x402-gated account balance endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides a "Premium API Access" resource at the path `/api/v1/accounts/2/balance`. It is part of a broader platform that offers dozens of x402-gated API endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services — all payable per-request in USDC on the Base network with no API keys or rate limits required.
The specific endpoint probed (`/api/v1/accounts/2/balance`) returns an x402 challenge requesting up to 20,000 base units of USDC (0.02 USD) per call, consistent with the site's advertised flat $0.02/request pricing. Payment is settled on-chain via the "exact" scheme to address `0x1A2B…85F3`, using the canonical Base USDC contract (`0x8335…2913`). The challenge specifies a 300-second payment timeout and accepts HTTP POST requests.
Documentation is extremely thin — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no explanation of what the balance endpoint actually returns. The endpoint name suggests it retrieves an account balance, but the exact input parameters and response format are unknown. The platform appears live and functional based on the 402 challenge, but without documentation it is difficult to use programmatically beyond the payment handshake.
Capabilities
Use cases
- —Querying account balance data with per-request USDC micropayments
- —Integrating x402-compatible agents that pay for API access on Base
- —Demonstrating x402 protocol payment flows in development/testing
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC payments on Base L2
- —Use cases needing keyless, pay-per-call API access
Not for
- —Production workloads requiring documented request/response schemas
- —Users who need fiat or non-crypto payment options
- —High-volume batch queries where per-call pricing is inefficient
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/2/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is zero documentation on request parameters, response schema, or what 'accounts/2/balance' actually returns. No OpenAPI spec, no examples, and all doc pages are empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided
- —Purpose of '/api/v1/accounts/2/balance' is unclear — could be a demo or placeholder
- —The hardcoded account ID '2' in the path suggests this may not be a general-purpose endpoint
Citations
- —The endpoint returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD) on Basehttps://lowpaymentfee.com/api/v1/accounts/2/balance
- —The platform advertises $0.02/request flat pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/accounts/2/balance
- —Docs, pricing, API, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs