Portfolio performance data via x402 micropayment on Base network, $0.02/request in USDC.
What it does
This endpoint at lowpaymentfee.com provides portfolio performance data for a specific portfolio (ID 7) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) with an exact-scheme micropayment of 20,000 base units, which equals $0.02 per request (USDC uses 6 decimals).
The provider lowpaymentfee.com hosts a broad catalog of x402-gated APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all priced at $0.02 per call. This particular endpoint falls under the finance category and appears to return performance metrics for a portfolio. No API keys or rate limits are advertised; access is granted purely through the x402 payment protocol.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI schema, no description of request parameters, and no sample response structure available. The endpoint is confirmed live (returns a proper 402 challenge), but the actual payload format and response fields are unknown.
Capabilities
Use cases
- —Retrieving performance metrics for a tracked investment portfolio
- —Integrating portfolio performance data into dashboards or agents
- —Programmatic access to portfolio returns without API key management
Fit
Best for
- —Agents or apps needing on-demand portfolio performance data with per-call payment
- —Developers who want keyless API access settled via Base USDC
- —Low-volume consumers who prefer pay-per-use over subscriptions
Not for
- —Users needing detailed API documentation or guaranteed SLA before integrating
- —High-frequency consumers who need bulk/subscription pricing
- —Anyone without a Base-network USDC wallet or x402-compatible client
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/7/performance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge and clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response documentation, no examples, and the crawled pages are essentially empty beyond the landing page catalog. The purpose of this specific endpoint (portfolio 7 performance) is only inferable from the URL path.
Warnings
- —No API documentation available — docs, pricing, and README pages all return only a wallet-connect prompt
- —No request body schema or response schema documented; input/output formats are unknown
- —Portfolio ID 7 is hardcoded in the URL; unclear if other portfolio IDs are available or how they are discovered
- —Provider appears to be a generic x402 demo site with many endpoints; actual data quality and reliability are unverified
Citations
- —Endpoint returns 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/7/performance
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/7/performance
- —All APIs priced at $0.02 per request with no API keys, no rate limitshttps://lowpaymentfee.com
- —maxAmountRequired is 20000 base units (= $0.02 with 6 decimal USDC)https://lowpaymentfee.com/api/v1/portfolios/7/performance