x402basequality 0.30

Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required.

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/transactions/139

What it does

lowpaymentfee.com is an x402-enabled API marketplace that offers a broad set of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. Every endpoint costs $0.02 per request, paid in USDC on the Base network via the x402 protocol. There are no API keys, no rate limits, and no subscriptions — callers simply attach an x402 payment header to each request.

The specific endpoint at `/api/v1/transactions/139` is listed as "Premium API Access" and accepts POST requests. Its x402 challenge advertises a maxAmountRequired of 20,000 base units of USDC (0x8335…2913 on Base), which equals $0.02 given USDC's 6 decimals. Payment is sent to address 0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3 with a 300-second timeout.

The site advertises additional endpoint categories including sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, token quotes, gas estimates, geocoding, validation, conversion, and generation — all at the same $0.02 price point. However, documentation is extremely sparse: the docs, API, pricing, and README pages all render only a "Connect wallet" prompt with no further technical detail. There is no OpenAPI spec, no request/response schema documentation, and no example payloads available. The actual functionality behind this specific `/transactions/139` endpoint is unclear from the available material.

Capabilities

x402-paymentpay-per-requestusdc-baseno-api-keypost-endpointjson-response

Use cases

  • —Accessing pay-per-call API services without managing API keys or subscriptions
  • —Making micropayment-gated API calls settled in USDC on Base
  • —Integrating x402-compatible endpoints into agent workflows

Fit

Best for

  • —Developers wanting zero-commitment, pay-as-you-go API access
  • —AI agents that can settle x402 payments autonomously
  • —Users who prefer crypto-native micropayments over subscription billing

Not for

  • —Users needing detailed API documentation or OpenAPI specs before integrating
  • —Applications requiring guaranteed SLAs or enterprise support
  • —Users without access to USDC on the Base network

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/transactions/139 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-header>"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/transactions/139
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.30/ 1.00

The endpoint is live and returns a valid x402 402 challenge, confirming it accepts payments. However, there is no documentation, no OpenAPI spec, no request/response examples, and the actual functionality of this specific endpoint (/api/v1/transactions/139) is entirely unclear. The docs, pricing, and README pages are all empty beyond a wallet-connect prompt.

Warnings

  • —No OpenAPI spec or schema documentation available
  • —The actual functionality behind /api/v1/transactions/139 is undocumented — 'Premium API Access' is the only description
  • —All documentation pages (docs, API, pricing, README) render only 'Connect wallet' with no technical content
  • —No request body schema or response schema is documented anywhere
  • —The broad claims of AI, analytics, finance, and utility endpoints cannot be verified from available material

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-19 12:08:53Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-22

Agent access

JSONhttps://clawmart.sh/api/listings/sgpYfs
Pay-per-call API platform on Base via x402 — $0.02/request, no API keys required. — Clawmart · Clawmart