x402-gated account balance endpoint on Base, paid per-call 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/44/balance` is described as "Premium API Access" and accepts POST requests. Payment is settled on the Base network using USDC (contract 0x8335…2913) with a maximum cost of 0.02 USDC per request (20,000 base units at 6 decimals).
The broader lowpaymentfee.com platform advertises a suite of x402-gated APIs spanning data & analytics (metrics, reports, data export, insights), AI & machine learning (sentiment analysis, text summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request with no API keys, no rate limits, and no minimum commitments.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The endpoint is confirmed live (returns a valid x402 402 challenge), but without documentation it is unclear what request body the balance endpoint expects or what shape the response takes.
Capabilities
Use cases
- —Querying account balance information via a pay-per-call model
- —Integrating x402 payment-gated endpoints into agent workflows
- —Accessing premium data without API key registration
Fit
Best for
- —Developers experimenting with x402 payment protocol integrations
- —Agents that need keyless, pay-per-request API access on Base
- —Low-volume or sporadic queries where $0.02/call is acceptable
Not for
- —High-volume production workloads needing documented, stable schemas
- —Users who need detailed API documentation or client libraries before integrating
Quick start
# The endpoint requires an X-PAYMENT header with a valid x402 payment proof.
# Using curl to see the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/accounts/44/balance
# Returns 402 with x402 challenge JSON. Use an x402-compatible client
# (e.g. @AgentzPay/x402-axios) to automatically settle the USDC payment.Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, and all documentation pages are empty beyond a wallet-connect prompt. The purpose of the specific /accounts/44/balance resource is undocumented.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or JSON schema provided for request or response bodies.
- —The specific endpoint /api/v1/accounts/44/balance has a hardcoded account ID (44); unclear if this is parameterizable.
- —The broader platform lists many endpoint categories (AI, finance, analytics, etc.) but none have documented schemas or examples.
Citations
- —The endpoint returns a valid x402 402 challenge with USDC on Base network, maxAmountRequired 20000 base unitshttps://lowpaymentfee.com/api/v1/accounts/44/balance
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/accounts/44/balance
- —All endpoints priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Platform lists APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com