{
  "id": "1b2212d9-aab6-4f7e-82aa-471f57b78a2b",
  "schema_version": 1,
  "posture": "skeptic",
  "phase": "understand",
  "round": 0,
  "understand_rounds": 0,
  "challenge_rounds": 0,
  "conversation": [],
  "problem_model": {
    "system_description": "Policy engine with deterministic rule evaluation using regex patterns and structured conditions. Supports Gate actions (requiring prior actions within timeframe) and Ensure actions (script-based verification). No NLP or network dependencies - regex and structured conditions only. First-match-wins evaluation with comprehensive condition functions including parameter checks, spending limits, credential verification, and recent action history. Features encrypted vault with tiered access (unencrypted ledger, session-encrypted state, compartment-encrypted credentials), Argon2id key derivation, device-specific session key caching, and preflight constraint tracking with violation escalation.",
    "stakeholders": [
      "AI agents",
      "Users of policy enforcement system",
      "CLI users managing policies",
      "System administrators"
    ],
    "failure_modes": [
      {
        "description": "ASK constraints with broad conditions fire on EVERY tool call touching related files, causing excessive permission prompts",
        "severity": "medium"
      },
      {
        "description": "CLI gaps in validate --fix / --dr functionality",
        "severity": "low"
      },
      {
        "description": "Policy HMAC verification failure falls back to safe defaults",
        "severity": "medium"
      },
      {
        "description": "Invalid JSON input to test command",
        "severity": "low"
      },
      {
        "description": "Mismatched vault passphrase confirmation",
        "severity": "low"
      },
      {
        "description": "Attempting to pause locked rules",
        "severity": "low"
      },
      {
        "description": "Invalid regex patterns in tool_pattern cause rules to be silently skipped during compilation",
        "severity": "medium"
      },
      {
        "description": "Condition evaluation errors cause rules to not match, falling through to default action",
        "severity": "medium"
      },
      {
        "description": "Large input sizes (1M+ characters) may impact evaluation performance",
        "severity": "low"
      },
      {
        "description": "Homoglyph attacks using Unicode lookalikes bypass string-based protections",
        "severity": "medium"
      },
      {
        "description": "Path traversal attempts in tool names don't cause crashes but may bypass intended restrictions",
        "severity": "low"
      },
      "Vault lockout after 5 failed passphrase attempts for 5 minutes",
      "Expired credentials return None during retrieval",
      "Session key decryption failure when device identifiers change",
      "Policy HMAC verification fails when policy modified without re-signing",
      "Database corruption could cause vault operations to fail",
      "Missing device identifiers fall back to generic string",
      "Credential capability requests fail when constraints don't match",
      "Preflight HMAC mismatch causes preflight to be ignored with warning"
    ],
    "dependencies": [
      "Rust build system (cargo)",
      "HMAC signing",
      "Vault storage",
      "Policy YAML files",
      "clap CLI parsing",
      "rpassword for secure input",
      "serde_yaml for policy files",
      "chrono for timestamps",
      "MCP protocol (optional feature)",
      "regex crate for pattern matching",
      "serde/serde_yaml for configuration serialization",
      "Vault for action history and credential storage",
      "tempfile for testing",
      "aes_gcm for AES-256-GCM encryption",
      "argon2 for memory-hard key derivation",
      "base64 encoding/decoding",
      "hkdf for key derivation",
      "hmac for authentication",
      "rusqlite for SQLite database",
      "sha2 for hashing",
      "Device-specific identifiers (/etc/machine-id, hardware UUID)",
      "SQLite database for vault storage",
      "File system permissions (Unix mode 0o600 for session keys)"
    ],
    "assumptions": [
      "Agents will submit structured plans before execution",
      "Pre-commitment mechanisms reduce goal pressure during planning",
      "Default policy path is ~/.signet/policy.yaml",
      "Home directory expansion works",
      "Vault passphrase is at least 8 characters",
      "SIGNET_SESSION environment variable for session-specific controls",
      "Tool calls have structured JSON parameters",
      "Rule evaluation budget is under 10ms for performance",
      "First matching rule wins - rule ordering matters",
      "Locked rules cannot be auto-fixed and protect core system functionality",
      "Self-protection rules are always first in evaluation order",
      "Ensure scripts are placed in ~/.signet/checks/ directory",
