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/135/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 suite of x402-gated APIs spanning data & analytics, AI/ML inference (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 model with no API keys, no rate limits, and no minimum commitments required — payment is handled entirely via the x402 protocol using USDC 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 description of what the balance endpoint actually returns or what input parameters it expects. The endpoint is confirmed live (returns a valid x402 challenge), but the lack of documentation makes it difficult to assess the actual utility or data quality of the response.
Capabilities
Use cases
- —Querying account balance data via a single paid API call
- —Integrating pay-per-request balance lookups into agent workflows
- —Demonstrating x402 protocol payment flows on Base
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing no-auth, pay-per-call API access
- —Low-volume balance queries without subscription commitments
Not for
- —Production use cases requiring documented request/response schemas
- —High-volume balance queries where per-call pricing adds up
- —Users who need detailed API documentation before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/accounts/135/balance \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages are empty beyond a wallet connect prompt. The purpose of the specific '/accounts/135/balance' endpoint is unclear — it could be a demo or placeholder. This is effectively a stub listing.
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 endpoint path '/api/v1/accounts/135/balance' references a hardcoded account ID (135); unclear if this is a demo or a real resource
- —Cannot verify what data the endpoint actually returns without making a paid request
Citations
- —The x402 challenge requires a maximum of 20,000 base units of USDC (USD Coin) on Base network, equaling $0.02 per requesthttps://lowpaymentfee.com/api/v1/accounts/135/balance
- —The provider advertises $0.02/request flat pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The provider offers APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (docs, API, pricing, README) render only a 'Connect wallet' prompt with no technical contenthttps://lowpaymentfee.com/docs