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 11) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) at a cost of $0.02 per request (20,000 base units with 6 decimals). No API keys or rate limits are required — callers simply include an X-PAYMENT header with a valid x402 payment proof.
The provider, lowpaymentfee.com, hosts a broad catalog of x402-gated APIs spanning data analytics, AI/ML inference, finance, and utility services, all priced uniformly at $0.02 per call. This specific endpoint (/api/v1/emails/11/attachments) appears to serve email attachment data, though the exact schema of the response body is not documented. The x402 challenge was successfully captured (HTTP 402 with version 1 challenge), confirming the endpoint is live.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema, and no usage examples available. The purpose and structure of the email attachments endpoint can only be inferred from the URL path and the generic "Premium API Access" description provided in the x402 challenge.
Capabilities
Use cases
- —Programmatically retrieving email attachments behind a paywall
- —Agent-driven access to stored email data with per-request micropayments
- —Integrating email attachment retrieval into automated workflows without API key management
Fit
Best for
- —Agents needing on-demand email attachment access with no subscription
- —Developers experimenting with x402 micropayment protocols on Base
- —Low-volume, pay-per-use email data retrieval
Not for
- —Bulk email processing requiring high throughput and documented schemas
- —Use cases requiring detailed API documentation or guaranteed SLAs
- —Accessing emails other than ID 11 (only this specific resource is confirmed)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/11/attachments \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, but there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the purpose of the endpoint is only inferable from the URL path. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and README pages all return only 'Connect wallet'
- —No request or response schema provided; callers must guess at the expected input and output format
- —The endpoint targets a specific email ID (11); it is unclear whether other email IDs are accessible or what the broader email API looks like
- —Provider hosts many advertised endpoints but none have documented schemas
Citations
- —Endpoint returns HTTP 402 with x402 version 1 challenge, confirming it is livehttps://lowpaymentfee.com/api/v1/emails/11/attachments
- —Payment is in USDC on Base network, maxAmountRequired 20000 base units ($0.02)https://lowpaymentfee.com/api/v1/emails/11/attachments
- —Provider advertises uniform $0.02/request pricing with no API keys, no rate limitshttps://lowpaymentfee.com
- —Docs, API, pricing, and README pages returned only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs