Pay-per-request premium API access on Base via x402 — $0.02/call in USDC.
What it does
This endpoint at lowpaymentfee.com is part of a broader platform offering pay-per-request APIs across data analytics, AI/ML, finance/Web3, and infrastructure categories. The specific endpoint `/api/v1/claims/21` is labeled "Premium API Access" and is gated by the x402 payment protocol on the Base network. Each call costs up to 20,000 base units of USDC (0x8335…), which equals $0.02 given USDC's 6 decimals. Payment is settled on-chain with no API keys, no rate limits, and no upfront commitments.
The platform advertises a wide range of sibling endpoints including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, geocoding, validation, conversion, and data export — all at the same $0.02 per request price point. However, the specific functionality behind `/api/v1/claims/21` ("Premium API Access") is not documented beyond its title. No request body schema, response schema, or usage examples are provided in the crawled material. The docs, pricing, and API pages all resolve to a minimal "Connect wallet" prompt with no additional detail.
The endpoint is confirmed live: it returns a well-formed x402 402 challenge with version 1, accepting the "exact" payment scheme on Base. The payment address is `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3`, and the timeout is 300 seconds. The output schema indicates it expects HTTP POST requests and is marked as discoverable.
Capabilities
Use cases
- —Accessing premium data or services with per-request USDC micropayments on Base
- —Agent-driven API consumption without pre-registration or API key management
- —Programmatic pay-as-you-go access to a claims endpoint
Fit
Best for
- —Developers wanting zero-signup, pay-per-call API access
- —AI agents with x402-compatible wallets on Base
- —Users who prefer on-chain micropayments over subscription billing
Not for
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
# 1. Send a POST to discover the x402 challenge
curl -X POST https://lowpaymentfee.com/api/v1/claims/21
# Returns 402 with X-Payment challenge
# 2. Construct and attach X-PAYMENT header with signed USDC payment on Base
# (use an x402 client library to handle payment automatically)Endpoint
Quality
The endpoint is confirmed live with a valid x402 challenge and clear pricing ($0.02 USDC on Base). However, the actual functionality behind 'Premium API Access' is completely undocumented — no request/response schemas, no examples, and no explanation of what the endpoint returns. Docs pages are empty beyond a wallet-connect prompt.
Warnings
- —The specific purpose and response format of /api/v1/claims/21 is undocumented; 'Premium API Access' is a generic label with no further detail.
- —All documentation pages (docs, pricing, API, README) resolve to a minimal 'Connect wallet' page with no substantive content.
- —No OpenAPI spec, no request body schema, and no example responses are available.
- —Cannot verify what data or service is actually delivered after payment.
Citations
- —Endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 USDC base units on Basehttps://lowpaymentfee.com/api/v1/claims/21
- —Platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/claims/21
- —Platform offers sibling endpoints across data analytics, AI/ML, finance, and infrastructure categorieshttps://lowpaymentfee.com