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 (portfolio ID 3) behind an x402 paywall. It accepts POST requests and responds with JSON. Payment is settled on the Base network using USDC (contract 0x8335…2913) at a cost of $0.02 per request (20,000 base units with 6 decimals).
The provider lowpaymentfee.com hosts a broad 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 with no API keys, no rate limits, and no commitments. This particular endpoint falls under the finance category and is discoverable via the x402 protocol. The x402 challenge was successfully captured, confirming the endpoint is live.
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 request/response examples, and no description of what fields the portfolio performance response contains or what parameters the POST body accepts. The endpoint path suggests it returns performance metrics for a pre-defined portfolio, but the exact schema is unknown.
Capabilities
Use cases
- —Retrieving performance metrics for a tracked portfolio via micropayment
- —Integrating portfolio performance data into agent workflows without API key management
- —Paying per-call for financial data using USDC on Base
Fit
Best for
- —Agents needing on-demand portfolio performance data without subscriptions
- —Developers experimenting with x402 pay-per-call finance APIs
- —Low-volume consumers who want no-commitment access to portfolio analytics
Not for
- —Users needing detailed API documentation or guaranteed schema stability
- —High-frequency trading systems requiring sub-second latency guarantees
- —Anyone who needs to query arbitrary portfolio IDs (this endpoint is hardcoded to portfolio 3)
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/3/performance \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The x402 challenge is live and confirms pricing and payment details, but there is zero documentation on request parameters or response schema. No OpenAPI spec, no examples, and all doc pages return only a wallet-connect prompt. The endpoint is effectively a stub listing.
Warnings
- —No API documentation available — all doc pages return only 'Connect wallet' with no technical content
- —No request body schema or response schema documented; consumers must guess at the interface
- —Endpoint is hardcoded to portfolio ID 3; unclear if other portfolio IDs are available or what portfolio 3 represents
- —No OpenAPI or ai-plugin manifest found
Citations
- —The endpoint returns HTTP 402 with an x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/3/performance
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/3/performance
- —maxAmountRequired is 20000 base units (USDC 6 decimals = $0.02)https://lowpaymentfee.com/api/v1/portfolios/3/performance
- —Provider advertises $0.02 per request, no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com