Pay-per-call premium API access on Base via x402 — $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides "Premium API Access" via the x402 payment protocol. It is one of many endpoints offered by the provider, which spans categories including data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. All endpoints are priced at $0.02 per request, payable in USDC on the Base network with no API keys, no rate limits, and no commitments required.
The specific endpoint `/api/v1/payments/128` returned a live 402 challenge confirming x402 version 1 support. The challenge specifies payment to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base, with a maxAmountRequired of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The payment scheme is "exact" with a 300-second timeout. The endpoint accepts HTTP POST requests.
Documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no description of what this particular endpoint actually returns. The provider's landing page lists sibling endpoints across analytics, AI, finance, and utility categories, but the specific functionality behind `/api/v1/payments/128` is not documented. Prospective callers should be aware that without schema documentation, the request body format and response structure are unknown.
Capabilities
Use cases
- —Accessing premium API functionality 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 undocumented premium services
Fit
Best for
- —Developers wanting zero-signup, pay-per-call API access
- —AI agents that can settle x402 payments on Base in USDC
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Anyone needing documented request/response schemas before integration
- —Use cases requiring free or fiat-only payment methods
- —High-volume callers who would benefit from bulk pricing or subscriptions
Quick start
# 1. POST to the endpoint — you'll get a 402 with payment challenge
curl -X POST https://lowpaymentfee.com/api/v1/payments/128
# 2. Pay the USDC challenge on Base, then resend with X-PAYMENT header
curl -X POST https://lowpaymentfee.com/api/v1/payments/128 \
-H "X-PAYMENT: <signed-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no documentation of what the endpoint actually does, no request/response schema, no OpenAPI spec, and all doc pages render only 'Connect wallet'. The specific purpose of /api/v1/payments/128 is entirely opaque.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided for this endpoint
- —The specific functionality of /api/v1/payments/128 is undocumented and unclear — it does not appear in the provider's listed API catalog
- —Cannot verify what data or service is returned after payment
Citations
- —Endpoint returns a live 402 challenge with x402 version 1, maxAmountRequired 20000 base units USDC on Basehttps://lowpaymentfee.com/api/v1/payments/128
- —All listed endpoints priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Provider offers endpoints across data & analytics, AI & ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/payments/128