x402-gated premium API access on Base, pay $0.02 per request in USDC — no API keys required.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" behind an x402 payment wall on the Base network. The specific resource `/api/v1/cards/66` is one of many endpoints offered by the platform, which spans categories including data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints on the platform share a uniform $0.02-per-request pricing model settled in USDC on Base.
The x402 challenge confirms the endpoint is live, accepting POST requests and requiring payment of up to 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals = $0.02) per call. Payment is made via the x402 "exact" scheme to the specified payTo address, with a 300-second timeout. No API keys, rate limits, or upfront commitments are needed — callers simply attach the X-PAYMENT header with a valid x402 payment proof.
The specific functionality behind `/api/v1/cards/66` is not documented in the crawled material. The platform's landing page lists endpoints for metrics, reports, data export, insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — but `/api/v1/cards/66` does not appear among them. It may be a card-specific resource or a distinct endpoint not yet listed on the homepage. The response MIME type is `application/json`.
Capabilities
Use cases
- —Programmatic access to premium data or services with per-call USDC micropayments
- —Agent-driven workflows that need keyless, pay-as-you-go API access on Base
- —Integrating x402-compatible payment flows into automated pipelines
Fit
Best for
- —Developers or agents wanting zero-signup, pay-per-call API access
- —x402-native applications settling micropayments in USDC on Base
- —Low-volume or bursty usage patterns where flat subscriptions are wasteful
Not for
- —Users who need detailed documentation or guaranteed SLAs for the /cards/66 resource
- —High-volume consumers who would benefit from bulk pricing or subscription plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/66 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge with clear pricing ($0.02 USDC on Base). However, the specific functionality of /api/v1/cards/66 is entirely undocumented — it does not appear on the platform's homepage or any crawled page. No request/response schema, no examples, and docs/pricing/README pages all render only a 'Connect wallet' stub. This is effectively a stub listing.
Warnings
- —The specific endpoint /api/v1/cards/66 is not listed among the platform's documented APIs — its purpose and expected input/output are unknown.
- —Documentation pages (/docs, /pricing, /README, /api) returned only 'Connect wallet' with no usable content.
- —No OpenAPI spec, request schema, or response examples are available.
- —The 'cards' resource path does not match any of the platform's advertised API categories.
Citations
- —The platform advertises $0.02 per request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The x402 challenge specifies maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base with exact scheme.https://lowpaymentfee.com/api/v1/cards/66
- —The platform lists endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categories but /api/v1/cards/66 is not among them.https://lowpaymentfee.com