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 64) 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 x402-gated APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/crypto data feeds, and infrastructure utilities — all priced at $0.02 per request. However, this specific listing covers only the `/api/v1/emails/64/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 valid accepts array), confirming the endpoint is live. Documentation on the site is extremely thin — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further technical detail. No OpenAPI spec or example payloads are available.
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 content access
Fit
Best for
- —AI agents that need to pay-per-call for email attachment retrieval
- —Developers experimenting with x402 protocol payments on Base
- —Workflows requiring no-signup, keyless API access to email data
Not for
- —Bulk email processing or mailbox management (only one email ID exposed)
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —Free-tier or subscription-based email API consumers
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/64/attachments \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is live (valid 402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the endpoint's purpose (email 64 attachments) is opaque. The docs pages are empty stubs.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or JSON schema describing request body or response format
- —The endpoint targets a hardcoded email ID (64); unclear if other IDs are available or what the attachment data contains
- —Provider appears to be a demo/showcase site for x402 micropayments; actual data quality and reliability are unknown
Citations
- —The endpoint returns HTTP 402 with x402Version 1 challenge, confirming it is livehttps://lowpaymentfee.com/api/v1/emails/64/attachments
- —maxAmountRequired is 20000 base units of USDC (6 decimals) on Base, equaling $0.02https://lowpaymentfee.com/api/v1/emails/64/attachments
- —The site advertises $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/emails/64/attachments