Pay-per-call premium API access on Base via x402 — $0.02 per 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-call 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/charges/232` is labeled "Premium API Access" and accepts POST requests. It returns an x402 challenge requiring an exact payment of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. No API keys or rate limits are advertised — access is gated purely by per-request 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 schema, no request/response examples, and no description of what data this particular endpoint actually returns. The site's landing page lists many endpoints but does not clarify what `/api/v1/charges/232` specifically provides versus the other listed routes. Prospective users should be aware that the actual functionality behind this endpoint is undocumented.
Capabilities
Use cases
- —Accessing premium data or services with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API keys
- —Programmatic pay-as-you-go access to analytics, AI, finance, or utility endpoints
Fit
Best for
- —Developers wanting keyless, pay-per-call API access settled in USDC on Base
- —AI agents that can handle x402 payment challenges autonomously
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —Anyone without a Base-compatible USDC wallet
- —High-volume consumers who would benefit from bulk pricing or subscriptions
Quick start
# 1. Send a POST to get the x402 payment challenge:
curl -X POST https://lowpaymentfee.com/api/v1/charges/232
# Returns 402 with x402 challenge JSON.
# 2. Construct and attach X-PAYMENT header per x402 spec,
# paying 20000 base-units USDC ($0.02) on Base to
# 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
# 3. Resend the POST with the payment header to receive the response.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, confirming pricing and payment details. However, there is no OpenAPI schema, no request/response examples, and no documentation beyond a wallet-connect prompt. The actual functionality of /api/v1/charges/232 is entirely undocumented, making this 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/charges/232 ('Premium API Access') is not described anywhere; it is unclear what data or service it returns.
- —No OpenAPI schema, no request body schema, and no response examples are provided.
- —The site lists many endpoints but none have detailed documentation visible in the crawl.
Citations
- —The endpoint returns a 402 x402 challenge requiring 20,000 base-units of USDC on Base ($0.02)https://lowpaymentfee.com/api/v1/charges/232
- —All listed APIs are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The site offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/232