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 46) 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).
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 priced at $0.02 per call. The platform advertises no API keys, no rate limits, and instant access. However, documentation is extremely sparse: the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail.
The specific endpoint `/api/v1/emails/46/attachments` is not listed on the site's landing page among the advertised API categories, making its purpose and response format unclear. It may be a demo or internal endpoint. Without documentation or example responses, the exact schema of the returned data is unknown.
Capabilities
Use cases
- —Programmatically retrieving email attachments behind a paywall
- —Agent-driven access to stored email data with per-request micropayments
- —Integrating email attachment retrieval into automated workflows
Fit
Best for
- —Agents needing on-demand email attachment access without API keys
- —Developers experimenting with x402 micropayment protocols
- —Workflows requiring pay-per-use email data retrieval on Base
Not for
- —Bulk email processing at scale (no documented batch endpoints)
- —Users needing detailed API documentation or guaranteed SLAs
- —Non-crypto users who cannot settle payments in USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/46/attachments \
-H "X-PAYMENT: <x402-payment-header>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (returns 402 with a valid x402 challenge), but there is no documentation, no OpenAPI schema, no example requests or responses, and the specific endpoint is not listed among the site's advertised APIs. The docs/pricing/README pages are all blank beyond a wallet connect prompt.
Warnings
- —This specific endpoint (/api/v1/emails/46/attachments) is not listed among the provider's advertised APIs — its purpose and reliability are unclear.
- —Documentation pages (docs, pricing, README, API) contain no usable content beyond 'Connect wallet'.
- —No OpenAPI spec, no request/response schema, and no example payloads are available.
- —The endpoint appears to reference a hardcoded email ID (46), suggesting it may be a demo or test resource.
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/46/attachments
- —The site advertises $0.02/request pricing with no API keys, no rate limits, and instant access across multiple API categories.https://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/emails/46/attachments
- —Docs, pricing, README, and API pages render only a 'Connect wallet' prompt with no further content.https://lowpaymentfee.com/docs