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 85) 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 market data, and infrastructure utilities — all priced at $0.02 per request. However, this specific listing covers only the `/api/v1/emails/85/attachments` endpoint, which retrieves attachments for a particular email resource. The exact nature of the email data (whether it is sample/demo data or a real mailbox) is not documented.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema, and no usage examples available from the provider. The endpoint is confirmed live via a valid x402 402 challenge.
Capabilities
Use cases
- —Retrieving email attachments programmatically via a pay-per-request model
- —Integrating email attachment access into agent workflows without API key management
- —Demonstrating x402 micropayment protocol usage on Base network
Fit
Best for
- —Agents needing on-demand email attachment retrieval without subscription overhead
- —Developers experimenting with x402 payment protocol integrations
- —Low-volume, pay-as-you-go access to email data
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 email IDs (this endpoint is hardcoded to email 85)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/emails/85/attachments \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is live with a valid x402 402 challenge, but there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and the endpoint path (emails/85/attachments) is oddly specific with no explanation. The purpose and data behind this endpoint are unclear.
Warnings
- —No API documentation available — docs, pricing, README pages all return only 'Connect wallet'
- —No request or response schema provided; input/output format is unknown
- —Endpoint is hardcoded to email ID 85 — unclear if other email IDs are accessible or what data this represents
- —Provider site lists many API categories but none mention an emails endpoint, raising questions about this resource's purpose
Citations
- —Endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 in USDC on Basehttps://lowpaymentfee.com/api/v1/emails/85/attachments
- —Provider advertises $0.02 per request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/emails/85/attachments