Pay-per-request email attachment retrieval via x402 on Base (USDC).
What it does
This endpoint at lowpaymentfee.com provides access to email attachments (specifically email ID 34) via a pay-per-request x402 protocol. The endpoint accepts POST requests and returns application/json responses. Payment is settled in USDC on the Base network at $0.02 per request (20,000 base units of USDC with 6 decimals).
The endpoint is part of a broader platform (lowpaymentfee.com) that offers a variety of x402-gated APIs spanning data & analytics, AI & machine learning, finance & Web3, and infrastructure utilities — all priced at $0.02 per call. The platform advertises no API keys, no rate limits, and instant access. However, the specific endpoint being listed here (`/api/v1/emails/34/attachments`) is not documented on the site's landing page among the advertised APIs, so its exact functionality and response schema are unclear.
The x402 challenge was successfully captured, confirming the endpoint is live. It uses x402 version 1 with the "exact" payment scheme, paying to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 in USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base. No OpenAPI spec, detailed documentation, or example responses were found during crawling — most documentation pages only showed a "Connect wallet" prompt with no further content.
Capabilities
Use cases
- —Retrieving email attachments programmatically with per-request micropayments
- —Agent-driven workflows that need to fetch specific email attachment data
- —Accessing gated email content without API keys or subscriptions
Fit
Best for
- —Agents or services that need on-demand email attachment access via crypto micropayments
- —Developers experimenting with x402 protocol integrations
- —Use cases where keyless, pay-as-you-go API access is preferred
Not for
- —Bulk email processing requiring thousands of calls (no documented rate limits but cost adds up)
- —Users who need detailed documentation or guaranteed SLAs before integrating
- —Non-crypto workflows that cannot settle payments in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/34/attachments \
-H "X-PAYMENT: <x402-payment-header>" \
-H "Content-Type: application/json"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but this specific endpoint (/api/v1/emails/34/attachments) is not listed among the site's advertised APIs. No OpenAPI spec, no request/response schema, and no documentation beyond a wallet-connect prompt were found. The endpoint's actual functionality is opaque.
Warnings
- —This specific endpoint (/api/v1/emails/34/attachments) is not listed on the provider's landing page among advertised APIs — its purpose and response format are undocumented.
- —All documentation pages (docs, api, pricing, README) returned only a 'Connect wallet' prompt with no usable content.
- —No OpenAPI spec or response schema available; request body format is unknown.
- —The hardcoded email ID '34' in the path suggests this may be a demo or test endpoint rather than a general-purpose API.
Citations
- —The endpoint returns a 402 challenge with x402 version 1, exact scheme, USDC on Base, maxAmountRequired 20000https://lowpaymentfee.com/api/v1/emails/34/attachments
- —The platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/emails/34/attachments
- —The site lists APIs in categories: Data & Analytics, AI & ML, Finance & Web3, Infrastructure — but does not list an emails endpointhttps://lowpaymentfee.com