x402-gated transaction receipt endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides a transaction receipt resource (specifically for transaction ID 256) behind an x402 paywall. The broader lowpaymentfee.com platform advertises a suite of pay-per-request 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 endpoints are priced at $0.02 per request, settled in USDC on the Base network via the x402 protocol.
The specific probed endpoint `/api/v1/transactions/256/receipt` returns a valid x402 challenge (HTTP 402) requesting up to 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this translates to $0.02 per call, consistent with the site's advertised pricing. Payment is made via the x402 "exact" scheme with a 300-second timeout. No API keys or rate limits are required — access is purely payment-gated.
Documentation is extremely thin. The /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no usage examples. The actual data returned by this receipt endpoint (or any of the other listed endpoints) is unknown beyond the MIME type `application/json`. The platform appears functional but poorly documented.
Capabilities
Use cases
- —Retrieving transaction receipts via programmatic payment
- —Demonstrating x402 protocol payment flows on Base
- —Agent-driven pay-per-call API consumption without API keys
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-per-call API access on Base
- —Projects requiring USDC-settled micropayment endpoints
Not for
- —Production use requiring documented request/response schemas
- —High-volume use cases needing bulk pricing or subscriptions
- —Users who need detailed API documentation before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/256/receipt
# Returns HTTP 402 with x402 challenge.
# Include X-PAYMENT header with valid x402 payment proof to receive the receipt.Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no documented request/response schema, no usage examples, and all documentation pages render only 'Connect wallet'. The specific purpose of this particular receipt endpoint is unclear beyond its URL path.
Warnings
- —No API documentation available — /docs, /api, /pricing, /README all show only 'Connect wallet'
- —No OpenAPI or schema definition found for any endpoint
- —No response examples or field descriptions available
- —The specific endpoint is for transaction ID 256 — unclear if this is a demo or a real resource
- —Platform lists many endpoints but none have documented schemas
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/256/receipt
- —All endpoints are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —The platform offers APIs across Data & Analytics, AI & Machine Learning, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/256/receipt