x402-gated portfolio data endpoint on Base, pay $0.02 per request in USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a specific portfolio resource (portfolio ID 76) via the x402 payment protocol. The endpoint is live and returns a standard x402 challenge requiring payment in USDC on the Base network. Each request costs $0.02 (20,000 base units of USDC with 6 decimals). No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid payment proof.
The hosting site lowpaymentfee.com offers a broad catalog of x402-gated APIs spanning data & analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are listed at $0.02 per request and settle on the Base network using USDC.
The specific portfolio endpoint (/api/v1/portfolios/76) does not have detailed documentation available — the docs, pricing, and API pages on the site only render a "Connect wallet" prompt with no further content. The response schema, input parameters, and exact data returned by this endpoint are unknown. The endpoint accepts POST requests and returns application/json content.
Capabilities
Use cases
- —Retrieving portfolio data (ID 76) with per-request micropayment in USDC
- —Integrating pay-per-call portfolio access into an AI agent workflow
- —Accessing financial portfolio information without API key registration
Fit
Best for
- —Agents or developers who want keyless, pay-per-use API access
- —Users already holding USDC on Base who need portfolio data
- —Prototyping x402 payment flows against a live endpoint
Not for
- —Users needing detailed documentation or guaranteed SLAs
- —Bulk data retrieval where per-request pricing becomes expensive
- —Anyone without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/76 \
-H "X-PAYMENT: <x402-payment-proof>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is no documentation, no OpenAPI schema, no example request/response, and no description of what portfolio data is actually returned. The docs pages are empty (wallet-connect only). This is effectively a stub listing.
Warnings
- —No documentation available — docs, pricing, API, and README pages all render only a 'Connect wallet' prompt with no content.
- —No input or output schema documented for this specific endpoint; the data returned is unknown.
- —The portfolio ID (76) is hardcoded in the URL with no explanation of what portfolio it represents.
- —Cannot verify what data is actually returned without making a paid request.
Citations
- —Endpoint returns HTTP 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/76
- —maxAmountRequired is 20000 base units of USDC (USD Coin, 6 decimals) = $0.02https://lowpaymentfee.com/api/v1/portfolios/76
- —Site advertises $0.02/request pricing with no API keys, no rate limits, instant access on Base networkhttps://lowpaymentfee.com
- —Site offers APIs across data & analytics, AI/ML, finance & Web3, and infrastructure categorieshttps://lowpaymentfee.com