits
• Network Timeout: Retry with exponential backoff (max 3 attempts)

References

See references/ folder for:

• x402-protocol.md - x402 payment protocol overview
• wallet-setup.md - Detailed wallet setup guide
• examples.md - More usage examples

Notes

• All amounts are in USDC (6 decimals)
• Default network is testnet for safety
• Testnet USDC has no real value
• Always verify network before mainnet usage
• Keep encryption key secure (never share or commit)