a2a-payments
Blockchain USDC payments via APay — pay services, manage budgets, open streaming channels, and handle x402 protocol.
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- modbender/skill-library-mcp
- Last source activity
- March 6, 2026 at 18:33
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- 12
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- 3
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- a2a-payments
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- Blockchain USDC payments via APay — pay services, manage budgets, open streaming channels, and handle x402 protocol.
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- {"openclaw":{"emoji":"💰","requires":{},"install":["[Truncated]"]}}
# A2A Payments (APay)
Blockchain-native USDC payments for AI agents on Base chain. Pay for services, manage budgets, and handle micropayments.
## Quick Start
Check your balance:
```
Use apay_check_balance to see my USDC balance
```
Pay a service:
```
Use apay_pay_service with serviceId "svc-123" and amount "0.50"
```
## Available Tools
### Balance & Budget
| Tool | Description |
|------|-------------|
| `apay_check_balance` | Check USDC balance, daily budget, spending limits |
| `apay_budget_check` | Verify if a specific amount is affordable |
| `apay_spending_history` | Get spending analytics and history |
### Payments
| Tool | Description |
|------|-------------|
| `apay_pay_service` | Pay a service (agent pays gas) |
| `apay_pay_signed` | Gasless signed payment (server submits on-chain) |
| `apay_estimate_cost` | Estimate cost including 0.5% platform fee |
### Services
| Tool | Description |
|------|-------------|
| `apay_list_services` | List available APay services |
| `apay_get_service` | Get detailed service info |
### Payment Channels (Streaming)
| Tool | Description |
|------|-------------|
| `apay_channel_status` | Check channel status |
| `apay_stream_open` | Open channel with USDC deposit |
| `apay_stream_pay` | Sign off-chain micropayment |
| `apay_stream_close` | Close channel (refund unspent) |
### x402 Protocol
| Tool | Description |
|------|-------------|
| `apay_x402_fetch` | Fetch URL with automatic x402 payment on HTTP 402 |
## Workflows
### Pay for a tool execution
1. `apay_budget_check` — verify affordability
2. `apay_estimate_cost` — see total with fees
3. `apay_pay_service` — execute payment
4. Receive payment receipt with tx hash
### Streaming micropayments
For services that charge per-request (API calls, data feeds):
1. `apay_stream_open` — deposit USDC into channel
2. `apay_stream_pay` — sign micropayments (off-chain, instant)
3. `apay_stream_close` — settle on-chain, refund remainder
### x402 auto-payment
For services using the HTTP 402 payment protocol:
```
Use apay_x402_fetch with url "https://api.example.com/premium/data" and maxPayment "1.00"
```
The tool automatically detects 402 responses, pays the required amount, and retries the request.
## Network
- **Chain**: Base (Coinbase L2)
- **Stablecoin**: USDC (6 decimals)
- **Model**: Escrow-based sessions with spending limits
- **Testnet**: base-sepolia for development
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