x402-gated email endpoint on Base, pay $0.02 per request in USDC with no API keys.
What it does
This endpoint at lowpaymentfee.com provides premium API access via the x402 payment protocol. The specific resource `/api/v1/emails/18` is part of a broader platform that offers dozens of pay-per-call endpoints spanning data analytics, AI/ML inference, finance, crypto, and utility services — all gated behind x402 micro-payments on the Base network.
The endpoint accepts POST requests and returns JSON. Payment is settled in USDC (contract 0x8335…2913 on Base) using the x402 "exact" scheme. The maximum amount required per call is 20,000 base units, which at 6 decimals for USDC equals $0.02. There are no API keys, no rate limits, and no subscription commitments — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The specific functionality behind `/api/v1/emails/18` is not documented in the crawled material. The existing title is simply "Premium API Access" with no further description of what email-related data or action this endpoint provides. The broader site lists categories like Data & Analytics, AI & ML, Finance & Web3, and Infrastructure utilities, but the emails path does not appear in any of those listings. Callers should be aware that the actual response payload and purpose of this particular endpoint are unclear from available documentation.
Capabilities
Use cases
- —Programmatic access to email-related data or actions via micro-payment
- —Agent-driven workflows that need to pay per API call without pre-registration
- —Integrating x402-gated services into crypto-native applications
Fit
Best for
- —Developers wanting zero-signup, pay-per-use API access
- —AI agents with x402 payment capability on Base
- —Users who prefer USDC micro-payments over subscription billing
Not for
- —Users needing detailed documentation or guaranteed SLAs before integrating
- —High-volume use cases where per-request pricing may add up quickly
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/18 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base). However, the specific functionality of /api/v1/emails/18 is completely undocumented — it does not appear in the site's own API listing, there is no OpenAPI spec, no request/response schema, and no examples. The docs, pricing, and README pages all render only a wallet-connect prompt with no useful content.
Warnings
- —The /api/v1/emails/18 endpoint is not listed among the site's advertised APIs — its purpose and expected input/output are unknown.
- —No OpenAPI spec, request schema, or response schema is available for this endpoint.
- —Documentation pages (/docs, /pricing, /README) returned no meaningful content beyond a wallet-connect prompt.
- —The actual data or action performed by this 'emails' endpoint is entirely unverified.
Citations
- —The endpoint returns a 402 challenge with x402Version 1, exact scheme, on Base network, requiring up to 20000 base units of USDC.https://lowpaymentfee.com/api/v1/emails/18
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/emails/18
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The /api/v1/emails/18 path does not appear in the site's listed available APIs.https://lowpaymentfee.com