Pay-per-request API platform on Base network via x402 — $0.02/call 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 at /api/v1/payments/241 is labeled "Premium API Access" and charges up to 20,000 base units of USDC (i.e., $0.02) per request. No API keys, rate limits, or subscriptions are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader platform advertises endpoints across four categories: 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 listed endpoints share the same $0.02/request pricing. However, the specific endpoint being listed here (/api/v1/payments/241) is described only as "Premium API Access" with no further documentation on what data or functionality it returns.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material. The endpoint is confirmed live (returns a proper 402 x402 challenge), but without documentation it is unclear what this specific endpoint actually does or what request body it expects.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Testing x402 protocol integration with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-as-you-go API access
- —Low-volume consumers who want no subscription commitments
Not for
- —Users who need detailed API documentation or guaranteed SLAs
- —High-volume consumers who would benefit from bulk pricing
- —Anyone without a Base-network USDC wallet
Quick start
# The endpoint requires an x402 X-PAYMENT header with a valid payment proof.
# Using curl to see the 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/payments/241 \
-H 'Content-Type: application/json'
# Returns 402 with x402 challenge. Attach a valid X-PAYMENT header to complete the call.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming it accepts USDC on Base at $0.02/request. However, there is no documentation, no OpenAPI spec, no request/response examples, and the purpose of this specific endpoint (/api/v1/payments/241) is entirely undocumented. The docs pages are empty. This is effectively a stub listing.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content.
- —The specific functionality of /api/v1/payments/241 ('Premium API Access') is undocumented; it is unclear what it returns or what request body it expects.
- —No OpenAPI spec or output schema beyond basic HTTP method metadata.
- —No request or response examples available from any source.
Citations
- —Endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/payments/241
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/payments/241
- —Platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com