"author:LembaGang" matching MCP servers:

A fail-closed cryptographic gate for the MCP tool-call boundary that intercepts tools/call requests, evaluates a policy, and either forwards or denies the call with signed receipts, providing tamper-evident evidence for AI agent actions.

Ed25519-signed market-state receipts for 28 exchanges: is the venue open right now, as a receipt any agent can verify without trusting the operator, fail-closed (unknown is reported as closed). MCP tools: get_market_status, get_market_schedule, list_exchanges, get_payment_options. Free tier 500 calls a day with an instant key; x402 pay-per-call at 0.001 USDC on Base; Builder 99 USDC a month