x402-gated transaction receipt endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a specific transaction receipt (transaction ID 281) 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 data (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 endpoint probed (/api/v1/transactions/281/receipt) returns a valid x402 challenge with a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base). Since USDC uses 6 decimals, this equals $0.02 per call. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using the "exact" scheme. The endpoint accepts POST requests and returns application/json. No API keys or rate limits are advertised; access is gated purely by micropayment.
Documentation is extremely sparse — 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 platform appears functional (root returns 200, x402 challenge is well-formed) but the lack of documentation makes it difficult to know what data is returned.
Capabilities
Use cases
- —Retrieving transaction receipt data for transaction 281 via micropayment
- —Demonstrating x402 protocol integration for pay-per-request APIs
- —Agent-driven access to paid API endpoints without API key management
Fit
Best for
- —Developers experimenting with x402 micropayment protocol
- —Agents that need keyless, pay-per-call API access on Base
- —Projects requiring USDC-settled API transactions
Not for
- —Production use requiring documented request/response schemas
- —Bulk or high-volume data retrieval (no documented batch endpoints)
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/transactions/281/receipt
# Returns 402 with x402 challenge. Include X-PAYMENT header with signed USDC payment on Base to access.Endpoint
Quality
The x402 challenge is live and well-formed, confirming the endpoint exists and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no documentation of request parameters or response schema, and the specific endpoint is for a single hardcoded transaction ID (281) with no explanation of what the receipt contains. The docs pages are empty.
Warnings
- —No OpenAPI or schema documentation available — request/response format is unknown
- —All documentation pages (/docs, /api, /pricing, /README) render only 'Connect wallet' with no content
- —This endpoint is for a specific transaction ID (281); unclear if it generalizes to other IDs
- —The platform advertises many API categories but none have documented schemas or examples
Citations
- —Endpoint returns x402 challenge with maxAmountRequired of 20000 base units USDC on Basehttps://lowpaymentfee.com/api/v1/transactions/281/receipt
- —All endpoints priced at $0.02 per request with no API keys, no rate limitshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/281/receipt
- —Platform offers APIs across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com