x402-gated portfolio transactions endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to portfolio transaction data via a POST request to `/api/v1/portfolios/69/transactions`. It is part of a broader platform (lowpaymentfee.com) that offers a variety of x402-payable APIs spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all priced at $0.02 per request.
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 USD. No API keys or rate limits are required; callers simply attach an `X-PAYMENT` header with a valid x402 payment proof. The endpoint accepts POST with `application/json` content type.
The specific functionality of this particular endpoint — portfolio transactions for portfolio ID 69 — is not well-documented. The site's docs, pricing, and API pages all resolve to a minimal "Connect wallet" prompt with no further detail. There is no OpenAPI spec, no request/response schema, and no example payloads available. The endpoint is confirmed live (returns 402 with a valid x402 challenge), but the lack of documentation makes it difficult to determine the exact request format or response structure.
Capabilities
Use cases
- —Retrieving transaction records for a specific portfolio
- —Integrating portfolio transaction data into dashboards or analytics tools
- —Agent-driven portfolio monitoring with per-call payment
Fit
Best for
- —Developers wanting keyless, pay-per-use portfolio transaction data
- —AI agents that can settle x402 payments on Base
- —Users who prefer no-subscription, no-rate-limit API access
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone needing non-USDC or non-Base payment options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/69/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live with a valid x402 challenge and clear pricing ($0.02/request in USDC on Base). However, there is no documentation, no request/response schema, no OpenAPI spec, and no examples. The specific purpose of portfolio 69's transactions endpoint is unclear. Docs pages return only a wallet-connect prompt.
Warnings
- —No API documentation available — docs, pricing, and API pages all show only a 'Connect wallet' prompt
- —No request or response schema provided; callers must guess the POST body format
- —The endpoint targets a hardcoded portfolio ID (69); unclear if this is a demo or production resource
- —No OpenAPI spec or ai-plugin manifest found
Citations
- —The endpoint returns a 402 x402 challenge with maxAmountRequired of 20000 base units in USDC on Basehttps://lowpaymentfee.com/api/v1/portfolios/69/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 Base networkhttps://lowpaymentfee.com/api/v1/portfolios/69/transactions