Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com is one of many x402-gated API endpoints offered by the provider. The specific path `/api/v1/payments/18` is labeled "Premium API Access" and accepts POST requests, settling payments in USDC on the Base network. The x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (6 decimals), which equals $0.02 per request — consistent with the provider's uniform $0.02/request pricing across all their endpoints.
The provider's landing page lists four categories of APIs: 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 (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request with no API keys, no rate limits, and no minimum commitments required. However, the specific functionality behind the `/api/v1/payments/18` path is not documented beyond its "Premium API Access" label, and the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further detail.
The endpoint is live and returns a valid x402 challenge. Payment is made via the x402 exact scheme to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base, with a 300-second timeout. No OpenAPI schema, request/response examples, or detailed documentation are available, so the actual data returned by this endpoint after payment is unknown.
Capabilities
Use cases
- —Accessing premium API data with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic access to gated endpoints without subscription commitments
Fit
Best for
- —Developers or agents who want zero-signup, pay-per-call API access
- —Users already holding USDC on Base who want frictionless micropayments
- —Exploring x402 protocol integrations with low per-call costs
Not for
- —Users who need detailed documentation or guaranteed SLAs before paying
- —Anyone without a Base-compatible wallet and USDC balance
- —High-volume consumers who need bulk pricing or rate-limit guarantees
Quick start
# Send a POST with x402 payment header (USDC on Base)
curl -X POST https://lowpaymentfee.com/api/v1/payments/18 \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and no documentation beyond a label. The actual functionality behind '/api/v1/payments/18' is entirely opaque — docs pages render only 'Connect wallet' with no content.
Warnings
- —The specific functionality of /api/v1/payments/18 is undocumented — 'Premium API Access' is the only label provided.
- —All documentation pages (docs, pricing, API, README) render only 'Connect wallet' with no usable content.
- —No OpenAPI spec, request schema, or response schema is available — callers cannot know what to send or what they will receive.
- —No rate limit or SLA information is published.
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC on Base network with a 300-second timeout.https://lowpaymentfee.com/api/v1/payments/18
- —The provider lists all endpoints at $0.02/request with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 and payTo is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3.https://lowpaymentfee.com/api/v1/payments/18