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 94) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled in USDC on the Base network using the x402 "exact" scheme, with a max amount of 20,000 base units (i.e., $0.02 per request, since USDC uses 6 decimals).
The provider lowpaymentfee.com hosts a broader suite of pay-per-call 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 with no API keys, no rate limits, and no commitments required. However, this specific endpoint is narrowly scoped to retrieving attachments for a single email resource (email 94). There is no OpenAPI schema, no detailed documentation, and no example request/response bodies available from the crawled material. The docs, API, pricing, and README pages all rendered only a "Connect wallet" prompt with no substantive content.
Capabilities
Use cases
- —Retrieving email attachments programmatically with per-request micropayments
- —Agent-driven workflows that need to fetch specific email attachments without pre-registration
- —Integrating email attachment retrieval into automated pipelines using x402 payments
Fit
Best for
- —Agents or scripts that need on-demand email attachment access without API key management
- —Low-volume, pay-as-you-go attachment retrieval
- —x402-compatible agent wallets on Base network
Not for
- —Bulk email processing or high-volume attachment downloads (no documented batch support)
- —Users who need access to arbitrary emails (this endpoint is scoped to email ID 94)
- —Non-crypto users who cannot settle payments in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/94/attachments \
-H "X-PAYMENT: <x402_payment_header>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (returns a valid 402 challenge) and pricing is clear ($0.02/request in USDC on Base). However, there is no OpenAPI schema, no documentation beyond a wallet-connect prompt, no example request/response bodies, and the endpoint is narrowly scoped to a single email ID with no explanation of what data it returns or what inputs it expects. This is effectively a stub listing.
Warnings
- —No OpenAPI or detailed documentation available — docs pages only show 'Connect wallet'
- —Endpoint is scoped to a single hardcoded email ID (94); unclear if other email IDs are accessible at different paths
- —No request body schema or response schema documented
- —The broader site advertises many API categories but none have visible documentation
Citations
- —The endpoint returns a 402 challenge with x402Version 1, accepting USDC on Base with maxAmountRequired of 20000 base units ($0.02)https://lowpaymentfee.com/api/v1/emails/94/attachments
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/emails/94/attachments