Portfolio performance data via x402 micropayment on Base network, $0.02 per request.
What it does
This endpoint at lowpaymentfee.com provides portfolio performance data for a specific portfolio (ID 98) behind an x402 paywall. The endpoint accepts POST requests and returns JSON. Payment is settled in USDC on the Base network at $0.02 per call (maxAmountRequired of 20,000 base units with 6 decimals = $0.02). No API keys or rate limits are required — access is granted per-request via the x402 payment protocol.
The parent site lowpaymentfee.com hosts a broader suite of pay-per-call APIs spanning data analytics, AI/ML inference, finance/crypto market data, and utility services, all priced at $0.02 per request. However, this specific endpoint is scoped to portfolio performance. The exact schema of the response payload is not documented in the crawled material; the endpoint description is simply "Premium API Access" and no OpenAPI spec or detailed field-level documentation was found.
Because the endpoint returned a well-formed 402 challenge with x402 version 1, it is confirmed live. The USDC asset contract (0x8335…2913) matches the canonical Base-mainnet USDC address. Timeout is 300 seconds. No input schema beyond HTTP POST is specified, so callers should experiment with request bodies or check for additional documentation.
Capabilities
Use cases
- —Retrieving performance metrics for a tracked 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
- —Developers who prefer pay-per-call over subscription billing
- —Crypto-native workflows that can settle USDC on Base
Not for
- —Users needing detailed API documentation or guaranteed response schemas
- —High-frequency bulk data pulls where per-request pricing adds up
- —Users without access to USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/98/performance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI spec, no response schema, no request body documentation, and the crawled docs/pricing/README pages all returned only 'Connect wallet' with no useful content. The endpoint's actual data output is unknown.
Warnings
- —No OpenAPI or response schema available — the structure of the returned portfolio performance data is undocumented.
- —The specific portfolio ID (98) is hardcoded in the URL; it is unclear whether other portfolio IDs are available or how they are discovered.
- —Documentation pages (/docs, /pricing, /README, /api) returned no meaningful content beyond 'Connect wallet'.
- —The broader site lists many API categories but this endpoint's relationship to the rest of the platform is unclear.
Citations
- —Endpoint returns 402 with x402 version 1 challenge, confirming it is livehttps://lowpaymentfee.com/api/v1/portfolios/98/performance
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02 per requesthttps://lowpaymentfee.com/api/v1/portfolios/98/performance
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/98/performance
- —Site advertises $0.02/request pricing with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com