Pay-per-call premium API access on Base network via x402 protocol at $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. The specific path `/api/v1/cards/3` is one of many endpoints offered by the provider, which hosts a broad catalog of pay-per-request APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities.
The endpoint accepts POST requests and charges 20,000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on the Base network, which equals $0.02 per request (USDC uses 6 decimals). Payment is handled via the x402 exact scheme with no API keys, no rate limits, and no commitments required. The payment timeout is 300 seconds.
The specific functionality behind `/api/v1/cards/3` is not documented beyond the label "Premium API Access." The provider's landing page lists various other endpoints (metrics, reports, sentiment analysis, summarization, classification, embeddings, price feeds, exchange rates, geocoding, etc.) all at the same $0.02 price point. Without further documentation or example responses for this particular path, the exact data returned is unclear.
Capabilities
Use cases
- —Accessing premium data or services without subscription commitments
- —Agent-driven API consumption with per-call crypto payments
- —Testing x402 payment protocol integrations
Fit
Best for
- —Developers wanting zero-friction API access without API keys
- —AI agents that can settle payments on Base network
- —Users who prefer pay-as-you-go pricing at $0.02/call
Not for
- —Users who need detailed documentation or guaranteed SLAs
- —High-volume consumers who would benefit from bulk pricing
- —Users without access to USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/3 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation of what this specific endpoint returns, no request/response schema, and the docs/pricing/README pages all just show 'Connect wallet' with no useful content.
Warnings
- —No documentation available for what /api/v1/cards/3 actually returns
- —No request or response schema provided
- —Docs, pricing, and README pages are empty (only show 'Connect wallet')
- —The specific functionality behind 'Premium API Access' at this path is unknown
Citations
- —Endpoint charges 20000 base units of USDC on Base network (=$0.02)https://lowpaymentfee.com/api/v1/cards/3
- —Provider advertises $0.02/request pricing with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/cards/3