x402-gated portfolio endpoint on Base, pay-per-request with USDC.
What it does
This endpoint at `/api/v1/portfolios/72` is part of the lowpaymentfee.com platform, which offers a collection of x402-protocol pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. The specific `/portfolios/72` resource is listed under "Premium API Access" and accepts POST requests gated by an x402 payment challenge. Payment settles in USDC on the Base network.
The x402 challenge advertises a maximum amount of 20,000 base units of USDC (0x8335…2913 on Base, 6 decimals), which translates to $0.02 per request. The platform's landing page confirms uniform $0.02/request pricing across all endpoints, with no API keys, no rate limits, and no minimum commitments required. The endpoint returns `application/json` responses.
Documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema documentation, and no examples available. The exact data returned by `/api/v1/portfolios/72` is unknown; the name "Premium API Access" and the path suggest it may return portfolio-related data, but this cannot be confirmed from available material.
Capabilities
Use cases
- —Fetching portfolio data via a single micropayment without needing an API key
- —Integrating pay-per-call data access into autonomous agent workflows
- —Testing x402 protocol payment flows on Base network
Fit
Best for
- —Agents or developers wanting keyless, pay-per-request API access
- —x402 protocol integrations on Base
- —Low-friction micropayment API consumption
Not for
- —Users needing detailed API documentation or request/response schemas before integrating
- —High-volume batch requests where per-call pricing may add up
- —Anyone requiring non-USDC or non-Base-network payment options
Quick start
# The endpoint requires an X-PAYMENT header with a valid x402 payment proof.
# Without payment, it returns 402 with the payment challenge.
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/72 \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge confirmed) with clear pricing ($0.02/request in USDC on Base), but there is no OpenAPI spec, no request/response schema, no documentation beyond a wallet-connect prompt, and no examples. The purpose of '/portfolios/72' specifically is unclear.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or schema definition for request or response payloads
- —The specific data returned by /api/v1/portfolios/72 is undocumented and cannot be verified
- —The platform lists many diverse endpoints (AI, finance, utilities) all at $0.02 — unclear if all are fully functional
Citations
- —The x402 challenge advertises maxAmountRequired of 20000 base units of USDC (asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/72
- —Platform pricing is $0.02 per request with no API keys, no rate limits, and no minimumshttps://lowpaymentfee.com
- —The endpoint is described as 'Premium API Access' and returns application/jsonhttps://lowpaymentfee.com/api/v1/portfolios/72