x402-gated portfolio endpoint on Base, pay $0.02 per request in USDC — no API keys required.
What it does
This endpoint at lowpaymentfee.com provides premium API access to a specific portfolio resource (`/api/v1/portfolios/25`) via the x402 payment protocol. It is part of a broader platform offering data & analytics, AI/ML inference, finance/Web3, and infrastructure utility APIs, all priced at $0.02 per request and settled in USDC on the Base network. No API keys, rate limits, or upfront commitments are required — callers simply attach an x402 payment header to each request.
The x402 challenge confirms the endpoint is live and accepts POST requests. Payment is made in USDC (contract `0x8335…2913` on Base) to address `0x1A2B…85F3`, with a maximum amount of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The response MIME type is `application/json`. The endpoint uses x402 version 1 with the "exact" payment scheme and a 300-second timeout.
However, the specific `/api/v1/portfolios/25` endpoint is not listed on the provider's landing page among the documented API categories, and no documentation, request schema, or response schema is available for it. The docs, pricing, and API pages all render only a "Connect wallet" prompt with no further content. As a result, the exact data returned by this portfolio endpoint is unknown — it could be financial portfolio data, but this is speculative. Callers should be prepared to experiment or contact the provider for details.
Capabilities
Use cases
- —Fetching portfolio data on-demand with per-request USDC micropayments
- —Agent-driven financial data retrieval without API key management
- —Programmatic access to premium data behind x402 paywall
Fit
Best for
- —Agents or bots that need keyless, pay-per-call API access
- —Developers experimenting with x402 payment protocol on Base
- —Low-volume consumers who want no subscription or commitment
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/25 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, and pricing is clear ($0.02/request in USDC on Base). However, this specific portfolio endpoint is not documented on the provider's site, no request/response schema exists, docs pages are empty, and the actual data returned is unknown. Effectively a stub listing.
Warnings
- —The /api/v1/portfolios/25 endpoint is not listed among the provider's documented APIs — its purpose and response format are unknown.
- —All documentation pages (docs, pricing, API, README) render only a 'Connect wallet' prompt with no usable content.
- —No OpenAPI spec, request schema, or response schema is available.
- —The exact nature of 'portfolio' data is unverified and may differ from expectations.
Citations
- —The endpoint returns a 402 challenge with x402 version 1, exact scheme, USDC on Base, maxAmountRequired 20000https://lowpaymentfee.com/api/v1/portfolios/25
- —USDC contract address on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/25
- —Platform advertises $0.02/request, no API keys, no rate limits, Base networkhttps://lowpaymentfee.com
- —The /api/v1/portfolios/25 path is not listed among the provider's documented API endpointshttps://lowpaymentfee.com