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 platform that gates a broad set of endpoints behind per-request micropayments settled in USDC on the Base network. The specific endpoint probed (/api/v1/trades/111) is listed as "Premium API Access" and accepts POST requests. The x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…), which at 6 decimals equals $0.02 per call. No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The provider's landing page advertises four endpoint 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/request pricing. The probed endpoint (/api/v1/trades/111) does not appear in the landing-page catalog, so its exact functionality is unclear — it may be a trade-specific data lookup or a demo endpoint.
Documentation is extremely sparse. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawl. The endpoint is confirmed live (402 challenge returned successfully), but without documentation it is difficult to know what request body to send or what response to expect.
Capabilities
Use cases
- —Accessing trade data or analytics via a single micropayment without needing an API key
- —Integrating pay-per-request AI inference (sentiment, summarization, classification, embeddings) into agent workflows
- —Fetching real-time crypto quotes, gas estimates, or exchange rates with per-call USDC payments
- —Using utility endpoints (geocoding, validation, conversion) on a pay-as-you-go basis
Fit
Best for
- —AI agents that need keyless, pay-per-call API access on Base
- —Developers prototyping with low-commitment, no-subscription API endpoints
- —Web3-native applications that prefer on-chain micropayment settlement
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume production workloads where per-request crypto settlement adds latency or cost overhead
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/trades/111 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live via a valid 402 x402 challenge, and pricing is clear ($0.02 USDC on Base). However, documentation is effectively nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, and the specific /api/v1/trades/111 endpoint is not even listed on the landing page. The breadth of advertised endpoints cannot be verified.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README all render only 'Connect wallet'
- —No OpenAPI or JSON schema provided for any endpoint
- —The probed endpoint /api/v1/trades/111 is not listed in the provider's public catalog; its exact purpose is unknown
- —The broad catalog of 16+ endpoints advertised on the landing page cannot be independently verified from the crawl
Citations
- —The x402 challenge returns maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/trades/111
- —All listed endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The provider advertises endpoints across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —Documentation pages (/docs, /api, /pricing, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs