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 resource `/api/v1/emails/99` 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 handled inline via the X-PAYMENT header — no API keys, accounts, or rate limits are required.
The provider operates a broader platform offering dozens of pay-per-call endpoints across categories including data & analytics, AI/ML (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints share the same $0.02/request pricing model and settle on the Base L2 network using USDC.
Documentation is extremely sparse — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further technical detail. The specific functionality of the `/api/v1/emails/99` endpoint (e.g., what email data it returns or processes, what request body it expects) is not documented anywhere in the crawled material. The endpoint is confirmed live via a valid 402 challenge, but without schema details or example payloads, integration requires experimentation.
Capabilities
Use cases
- —Accessing email-related data or functionality on a per-call basis without needing an API key
- —Integrating email services into agent workflows that support x402 micropayments
- —Programmatic email operations settled instantly on Base L2
Fit
Best for
- —Developers or agents that already support x402 payment flows
- —Low-volume or sporadic email API usage where subscription pricing is wasteful
- —Crypto-native applications on the Base network
Not for
- —Users who need detailed API documentation before integrating
- —High-volume email operations where per-call pricing becomes expensive
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/99 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, but there is no documentation on what the /api/v1/emails/99 endpoint actually does, what request body it expects, or what it returns. Docs pages are empty. This is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, API, and README pages all render only 'Connect wallet' with no technical content.
- —The specific purpose and expected input/output of /api/v1/emails/99 is completely undocumented; the name 'Premium API Access' is generic.
- —No OpenAPI schema, no example requests or responses, no error documentation.
- —The '/emails/99' path suggests a specific resource ID but its meaning is unclear.
Citations
- —Endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/emails/99
- —All endpoints priced at $0.02/request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/emails/99
- —Provider offers endpoints across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com