x402-gated portfolio endpoint on Base, pay-per-call with USDC at $0.02/request.
What it does
This endpoint at lowpaymentfee.com provides access to a portfolio resource (portfolio ID 14) via the x402 payment protocol. It is part of a broader platform offering dozens of pay-per-request API endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all gated behind x402 micropayments on the Base network using USDC.
The specific endpoint `/api/v1/portfolios/14` is listed under "Premium API Access" and accepts POST requests. Payment is settled on-chain via USDC (contract 0x8335…2913 on Base) with a maximum amount of 20,000 base units, which equals $0.02 (USDC uses 6 decimals). No API keys or rate limits are advertised; access is granted per-request upon valid x402 payment. The payment timeout is 300 seconds.
Documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further content. There is no OpenAPI schema, no request/response examples, and no description of what the portfolio endpoint actually returns. The platform's landing page confirms the $0.02 per-request pricing model and lists many endpoints, but this specific portfolios endpoint is not listed among them, making its purpose unclear. It may return portfolio-related financial data, but this is speculative.
Capabilities
Use cases
- —Retrieving portfolio data (ID 14) with a single USDC micropayment on Base
- —Integrating pay-per-request financial data into agent workflows without API keys
- —Demonstrating x402 protocol payment flows for on-chain API access
Fit
Best for
- —Developers experimenting with x402 payment protocol
- —Agents needing keyless, pay-per-call API access on Base
- —Low-volume consumers who prefer micropayments over subscriptions
Not for
- —Users needing detailed API documentation or response schemas before integrating
- —High-volume consumers who need bulk pricing or rate-limit guarantees
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/14 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI schema, no request/response examples, and the specific portfolio endpoint is not even listed on the provider's landing page. The purpose and output of this endpoint are unknown.
Warnings
- —No documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or output schema provided; response format is completely unknown
- —The /api/v1/portfolios/14 endpoint is not listed among the provider's advertised APIs on the landing page
- —Purpose of 'portfolio 14' is unclear — no description of what data is returned
Citations
- —The endpoint returns HTTP 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/14
- —maxAmountRequired is 20000 base units of USDC (0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913), equaling $0.02https://lowpaymentfee.com/api/v1/portfolios/14
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —Docs, pricing, API, and README pages render only 'Connect wallet' with no additional contenthttps://lowpaymentfee.com/docs