x402-gated portfolio endpoint on Base, pay $0.02 per request in USDC — no API keys needed.
What it does
This endpoint at `/api/v1/portfolios/74` is part of the lowpaymentfee.com platform, which offers a collection of x402-protocol pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. The specific `/portfolios/74` resource is listed under "Premium API Access" but its exact data payload is not documented beyond the generic description. All endpoints on the platform share the same pricing model: $0.02 per request, settled in USDC on the Base network via the x402 exact-payment scheme.
The platform advertises a no-friction model: no API keys, no rate limits, and no minimum commitments. Callers send a POST request with an `X-PAYMENT` header containing the x402 payment proof. The 402 challenge confirms the endpoint is live, accepts USDC (contract `0x8335…2913` on Base), and requires a maximum of 20,000 base units (i.e., $0.02 given USDC's 6 decimals). The payment timeout is 300 seconds.
Documentation is extremely thin — 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 example payloads for this specific portfolio endpoint. The platform hosts many other endpoints (analytics, AI, finance, utils) at the same price point, but without documentation it is impossible to confirm what data `/portfolios/74` actually returns.
Capabilities
Use cases
- —Fetching portfolio data without managing API keys or subscriptions
- —Agent-driven data retrieval with per-call USDC micropayments on Base
- —Integrating pay-as-you-go financial data into automated workflows
Fit
Best for
- —Developers wanting zero-signup, pay-per-request API access
- —AI agents that can settle x402 payments autonomously on Base
- —Users who prefer crypto micropayments over traditional billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/74 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is zero documentation on what the endpoint actually returns. No OpenAPI spec, no request/response examples, and all doc pages render only 'Connect wallet'. The specific resource '/portfolios/74' is not even listed on the homepage catalog, making it effectively a stub.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema describing request parameters or response format for /portfolios/74
- —The /portfolios/74 endpoint is not listed among the homepage's advertised APIs; its purpose is unclear
- —Cannot verify what data this endpoint actually returns without paying
Citations
- —The endpoint returns a 402 challenge requiring USDC payment on Base with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/portfolios/74
- —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/74
- —Documentation pages (docs, pricing, API, README) render only 'Connect wallet' with no technical contenthttps://lowpaymentfee.com/docs