x402basequality 0.35

Pay-per-call API platform on Base (USDC) covering data, AI, finance, and utility endpoints at $0.02/request.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/inbox/37

What it does

lowpaymentfee.com is an x402-enabled API marketplace that exposes a broad set of endpoints across four categories: Data & Analytics (metrics, reports, data export, insights), AI & Machine Learning (sentiment analysis, text summarization, classification, embeddings), Finance & Web3 (price feeds, exchange rates, token quotes, gas estimates), and Infrastructure utilities (geocoding, validation, conversion, generation). All endpoints are priced at $0.02 per request, paid in USDC on the Base network via the x402 protocol — no API keys, no rate limits, and no upfront commitments.

The specific endpoint `/api/v1/inbox/37` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (0.02 USD, since USDC uses 6 decimals) on Base. Payment is made via the x402 exact scheme to the specified payTo address. The endpoint accepts HTTP POST and returns `application/json`.

Documentation beyond the landing page is sparse — the /api, /pricing, and /README pages all resolve to a "Connect wallet" prompt with no additional technical detail. There is no OpenAPI spec, no request/response schema documentation, and no usage examples available from the crawled material. The actual functionality behind the "Premium API Access" label for this particular inbox endpoint is unclear and may differ from the named category endpoints listed on the homepage.

Capabilities

x402-paymentusdc-basepay-per-requestdata-analyticsai-inferencesentiment-analysistext-summarizationclassificationembeddingsfinance-datacrypto-quotesgeocodingvalidationconversion

Use cases

  • —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) without API key management
  • —Fetching real-time crypto quotes, gas estimates, and exchange rates on a per-call basis
  • —Geocoding, data validation, and format conversion via simple paid HTTP calls
  • —Exporting analytics data and generating reports with no subscription commitment

Fit

Best for

  • —Agents or developers who want zero-signup, pay-per-use API access
  • —Projects needing low-cost micropayment-gated endpoints on Base
  • —Prototyping workflows that combine AI, finance, and utility calls without rate limits

Not for

  • —Production workloads requiring detailed SLAs, uptime guarantees, or documented error handling
  • —Users who need comprehensive API documentation or OpenAPI specs before integration
  • —Teams that cannot pay in USDC on the Base network

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/inbox/37 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-token>" \
  -d '{}'

Example

Request

{
  "url": "https://lowpaymentfee.com/api/v1/inbox/37",
  "body": {},
  "method": "POST",
  "headers": {
    "X-PAYMENT": "<x402-payment-token>",
    "Content-Type": "application/json"
  }
}

Endpoint

URLhttps://lowpaymentfee.com/api/v1/inbox/37
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.35/ 1.00

The endpoint is live and returns a valid x402 402 challenge with clear pricing ($0.02 USDC on Base). However, there is no OpenAPI spec, no request/response schema, no documentation beyond a landing page listing, and the specific purpose of /api/v1/inbox/37 ('Premium API Access') is undefined. The /api, /pricing, and /README pages are gated behind wallet connection and yield no useful content.

Warnings

  • —No OpenAPI or schema documentation available for any endpoint
  • —The specific functionality of /api/v1/inbox/37 ('Premium API Access') is not described anywhere — it may be a generic or placeholder endpoint
  • —All documentation pages (/api, /pricing, /README) return only a 'Connect wallet' prompt with no technical content
  • —No example request or response payloads are documented
  • —The broad range of claimed capabilities (AI, finance, geo, etc.) cannot be verified from available material

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-21 21:54:01Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-21
Last seen2026-04-22

Agent access

JSONhttps://clawmart.sh/api/listings/nWLwPK