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/76/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, rate limits, or commitments required.
Payment is settled on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The x402 challenge specifies a maxAmountRequired of 20,000 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 for this specific endpoint beyond the x402 challenge and the provider's landing page.
The specific endpoint listed here (`/portfolios/76/transactions`) appears to be a single portfolio's transaction resource. The broader platform advertises categories including analytics metrics, AI sentiment analysis, text summarization, classification, embeddings, financial price feeds, exchange rates, crypto quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 per-request price point. However, documentation pages returned only a "Connect wallet" prompt with no substantive content, so the actual behavior and response format of this endpoint remain unclear.
Capabilities
Use cases
- —Fetching transaction history for a specific portfolio
- —Integrating portfolio transaction data into automated trading or analytics pipelines
- —Agent-driven financial data retrieval with per-call USDC micropayments
Fit
Best for
- —Agents needing on-demand portfolio transaction data without subscription commitments
- —Developers experimenting with x402 pay-per-call patterns on Base
- —Low-volume or sporadic access to financial transaction records
Not for
- —High-frequency bulk data retrieval where per-call pricing becomes expensive
- —Users who need detailed API documentation or response schema guarantees before integrating
- —Non-crypto-native users without access to USDC on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/76/transactions \
-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/request in USDC on Base). However, there is no OpenAPI schema, no documented request/response format, no examples, and all documentation pages returned only 'Connect wallet' with no content. The specific purpose of this portfolio/76/transactions endpoint is unclear beyond its URL path.
Warnings
- —No OpenAPI or request/response schema available for this endpoint
- —All documentation pages (/docs, /api, /pricing, /README) returned only 'Connect wallet' with no substantive content
- —The endpoint path references a hardcoded portfolio ID (76); unclear if this is parameterized or fixed
- —Actual response format and fields are unknown — integration requires trial-and-error
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/76/transactions
- —All APIs on the platform are priced at $0.02 per request with no API keys, rate limits, or minimumshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/76/transactions