Pay-per-call portfolio transactions API on Base via x402 (USDC), $0.02/request.
What it does
This endpoint at lowpaymentfee.com provides access to portfolio transaction data via a POST request to `/api/v1/portfolios/30/transactions`. It is part of a broader platform offering data & analytics, AI/ML, finance/Web3, and infrastructure APIs, all priced at $0.02 per request with no API keys, no rate limits, and no commitments.
Payment is handled via the x402 protocol on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The challenge advertises a `maxAmountRequired` of 20000 base units, which at 6 decimals equals $0.02 per call. The endpoint accepts POST requests and returns `application/json` responses. The payment recipient address is `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` with a max timeout of 300 seconds.
The specific endpoint targets portfolio ID 30's transactions. However, documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI schema, no request/response examples, and no description of what fields the transactions endpoint accepts or returns. The endpoint is confirmed live (402 challenge captured), but the lack of documentation makes it difficult to know what request body to send or what response structure to expect.
Capabilities
Use cases
- —Retrieving transaction records for a specific portfolio
- —Integrating portfolio transaction data into dashboards or analytics pipelines
- —Agent-driven portfolio monitoring with per-call micropayments
Fit
Best for
- —Developers wanting keyless, pay-per-use portfolio transaction data
- —AI agents that can settle x402 payments in USDC on Base
- —Quick prototyping without subscription commitments
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume batch queries where per-call pricing may add up
- —Users without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/30/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-token>" \
-d '{}'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 examples, and all documentation pages render only 'Connect wallet' with no usable content. The specific purpose of portfolio 30's transactions endpoint is undocumented.
Warnings
- —No OpenAPI or schema documentation available — request and response formats are unknown
- —All doc/pricing/API pages return only a 'Connect wallet' prompt with no technical content
- —The endpoint targets a hardcoded portfolio ID (30); unclear if other portfolio IDs are available or how they are discovered
- —No examples of request body or response structure exist in crawled material
Citations
- —Endpoint returns 402 with x402 challenge advertising USDC on Base network at maxAmountRequired 20000 (=$0.02)https://lowpaymentfee.com/api/v1/portfolios/30/transactions
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/30/transactions