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MARKET MONITOR / CATALOGUE Services 116,093 MCP listed 39,929 x402 76,222 Rails Base / Solana / Polygon / Arbitrum Imported 2026-10-26 · 3 sources
Provider

spark-api-preflight.replit.app

spark-api-preflight.replit.app · 1 listed service · provider site

Spark Invocation Assurance x402 REST

Validate an intended paid API request against its declared contract before spending. Returns VALID, INVALID, or UNKNOWN with machine-readable reasons. Target URL is never called.

spark-api-preflight.replit.app Crypto & Payments checked 2026-10-26
0.001 USDC per call per call

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