S1Gate: System-1 Pre-Commit Gate for IBM Bob

Problem: Modern AI coding harnesses (such as IBM Bob, Claude Code, and autonomous multi-agent systems) possess immense deliberative capability (System-2 thinking) for multi-file architecture synthesis. However, deploying heavy reasoning models on every micro-commit creates two critical bottlenecks: 1. Flow-State Latency: Waiting 10 to 30 seconds per commit forces developers to bypass safeguards with `git commit --no-verify`. 2. Quota & Cost Exhaustion: Over 85% of real-world commits are routine, non-breaking edits (formatting, documentation, isolated internal refactors). Running heavy frontier models on every git action rapidly exhausts token budgets and strict quota allowances (like IBM Bob's 40 Bobcoins limit). Solution: S1Gate introduces an ultra-fast System-1 Decision Layer at the pre-commit boundary, inspired by Daniel Kahneman's dual-process cognitive model. By separating fast, deterministic triage from deep reasoning, S1Gate acts as an autonomous guardian: - Fast Pre-Filter (< 2ms): Instant Shannon entropy and regex scanning detects high-entropy secrets (AWS, GitHub, Slack tokens, private keys) in 0.05 milliseconds. - System-1 Triage (~1.2s): Evaluates unified diffs using Google Gemini 3.1 Flash Lite or offline local GPU models (via LM Studio), returning structured decisions: PASS (routine safe changes), WARN (minor API contract modifications), or BLOCK (security flaws, unprotected resources, unhandled failures). - Actor-Critic Remediation Loop: When a commit is blocked, S1Gate generates a structured Remediation Intent Protocol (RIP) task in `.bob/tasks/pending_remediation.json`. IBM Bob's Agent mode autonomously ingests the diagnosis, generates a targeted patch, and verifies it with S1Gate's critic tool (`s1gate_verify_remediation`) before committing. Target Users & Interaction: - Individual Developers & Teams: Install S1Gate as a native git pre-commit hook (`s1gate hook install`) or run manual checks via CLI (`s1gate check`). - Autonomous Agent Harnesses & Evaluators: Connect via the Model Context Protocol (MCP) using local stdio or the hosted remote SSE server (`https://mcp.cuang.dev/s1gate/sse`). - Web Evaluators: Test live diffs in real time via our browser playground at `https://mcp.cuang. dev/s1gate`. What Makes S1Gate Creative, Unique & Effective: 1. Sub-Second Performance: Persistent connection pooling, token capping, and deterministic short- circuiting deliver latency under 1.5 seconds. 2. Zero Escapes: In our rigorous benchmark against 12 realistic production vulnerabilities (SSRF, Prototype Pollution, BOLA/IDOR, TOCTOU Race Conditions, Deserialization RCE, Zip Slip, JWT Confusion), S1Gate achieved a 100% block rate (0 Type II escapes). 3. Zero Quota Waste: Routine commits pass instantly without burning a single Bobcoin or LLM reasoning token.