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 14) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled in USDC on the Base network at $0.02 per call (maxAmountRequired of 20,000 base units with 6 decimals = $0.02), with no API keys, rate limits, or subscriptions required.
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 utility services — all priced at $0.02 per request via the x402 protocol. However, this specific listing covers only the `/api/v1/emails/14/attachments` endpoint. The endpoint's purpose and response schema are not documented beyond the generic "Premium API Access" label, so the exact structure of the returned attachment data is unknown.
The x402 challenge was successfully captured (HTTP 402 with a well-formed accepts array), confirming the endpoint is live. Documentation pages (/docs, /pricing, /api, /README) all returned only a "Connect wallet" prompt with no substantive content, so detailed request/response schemas are unavailable.
Capabilities
Use cases
- —Retrieving email attachments programmatically via micropayment
- —Agent-driven email data access without API key management
- —On-demand attachment fetching settled in USDC on Base
Fit
Best for
- —Agents needing one-off email attachment retrieval without subscriptions
- —Developers experimenting with x402 pay-per-call patterns
- —Workflows requiring keyless, instant API access
Not for
- —Bulk email processing or high-volume attachment downloads (no documented batch support)
- —Users who need detailed 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/14/attachments \
-H "X-PAYMENT: <x402_payment_token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, and the endpoint path is oddly specific (email ID 14). The docs, pricing, API, and README pages are all empty beyond a wallet connect prompt.
Warnings
- —No request or response schema documented — the exact payload structure is unknown.
- —The endpoint targets a hardcoded email ID (14), which is unusual and suggests either a demo or a very narrow use case.
- —All documentation pages (/docs, /pricing, /api, /README) returned no useful content.
- —No OpenAPI spec, no ai-plugin manifest, and no agents.txt found.
- —The nature of the 'email attachments' data is unclear — could be sample/demo data.
Citations
- —Endpoint returns 402 with x402 challenge advertising USDC on Base, maxAmountRequired 20000https://lowpaymentfee.com/api/v1/emails/14/attachments
- —All APIs priced at $0.02 per request with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 is USDC on Basehttps://lowpaymentfee.com/api/v1/emails/14/attachments