x402-gated account balance endpoint on Base, pay-per-call with 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/144/balance` is gated behind a per-request USDC payment on the Base network. The x402 challenge confirms the endpoint is live and accepts exact-scheme payments of up to 20,000 base units of USDC (0.02 USD per request) settled to a specified wallet address.
The broader lowpaymentfee.com platform advertises a suite of pay-per-call APIs spanning data & analytics, AI/ML (sentiment analysis, 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 commitments — payment is handled entirely via the x402 protocol on Base.
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 schema, no request/response examples, and no explanation of what the account balance endpoint actually returns or what input it expects beyond an HTTP POST. The endpoint's purpose — whether it returns a crypto wallet balance, a platform account balance, or something else — is not documented.
Capabilities
Use cases
- —Querying an account balance via a pay-per-call model without API keys
- —Integrating x402-gated endpoints into agent workflows on Base
- —Demonstrating x402 protocol payment flows for USDC on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that can settle USDC payments on Base L2
- —Use cases requiring keyless, per-request API access
Not for
- —Production workloads requiring documented request/response schemas
- —Users who need detailed API documentation or support
- —High-volume use cases where per-call pricing may not be optimal
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/144/balance
# Returns 402 with x402 payment challenge.
# Include X-PAYMENT header with a valid x402 payment token to access the resource.Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what the endpoint actually returns. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided
- —Purpose of the /api/v1/accounts/144/balance endpoint is unclear — no description of what 'balance' refers to
- —The hardcoded account ID '144' in the path suggests this may be a single-account resource, not a general-purpose API
Citations
- —The endpoint returns a 402 challenge with x402Version 1, accepting USDC on Base with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/accounts/144/balance
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform lists APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs