Retrieve email attachments via x402 micropayment on Base for $0.02 per request.
What it does
This endpoint at lowpaymentfee.com provides access to email attachments (specifically email ID 58) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled in USDC on the Base network at $0.02 per call (maxAmountRequired of 20,000 base units with 6 decimals = $0.02), with no API keys, rate limits, or subscriptions required.
The hosting site lowpaymentfee.com offers a broad catalog of x402-gated API endpoints spanning data analytics, AI/ML inference, finance, crypto, and utility services — all priced at $0.02 per request. However, this specific endpoint (/api/v1/emails/58/attachments) is not listed on the site's public landing page among the advertised APIs. Its purpose — retrieving attachments for a specific email — is unclear in context; it may be a demo, internal, or niche endpoint. No OpenAPI schema, request/response examples, or detailed documentation were found for this endpoint.
The endpoint is confirmed live: it returns a valid x402 version-1 challenge with a 402 status code. Payment is directed to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base. The timeout for payment settlement is 300 seconds.
Capabilities
Use cases
- —Retrieving attachments from a specific email record via programmatic API call
- —Demonstrating x402 micropayment flows for content retrieval
- —Agent-driven document or file retrieval behind a paywall
Fit
Best for
- —Developers experimenting with x402 payment protocol on Base
- —Agents that need to fetch email attachments with per-call micropayments
- —Use cases requiring no-auth, pay-per-use access to email data
Not for
- —Bulk email processing or mailbox management — this targets a single email ID
- —Users who need detailed API documentation or guaranteed SLAs
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/58/attachments \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and the endpoint is not listed among the site's advertised APIs. The purpose of retrieving attachments for email ID 58 is opaque. This is effectively a stub listing.
Warnings
- —Endpoint /api/v1/emails/58/attachments is not listed among the site's publicly advertised APIs — may be a demo or internal endpoint
- —No documentation, OpenAPI schema, or example request/response bodies are available
- —The endpoint targets a hardcoded email ID (58); unclear if other email IDs are supported or how to discover them
- —Crawled docs, API, pricing, and README pages all returned only 'Connect wallet' with no substantive content
Citations
- —Endpoint returns a valid x402 version-1 challenge with 402 status, accepting USDC on Basehttps://lowpaymentfee.com/api/v1/emails/58/attachments
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02https://lowpaymentfee.com/api/v1/emails/58/attachments
- —Site advertises $0.02/request pricing with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Payment address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3, USDC asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/emails/58/attachments