Pay-per-call portfolio transactions endpoint on Base via x402 (USDC, $0.02/request).
What it does
This x402-enabled endpoint at lowpaymentfee.com provides access to portfolio transaction data via a POST request to `/api/v1/portfolios/80/transactions`. It is part of a broader platform offering data & analytics, AI/ML inference, finance/Web3, and infrastructure utility APIs, all priced at $0.02 per request with no API keys, no rate limits, and no commitments required.
Payment is settled on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The x402 challenge specifies a `maxAmountRequired` of 20000 base units, which at 6 decimals equals $0.02 USD per call. The endpoint uses the "exact" payment scheme with a 300-second timeout. No OpenAPI schema or detailed documentation was found beyond the landing page; the docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no substantive content.
Because this specific endpoint path (`/portfolios/80/transactions`) is not listed among the advertised APIs on the landing page, its exact functionality is unclear. The name "Premium API Access" and the portfolio/transactions path suggest it returns transaction records for a specific portfolio (ID 80), but the request and response schemas are undocumented. Agents should expect to POST JSON and receive JSON back, but the required fields and response structure are unknown.
Capabilities
Use cases
- —Retrieving transaction records for a specific portfolio via micropayment
- —Integrating pay-per-call financial data into agent workflows
- —Accessing portfolio data without API key registration
Fit
Best for
- —Agents needing on-demand portfolio transaction data without subscriptions
- —Developers experimenting with x402 payment protocol on Base
- —Low-volume, pay-as-you-go financial data access
Not for
- —High-volume bulk transaction data exports (no documented batch support)
- —Users who need detailed API documentation or guaranteed schema stability
- —Non-crypto-native users who cannot settle USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/80/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02/request in USDC on Base), but there is no OpenAPI schema, no documented request/response format, and the docs/pricing/README pages are all empty beyond a wallet connect prompt. The specific endpoint path is not listed among the site's advertised APIs, making its purpose uncertain.
Warnings
- —No OpenAPI or request/response schema available — input and output formats are unknown
- —This specific endpoint (/portfolios/80/transactions) is not listed among the site's advertised APIs
- —All documentation pages (docs, api, pricing, README) returned only 'Connect wallet' with no content
- —The hardcoded portfolio ID (80) in the path suggests this may be a specific resource rather than a general-purpose API
Citations
- —The x402 challenge specifies maxAmountRequired of 20000 base units in USDC on Base network with exact scheme and 300-second timeouthttps://lowpaymentfee.com/api/v1/portfolios/80/transactions
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/80/transactions