Policy Engine

Deterministic governance layer for OpenClaw tool execution. Enforces tool allowlists, deny patterns, path allowlists, risk tiers, dry-run mode, and escalation tracking via the before_tool_call hook. Every decision is logged for audit. Production-hardened with 88 tests and three deadlock classes fixed.

A deterministic governance layer that hooks into before_tool_call to control which tools agents can use, block dangerous commands, enforce write-path restrictions, and audit every decision.

Installation

bash

clawhub install policy-engine

Then enable in your openclaw.json:

jsonc

{
  "plugins": {
    "policy-engine": {
      "enabled": true
    }
  }
}

Quick Start

Minimal restrictive config — limit a sub-agent to read-only tools:

jsonc

{
  "plugins": {
    "policy-engine": {
      "enabled": true,
      "allowlists": {
        "readonly": ["read", "web_fetch", "web_search", "message"]
      },
      "routing": {
        "research-agent": { "toolProfile": "readonly" }
      }
    }
  }
}

Features

Tool Allowlists

Per-agent profiles controlling which tools are permitted. Assign profiles via routing rules keyed by agent ID.

Deny Patterns

Built-in patterns block fork bombs, rm -rf, mkfs, disk wipes, and system path writes. Scoped matching checks only relevant params (e.g., command for exec, path for write) — never file content. Add custom patterns per tool.

Path Allowlist Enforcement

Canonicalizes file paths via path.resolve() then checks against allowed directory prefixes. Prevents path traversal attacks (e.g., ../../etc/passwd) even via prompt injection.

jsonc

{
  "pathAllowlists": {
    "write": ["/Users/joe/.openclaw/workspace"],
    "edit": ["/Users/joe/.openclaw/workspace"]
  }
}

With this config, write to /Users/joe/.openclaw/workspace/foo.txt → allowed. write to /Users/joe/.openclaw/workspace/../../etc/hosts → blocked (resolves to /Users/joe/etc/hosts, outside prefix).

Risk Tiers

• T0 — read-only (read, web_fetch, search) — always allowed, even under escalation
• T1 — write (write, edit, message)
• T2 — exec/system (exec, browser, deploy)

Override with riskTiers map:

jsonc

{ "riskTiers": { "my_custom_tool": "T2" } }

Dry-Run Mode

Test policies without blocking. Essential tools (message, gateway, session_status) always pass through to prevent agent deadlock.

jsonc

{ "dryRun": true, "dryRunAllowT0": true }

Escalation Tracking

Counts blocked attempts per session. After maxBlockedRetries (default: 3), further non-essential calls are blocked with a remediation message.

Hot-Reload

Config changes via gateway config.patch take effect immediately — no restart needed.

Fail-Open on Error

If the engine itself throws, the tool call proceeds. Safety over availability of governance.

Break-Glass

Set OPENCLAW_POLICY_BYPASS=1 to bypass all checks. Logged as a warning for audit.

Configuration Reference

Field	Type	Default	Description
enabled	boolean	true	Global kill-switch
dryRun	boolean	false	Log-only mode (no blocking)
dryRunAllowT0	boolean	true	Allow T0 tools in dry-run
dryRunEssentialTools	string[]	[message, gateway, session_status, sessions_send, sessions_list, tts]	Tools that always pass in dry-run
maxBlockedRetries	number	3	Escalation threshold per session
riskTiers	object	{}	Tool → "T0"|"T1"|"T2" overrides
denyPatterns	object	{}	Tool → string[] of blocked argument patterns
allowlists	object	{}	Profile → string[] of allowed tool names
routing	object	{}	AgentId → { model?, toolProfile? }
pathAllowlists	object	{}	Tool → string[] of allowed directory prefixes

Common Patterns

Restrictive Sub-Agent

jsonc

{
  "allowlists": {
    "researcher": ["read", "web_fetch", "web_search", "message"],
    "coder": ["read", "write", "edit", "exec", "message"]
  },
  "routing": {
    "research-bot": { "toolProfile": "researcher" },
    "code-bot": { "toolProfile": "coder" }
  }
}

Block Dangerous Commands + Custom Patterns

jsonc

{
  "denyPatterns": {
    "exec": ["npm publish", "docker push"],
    "write": ["/secrets/", "/credentials/"]
  }
}

Dry-Run Testing

Enable dry-run to see what would be blocked before enforcing:

jsonc

{ "dryRun": true }

Check logs for [policy-engine] DRYRUN entries, then disable when satisfied.

Per-Agent Model Routing

jsonc

{
  "routing": {
    "cheap-tasks": { "model": "ollama/qwen2.5:latest" },
    "complex-tasks": { "model": "anthropic/claude-opus-4", "toolProfile": "full" }
  }
}

Slash Command

The plugin registers a /policy command:

• /policy status — show current config and session stats
• /policy reset — reset escalation counters

Architecture

See DESIGN.md for detailed design decisions, deadlock analysis, and the three deadlock classes that were discovered and fixed during development.