x402-gated portfolio transactions endpoint on Base, pay-per-call with USDC.
What it does
This endpoint at lowpaymentfee.com exposes a POST-based transactions API for portfolio #53. It is part of a broader platform (lowpaymentfee.com) that offers dozens of x402-gated endpoints spanning data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all settled on the Base network using USDC.
The specific endpoint `/api/v1/portfolios/53/transactions` is gated via the x402 protocol. The 402 challenge indicates a maximum cost of $0.02 per request (20,000 base units of USDC with 6 decimals = $0.02), paid to address `0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3` on Base. The payment scheme is "exact," meaning the caller pays the precise amount per call with no subscription or session model. No API keys are required; authentication and authorization are handled entirely through the x402 payment header.
Documentation is extremely sparse. The crawled docs, API, pricing, and README pages all returned only a "Connect wallet" prompt with no further content. The endpoint's purpose — portfolio transactions — is inferred solely from the URL path; no request/response schema, field definitions, or usage examples are provided by the source. It is unclear whether this endpoint creates, retrieves, or manages transactions for a financial portfolio. The platform's landing page confirms a flat $0.02/request pricing model across all endpoints, with no rate limits and instant access.
Capabilities
Use cases
- —Submitting or retrieving transactions for a specific portfolio via a pay-per-call model
- —Integrating x402-gated financial data into agent workflows without API key management
- —Programmatic portfolio transaction access settled in USDC on Base
Fit
Best for
- —Developers building on Base who want frictionless pay-per-call API access
- —AI agents that can settle x402 payments autonomously
- —Users who prefer no-subscription, no-API-key access to financial endpoints
Not for
- —Users needing detailed API documentation or guaranteed SLAs before integration
- —High-volume consumers who would benefit from bulk/subscription pricing
- —Anyone requiring non-USDC or non-Base settlement options
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/53/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>" \
-d '{}'Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02/request in USDC on Base). However, there is no documentation, no request/response schema, no examples, and the purpose of the endpoint is only inferable from the URL path. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, README, and API pages all return only a wallet-connect prompt with no content.
- —No request or response schema provided; the purpose of the endpoint (create vs. read transactions, what fields are accepted) is unknown.
- —The endpoint targets a specific portfolio ID (53); it is unclear if other portfolio IDs are available or how they are obtained.
- —The platform appears to host many endpoints but none have published schemas or documentation.
Citations
- —The endpoint returns a 402 challenge with x402Version 1, scheme 'exact', network 'base', maxAmountRequired 20000, asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 (USDC).https://lowpaymentfee.com/api/v1/portfolios/53/transactions
- —The platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on the Base network.https://lowpaymentfee.com
- —Docs, API, pricing, and README pages return only a 'Connect wallet' prompt with no substantive documentation.https://lowpaymentfee.com/docs