x402-gated portfolio transactions endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to portfolio transaction data via the x402 payment protocol. The specific resource `/api/v1/portfolios/27/transactions` accepts POST requests and charges up to $0.02 per call in USDC on the Base network. Payment is handled entirely through the x402 challenge-response mechanism — no API keys or accounts are required.
The hosting site lowpaymentfee.com advertises a broad catalog of pay-per-request APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities, all priced at $0.02 per request. However, the specific endpoint listed here targets portfolio transactions (portfolio ID 27). There is no published OpenAPI schema, request body documentation, or example responses for this particular endpoint. The crawled docs, pricing, and API pages returned only a "Connect wallet" prompt with no further technical detail.
Because the endpoint returns a valid x402 challenge (HTTP 402 with well-formed accepts array), it is confirmed live. The payment is settled in USDC (contract 0x8335…2913) on Base to address 0x1A2B…85F3, with a max timeout of 300 seconds. Without request/response schema documentation, callers will need to experiment or contact the provider to determine the expected POST body and the shape of returned transaction data.
Capabilities
Use cases
- —Fetching transaction history for a specific portfolio via micropayment
- —Integrating portfolio transaction data into an agent workflow without API key management
- —Programmatic access to financial transaction records with per-call USDC settlement
Fit
Best for
- —Agents or bots that need on-demand portfolio transaction data without subscription commitments
- —Developers experimenting with x402 payment-gated APIs on Base
- —Low-volume, pay-as-you-go access to financial transaction endpoints
Not for
- —Users who need detailed API documentation or guaranteed schema stability before integrating
- —High-volume consumers who would benefit from bulk pricing or subscription plans
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/27/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402_payment_token>" \
-d '{}'Endpoint
Quality
The endpoint is confirmed live via a valid x402 402 challenge, but there is no OpenAPI schema, no request/response documentation, and the crawled pages beyond the landing page returned only 'Connect wallet' stubs. The purpose of this specific portfolio endpoint (ID 27) is unclear and undocumented.
Warnings
- —No OpenAPI or request/response schema is published for this endpoint.
- —The docs, pricing, API, and README pages all returned only a 'Connect wallet' prompt with no technical content.
- —The endpoint targets a hardcoded portfolio ID (27); it is unclear whether this is a demo or a real resource.
- —The broader site advertises many API categories but none of the crawled pages provided substantive documentation.
Citations
- —Endpoint returns HTTP 402 with x402 challenge, confirming it is live.https://lowpaymentfee.com/api/v1/portfolios/27/transactions
- —Max amount required is 20000 base units of USDC (6 decimals) = $0.02 per request.https://lowpaymentfee.com/api/v1/portfolios/27/transactions
- —Payment is in USDC on Base network to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3.https://lowpaymentfee.com/api/v1/portfolios/27/transactions
- —Site advertises $0.02/request pricing with no API keys, no rate limits, and instant access.https://lowpaymentfee.com