Pay-per-request premium API collection on Base via x402, settled in USDC at $0.02/call.
What it does
lowpaymentfee.com hosts a suite of pay-per-request APIs accessible via the x402 payment protocol on the Base network. The endpoint `/api/v1/collections/3` is labeled "Premium API Access" and requires a per-call payment of up to $0.02 in USDC (USD Coin on Base, contract 0x8335…2913). No API keys, rate limits, or upfront commitments are needed — each request is individually settled on-chain.
The broader platform advertises endpoints across four categories: 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 per-request pricing. However, the specific endpoint being listed here (`/api/v1/collections/3`) is described only as "Premium API Access" with no further documentation on what data or functionality it returns.
The endpoint is live and returns a valid x402 challenge (HTTP 402) with scheme "exact" and a 300-second payment timeout. Documentation on the site is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema, and no usage examples available from the crawled material.
Capabilities
Use cases
- —Accessing a bundled collection of API services with a single per-request crypto payment
- —Agent-driven workflows that need keyless, on-demand API access settled in USDC
- —Exploring x402 protocol integration for pay-as-you-go API consumption
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —Agents needing keyless API access with per-call micropayments
- —Users who want to avoid subscription commitments for occasional API calls
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/collections/3 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what the endpoint actually does or returns. No OpenAPI spec, no request/response schemas, and no examples are available. The 'Premium API Access' label is completely opaque. The docs pages are empty beyond a wallet-connect prompt.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet' with no content
- —The specific functionality of /api/v1/collections/3 ('Premium API Access') is undocumented; it is unclear what data or service it provides
- —No OpenAPI spec or request/response schema is published
- —No usage examples or error handling documentation found
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/collections/3
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/collections/3
- —All listed endpoints share $0.02 per-request pricing with no API keys, rate limits, or commitmentshttps://lowpaymentfee.com
- —The platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com