x402-gated portfolio data endpoint on Base, pay-per-request with USDC.
What it does
This endpoint at lowpaymentfee.com provides access to a "portfolios" resource (specifically portfolio ID 2) via the x402 payment protocol. The endpoint is live and returns a 402 challenge requiring payment in USDC on the Base network. The price per request is $0.02 (20,000 base units of USDC with 6 decimals). The endpoint accepts POST requests and returns application/json responses.
The broader lowpaymentfee.com platform advertises a wide range of pay-per-call APIs spanning data & analytics, AI & machine learning (sentiment analysis, summarization, classification, embeddings), finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and infrastructure utilities (geocoding, validation, conversion, generation) — all at $0.02 per request. However, this specific listing is for the `/api/v1/portfolios/2` endpoint only, and no documentation exists describing what data it returns or what input it expects beyond a POST body.
Payment is settled on-chain via USDC (contract 0x8335…2913) on Base to address 0x1A2B…85F3. No API keys or rate limits are advertised. The platform's docs, pricing, and API pages all render only a "Connect wallet" prompt with no further content, so the actual request/response schema for this endpoint is unknown.
Capabilities
Use cases
- —Fetching portfolio data on-demand with per-request USDC micropayments
- —Integrating pay-per-call financial data into agent workflows without API keys
- —Accessing premium data endpoints without subscriptions or rate limits
Fit
Best for
- —Agents or developers who want keyless, pay-per-request API access
- —Users already holding USDC on Base who need low-friction data calls
- —Prototyping integrations where subscription commitments are undesirable
Not for
- —Users needing detailed API documentation or guaranteed SLAs
- —High-volume consumers who would benefit from bulk pricing or subscriptions
- —Anyone without USDC on the Base network
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/2 \
-H "Content-Type: application/json" \
-H "X-PAYMENT: <x402-payment-header>"Endpoint
Quality
The endpoint is live and returns a valid x402 challenge, but there is zero documentation on what the portfolios/2 resource actually returns, what POST body it expects, or what 'portfolio 2' represents. Docs pages are empty (only 'Connect wallet'). No OpenAPI spec, no examples, no schema beyond the x402 challenge metadata.
Warnings
- —No documentation available — all doc/pricing/API pages render only 'Connect wallet' with no content
- —Request and response schemas for /api/v1/portfolios/2 are completely unknown
- —The nature of 'portfolio 2' data is undocumented; unclear what this endpoint actually provides
- —The broader platform lists many endpoints but none have published schemas or examples
Citations
- —Endpoint returns 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/2
- —Price is $0.02 per request (maxAmountRequired 20000 base units USDC, 6 decimals)https://lowpaymentfee.com/api/v1/portfolios/2
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Basehttps://lowpaymentfee.com/api/v1/portfolios/2
- —Docs, pricing, and API pages show only 'Connect wallet' with no further contenthttps://lowpaymentfee.com/docs