Transaction receipt endpoint on Base, paid per-call via x402 with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a transaction receipt (resource ID 352) behind an x402 paywall. The broader lowpaymentfee.com platform advertises a suite of 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 priced at $0.02 per request with no API keys, no rate limits, and no commitments.
The specific endpoint probed (`/api/v1/transactions/352/receipt`) returns a valid x402 challenge on POST, accepting payment in USDC on the Base network. The `maxAmountRequired` is 20000 base units of USDC (6 decimals), which equals $0.02 — consistent with the site's advertised flat pricing. Payment is settled on-chain to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the exact-amount scheme with a 300-second timeout.
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 examples of what the receipt payload actually contains. The endpoint is live and the x402 challenge is well-formed, but without documentation it is unclear what fields the receipt response includes or what input parameters (if any) the POST body expects.
Capabilities
Use cases
- —Retrieving a transaction receipt by paying $0.02 in USDC on Base
- —Programmatic access to paid API endpoints without API key management
- —Agent-driven micropayment workflows using x402 protocol
Fit
Best for
- —Developers experimenting with x402 pay-per-call patterns
- —Agents that can settle USDC payments on Base L2
- —Use cases requiring keyless, on-demand API access
Not for
- —Users who need detailed API documentation or OpenAPI specs before integrating
- —High-volume batch processing where per-call crypto settlement adds overhead
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/352/receipt
# Returns 402 with x402 challenge; include X-PAYMENT header with signed USDC payment to proceed.Endpoint
Quality
The endpoint is live and returns a well-formed x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no documentation beyond a landing page listing, no request/response schema, and no examples of what the receipt payload contains. The docs pages are all empty 'Connect wallet' stubs.
Warnings
- —No API documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or schema definition found; request body and response structure are unknown.
- —The specific endpoint (/api/v1/transactions/352/receipt) is a hardcoded resource ID — unclear if this is a demo or a real transaction receipt.
- —The platform advertises many API categories (AI, analytics, finance, utils) but no evidence of actual functionality behind them was found in the crawl.
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/352/receipt
- —The platform advertises $0.02 per request flat pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/transactions/352/receipt
- —Payment recipient address is 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3https://lowpaymentfee.com/api/v1/transactions/352/receipt
- —The /docs, /api, /pricing, and /README pages render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs