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 attachment data (specifically email ID 57) 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 (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 pay-per-call APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/crypto market data, and utility services (geocoding, validation, conversion, generation), all priced at $0.02 per request. However, this specific endpoint — `/api/v1/emails/57/attachments` — is not listed on the site's public catalog, and no documentation describes its request body schema, expected parameters, or response format. The endpoint is live and returns a proper x402 challenge, but the actual functionality behind the paywall is undocumented.
Because there is no OpenAPI spec, no request/response examples, and no documentation beyond the generic "Premium API Access" label, the precise behavior of this endpoint is unclear. Callers should treat this as an opaque paid endpoint until more documentation surfaces.
Capabilities
Use cases
- —Retrieving attachments from a specific email record via programmatic API call
- —Agent-driven workflows that need to fetch email attachment data without API key provisioning
- —Pay-per-use access to email content behind a crypto micropayment wall
Fit
Best for
- —Agents or scripts that need one-off email attachment retrieval without signup
- —Developers experimenting with x402 payment protocol on Base
- —Workflows requiring keyless, pay-as-you-go API access
Not for
- —Bulk email processing or mailbox-level access — this targets a single email ID
- —Users who need detailed API documentation or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/57/attachments \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no OpenAPI spec, no request/response schema, no documentation for this specific route, and the endpoint path (emails/57/attachments) is not listed in the site's public catalog. Functionality is essentially unknown beyond the payment parameters.
Warnings
- —This specific endpoint (/api/v1/emails/57/attachments) is not listed in the provider's public API catalog — its purpose and data source are unclear.
- —No request body schema or response schema is documented anywhere.
- —The docs, pricing, API, and README pages all render only a 'Connect wallet' prompt with no useful content.
- —The hardcoded email ID '57' suggests this may be a demo or test endpoint rather than a general-purpose API.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 in USDC on Base networkhttps://lowpaymentfee.com/api/v1/emails/57/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 address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/emails/57/attachments