Pay-per-call ETH quote endpoint on Base via x402 — $0.02 per request in USDC.
What it does
This endpoint at `/api/v1/crypto/quotes/eth` returns ETH token quote data, paid per request using the x402 protocol. It is part of a broader suite of APIs offered by lowpaymentfee.com spanning finance, AI/ML, data analytics, and utility services, all priced at $0.02 per call.
Payment is settled on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The x402 challenge specifies a `maxAmountRequired` of 20000 base units, which at 6 decimals equals $0.02. The endpoint uses the "exact" payment scheme, meaning a single fixed payment per request. No API keys or rate limits are advertised; access is gated entirely by the x402 payment header.
Documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no example request/response documentation, and no description of the response format beyond the MIME type `application/json`. The endpoint accepts POST requests. The actual fields returned in the ETH quote (e.g., price, volume, timestamp) are unknown from available materials.
Capabilities
Use cases
- —Fetching real-time or recent ETH price quotes for trading bots or dashboards
- —Integrating ETH pricing data into DeFi applications without managing API keys
- —Agent-driven crypto portfolio valuation requiring per-call payment
Fit
Best for
- —Agents or apps needing keyless, pay-per-use ETH quote data
- —Developers who want to avoid API key management and subscriptions
- —Low-volume or bursty crypto price lookups settled on Base L2
Not for
- —High-frequency trading requiring sub-second latency guarantees (no SLA documented)
- —Users needing detailed historical OHLCV candle data (no evidence this is provided)
- —Anyone requiring comprehensive documentation or guaranteed response schemas
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/crypto/quotes/eth \
-H "X-PAYMENT: <x402-payment-token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI schema, no documented request/response format, no examples, and all documentation pages are empty beyond a wallet-connect prompt. The actual data returned is unknown.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request parameters or response fields
- —Response format and fields for ETH quotes are entirely unknown
- —No SLA, rate limit, or uptime guarantees documented
Citations
- —Endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units on Base network using USDChttps://lowpaymentfee.com/api/v1/crypto/quotes/eth
- —All APIs priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/crypto/quotes/eth
- —The /api/v1/crypto/quotes endpoint is listed under Finance & Web3 as 'Token Quotes'https://lowpaymentfee.com