x402-gated portfolio endpoint on Base, pay $0.02 per request in USDC — no API keys required.
What it does
This endpoint at lowpaymentfee.com provides access to a "portfolios" resource (ID 60) via the x402 payment protocol. 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 behind x402 micropayments on the Base network using USDC.
The specific endpoint `/api/v1/portfolios/60` is listed under "Premium API Access" and accepts POST requests. Payment is settled on-chain via USDC (contract 0x8335…2913 on Base) to the provider's wallet. The x402 challenge advertises a maxAmountRequired of 20,000 base units, which equals $0.02 USD (USDC uses 6 decimals). The platform's landing page confirms a flat $0.02 per request across all endpoints, with no API keys, no rate limits, and no minimum commitments.
Documentation is extremely sparse — the /docs, /pricing, /api, 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 endpoint actually returns. The endpoint is live (returns a proper 402 challenge), but without documentation it is unclear what data or functionality the "portfolios/60" resource provides. Callers should be prepared to experiment or contact the provider for details.
Capabilities
Use cases
- —Fetching portfolio data via a single micropayment without needing an API key
- —Agent-driven on-chain pay-per-call access to premium data endpoints
- —Integrating low-friction paid API calls into Web3 workflows
Fit
Best for
- —Developers wanting zero-signup, pay-per-call API access
- —AI agents that can settle x402 payments on Base
- —Users who prefer on-chain micropayments over subscription billing
Not for
- —Users who need detailed API documentation or response schemas before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without a Base-compatible USDC wallet
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/60 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no documentation, no OpenAPI schema, no request/response examples, and no description of what the portfolios/60 resource actually returns. The listing is essentially a stub with confirmed liveness.
Warnings
- —No documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content.
- —No OpenAPI or schema describing request parameters or response format for /api/v1/portfolios/60.
- —The purpose and data returned by the 'portfolios/60' endpoint is undocumented and unclear.
- —No robots.txt or agents.txt found on the origin.
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units of USDC on Base network.https://lowpaymentfee.com/api/v1/portfolios/60
- —The platform charges $0.02 per request with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —USDC asset contract on Base is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.https://lowpaymentfee.com/api/v1/portfolios/60