Portfolio performance data via x402 micropayment on Base network, $0.02 per request.
What it does
This endpoint at lowpaymentfee.com returns portfolio performance data for a specific portfolio (ID 22) behind an x402 paywall. The endpoint accepts POST requests and responds with JSON. Payment is settled on the Base network using USDC (USD Coin) at a cost of $0.02 per request (20,000 base units with 6 decimals). No API keys or rate limits are required — access is granted per-call via the x402 payment protocol.
The provider site (lowpaymentfee.com) hosts a broader catalog of pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3 data, and utility services, all priced at $0.02 per request. However, this specific endpoint is focused on portfolio performance. The exact schema of the response body is not documented in the crawled material; the only confirmed output detail is that the MIME type is application/json. Documentation pages (/docs, /pricing, /api) returned minimal content (just a "Connect wallet" prompt), so the request/response structure must be inferred.
The endpoint is live: it returned a valid x402 version-1 challenge with a 402 status code. Payment is made to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 using USDC contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base. The maximum timeout for payment settlement is 300 seconds.
Capabilities
Use cases
- —Retrieve performance metrics for a tracked portfolio via a single paid API call
- —Integrate portfolio performance data into automated trading or reporting agents
- —Access financial portfolio data without API key registration using x402 micropayments
Fit
Best for
- —Agents needing on-demand portfolio performance data without signup
- —Developers prototyping pay-per-call financial data integrations
- —Web3-native applications that can settle USDC on Base
Not for
- —Users who need detailed API documentation or response schema guarantees before integrating
- —High-frequency bulk data retrieval where per-call pricing becomes expensive
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/22/performance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing and payment details. However, there is no documented request body schema, no response schema, and the docs/pricing/API pages are effectively empty. The purpose of 'portfolio 22 performance' is opaque — it is unclear what portfolio this refers to or what data is returned.
Warnings
- —No request or response schema is documented; the exact fields returned are unknown.
- —Documentation pages (/docs, /pricing, /api, /README) all returned only a 'Connect wallet' prompt with no useful content.
- —The specific portfolio (ID 22) is hardcoded in the URL with no explanation of what it represents.
- —The broader site lists many API categories but it is unclear whether all endpoints are functional or placeholders.
Citations
- —Endpoint returns a 402 x402 challenge with USDC on Base, maxAmountRequired 20000 (=$0.02)https://lowpaymentfee.com/api/v1/portfolios/22/performance
- —Site advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/22/performance