Premium API access via x402 micropayment on Base — $0.02 per request in USDC.
What it does
lowpaymentfee.com is an x402-enabled API platform that offers a broad catalog of pay-per-call endpoints spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities. Every endpoint costs $0.02 per request, paid in USDC on the Base network, with no API keys, no rate limits, and no upfront commitments required.
The specific endpoint at `/api/v1/apikeys/77` is listed as "Premium API Access." The x402 challenge confirms it is live, accepting POST requests and settling payments in USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`) on Base. The maximum amount required is 20,000 base units, which at 6 decimals for USDC equals $0.02. The payment scheme is "exact," meaning the caller pays a fixed amount per request.
The broader platform advertises additional endpoints including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, documentation beyond the landing page is extremely thin; the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material.
Capabilities
Use cases
- —Agents needing on-demand access to AI inference (sentiment, summarization, classification, embeddings) without API key management
- —Fetching real-time crypto token quotes and gas estimates with per-call USDC micropayments
- —Running geocoding or data validation utilities without subscription commitments
- —Exporting analytics data or generating reports on a pay-as-you-go basis
Fit
Best for
- —AI agents that can settle x402 payments in USDC on Base
- —Developers wanting zero-commitment, no-API-key access to a variety of utility endpoints
- —Use cases requiring low-cost micropayments ($0.02/call) without rate limits
Not for
- —Users who need detailed API documentation, request/response schemas, or OpenAPI specs before integrating
- —High-volume production workloads that would benefit from bulk pricing or subscription discounts
- —Users who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/apikeys/77 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is no OpenAPI spec, no request/response schema, no documentation, and no examples. The docs, pricing, and README pages all render only 'Connect wallet' with no usable content. The purpose of this specific endpoint (/api/v1/apikeys/77) is unclear beyond the generic label 'Premium API Access.'
Warnings
- —No OpenAPI spec or request/response schema available for any endpoint
- —Documentation pages (docs, pricing, README, api) contain no usable content — only a 'Connect wallet' prompt
- —The specific function of /api/v1/apikeys/77 ('Premium API Access') is not documented; it may be a meta-endpoint for purchasing API keys rather than a data endpoint
- —No examples of expected input or output are available from any crawled source
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/apikeys/77
- —All listed endpoints cost $0.02 per request with no API keys, no rate limits, and instant access on the Base networkhttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/apikeys/77