# ARN x402 PayGuard

Agent Reliability Network presents ARN x402 PayGuard: payment security for autonomous agents. Check the seller before you pay. Use detailed payment preflight or the simple before-spend security check to verify an x402 seller, validate its payment challenge, and assess counterparty risk before an agent spends funds. Returns ALLOW, CAUTION, or BLOCK.

Use Agent Reliability Network's ARN x402 PayGuard before an agent pays an x402 seller. It performs two unsigned live reads of the seller's payment challenge and validates payment requirements, price, supported Base or Solana network, canonical USDC asset, payTo address, unsafe redirects, and payment-challenge consistency. ARN does not pay the seller.

## Paid preflight

Endpoint: https://arn-x402-payguard-payment-security.rajdeep-dutta-in.workers.dev/preflight
Method: POST
Price: $0.001 USDC
Networks: Base mainnet (eip155:8453) and Solana mainnet (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp)
Protocol: x402 v2, exact payment scheme
Methodology: live-security-v1

JSON input: required url (HTTPS seller endpoint); optional intended_spend_usdc (numeric buyer spend ceiling).

## Flagship before-spend check

Endpoint: https://arn-x402-payguard-payment-security.rajdeep-dutta-in.workers.dev/before-spend
Method: POST

Use this simple integration endpoint immediately before an autonomous agent spends money on an x402 seller. It has the same $0.001 USDC payment requirement and accepts the same JSON input as payment preflight.

Read the HTTP 402 payment challenge first. An x402-capable buyer authorizes payment to ARN and retries the same request. The paid response is a live-security-v1 ALLOW, CAUTION, or BLOCK result.

Machine references:
- OpenAPI: https://arn-x402-payguard-payment-security.rajdeep-dutta-in.workers.dev/openapi.json
- Capabilities: https://arn-x402-payguard-payment-security.rajdeep-dutta-in.workers.dev/capabilities
- x402 manifest: https://arn-x402-payguard-payment-security.rajdeep-dutta-in.workers.dev/.well-known/x402-service.json