x402-gated portfolio endpoint on Base, pay $0.02 per request in USDC — no API keys needed.
What it does
This endpoint at lowpaymentfee.com provides premium API access to a specific portfolio resource (ID 64) via the x402 payment protocol. It is part of a broader platform that offers data & analytics, AI & machine learning, finance & Web3, and infrastructure utility APIs — all gated behind per-request USDC micropayments on the Base network.
The endpoint accepts POST requests and returns JSON. Payment is handled inline via the x402 protocol: callers attach an X-PAYMENT header containing a signed USDC payment on Base. The maximum amount required is 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals). There are no API keys, no rate limits, and no subscription commitments — each call is independently paid.
The specific resource at `/api/v1/portfolios/64` is labeled "Premium API Access" but no further documentation describes the portfolio data schema or what fields are returned. The platform's docs, pricing, and API pages all render only a "Connect wallet" prompt with no additional technical detail. Without an OpenAPI spec, response examples, or field-level documentation, the exact shape of the response is unknown. Callers should expect a JSON object but will need to experiment to discover the schema.
Capabilities
Use cases
- —Fetching portfolio data on-demand with per-request USDC micropayments
- —Integrating pay-per-call financial data into autonomous agent workflows
- —Accessing premium API resources without managing API keys or subscriptions
Fit
Best for
- —Agents or apps that need keyless, pay-per-use API access
- —Developers experimenting with x402 micropayment-gated endpoints
- —Use cases where per-request billing at $0.02 is preferable to subscriptions
Not for
- —High-volume bulk data retrieval where per-request costs add up quickly
- —Users who need detailed API documentation or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/64 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-signed-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge, confirming it is operational. However, there is no OpenAPI spec, no response schema, no example responses, and the docs/pricing/API pages are all empty beyond a wallet-connect prompt. The specific purpose of 'portfolios/64' is undocumented. This is effectively a stub listing.
Warnings
- —No OpenAPI or schema documentation available — response format is unknown
- —All documentation pages (docs, pricing, API, README) render only 'Connect wallet' with no technical content
- —The specific meaning of 'portfolios/64' is not documented anywhere in the crawled material
- —Platform lists many endpoint categories but none have detailed docs; quality of underlying services is unverifiable
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/64
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/64
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers Data & Analytics, AI & ML, Finance & Web3, and Infrastructure API categorieshttps://lowpaymentfee.com