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Northline ChainKit Payment Verify
x402
Northline ChainKit Payment Verify is a paid API for AI agents from northline-chainkit.northline-c86.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-31).
Verifies that a USDC payment transaction on Base or Arc blockchain was received by a specified address with optional amount and confirmation thresholds
Price / call$0.003
Success—
StatusUnknown
How this service works
x402 pay-per-call onchain API (Base + Arc).
Output
Returns a JSON object with a boolean 'verified' field, the 'receivedUsdc' amount as a string, the number of 'confirmations', and a 'reasons' array listing any failure conditions (e.g. insufficient amount, unconfirmed, wrong recipient).
Example use cases
Gate API access after payment
“Before giving this user access to the premium report, verify their payment — transaction hash is 0x4f2a...9c1b, it should have gone to our treasury wallet 0x1234...5678 on Base, and we need at least 0.003 USDC received.”
Confirm marketplace escrow settlement
“Check if the buyer's payment cleared on Arc — the tx hash is 0xd9e3...7f2c, destination address is 0xABCD...EF01, and make sure we got at least 5 USDC with 20 confirmations before I release the digital goods.”
Validate pay-per-call charge before fulfillment
“I need to confirm transaction 0x8b1f...3a04 actually paid our service wallet 0x9999...0001 on Base — did it go through and how much USDC did we receive?”
Technical details
Endpoint
GEThttps://northline-chainkit.northline-c86.workers.dev/v1/payment/verify?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to programmatically confirm that a specific USDC transaction landed on the Base or Arc blockchain before delivering a product, granting access, or continuing a workflow. It is purpose-built for x402 pay-per-call patterns where each API invocation is gated behind a micropayment. Prefer it over generic blockchain explorers when you need structured machine-readable output, support for both Base and Arc networks, and configurable minimum amount and confirmation thresholds in a single call.
Side effects
- Invalid transaction hash format returns schema validation error
- Transaction not found on specified chain returns verified:false with reasons
- Received amount below minAmount threshold returns verified:false
- Confirmation count below minConfirmations returns verified:false
- Incorrect 'to' address mismatch returns verified:false
- Network issues with Base or Arc RPC returns 5xx error
- Missing required 'tx' or 'to' query parameters returns 400 error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"reasons": [],
"verified": true,
"receivedUsdc": "0.01",
"confirmations": 120
}
}Tags
x402
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