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 37) 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 $0.02 per request (20,000 base units at 6 decimals).
The provider lowpaymentfee.com hosts a broader suite of x402-gated APIs spanning data & analytics, AI/ML inference (sentiment, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation) — all priced at $0.02 per call with no API keys, no rate limits, and no commitments. However, this specific listing covers only the `/api/v1/emails/37/attachments` endpoint.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no examples available. The endpoint is confirmed live (returns a valid x402 402 challenge), but the actual behavior, required POST body, and response format are 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 without API keys
Fit
Best for
- —Agents needing on-demand email attachment access without subscription
- —Developers experimenting with x402 payment flows on Base
- —Low-volume, pay-per-use email data retrieval
Not for
- —Bulk email processing or high-volume attachment downloads (no documented batch support)
- —Users who need detailed API documentation or guaranteed SLAs
- —Accessing arbitrary emails — this endpoint is scoped to email ID 37 only
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/37/attachments \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, but there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and no examples. The endpoint path suggests a single hardcoded email ID (37), making its general utility unclear. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and README pages all return only 'Connect wallet' with no content
- —No request body schema or response schema documented; actual behavior is unknown
- —Endpoint is scoped to a single email ID (37) — unclear if this is a demo or production resource
- —No OpenAPI spec or ai-plugin manifest found
- —Provider site lists many endpoints but none have documented schemas
Citations
- —Endpoint returns a valid x402 402 challenge with USDC on Base, maxAmountRequired 20000https://lowpaymentfee.com/api/v1/emails/37/attachments
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/emails/37/attachments
- —Provider advertises $0.02 per request, no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Provider hosts additional API categories: Data & Analytics, AI & ML, Finance & Web3, Infrastructurehttps://lowpaymentfee.com