Retrieve email attachments via x402 micropayment on Base (USDC, $0.02/request).
What it does
This endpoint at lowpaymentfee.com provides access to email attachments (specifically for email ID 60) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) with a maximum cost of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals).
The provider lowpaymentfee.com hosts a broader suite 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 advertised at $0.02 per request with no API keys, no rate limits, and no minimum commitments. However, the specific endpoint being listed here — `/api/v1/emails/60/attachments` — is not mentioned on the provider's landing page, so its exact behavior and response format are unclear.
The endpoint is live and returns a valid x402 challenge (HTTP 402 with version 1 accepts array). No OpenAPI schema, detailed documentation, or example responses were found in the crawl. The docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no substantive content.
Capabilities
Use cases
- —Programmatically retrieving email attachments behind a paywall
- —Agent-driven email data extraction with per-request micropayments
- —Accessing premium email content without API key registration
Fit
Best for
- —AI agents needing on-demand email attachment retrieval
- —Developers wanting keyless, pay-per-use email data access
- —Workflows requiring Base-network USDC micropayments
Not for
- —Bulk email processing at scale (no documented batch support)
- —Users who need detailed API documentation or OpenAPI specs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/60/attachments \
-H "X-PAYMENT: <x402-payment-header>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (valid 402 challenge captured), but there is no OpenAPI schema, no documentation, no example request/response, and the specific email attachments endpoint is not listed on the provider's own landing page. The crawled docs/pricing/README pages were all empty beyond a wallet connect prompt. The purpose and response format must be entirely inferred.
Warnings
- —This specific endpoint (/api/v1/emails/60/attachments) is not listed on the provider's landing page — its existence and behavior are only confirmed by the 402 probe.
- —No OpenAPI spec, request schema, or response schema available — integration requires trial and error.
- —All documentation pages (docs, api, pricing, README) returned no useful content beyond 'Connect wallet'.
- —The endpoint appears hardcoded to email ID 60; it is unclear if other email IDs are supported or what the attachments contain.
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/emails/60/attachments
- —All endpoints on lowpaymentfee.com are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/emails/60/attachments