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 access to a specific portfolio resource (`/api/v1/portfolios/65`) behind an x402 paywall. The provider operates a broad catalog of pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities, 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 specific `/api/v1/portfolios/65` endpoint is listed as "Premium API Access" with a maximum payment of 20,000 base units of USDC (0.02 USDC, i.e., $0.02) per call. The x402 challenge confirms the endpoint is live, accepts POST requests, and returns `application/json`. The payment is sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` using the USDC contract on Base (`0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`).
Documentation beyond the landing page is extremely sparse — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema, and no description of what the portfolio resource actually contains or what parameters it accepts. The endpoint name "portfolios/65" suggests a specific portfolio record, but its contents and structure are unknown.
Capabilities
Use cases
- —Fetching portfolio data on-demand with per-request USDC micropayments
- —Agent-driven data retrieval without pre-registration or API key management
- —Programmatic access to portfolio information settled on Base L2
Fit
Best for
- —Agents or services that need keyless, pay-as-you-go API access
- —Developers experimenting with x402 payment protocol integrations
- —Use cases requiring low-friction, per-call billing in stablecoins
Not for
- —Users who need detailed documentation or well-defined schemas before integrating
- —High-volume consumers who prefer subscription or bulk pricing
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/65 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation of what the portfolio resource contains, and all doc pages render only a wallet-connect prompt. The listing is essentially a stub with verified liveness and pricing but no usable technical detail.
Warnings
- —No OpenAPI or schema available — request parameters and response structure are completely unknown
- —All documentation pages (docs, API, pricing, README) render only a 'Connect wallet' prompt with no content
- —The specific resource '/api/v1/portfolios/65' is not listed on the provider's landing page catalog — its purpose is unclear
- —No examples of successful responses are available
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/65
- —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 on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/65