Pay-per-call API platform on Base network via x402 — $0.02/request in USDC.
What it does
lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to accept USDC payments on the Base network. The specific endpoint `/api/v1/transactions/308` is listed as "Premium API Access" and returns a 402 challenge requiring payment of up to 20,000 base units of USDC (i.e., $0.02) per call. No API keys, rate limits, or subscriptions are required — each request is individually settled on-chain.
The broader platform advertises multiple API categories including 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 endpoints are listed at the same $0.02/request price point.
However, documentation for this specific endpoint (`/api/v1/transactions/308`) is essentially absent. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what data or functionality this particular transactions endpoint provides. The endpoint is live and responds with a valid x402 challenge, but what it actually returns after payment is unknown from available materials.
Capabilities
Use cases
- —Accessing premium transaction data with per-call USDC micropayments
- —Integrating pay-as-you-go API calls into agent workflows without API key management
- —Programmatic on-chain payment for API access on Base L2
Fit
Best for
- —Developers wanting keyless, pay-per-use API access
- —AI agents with x402-compatible payment capabilities
- —Users who prefer on-chain USDC settlement over subscriptions
Not for
- —Users needing detailed API documentation or schemas before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-network USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/308
# Returns 402 with x402 challenge. Attach X-PAYMENT header with valid USDC payment to receive response.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and no description of what the /api/v1/transactions/308 endpoint actually returns. The crawled pages beyond the homepage were empty (wallet-connect only). This is effectively a stub listing.
Warnings
- —No documentation available — all doc/API/pricing/README pages returned only 'Connect wallet' with no content.
- —No OpenAPI or output schema describing what this endpoint returns after payment.
- —The purpose of /api/v1/transactions/308 is unknown — 'Premium API Access' is the only description provided.
- —Cannot verify what data or functionality is delivered after payment.
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/308
- —All endpoints are priced at $0.02/request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/308