x402-gated portfolio endpoint on Base, pay $0.02 per request in USDC — no API keys needed.
What it does
This endpoint at lowpaymentfee.com provides a "Premium API Access" resource at the path `/api/v1/portfolios/83`. It is part of a broader platform that offers dozens of pay-per-call API endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all gated via the x402 payment protocol on the Base network.
The specific `/api/v1/portfolios/83` endpoint accepts POST requests and returns JSON. Payment is settled in USDC (contract `0x8335…2913` on Base) with a maximum amount of 20,000 base units, which equals $0.02 (USDC uses 6 decimals). There are no API keys, no rate limits, and no subscription commitments — each call is paid individually via the x402 `X-PAYMENT` header. The payment timeout is 300 seconds.
The broader lowpaymentfee.com platform advertises a uniform $0.02/request pricing across all its endpoints. However, documentation beyond the landing page is essentially empty (all sub-pages just show "Connect wallet"), so the exact schema of the request body and the structure of the portfolio data returned are unknown. The endpoint is confirmed live via a valid 402 challenge response.
Capabilities
Use cases
- —Fetching portfolio data (ID 83) on demand with per-request USDC micropayments
- —Agent-driven data retrieval without pre-registration or API key management
- —Integrating pay-as-you-go financial data into automated workflows
Fit
Best for
- —Developers wanting keyless, pay-per-call API access on Base
- —AI agents that can settle x402 payments autonomously
- —Users who need occasional portfolio lookups without subscription overhead
Not for
- —High-volume consumers who need bulk/subscription pricing
- —Users who need detailed API documentation or client SDKs before integrating
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/83 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no documentation for this specific endpoint — no request/response schema, no examples, and all doc pages are empty. The purpose of 'portfolios/83' is entirely opaque beyond the generic 'Premium API Access' label.
Warnings
- —No documentation available — all doc/pricing/README pages return only 'Connect wallet' with no content.
- —The request body schema and response format for /api/v1/portfolios/83 are completely unknown.
- —The meaning of 'portfolios/83' (what portfolio, what data) is not documented anywhere.
- —This endpoint is not listed on the provider's own landing page catalog, raising questions about its status.
Citations
- —The endpoint returns a 402 challenge with x402Version 1, accepting USDC on Base with maxAmountRequired of 20000 base unitshttps://lowpaymentfee.com/api/v1/portfolios/83
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/83
- —Platform advertises $0.02/request uniform pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Platform offers endpoints across Data & Analytics, AI & ML, Finance & Web3, and Infrastructure categorieshttps://lowpaymentfee.com