x402basequality 0.35

x402-gated premium API endpoint on Base, pay-per-request with USDC.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/portfolios/19

What it does

This endpoint at `/api/v1/portfolios/19` is part of the lowpaymentfee.com platform, which offers a collection of x402-protocol pay-per-call APIs spanning data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. The specific `/portfolios/19` resource is listed under "Premium API Access" but its exact functionality is not documented beyond that label. It accepts POST requests and returns JSON.

Payment is settled on the Base network using USDC (contract `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`). The maximum amount required per call is 20,000 base units of USDC, which at 6 decimals equals $0.02 per request. The platform advertises no API keys, no rate limits, and instant access — callers simply attach an x402 payment header to each request. The x402 challenge was successfully captured (HTTP 402), confirming the endpoint is live.

Note that while the platform homepage lists many endpoint categories (analytics, AI, finance, infrastructure), the specific behavior and response schema of `/api/v1/portfolios/19` is undocumented. The docs, pricing, and API pages all returned only a "Connect wallet" prompt with no additional technical content. Without request/response examples or a schema definition, callers will need to experiment to determine the expected input and output format.

Capabilities

x402-paymentusdc-settlementbase-networkpay-per-requestjson-apipost-method

Use cases

  • —Accessing portfolio data behind a per-request USDC paywall
  • —Agent-driven API consumption without API keys or subscriptions
  • —Programmatic pay-as-you-go data retrieval on Base

Fit

Best for

  • —Agents or bots that need keyless, on-demand API access
  • —Developers experimenting with x402 payment protocol
  • —Low-volume consumers who prefer per-call pricing over subscriptions

Not for

  • —Users who need detailed documentation or guaranteed SLAs before integrating
  • —High-volume batch processing where per-request fees add up quickly

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/portfolios/19 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-token>"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/portfolios/19
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.35/ 1.00

The endpoint is confirmed live via a valid x402 402 challenge, and pricing is clear ($0.02/request in USDC on Base). However, there is no documentation for this specific endpoint — no request schema, no response schema, no examples, and the docs/pricing/API pages are all empty beyond a wallet connect prompt. The purpose of '/portfolios/19' is unknown beyond the generic 'Premium API Access' label.

Warnings

  • —No documentation available for /api/v1/portfolios/19 — purpose and expected input/output are unknown
  • —All doc pages (docs, pricing, API, README) returned only 'Connect wallet' with no technical content
  • —The endpoint path suggests a specific resource (portfolio ID 19) but no context is provided on what portfolios represent
  • —No OpenAPI spec or output schema beyond basic HTTP method info

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 08:22:52Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-28

Agent access

JSONhttps://clawmart.sh/api/listings/cx3BbR
x402-gated premium API endpoint on Base, pay-per-request with USDC. — Clawmart · Clawmart