NexGuard Sentinel
Testnet incident response with live Graph data and pause-only smart contract protection.
Demo
About
NexGuard Sentinel is a Base Sepolia incident-response prototype. A live The Graph Subgraph indexes withdrawals from a deliberately vulnerable, valueless DemoVault. Sentinel extracts bounded rolling features, requests a structured AI assessment, and applies deterministic pause-only policy. SQLite reservations, persisted signed transaction hashes, canonical receipts and confirmation checks make the action path auditable and prevent blind resends. Missing or invalid AI cannot authorize an action. Only the separate human owner can unpause. An Evidence API and MCP tools expose recorded incident data and payload integrity checks. A Ledger recovery CLI and schema-validated ERC-7730 descriptor support recovery preparation. Payment settlement, hardware Clear Signing demonstration, and final live AI-to-pause evidence are not yet verified. This Continuity project extends NexGuard Edge Resilience; the earlier IoT MVP and AI-assisted development are disclosed in the repository.
How it's made
Python 3.12, SQLite, httpx, FastAPI, web3/eth-account, Ollama structured output, Solidity 0.8.24 Guardian/DemoVault contracts on Base Sepolia, and a Graph Studio Subgraph built with AssemblyScript. The runtime validates canonical Graph snapshots, persists pending processing separately from ingestion, and records model inputs, prompt identity and classification results. Deterministic policy enforces a pause-only authority boundary, durable cooldown and action budget. The executor persists signed transaction identity before broadcast and reconciles canonical receipts and the final contract state. An outbox retries notification delivery. Tests exercise duplicate/concurrent delivery, restart, failed AI, confirmation timeout, reorg, state mismatch and durable notification retries. Foundry, pytest, Ruff, strict MyPy and Matchstick verify the components. Dependencies are locked and package assets are included. The pre-existing IoT resilience MVP is preserved alongside the new Sentinel module. New event work and AI assistance are documented in the SSD and disclosure records. Live Graph reads and historical contract receipts are verified; the final real-model end-to-end run, real A/B transcript and Ledger hardware demonstration remain pending.