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/17/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 for this specific endpoint beyond the x402 challenge metadata.
The specific endpoint listed here (`/portfolios/17/transactions`) appears to be a single portfolio's transaction resource. The broader platform advertises categories including analytics metrics, AI sentiment analysis, text summarization, finance price feeds, crypto gas estimates, geocoding, and more — all at the same $0.02 per-request price point. However, documentation pages returned only a "Connect wallet" prompt with no further technical detail, so the exact request/response schema for this endpoint is unknown.
Capabilities
Use cases
- —Fetching transaction history for a specific portfolio
- —Integrating portfolio transaction data into dashboards or analytics pipelines
- —Agent-driven portfolio monitoring with per-call USDC payments
Fit
Best for
- —Developers wanting keyless, pay-per-call access to portfolio transaction data
- —AI agents that can settle x402 payments on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone requiring non-USDC or non-Base-network payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/17/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response documentation, and the docs/pricing/API pages all return only a 'Connect wallet' stub. The purpose of this specific endpoint (portfolios/17/transactions) is only inferable from the URL path.
Warnings
- —No OpenAPI or request/response schema available for this endpoint
- —Documentation pages (/docs, /api, /pricing, /README) all return only a 'Connect wallet' prompt with no technical content
- —The endpoint path references a hardcoded portfolio ID (17); unclear if other portfolio IDs are supported
- —The platform advertises many API categories but documentation is absent for all of them
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/17/transactions
- —All APIs on the platform are priced at $0.02 per request with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/17/transactions