Agent Security Guard

AgentSecurityGuard Skill

A runtime security layer that sits beside (not inside) the agent-memory skill. The memory skill protects long-term truth; this guard protects the dangerous moment before an action: context intake, tool call, memory write, external action, and chain drift.

It is not a brake on autonomy. Reading, browsing, GET/search, and summarizing stay free. The guard removes command-authority from untrusted content and gates only the risky transitions through a deterministic policy engine. Default mode: autonomous-safe.

Core principle

A source's trust does not grant it authority over an action.

Decisions come from hard, deterministic rules first; the risk score is for logging and prioritization only, never the sole judge.

Two independent dimensions

• OriginTrust (may this source give instructions?): trusted_user > local_project / trusted_tool_output > tool_output > external_web > external_document > unknown
• DataSensitivity (how dangerous if it leaks?): public < internal < sensitive < secret

A .env file is high-trust origin but secret-sensitivity. Tool output inherits its payload origin (a web-fetch tool produces external_web, not trusted tool knowledge).

Status

v0.2.0: adds self-modification governance on top of v0.1.0. Skill patch / self-improvement / procedural-rule changes are a dedicated SELF_MODIFICATION tier that is never a direct allow; explicit no-write scopes and ambiguous "yes" confirmations are denied before any per-tier rule; and real writes require an explicit, hash-bound two-phase confirmation (see references/self-modification.md). v0.1.0 delivered the deterministic policy core, scanner + boundary wrapper, sequence kill-chain detection, SQLite/JSONL audit, advice-only memory bridge, CLI, and the Hermes/OpenClaw plugin, hardened by a Bugbot + security-review pass. 180 tests pass, including the self-improvement end-to-end bar and the OpenClaw threat-class regressions. See README.md, ROADMAP.md, and references/ for design and threat model.