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 behind an x402 paywall. The specific path `/api/v1/transactions/30/receipt` returns a receipt for transaction ID 30 in JSON format, payable via USDC on the Base network. The broader lowpaymentfee.com platform advertises a wide catalog of x402-protected APIs spanning data & analytics, AI/ML (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation).
The x402 challenge confirms the endpoint is live and accepts the "exact" payment scheme. The maximum amount required is 20,000 base units of USDC (6 decimals), which equals $0.02 per request. The platform advertises uniform $0.02/request pricing across all endpoints with no API keys, no rate limits, and no minimum commitments. Payment settles on the Base network to a specified wallet address, with a 300-second timeout.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no detailed documentation describing what fields the receipt contains or what input the POST body expects. The endpoint's actual behavior and response structure remain unknown beyond the MIME type (application/json).
Capabilities
Use cases
- —Retrieving a transaction receipt for transaction ID 30 via micropayment
- —Demonstrating x402 protocol payment flows on Base
- —Agent-driven pay-per-call data retrieval without API key management
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents that need keyless, pay-per-call API access
- —Use cases requiring USDC micropayments on Base L2
Not for
- —Production workloads requiring documented request/response schemas
- —Users who need free or subscription-based API access
- —Bulk retrieval of many transaction receipts (no batch endpoint documented)
Quick start
# The endpoint requires an X-PAYMENT header with a valid x402 payment proof.
# Without a payment SDK, you'll get a 402 challenge:
curl -X POST https://lowpaymentfee.com/api/v1/transactions/30/receipt
# Returns 402 with x402 challenge. Use an x402-compatible client to pay $0.02 USDC on Base.Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request body specification, and no example responses. The docs pages are empty beyond a wallet connect prompt. The specific endpoint path (transaction 30 receipt) is narrow and not explained.
Warnings
- —No documentation available — /docs, /api, /pricing, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema describing request body or response structure
- —The endpoint path references a specific transaction ID (30); unclear if this is parameterized or static
- —No information on what fields the receipt JSON contains
- —Platform advertises many API categories but none have documented schemas or examples
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/transactions/30/receipt
- —Platform advertises $0.02/request uniform pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/transactions/30/receipt
- —Platform lists APIs across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com