x402-gated portfolio data endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a "portfolios" resource (ID 91) 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 gated behind x402 micropayments at $0.02 per request settled in USDC on the Base network.
The specific endpoint `/api/v1/portfolios/91` is labeled "Premium API Access" and accepts POST requests. Payment is handled inline via the X-PAYMENT header using the x402 exact scheme. The asset used is USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base) with a maxAmountRequired of 20000 base units, which equals $0.02 (USDC uses 6 decimals). No API keys or rate limits are advertised; access is instant upon valid payment.
Documentation is extremely sparse—the docs, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what the portfolios endpoint actually returns. The platform appears legitimate and live (402 challenge confirmed), but the lack of documentation makes it difficult to know what data or functionality this specific endpoint provides.
Capabilities
Use cases
- —Retrieving portfolio data with per-request USDC micropayments
- —Agent-driven data access without API key management
- —Programmatic access to financial portfolio information
Fit
Best for
- —Agents that can settle x402 payments on Base
- —Use cases requiring keyless, pay-per-call API access
- —Low-volume consumers who want no subscription commitment
Not for
- —Users needing detailed API documentation before integration
- —High-volume consumers who need bulk pricing or rate guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/91 \
-H "X-PAYMENT: <x402_payment_token>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, but there is virtually no documentation—no OpenAPI spec, no request/response schema, no explanation of what 'portfolios/91' returns. The listing is essentially a stub with pricing and liveness confirmed.
Warnings
- —No documentation available beyond the landing page listing
- —No request or response schema provided—unknown what data is returned
- —Docs, pricing, and README pages all render only 'Connect wallet' with no content
- —The specific purpose of /api/v1/portfolios/91 is unclear
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/91
- —Platform advertises $0.02 per request with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/91