x402-gated account balance API on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides an account balance lookup via the x402 payment protocol. The specific resource `/api/v1/accounts/45/balance` is one of many endpoints offered by the provider, which hosts a broad catalog spanning data & analytics, AI/ML inference, finance & Web3 data, and infrastructure utilities — all gated behind x402 micropayments on the Base network.
The endpoint accepts POST requests and returns JSON. Payment is settled in USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base using the "exact" x402 scheme. The maximum amount required per call is 20,000 base units of USDC (6 decimals), which equals $0.02 USD. No API keys are needed; callers simply attach an X-PAYMENT header with a valid x402 payment proof. The provider advertises no rate limits and instant access.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no additional technical content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The exact semantics of the "account balance" resource (what account 45 refers to, what fields are returned) are not documented in any crawled material.
Capabilities
Use cases
- —Querying account balance data with per-request USDC micropayments
- —Integrating x402-compatible agents that need on-chain payment gating
- —Demonstrating x402 protocol payment flows on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC micropayments on Base
- —Low-volume, pay-as-you-go API consumption without API key management
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume consumers who need bulk pricing or rate guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/45/balance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"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/response schemas, no OpenAPI spec, and no examples. The purpose of 'accounts/45/balance' is unexplained. All non-root pages returned only 'Connect wallet' with no content.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all render only 'Connect wallet'
- —No OpenAPI or schema definition for request or response payloads
- —The meaning of 'accounts/45/balance' (what account 45 is, what balance is returned) is completely undocumented
- —Cannot verify what data this endpoint actually returns without making a paid request
Citations
- —The endpoint returns HTTP 402 with x402 challenge requiring 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/accounts/45/balance
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/accounts/45/balance
- —Provider advertises $0.02 per request, no API keys, no rate limits, instant accesshttps://lowpaymentfee.com
- —Provider offers endpoints across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com