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 specific portfolio resource (ID 43) via the x402 payment protocol. It is part of a broader platform that offers a variety of pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all gated behind x402 micropayments on the Base network.
The specific endpoint `/api/v1/portfolios/43` is listed as "Premium API Access" and accepts POST requests. Payment is settled in USDC (contract 0x8335…2913 on Base) at a maximum cost of $0.02 per request (20,000 base units with 6 decimals). The platform advertises no API keys, no rate limits, and instant access — callers simply attach an X-PAYMENT header with a valid x402 payment proof.
Documentation is extremely sparse. The landing page lists available endpoints and pricing, but the /docs, /pricing, /api, and /README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema, and no description of what the portfolios endpoint actually returns. The endpoint is confirmed live (returns a proper 402 challenge), but without documentation it is unclear what data or functionality the portfolio resource provides.
Capabilities
Use cases
- —Fetching portfolio data with per-request USDC micropayments
- —Agent-driven access to financial portfolio information without API keys
- —Programmatic portfolio queries settled on Base L2
Fit
Best for
- —Developers wanting keyless, pay-per-call portfolio data access
- —AI agents that can settle x402 payments on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or response schemas before integrating
- —High-volume consumers who need bulk/subscription pricing
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/43 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no documentation, no OpenAPI spec, no request/response schema, and no explanation of what the portfolios/43 resource actually returns. The docs, pricing, and README pages are all empty beyond a wallet-connect prompt. This is effectively a stub listing.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema describing request parameters or response format for /api/v1/portfolios/43
- —It is unclear what data the 'portfolios/43' endpoint actually returns
- —The endpoint name 'Premium API Access' is generic and does not describe functionality
Citations
- —The endpoint returns a valid x402 402 challenge with maxAmountRequired of 20000 in USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/43
- —Platform pricing is $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/43