Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The site hosts a broad catalog of pay-per-request 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 are priced at $0.02 per request, settled in USDC on the Base network.
The specific endpoint `/api/v1/payments/279` is labeled "Premium API Access" and returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals). Payment is made via the x402 exact scheme to a specified wallet address on Base. The endpoint accepts POST requests and returns application/json. No API keys or rate limits are advertised — access is gated purely by per-call micropayment.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples of what this particular endpoint actually returns. The site lists many endpoint paths but provides no detail on input parameters or output formats for any of them. As a result, it is unclear what data or functionality `/api/v1/payments/279` specifically provides beyond the generic "Premium API Access" label.
Capabilities
Use cases
- —Accessing premium API functionality with per-call USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to undocumented premium features
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone unable to transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/payments/279 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming pricing and payment details. However, there is no OpenAPI spec, no documentation of request/response schemas, no examples, and the specific functionality of this endpoint is entirely undocumented. The docs pages are empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition for request or response payloads
- —The specific functionality of /api/v1/payments/279 ('Premium API Access') is undefined — it is unclear what data or service it provides
- —The endpoint path '/api/v1/payments/279' does not match any of the listed API categories on the homepage
Citations
- —All endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Basehttps://lowpaymentfee.com/api/v1/payments/279
- —Site offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com