Pay-per-call portfolio data endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This x402-enabled endpoint at `/api/v1/portfolios/100` is part of the lowpaymentfee.com platform, which offers a suite of pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities. All endpoints use the x402 payment protocol on the Base network, accepting USDC (contract 0x8335…2913) with no API keys, no rate limits, and no subscriptions required.
The specific endpoint probed (`/api/v1/portfolios/100`) is listed under "Premium API Access" and accepts POST requests. The x402 challenge confirms it is live, requesting a maximum of 20,000 base units of USDC (6 decimals), which equals $0.02 per request. The payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout. The response MIME type is `application/json`.
Documentation is extremely sparse — the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The endpoint name suggests it returns portfolio-related data (possibly for portfolio ID 100), but the exact request body format and response structure are unknown. The broader platform advertises categories including analytics, AI, finance, and utilities, all at the same $0.02 price point.
Capabilities
Use cases
- —Fetching portfolio data without managing API keys or subscriptions
- —Agent-driven portfolio lookups with automatic USDC micropayments on Base
- —Integrating pay-per-request financial data into automated workflows
Fit
Best for
- —Developers wanting zero-friction API access without signup
- —AI agents that can settle payments via x402 on Base
- —Low-volume or sporadic portfolio data consumers who prefer pay-as-you-go
Not for
- —Users needing detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/100 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The purpose of the endpoint (portfolios/100) is only inferable from the URL path. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition found; request body format and response structure are completely unknown
- —The specific data returned by /api/v1/portfolios/100 is undocumented; 'Premium API Access' is a generic label
- —The broader platform lists many endpoint categories but none have documented schemas
Citations
- —The endpoint returns a 402 x402 challenge requesting 20000 base units of USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/100
- —All APIs are priced at $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 (Base USDC, 6 decimals)https://lowpaymentfee.com/api/v1/portfolios/100
- —Documentation pages (/docs, /pricing, /api, /README) render only a 'Connect wallet' prompthttps://lowpaymentfee.com/docs