Pay-per-call portfolio data endpoint on Base via x402, settled in USDC at $0.02/request.
What it does
This endpoint at lowpaymentfee.com provides premium API access to portfolio data (specifically the `/api/v1/portfolios/20` resource). It uses the x402 payment protocol on the Base network, accepting USDC payments at approximately $0.02 per request. No API keys or rate limits are required — callers simply attach an X-PAYMENT header with a valid payment proof to access the resource.
The broader lowpaymentfee.com platform offers a suite of pay-per-call APIs spanning data analytics, AI/ML inference (sentiment analysis, summarization, classification, embeddings), finance/Web3 data (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation). All endpoints share the same $0.02/request pricing model and x402 payment flow on Base.
The specific `/portfolios/20` endpoint accepts POST requests and returns JSON. Beyond the payment challenge metadata, no detailed documentation, request schema, or response schema is available from the crawled pages. The docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no additional technical content.
Capabilities
Use cases
- —Retrieving portfolio data without managing API keys or subscriptions
- —Agent-driven data access with per-call USDC micropayments on Base
- —Integrating portfolio information into automated trading or analytics pipelines
Fit
Best for
- —Developers wanting zero-commitment pay-per-call portfolio data
- —AI agents that can settle x402 payments autonomously
- —Users who prefer crypto-native API access without accounts
Not for
- —Users needing detailed API documentation or OpenAPI specs before integrating
- —High-volume consumers who need bulk pricing or rate-limited tiers
- —Developers who cannot transact in USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/20 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <valid_x402_payment_proof>"Endpoint
Quality
The endpoint is live (402 challenge confirmed) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no request/response schema, and no examples available. The docs pages are empty beyond a wallet-connect prompt, making integration details entirely opaque.
Warnings
- —No request or response schema documented — input/output format unknown
- —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no technical content
- —The specific purpose of /portfolios/20 is unclear — 'Premium API Access' is generic
Citations
- —Endpoint returns 402 with x402 challenge accepting USDC on Base network at maxAmountRequired 20000 (≈$0.02)https://lowpaymentfee.com/api/v1/portfolios/20
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant access on Base networkhttps://lowpaymentfee.com
- —USDC asset contract on Base: 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913https://lowpaymentfee.com/api/v1/portfolios/20