x402-gated email data endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides premium API access to an email-related resource (specifically `/api/v1/emails/63`) gated by the x402 payment protocol. 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 attach an X-PAYMENT header with a valid x402 payment proof.
The provider, lowpaymentfee.com, hosts a broader catalog of x402-gated APIs spanning data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request. However, the specific endpoint being listed here (`/api/v1/emails/63`) is not described on the provider's landing page among the advertised categories, and its exact functionality (e.g., whether it retrieves a specific email record, performs email validation, or something else) is unclear from available documentation.
Documentation is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no description of what the emails endpoint actually returns. Callers should be aware that the endpoint's behavior must be discovered empirically.
Capabilities
Use cases
- —Retrieving email-related data behind a micropayment wall
- —Agent-driven workflows that need on-demand email data without subscription commitments
- —Testing x402 payment protocol integrations with a low-cost endpoint
Fit
Best for
- —Developers experimenting with x402 payment flows on Base
- —Agents that need pay-per-call access without API key management
- —Low-volume, on-demand email data retrieval
Not for
- —High-volume email processing where per-request costs add up
- —Users who need detailed API documentation or guaranteed SLAs
- —Email sending or SMTP relay — this appears to be a data retrieval endpoint
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/63 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The endpoint is live (returns a valid 402 x402 challenge), but there is no documentation, no OpenAPI schema, no request/response examples, and the specific emails/63 endpoint is not even listed among the provider's advertised APIs. The endpoint's actual functionality is unknown.
Warnings
- —The /api/v1/emails/63 endpoint is not listed among the provider's advertised API catalog — its purpose is unclear.
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no substantive content.
- —No OpenAPI schema, request body schema, or response examples are available.
- —The exact nature of the data returned (email content, metadata, validation result, etc.) cannot be determined from available sources.
Citations
- —Endpoint returns HTTP 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/emails/63
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02https://lowpaymentfee.com/api/v1/emails/63
- —Provider advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/emails/63
- —Documentation pages render only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs