x402-gated API platform on Base offering data, AI, finance, and utility endpoints at $0.02/request.
What it does
lowpaymentfee.com is an x402-protocol API marketplace that gates access to a variety of endpoints behind per-request micropayments settled in USDC on the Base network. The specific endpoint at `/api/v1/cards/68` is listed as "Premium API Access" and costs up to $0.02 per call (20,000 base units of USDC with 6 decimals). Payment is handled via the x402 exact scheme — no API keys, no rate limits, and no subscriptions required.
The broader platform advertises four categories of endpoints: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All listed endpoints share the same $0.02/request pricing. However, the specific functionality behind `/api/v1/cards/68` is not documented beyond the generic "Premium API Access" label, and the crawled documentation pages (docs, pricing, README) returned only a wallet-connect prompt with no substantive content.
Because there is no OpenAPI schema, no request/response examples, and no detailed documentation available for this endpoint, its actual behavior and output format remain unclear. The endpoint is confirmed live (returns a valid 402 challenge), but agents should be aware that the lack of documentation makes integration speculative.
Capabilities
Use cases
- —Paying per-request for API access without managing API keys or subscriptions
- —Integrating x402-gated endpoints into autonomous agent workflows
- —Accessing data, AI, finance, or utility services via micropayments on Base
Fit
Best for
- —Agents that need keyless, pay-as-you-go API access
- —Developers experimenting with x402 protocol micropayments
- —Use cases where avoiding subscription commitments is important
Not for
- —Production workloads requiring well-documented, schema-defined APIs
- —Users who need detailed request/response contracts before integration
- —High-volume use cases where per-request pricing may not be cost-effective
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/cards/68 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, but there is no OpenAPI schema, no request/response examples, and all documentation pages returned only a wallet-connect stub. The specific purpose of /api/v1/cards/68 is unknown beyond the generic 'Premium API Access' label.
Warnings
- —No documentation available — docs, pricing, and README pages all returned only a wallet-connect prompt with no content.
- —The specific functionality of /api/v1/cards/68 is undocumented; 'Premium API Access' is a generic label.
- —No OpenAPI schema or request/response examples are provided.
- —No input schema is documented, so the expected POST body is unknown.
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 in USDC on Basehttps://lowpaymentfee.com/api/v1/cards/68
- —All listed endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/cards/68