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/28/balance` is gated behind a per-request USDC payment on the Base network. The x402 challenge indicates a maximum cost of 20,000 base units of USDC (0.02 USD per request), consistent with the provider's advertised flat $0.02/request pricing across all their API endpoints.
The provider, lowpaymentfee.com, hosts a broader catalog of x402-gated 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 share the same $0.02/request pricing with no API keys, no rate limits, and no commitments required — payment is handled entirely via the x402 protocol using USDC on Base.
This particular endpoint appears to return account balance information in JSON format. However, 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 description of what fields the balance response contains or what parameters the POST request accepts. The endpoint is confirmed live (returns a valid 402 challenge), but the lack of documentation makes integration uncertain without experimentation.
Capabilities
Use cases
- —Querying account balance data with per-request USDC micropayments
- —Integrating keyless API access into agent workflows via x402 protocol
- —Programmatic balance lookups without subscription or API key management
Fit
Best for
- —Developers wanting zero-signup API access via crypto micropayments
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer pay-per-use over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume use cases where per-request pricing may add up versus flat-rate plans
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/28/balance \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing, but there is no OpenAPI schema, no request/response examples, and all documentation pages render only a wallet-connect prompt. The purpose of this specific endpoint (account 28 balance) is unclear and undocumented.
Warnings
- —No API documentation available — docs, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request parameters or response format
- —The specific endpoint /api/v1/accounts/28/balance references a hardcoded account ID (28) with no explanation of what this account represents
- —Cannot verify what data is actually returned without making a paid request
Citations
- —The x402 challenge requires a maximum of 20,000 base units of USDC (USD Coin) on the Base network, equating to $0.02 per requesthttps://lowpaymentfee.com/api/v1/accounts/28/balance
- —The provider advertises $0.02/request flat pricing with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The provider offers additional API categories including Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure utilitieshttps://lowpaymentfee.com