Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/transfers/99` is listed as "Premium API Access" and returns a 402 challenge requiring payment of up to 20,000 base units of USDC (i.e., $0.02) per call. No API keys or rate limits are advertised; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises multiple API categories including 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.
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 spec, no request/response schema documentation, and no example payloads available. The actual functionality behind `/api/v1/transfers/99` ("Premium API Access") is unclear — the name and path do not map obviously to any of the listed API categories. Without documentation or example responses, it is impossible to confirm what data or service this endpoint returns.
Capabilities
Use cases
- —Programmatic access to API services paid per-request with USDC on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Exploring x402 protocol payment flows for micro-transactions
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-as-you-go API access on Base
- —Low-volume consumers who want no subscription commitments
Not for
- —Production workloads requiring documented request/response schemas
- —Users without USDC on Base network
- —High-volume use cases where per-call pricing may be inefficient
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transfers/99 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no OpenAPI spec, no documentation beyond a wallet-connect prompt, no request/response examples, and the purpose of this specific endpoint ('transfers/99') is undocumented. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — all docs/pricing/README pages render only 'Connect wallet'
- —The purpose and response format of /api/v1/transfers/99 ('Premium API Access') is completely undocumented
- —No request body schema or response examples could be found
- —The endpoint path 'transfers/99' does not correspond to any of the advertised API categories on the landing page
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transfers/99
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transfers/99
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —Listed API categories include Data & Analytics, AI & ML, Finance & Web3, and Infrastructurehttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages all show only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs