x402-gated portfolio transactions endpoint on Base, paid per-call in USDC.
What it does
This endpoint at lowpaymentfee.com exposes a POST-based API for portfolio transactions at `/api/v1/portfolios/59/transactions`. It is part of a broader platform (lowpaymentfee.com) that offers dozens of x402-payable endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and utility services. All endpoints on the platform use the x402 protocol on the Base network, settling payments in USDC.
The specific endpoint probed here returns a valid x402 challenge with a `maxAmountRequired` of 20,000 base units of USDC (6 decimals), which equals $0.02 per request. The platform advertises uniform $0.02/request pricing across all its APIs, with no API keys, no rate limits, and no minimum commitments required. Payment is made via the x402 `exact` scheme to a specified wallet address on Base.
Documentation on the site 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 description of what the portfolio transactions endpoint actually accepts or returns. The endpoint name suggests it deals with financial portfolio transaction data, but without documentation this is speculative. The platform appears to be a demonstration or early-stage deployment of x402-gated APIs.
Capabilities
Use cases
- —Fetching or submitting portfolio transaction records via a pay-per-call model
- —Integrating x402-based micropayments into agent workflows
- —Accessing financial data without API key registration
Fit
Best for
- —Developers experimenting with x402 protocol payments
- —Agents that need keyless, pay-per-request API access on Base
- —Low-volume or sporadic API consumers who prefer no subscriptions
Not for
- —Production workloads requiring documented request/response schemas
- —Users needing detailed API documentation or support
- —High-throughput use cases where per-call pricing may not be cost-effective
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/59/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no request/response examples, and no explanation of what the endpoint actually does. The docs pages are empty. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, and README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or request/response schema provided; the actual functionality of the portfolio transactions endpoint is unknown.
- —The endpoint path references a specific portfolio ID (59), which may not be generalizable.
- —Platform appears to be early-stage or a demo; reliability and longevity are uncertain.
Citations
- —The endpoint returns a valid x402 challenge with maxAmountRequired of 20000 base units of USDC on Base network.https://lowpaymentfee.com/api/v1/portfolios/59/transactions
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base network.https://lowpaymentfee.com
- —The USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/portfolios/59/transactions