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 pay-per-request email-related API accessible via the x402 payment protocol. The specific resource path `/api/v1/emails/20` suggests an email retrieval or email data endpoint. Payment is settled on the Base network using USDC (USD Coin) at a cost of $0.02 per request (20,000 base units with 6 decimals). No API keys, accounts, or rate limits are required — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
The provider (lowpaymentfee.com) hosts a broader suite of APIs spanning data & analytics, AI/ML inference (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 x402 payment flow on Base. Documentation pages exist but appear to require wallet connection and contain no substantive content beyond the landing page.
The endpoint is live and returns a proper 402 challenge with x402 version 1. The POST method is specified in the output schema. However, no detailed request/response schema, example payloads, or documentation for the emails endpoint specifically are available, so the exact input parameters and response format remain unknown.
Capabilities
Use cases
- —Retrieving email data or records on a per-request payment basis
- —Integrating email functionality into agent workflows without managing API keys
- —Programmatic access to email resources settled via crypto micropayments
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 email data without subscription commitments
Not for
- —High-volume email sending requiring bulk pricing or dedicated infrastructure
- —Users without USDC on the Base network
- —Applications requiring detailed, documented request/response contracts
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/20 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it works. However, there is no documentation, no request/response schema, and no examples for the /api/v1/emails/20 endpoint specifically. The docs, pricing, and README pages all render only a 'Connect wallet' prompt with no useful content. The exact functionality of this email endpoint is unclear.
Warnings
- —No request or response schema available for /api/v1/emails/20
- —Documentation pages (docs, pricing, README) contain no substantive content — only 'Connect wallet'
- —Exact functionality of the emails endpoint is unknown — could be email retrieval, validation, or something else
- —The endpoint path '/emails/20' is ambiguous — '20' could be an ID, a batch size, or part of the pricing model
Citations
- —Endpoint returns a 402 challenge with x402 version 1, accepting USDC on Base networkhttps://lowpaymentfee.com/api/v1/emails/20
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02https://lowpaymentfee.com/api/v1/emails/20
- —All APIs priced at $0.02/request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Provider offers APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com