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 63) 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 provider lowpaymentfee.com hosts a broader suite of x402-gated APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance and crypto market data, and infrastructure utilities — all priced at $0.02 per request. However, this specific listing covers only the `/api/v1/emails/63/attachments` endpoint. The exact nature of the email data served (whether it is sample/demo data or a real mailbox) is not documented, and the provider's docs, pricing, and API pages are essentially empty beyond a wallet-connect prompt. The endpoint is confirmed live via a valid x402 402 challenge.
Capabilities
Use cases
- —Retrieving email attachments programmatically with per-call micropayments
- —Integrating email data retrieval into agent workflows without API key management
- —Demonstrating x402 payment protocol usage on Base network
Fit
Best for
- —Agents needing one-off email attachment retrieval without subscription overhead
- —Developers experimenting with x402 protocol integrations
- —Workflows requiring keyless, pay-per-use API access
Not for
- —Bulk email processing or high-volume mailbox access
- —Users who need documented request/response schemas before integrating
- —Anyone needing access to arbitrary email IDs (this endpoint is scoped to email 63)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/63/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 OpenAPI schema, no request/response documentation, no examples, and the docs pages are empty. The purpose of the email attachments endpoint is unclear — it references a hardcoded email ID 63 with no explanation. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and API pages only show a wallet-connect prompt
- —Endpoint is scoped to a single hardcoded email ID (63); unclear what data is returned
- —No request body schema or response schema documented
- —Provider appears to be a demo/showcase site for x402 protocol; data authenticity is unknown
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 in USDC on Basehttps://lowpaymentfee.com/api/v1/emails/63/attachments
- —All APIs on lowpaymentfee.com are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/emails/63/attachments