      "Gate actions fail closed when vault is unavailable",
      "Session TTL is 30 minutes (1800 seconds)",
      "Maximum 5 failed vault unlock attempts before 5-minute lockout",
      "Maximum 20 preflight constraints per preflight",
      "Default violation threshold of 5 before escalation",
      "AES-256-GCM provides sufficient encryption",
      "Argon2id default parameters provide adequate protection",
      "Device identifiers remain stable across reboots",
      "SQLite database integrity is maintained",
      "File system supports Unix permissions on supported platforms"
    ],
    "boundaries": [
      "Single binary implementation",
      "Deterministic policy enforcement scope",
      "Policy file must be YAML format",
      "Pause duration limited to 0-60 minutes",
      "Session-based controls require environment variable",
      "No NLP or network operations in policy evaluation",
      "Regex patterns only - no code execution in conditions",
      "Gate timeframe limited to 1-500 actions",
      "Ensure timeout clamped to 1-30 seconds",
      "Script names must be simple filenames without path separators",
      "Self-protection rules cannot be disabled or bypassed",
      "Vault tiers: Tier 1 unencrypted (ledger), Tier 2 session-encrypted (state), Tier 3 compartment-encrypted (credentials)",
      "Session key cache encrypted with device key, not plaintext",
      "Failed attempt lockout limited to 5 minutes",
      "Preflight constraints capped at 20 per submission",
      "Device key derivation uses machine ID and username only",
      "One-time credentials invalidated after first successful use"
    ],
    "history": [
      "Preflight subsystem added as extension",
      "Plan B alternatives implemented for existing rules",
      "Gate/ensure actions completed in v3.3.0",
      "88 tests currently passing"
    ],
    "success_shape": [
      "Aviation-inspired safety mechanisms",
      "Deterministic enforcement",
      "Pre-execution planning reduces risk",
      "Structured mission plans with identified risks and constraints",
      "Comprehensive CLI with clear subcommands",
      "Secure vault operations with passphrase confirmation",
      "Graceful fallback to safe defaults on policy tampering",
      "Flexible pause/resume controls at global, rule, or session level",
      "Evaluation completes under 10ms performance budget",
      "Self-protection rules prevent policy tampering",
      "Gate actions enforce proper sequencing of operations",
      "Ensure actions enable external script validation",
      "Comprehensive condition functions for flexible rule authoring",
      "Auto-fix capability for common policy errors while preserving locked rules",
      "Graceful degradation on condition evaluation errors",
      "Three-tier security model with appropriate encryption levels",
      "Device-specific session key caching for seamless hook mode operation",
      "Brute-force protection with progressive lockout",
      "Credential scoping by domain, purpose, amount, and one-time usage",
      "Preflight constraint tracking with violation counting and escalation",
      "HMAC-based integrity protection for policies and preflights",
      "Graceful fallback when device identifiers unavailable",
      "Comprehensive audit logging of all vault operations"
    ],
    "acceptance_criteria": [
      "cargo build --release works",
      "cargo test passes (88 tests)",
      "Policy YAML loading functions correctly",
      "HMAC-signed vault-stored mission plans supported",
      "Policy engine evaluates 1000+ rules under 10ms",
      "Self-protection rules cannot be bypassed by any tool call",
      "Gate actions correctly check vault action history",
      "Ensure actions return unresolved for external script execution",
      "Validation identifies and can auto-fix regex errors, timeout ranges",
      "Default policy blocks known dangerous operations (rm, force push, etc.)",
      "Locked rules are preserved during auto-fix operations",
      "Vault setup and unlock with passphrase works correctly",
      "Credential storage and retrieval across all tiers functions properly",
      "Session spending tracking and limits enforced accurately",
      "Recent action queries support pipe-delimited OR searches",
      "Policy HMAC signing and verification prevents tampering",
      "Preflight storage, violation tracking, and escalation work as designed",
      "Device key encryption/decryption of session keys successful",
      "Failed attempt lockout and recovery timing correct",
      "Credential capability requests respect all metadata constraints",
      "One-time credentials properly invalidated after use"
    ]
  },
  "prompt_md": "",
  "constraints_yaml": "",
  "trust_policy_yaml": "",
  "component_map_yaml": "",
  "schema_hints_yaml": "",
  "created_at": "2026-04-02T05:37:34.693576+00:00",
  "updated_at": "2026-04-02T05:38:57.714720+00:00"
}