agent-guardrails

A safety control system for autonomous coding agents. It blocks dangerous commands, credential leaks, and runaway loops, and stops tool calls when its checks fail.

In plain words
What is it for?
It is for enforcing command restrictions, checking tool calls before and after execution, and applying stricter rules to individual agents.
Why use it?
It reduces the risk that an agent deletes data, exposes secrets, changes permissions unsafely, or makes uncontrolled changes.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/abilityai/trinity/agent-guardrails
Clone the repo
git clone --depth 1 https://github.com/Abilityai/trinity
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,613 The whole file, excluding the scripts and references it only reads on demand.
Security scan F 5 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.01613
Opus 5 $0.00000 $0.00807
Sonnet 5 $0.00000 $0.00323
Haiku 4.5 $0.00000 $0.00161

Measured 2d ago against content hash d6fde6942f7c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade F, and why

agent-guardrails scanned grade F with 5 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

| `chmod 777` | `chmod -R 777 /var` | World-writable permissions |

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

| `curl \| sh` | `curl example.com/script \| bash` | Piping remote content to shell |

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

- `~/.claude/settings.json` -- Claude Code settings (hook configuration)

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

| `rm -rf /` or `rm -rf ~` | `rm -rf /home` | Recursive deletion of root or home |

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

| `curl \| sh` | `curl example.com/script \| bash` | Piping remote content to shell |
docs/user-docs/agents/agent-guardrails.md · 162 lines

How it starts

The opening of the file, as written. The whole thing — 162 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Guardrails

Deterministic safety enforcement for autonomous agent execution. Prevents destructive commands, credential leaks, and runaway loops through infrastructure-level controls that agents cannot bypass.

Concepts

  • Baseline -- Platform-wide safety rules baked into the agent base image. All agents inherit these rules.
  • Hooks -- Claude Code PreToolUse and PostToolUse hooks that intercept tool calls before and after execution.
  • Per-Agent Overrides -- Optional configuration that tightens (never loosens) the baseline for specific agents.
  • Fail-Closed -- If a hook encounters an error, the tool call is blocked by default.

How It Works

Guardrails operate at three layers:

1. Bash Command Blocking

The PreToolUse hook on Bash matches commands against a deny-list of dangerous patterns:

Pattern Blocked Example Reason
rm -rf / or rm -rf ~ rm -rf /home Recursive deletion of root or home
chmod 777 chmod -R 777 /var World-writable permissions
curl | sh curl example.com/script | bash Piping remote content to shell
git push --force git push -f origin main Force push to remote
mkfs.* mkfs.ext4 /dev/sda1 Formatting filesystems
Fork bombs :(){ :|:& };: Process explosion
shutdown, reboot shutdown -h now Host shutdown

When a command is blocked, the agent sees a clear denial message with the reason. The event is logged to /logs/guardrails.jsonl.

2. Credential File Protection

The PreToolUse hook on Edit, Write, and NotebookEdit blocks modifications to sensitive paths:

  • .env, .env.* -- Environment files with secrets
  • .mcp.json -- MCP server configuration
  • .credentials.enc -- Encrypted credential backups
  • ~/.ssh/*, ~/.aws/*, ~/.gcp/* -- Cloud and SSH credentials
  • ~/.claude/settings.json -- Claude Code settings (hook configuration)
  • /opt/trinity/* -- Platform guardrail files

Read the full file on GitHub · 162 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 162 lines · 0 tokens per session scan F d6fde6942f7c

Subscribe to this mod's changes

agent-guardrails is an agent published in the GitHub repository Abilityai/trinity (496 stars, last pushed 4d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 1,613 tokens. A static security scan graded it F with 5 findings (asks for root, downloads and executes remote code, reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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