Retrieve email attachments via x402 micropayment on Base network for $0.02 per request.
What it does
This endpoint at lowpaymentfee.com provides access to email attachments (specifically email ID 45) 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 endpoint is part of a broader platform (lowpaymentfee.com) that offers numerous x402-gated APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities, all priced at $0.02 per call. However, this specific endpoint — `/api/v1/emails/45/attachments` — is not listed on the provider's homepage among the advertised API categories. Its purpose (email attachment retrieval) and the hardcoded email ID (45) suggest it may be a demo, test, or niche endpoint rather than a general-purpose service.
Documentation is extremely sparse. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what fields the POST body should contain or what the response payload looks like. Callers will need to experiment or contact the provider to understand the expected input format and output structure.
Capabilities
Use cases
- —Retrieving email attachments programmatically with per-request micropayments
- —Agent-driven workflows that need to fetch specific email attachments without API key management
- —Demonstrating x402 payment protocol integration on Base network
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-per-call access to email data
- —Low-volume attachment retrieval without subscription commitments
Not for
- —Bulk email processing or high-volume attachment downloads (no documented batch support)
- —Users who need comprehensive email management (send, search, organize) — this is a single-resource endpoint
- —Anyone requiring detailed API documentation or SLA guarantees
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/45/attachments \
-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 endpoint is not listed among the provider's advertised APIs. The purpose and expected input/output are unclear, making this effectively a stub listing.
Warnings
- —No OpenAPI schema or request/response documentation available
- —The endpoint /api/v1/emails/45/attachments is not listed among the provider's advertised APIs — may be a test or unlisted endpoint
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no usable content
- —Hardcoded email ID 45 in the URL suggests this may not be a general-purpose endpoint
- —No information on what POST body fields are expected or what the response contains
Citations
- —The endpoint returns a 402 x402 challenge with USDC on Base network at maxAmountRequired 20000https://lowpaymentfee.com/api/v1/emails/45/attachments
- —USDC asset contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/emails/45/attachments
- —Platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Documentation pages render only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs