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/93/transactions`. It is part of a broader platform (lowpaymentfee.com) that offers a variety of x402-gated 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. There are no API keys, no rate limits, and no signup required — callers simply attach an `X-PAYMENT` header with a valid x402 payment proof. The payment timeout is 300 seconds.
The specific endpoint (`/portfolios/93/transactions`) appears to serve transaction records for portfolio ID 93. However, documentation is extremely sparse — the docs, pricing, API, and README pages all render only a "Connect wallet" prompt with no further detail. There is no OpenAPI schema, no request/response examples, and no description of what fields the transaction data contains or what POST body parameters are accepted. The endpoint is confirmed live (returns 402 as expected), but the lack of documentation makes it difficult to use without experimentation.
Capabilities
Use cases
- —Retrieving transaction history for a specific portfolio
- —Integrating portfolio transaction data into dashboards or analytics pipelines
- —Agent-driven portfolio monitoring with per-request micropayments
Fit
Best for
- —Developers wanting keyless, pay-per-use access to portfolio transaction data
- —AI agents that can settle x402 payments on Base
- —Users who prefer crypto micropayments over subscription billing
Not for
- —Users who need detailed API documentation or request/response schemas before integrating
- —Applications requiring bulk or high-volume transaction exports at lower per-unit cost
- —Non-crypto users who cannot settle USDC payments on Base
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/93/transactions \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-proof>"Endpoint
Quality
The endpoint is confirmed live via a valid 402 challenge, and pricing is clear ($0.02 USDC on Base). However, there is no OpenAPI schema, no request/response examples, and all documentation pages return only a 'Connect wallet' stub. The specific purpose of portfolio 93 transactions is unexplained. This is effectively a stub listing.
Warnings
- —No API documentation available — docs, pricing, API, and README pages all show only 'Connect wallet'
- —No OpenAPI or request/response schema provided
- —The endpoint targets a hardcoded portfolio ID (93) with no explanation of what this portfolio represents
- —No information on what POST body parameters are accepted or what the response format looks like
Citations
- —The endpoint returns a 402 challenge with maxAmountRequired of 20000 base units in USDC on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/93/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 Basehttps://lowpaymentfee.com/api/v1/portfolios/93/transactions