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 54) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. 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 or rate limits are required — callers simply include an X-PAYMENT header with a valid x402 payment proof.
The broader lowpaymentfee.com platform advertises a suite of APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/crypto data feeds, and infrastructure utilities — all priced at $0.02 per request on the Base network. However, this specific endpoint (`/api/v1/emails/54/attachments`) is not listed on the site's public API catalog, and its exact functionality (what email, what attachments, what data format) is not documented. The endpoint is live and returns a valid x402 challenge, but the lack of documentation about the email attachment resource makes its practical utility unclear.
Payment is made to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using USDC contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` on Base. The maximum timeout for payment settlement is 300 seconds.
Capabilities
Use cases
- —Retrieving email attachments programmatically via micropayment
- —Agent-driven access to gated email content without API keys
- —Paying per-request for email data on Base L2
Fit
Best for
- —Agents needing on-demand email attachment retrieval with crypto payment
- —Developers experimenting with x402 payment protocol on Base
- —Scenarios requiring keyless, pay-per-use API access
Not for
- —Bulk email processing or mailbox management
- —Users who need well-documented, production-grade email APIs
- —Anyone without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/54/attachments \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, but there is no documentation about what this specific email attachment endpoint returns, no request/response schema, and the endpoint is not listed in the site's own API catalog. The crawled docs/pricing/API pages are all blank ('Connect wallet'). This is effectively a stub listing.
Warnings
- —This specific endpoint (/api/v1/emails/54/attachments) is not listed in the provider's public API catalog — its purpose and output are unknown.
- —No request or response schema is available; the actual data returned is undocumented.
- —All documentation pages (docs, api, pricing, README) returned only 'Connect wallet' with no useful content.
- —The endpoint references a hardcoded email ID (54), suggesting it may be a demo or test resource rather than a general-purpose API.
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 in USDC on Basehttps://lowpaymentfee.com/api/v1/emails/54/attachments
- —The platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/emails/54/attachments
- —The site lists APIs for analytics, AI/ML, finance, and infrastructure but does not list this email attachments endpointhttps://lowpaymentfee.com