x402basequality 0.35

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

Price
0.02 USDC / call
Protocol
x402
Verified
no
Endpoint
https://lowpaymentfee.com/api/v1/invoices/8

What it does

lowpaymentfee.com is a pay-per-request API platform that uses the x402 protocol to gate access to a variety of endpoints across data analytics, AI/ML inference, finance/Web3, and infrastructure utilities. Each call costs $0.02 in USDC on the Base network, with no API keys, rate limits, or upfront commitments required. Payment is handled inline via the x402 payment header.

The specific endpoint at `/api/v1/invoices/8` is listed as "Premium API Access" and returns a 402 challenge requesting up to 20,000 base units of USDC (i.e., $0.02) on Base. The broader platform advertises endpoints for sentiment analysis, text summarization, classification, embeddings, price feeds, exchange rates, gas estimates, geocoding, validation, conversion, and data export — all at the same $0.02 per request price point.

Documentation is extremely sparse: the /docs, /pricing, /api, 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 usage examples available from the crawled material. The endpoint is live (returns a valid x402 402 challenge), but without documentation it is unclear what request body this particular invoices endpoint expects or what it returns.

Capabilities

x402-paymentpay-per-requestusdc-baseno-api-keydata-analyticsai-inferencesentiment-analysistext-summarizationclassificationembeddingsfinance-datageocodingutility-services

Use cases

  • —Accessing AI inference endpoints (sentiment, summarization, classification, embeddings) on a per-call basis without subscription
  • —Fetching real-time financial data such as token quotes, exchange rates, and gas estimates
  • —Running utility operations like geocoding, validation, and data conversion with instant pay-per-use billing
  • —Exporting data or generating analytics reports without needing API key provisioning

Fit

Best for

  • —Agents or developers who want instant, keyless API access paid in USDC on Base
  • —Low-volume or sporadic API consumers who don't want subscriptions
  • —Web3-native applications that can settle payments on-chain per request

Not for

  • —High-volume production workloads where $0.02/request adds up and bulk pricing is needed
  • —Users who need detailed API documentation, SDKs, or guaranteed SLAs
  • —Developers without a Base-compatible wallet or USDC holdings

Quick start

curl -X POST https://lowpaymentfee.com/api/v1/invoices/8 \
  -H "Content-Type: application/json" \
  -H "X-PAYMENT: <x402-payment-token>"

Endpoint

URLhttps://lowpaymentfee.com/api/v1/invoices/8
Transporthttp
Protocolx402
Pay to0x1A2B13E97f5F837C8F9FA1F95a1484B7C70d85F3
CurrencyUSD COIN

Quality

0.35/ 1.00

The endpoint is live and returns a valid x402 402 challenge, confirming it accepts USDC payments on Base. However, documentation is essentially nonexistent — all doc pages show only 'Connect wallet'. There is no OpenAPI spec, no request/response schema, no examples, and the purpose of the specific /invoices/8 endpoint is unclear beyond the generic 'Premium API Access' label.

Warnings

  • —No API documentation available — /docs, /pricing, /api, and /README all render only 'Connect wallet'
  • —No OpenAPI or schema specification found for any endpoint
  • —The specific purpose and expected input/output of /api/v1/invoices/8 is undocumented
  • —The broader platform lists many endpoints but none have documented request/response formats
  • —Cannot verify that the advertised AI, finance, and utility endpoints actually function as described

Citations

Provenance

Indexed fromx402_bazaar
Enriched2026-04-18 22:32:32Z · anthropic/claude-opus-4.6 · v2
First seen2026-04-18
Last seen2026-04-22

Agent access

JSONhttps://clawmart.sh/api/listings/Qn3Qce