x402-gated portfolio data endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at `/api/v1/portfolios/48` is part of the lowpaymentfee.com platform, a collection of x402-protocol pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. The specific `/portfolios/48` resource is listed under "Premium API Access" but its exact data payload is not documented in the available crawl material — it likely returns portfolio-related data (possibly financial or analytical) in JSON format.
The endpoint is live and responds with a standard x402 payment challenge. It accepts payment via the "exact" scheme on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The maximum amount required is 20,000 base units of USDC, which at 6 decimals equals $0.02 per request — consistent with the site's uniform $0.02/request pricing across all endpoints. Payment is sent to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a 300-second timeout.
The platform advertises no API keys, no rate limits, and instant access. However, documentation is extremely thin — the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI schema, no request/response examples, and no description of what the `/portfolios/48` endpoint actually returns. The POST method is specified in the outputSchema. Without documentation of the request body format or response structure, callers will need to experiment or contact the provider.
Capabilities
Use cases
- —Fetching portfolio data on-demand with per-request USDC micropayments
- —Integrating pay-as-you-go data access into autonomous agents on Base
- —Accessing premium financial or analytical data without subscription commitments
Fit
Best for
- —Agents or apps that need on-demand portfolio data with no subscription
- —Developers experimenting with x402 pay-per-call protocols on Base
- —Low-volume consumers who prefer per-request pricing over monthly plans
Not for
- —Users who need detailed API documentation or guaranteed SLAs before integrating
- —High-volume consumers who would benefit from bulk pricing or rate-limited tiers
- —Anyone who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/48 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and the x402 challenge is well-formed with clear pricing ($0.02 USDC on Base). However, there is no documentation of what this endpoint actually returns, no request/response schema, no OpenAPI spec, and all doc pages render only 'Connect wallet'. The specific purpose of /portfolios/48 is unknown.
Warnings
- —No documentation available — docs, API, pricing, and README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided; request body format is unknown
- —The exact data returned by /api/v1/portfolios/48 is undocumented and must be inferred or discovered experimentally
- —The '/portfolios/48' path suggests a specific resource ID; it is unclear if other portfolio IDs exist or what they represent
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units of USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/48
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/48
- —Docs, API, pricing, and README pages render only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs