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 49) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) at a maximum 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 broader lowpaymentfee.com platform advertises a suite of APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/Web3 data (price feeds, exchange rates, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation), all priced at $0.02 per call. However, this specific listing covers only the `/api/v1/emails/49/attachments` endpoint, which appears to serve email attachment data. Documentation beyond the landing page is essentially empty (all sub-pages just show "Connect wallet"), so the exact request body schema, response format, and attachment content details are unknown.
Capabilities
Use cases
- —Programmatically retrieving email attachments behind a paywall
- —Agent-driven workflows that need to fetch specific email attachment data
- —Demonstrating x402 micropayment integration for data access
Fit
Best for
- —Agents or scripts that need on-demand email attachment retrieval without API key management
- —Developers exploring x402 payment protocol integrations
- —Low-volume, pay-per-use data access on Base network
Not for
- —Bulk email processing or high-volume attachment downloads (no documented batch support)
- —Users who need detailed API documentation or guaranteed SLAs
- —Accessing emails other than ID 49 (only this specific resource is listed)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/49/attachments \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation on request/response schemas, no OpenAPI spec, and all doc pages are empty. The endpoint path (/emails/49/attachments) is very specific and its purpose is opaque without further context.
Warnings
- —No API documentation available — all doc/pricing/README pages return only 'Connect wallet' with no content.
- —Request body schema and response format are completely unknown; no OpenAPI or examples provided.
- —The endpoint targets a single hardcoded email ID (49); unclear if other email IDs are available or what the attachments contain.
- —The platform lists many other API categories but none have documented schemas or examples.
Citations
- —Endpoint returns 402 with x402 challenge advertising USDC on Base network at maxAmountRequired 20000https://lowpaymentfee.com/api/v1/emails/49/attachments
- —Platform advertises $0.02 per request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/emails/49/attachments