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 18) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled in USDC on the Base network using the x402 "exact" scheme, with a maximum cost of $0.02 per request (20,000 base units of USDC with 6 decimals).
The provider lowpaymentfee.com hosts a broad catalog of x402-gated APIs spanning data & analytics, AI/ML inference, finance/Web3, and infrastructure utilities — all priced at $0.02 per call. This specific endpoint (/api/v1/emails/18/attachments) is not listed on the provider's landing page among the advertised API categories, so its exact functionality is unclear. The endpoint title "Premium API Access" is generic and does not describe the actual data returned. No OpenAPI schema, request body documentation, or response examples are available from the crawled pages (docs, pricing, and API pages all rendered only a "Connect wallet" prompt with no substantive content).
Because of the lack of documentation, callers should treat this endpoint experimentally. The x402 challenge is live and well-formed, confirming the endpoint is operational, but without knowing the expected POST body or response shape, integration requires trial and error.
Capabilities
Use cases
- —Retrieving attachments from a specific email record via programmatic API call
- —Agent-driven document retrieval behind a micropayment wall
- —Automated email attachment download with per-request USDC payment
Fit
Best for
- —Agents needing on-demand email attachment retrieval with no API key
- —Developers experimenting with x402 micropayment protocols on Base
- —Programmatic access to email data without subscription commitments
Not for
- —Bulk email processing or high-volume attachment downloads (no documented batch support)
- —Users who need detailed API documentation or guaranteed SLAs
- —General-purpose email sending or inbox management
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/18/attachments \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint works, but there is no documentation, no request/response schema, and the endpoint is not listed among the provider's advertised APIs. The generic title 'Premium API Access' provides no insight into actual functionality.
Warnings
- —Endpoint /api/v1/emails/18/attachments is not listed on the provider's landing page among advertised APIs — its purpose is unclear.
- —No API documentation available; docs, pricing, and API pages all render only 'Connect wallet' with no content.
- —No request body schema or response schema documented; callers must experiment.
- —The title 'Premium API Access' is generic and does not describe the endpoint's actual function.
Citations
- —The x402 challenge returns a maxAmountRequired of 20000 in USDC (6 decimals) on Base, equaling $0.02 per request.https://lowpaymentfee.com/api/v1/emails/18/attachments
- —The provider advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —The USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base.https://lowpaymentfee.com/api/v1/emails/18/attachments