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 "Premium API Access" resource at `/api/v1/portfolios/42` via the x402 payment protocol. It is part of a broader platform offering numerous pay-per-call API endpoints across categories including data analytics, AI/ML inference, finance/Web3 data, and infrastructure utilities — all priced at $0.02 per request settled in USDC on the Base network.
The specific `/api/v1/portfolios/42` endpoint accepts POST requests and returns JSON. Payment is handled via the x402 exact-payment scheme: callers attach an `X-PAYMENT` header with a signed USDC payment of up to 20,000 base units (i.e., $0.02, since USDC uses 6 decimals) to the payee address `0x1A2B...85F3`. No API keys are required; access is granted per-request upon valid payment. The platform advertises no rate limits and instant access.
Documentation beyond the landing page is extremely sparse — the /docs, /api, /pricing, and /README pages all render only a "Connect wallet" prompt with no substantive content. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The exact data returned by the portfolios endpoint is unknown; the name suggests financial portfolio information but this cannot be confirmed from available materials.
Capabilities
Use cases
- —Retrieving portfolio data (likely financial) on a per-request payment basis
- —Integrating pay-per-call data access into agent workflows without API key management
- —Demonstrating x402 protocol payment flows on Base network
Fit
Best for
- —Agents or developers wanting keyless, pay-per-use API access
- —x402-compatible wallets and agent frameworks on Base
- —Low-volume or sporadic data consumers who prefer per-request billing
Not for
- —Users needing detailed API documentation or schema guarantees before integrating
- —High-volume consumers who would benefit from subscription pricing
- —Anyone requiring non-crypto payment methods
Quick start
curl -X POST https://lowpaymentfee.com/api/v1/portfolios/42 \
-H "X-PAYMENT: <signed-x402-payment-header>" \
-H "Content-Type: application/json"Endpoint
Quality
The endpoint is live (402 challenge captured) and pricing is clear ($0.02 USDC on Base), but there is no documentation, no OpenAPI spec, no request/response schema, and no examples. The actual data returned by /api/v1/portfolios/42 is entirely unknown. This is effectively a stub listing.
Warnings
- —No API documentation available — /docs, /pricing, /api, and /README pages all show only 'Connect wallet' with no content
- —No OpenAPI or schema definition; request body and response format are completely unknown
- —The purpose and data returned by /api/v1/portfolios/42 is unverified — 'portfolio' is inferred from the URL path only
- —Platform appears to be a demonstration or early-stage service with many generic endpoint names
Citations
- —Endpoint returns 402 with x402 challenge requiring USDC payment on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/42
- —maxAmountRequired is 20000 base units of USDC (6 decimals) = $0.02https://lowpaymentfee.com/api/v1/portfolios/42
- —Platform advertises $0.02/request pricing with no API keys, no rate limits, and instant accesshttps://lowpaymentfee.com
- —USDC asset address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base networkhttps://lowpaymentfee.com/api/v1/portfolios/42
- —Docs, pricing, API, and README pages render only 'Connect wallet' with no substantive contenthttps://lowpaymentfee.com/docs