Pay-per-call portfolio data endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This x402-enabled endpoint at `/api/v1/portfolios/50` is part of the lowpaymentfee.com platform, which offers a broad catalog of pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. Each call is settled on the Base network using USDC (contract `0x8335…2913`) through the x402 exact-payment scheme. The specific endpoint probed here serves portfolio data (resource ID 50) and accepts POST requests.
Pricing is straightforward: the x402 challenge advertises a `maxAmountRequired` of 20,000 base units. Since USDC uses 6 decimals, this equals $0.02 per request — consistent with the site's published flat rate of $0.02/request across all endpoints. There are no API keys, no rate limits, and no subscription commitments; you simply attach an `X-PAYMENT` header with a valid x402 payment proof for each call.
The broader lowpaymentfee.com platform lists endpoints for metrics, reports, data export, insights, sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, documentation is extremely sparse: the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. No OpenAPI schema, request/response examples, or parameter documentation were found for this or any other endpoint.
Capabilities
Use cases
- —Fetching portfolio data on-demand without subscription or API key management
- —Integrating pay-per-call financial data into autonomous agent workflows
- —Programmatic access to portfolio information settled via crypto micropayments
Fit
Best for
- —Agents or bots that need keyless, on-demand portfolio data access
- —Developers experimenting with x402 payment-gated APIs on Base
- —Low-volume consumers who prefer per-request pricing over subscriptions
Not for
- —High-volume production use cases where $0.02/request adds up and bulk pricing is needed
- —Users who need detailed API documentation, schemas, or guaranteed SLAs before integrating
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/50 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_proof>"Endpoint
Quality
The endpoint is live and returns a valid x402 402 challenge with clear pricing. However, there is no OpenAPI schema, no request/response examples, no parameter documentation, and the docs/pricing/README pages are all empty beyond a wallet-connect prompt. The purpose of 'portfolios/50' is not explained anywhere. This is effectively a stub listing.
Warnings
- —No API documentation found — docs, pricing, and README pages all render only 'Connect wallet'
- —No OpenAPI or JSON schema available for request or response payloads
- —The specific meaning of '/api/v1/portfolios/50' (what portfolio, what data) is undocumented
- —Cannot verify what data is actually returned without making a paid request
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/50
- —All endpoints 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 is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/50
- —The platform offers endpoints across data/analytics, AI/ML, finance/Web3, and infrastructure categorieshttps://lowpaymentfee.com