Pay-per-request premium API access on Base via x402 — $0.02/call in USDC.
What it does
lowpaymentfee.com hosts a collection of pay-per-request API endpoints accessible via the x402 protocol on the Base network. This specific endpoint (`/api/v1/charges/298`) is listed as "Premium API Access" and accepts payment in USDC (contract 0x8335…2913 on Base). The x402 challenge indicates a maximum amount of 20,000 base units, which at 6 decimals for USDC equals $0.02 per request. No API keys or rate limits are advertised; callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com 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 are priced at $0.02 per request.
Documentation is extremely sparse — 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 example payloads available. The endpoint is live (returns a proper 402 challenge), but without documentation it is unclear what request body this particular endpoint expects or what response it returns.
Capabilities
Use cases
- —Accessing premium API functionality with per-request USDC micropayments on Base
- —Agent-driven workflows that need keyless, pay-as-you-go API access
- —Programmatic access without subscription commitments or rate limits
Fit
Best for
- —Developers wanting zero-commitment, pay-per-use API access
- —AI agents with x402-compatible wallets on Base
- —Users who prefer crypto micropayments over API key management
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Developers without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/charges/298 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The purpose of this specific '/charges/298' endpoint is entirely opaque beyond its title.
Warnings
- —No OpenAPI or schema documentation available — request/response format is unknown
- —All documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no technical content
- —The specific purpose of /api/v1/charges/298 ('Premium API Access') is not explained anywhere
- —No robots.txt or agents.txt present
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/charges/298
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —The platform offers endpoints in Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/charges/298