Pay-per-call email API on Base via x402 — $0.02/request in USDC, no API keys required.
What it does
This endpoint at lowpaymentfee.com provides a premium email-related API accessible via the x402 payment protocol. The specific route `/api/v1/emails/30` accepts POST requests and charges $0.02 per call (20,000 base units of USDC on the Base network, where USDC has 6 decimals). Payment is settled on-chain to a specified wallet address using USD Coin (USDC) on Base.
The endpoint is part of a broader platform (lowpaymentfee.com) that offers dozens of pay-per-call APIs spanning data & analytics, AI/ML inference, finance & Web3 data, and infrastructure utilities — all priced at $0.02 per request. The platform advertises no API keys, no rate limits, and instant access. However, the specific functionality of the `/api/v1/emails/30` endpoint is not documented in the crawled material; the existing title simply says "Premium API Access" and no further schema, input parameters, or response format details are available.
The endpoint is live and returns a valid x402 402 challenge. The payment scheme is "exact" with a max amount of 20,000 USDC base units ($0.02) and a timeout of 300 seconds. Without documentation on what the email endpoint actually does (e.g., send email, validate email, lookup email), users should test with a small payment to discover the response format.
Capabilities
Use cases
- —Programmatic email operations paid per-call without subscription or API key management
- —Agent-driven workflows that need email functionality with on-chain micropayments
- —Integrating email capabilities into Web3 or crypto-native applications
Fit
Best for
- —Developers wanting zero-signup, pay-as-you-go email API access
- —AI agents that can settle x402 payments on Base
- —Projects needing low-cost per-request email operations without rate limits
Not for
- —High-volume email sending where per-call pricing becomes expensive at scale
- —Users who need detailed API documentation and guaranteed SLAs before integrating
- —Teams without USDC on Base or x402-compatible payment infrastructure
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/30 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation on what the /api/v1/emails/30 endpoint actually does, what inputs it expects, or what it returns. The crawled docs/pricing/README pages all rendered as just 'Connect wallet' with no useful content. This is effectively a stub listing.
Warnings
- —No documentation available for the /api/v1/emails/30 endpoint — its actual functionality (send, validate, lookup, etc.) is unknown
- —All doc pages (docs, api, pricing, README) returned only 'Connect wallet' with no substantive content
- —No input schema or response schema available; callers must discover behavior empirically
- —The endpoint path includes '/30' which may be a parameter (e.g., batch size, record ID) but this is unconfirmed
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 USDC base units on Basehttps://lowpaymentfee.com/api/v1/emails/30
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/emails/30