Pay-per-call portfolio transactions API on Base via x402, settled in USDC at $0.02/request.
What it does
This endpoint at lowpaymentfee.com provides access to portfolio transaction data (portfolio ID 24) via a POST request, gated by the x402 payment protocol. Each call costs $0.02 in USDC on the Base network — no API keys, no rate limits, and no subscriptions required. Payment is handled inline via the X-PAYMENT header using the x402 exact scheme.
The provider (lowpaymentfee.com) hosts a broader suite of APIs spanning data & analytics, AI/ML inference, finance/Web3, and infrastructure utilities, all priced uniformly at $0.02 per request. This specific endpoint targets portfolio transactions, though the crawled documentation is extremely sparse — the docs, pricing, and API pages all render only a "Connect wallet" prompt with no further detail on request/response schemas or field definitions.
Because no OpenAPI spec, request body schema, or response example is available, the exact input parameters and output format remain unknown. The endpoint is confirmed live (returns a proper 402 challenge), settles to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3, and accepts USDC (contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) on Base mainnet.
Capabilities
Use cases
- —Retrieving transaction history for a specific portfolio
- —Integrating portfolio data into automated trading or analytics pipelines
- —Agent-driven portfolio monitoring without managing API keys
Fit
Best for
- —Agents needing keyless, pay-per-call access to portfolio transaction data
- —Developers who want to avoid subscription commitments for occasional queries
- —Crypto-native workflows already operating on Base with USDC
Not for
- —Users needing detailed API documentation or guaranteed SLA
- —High-frequency bulk data export (no documented batch endpoint)
- —Users without USDC on Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/24/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>"Endpoint
Quality
The endpoint is confirmed live with a valid 402 challenge and clear pricing, but there is no OpenAPI spec, no request/response schema, and the documentation pages are empty beyond a wallet-connect prompt. Effectively a stub listing.
Warnings
- —No request body schema or response schema documented
- —All documentation pages render only 'Connect wallet' with no usable content
- —Purpose of 'portfolios/24/transactions' is inferred from URL path alone — no description of fields or parameters available
- —No examples of successful responses exist in crawled material
Citations
- —Endpoint returns HTTP 402 with x402 challenge advertising USDC on Base at maxAmountRequired 20000 (=$0.02)https://lowpaymentfee.com/api/v1/portfolios/24/transactions
- —Provider advertises $0.02/request pricing with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/24/transactions