Auto-Guard

Auto-Guard checks every tool call your coding agent makes before it runs. It sends the proposed call and your request to Jev, TypeSafe's decision model, and gets back one of three verdicts:

Verdict	What happens
🟢 allow	The call runs normally.
🟡 escalate	You're asked to approve it, with a one-line reason written by an LLM.
🔴 block	The call doesn't run. The agent is told why and tries something else.

A check takes about 0.4s and costs about $0.000025.

Quick start

Install it (Python 3.9+, no other dependencies):

pip install agent-autoguard

Add an API key. An OpenRouter key is the easiest option:

mkdir -p ~/.autoguard && echo 'OPENROUTER_API_KEY=sk-or-...' >> ~/.autoguard/env

Turn it on in your project for your agent:

autoguard install                   # Claude Code
autoguard install --agent cursor    # or codex, gemini, copilot, windsurf

Add --user to turn it on for every project. To confirm your key works:

autoguard check
# BLOCK      402ms  $0.000025  rm -rf /tmp/build && rm -rf ~/.aws
# ALLOW      402ms  $0.000025  ls -la build/

To watch decisions as they happen, run autoguard console and open http://127.0.0.1:8787.

Supported agents

Agent	Install	What gets checked	When Jev is unsure
Claude Code	autoguard install	Bash, file edits and writes, WebFetch	asks you
Cursor	--agent cursor	shell commands, MCP tools, file writes	asks you (shell and MCP), blocks (file writes)
GitHub Copilot CLI	--agent copilot	every tool call	asks you
OpenAI Codex CLI	--agent codex	shell commands, patches, MCP tools	blocks
Gemini CLI	--agent gemini	shell commands, file writes, MCP tools	blocks
Windsurf	--agent windsurf	shell commands, file writes, MCP tools	blocks

Codex, Gemini CLI and Windsurf hooks can only allow or block, so an unsure call gets blocked with the reason shown. To let those calls through instead, set "escalate_without_ask": "allow" in your policy file.

Codex only runs a new hook after you approve it, so open Codex and run /hooks once after installing.

Claude Code has been tested end to end in real sessions. The other five adapters are built from each agent's hook documentation and tested against the documented inputs and outputs, but haven't been run inside those agents yet. If one misbehaves, please open an issue.

Auto-Guard never approves anything on its own in Claude Code, Codex, Copilot or Windsurf. When it allows a call, the agent's normal permission rules still apply. Cursor needs every hook to answer, so there an allowed call gets an explicit allow.

Use it in your own agent

from autoguard import guard

decision = guard("bash", "rm -rf ./build && rm -rf ~/.aws", task="clean up the build directory")

decision.action      # "block"
decision.reasons     # ["risk 3.8/4 is critical", "destructive (0.95) and outside the task (in-scope 0.18)"]
decision.rationale   # LLM-written reason (escalations only)
decision.latency_ms  # 419.1
decision.cost        # 0.0000252

Call guard(tool, args, task="", plan="") after your agent picks a tool and before the tool runs. args can be a string or a dict.

How it decides

Each check is one Jev request that asks five questions at once:

Question	Answer type	Asks
destructive	probability	Does it irreversibly delete, overwrite or leak data?
in_scope	probability	Is it what the user asked for?
sensitive	probability	Does it touch credentials, secrets, production or payments?
action_class	choice	read, local-write, network, destructive or privileged
risk	0–4 scale	none, low, medium, high or critical

A call is blocked when its risk is critical, or when it's destructive, out of scope and high-risk. It's escalated when the risk is high, it touches sensitive systems, the action is privileged, or Jev isn't confident. Everything else is allowed. If Jev can't be reached, the call is escalated, and you can change that.

Configuration

Auto-Guard reads API keys from environment variables first, then from .env.local or .env in the current folder or any parent, then from ~/.autoguard/env.

Variable	Get one	Used for
OPENROUTER_API_KEY	openrouter.ai/keys	Jev checks and the written escalation reasons
TYPESAFE_API_KEY	console.typesafe.ai (early access)	Jev checks, direct from TypeSafe

If both are set, OpenRouter is used. With only a TypeSafe key, escalations work but come without a written reason.

To change a threshold, put a JSON file at .autoguard.json (one project) or ~/.autoguard/policy.json (all projects):

{
  "block_risk": 3.5,
  "escalate_risk": 2.5,
  "escalate_sensitive": 0.7,
  "on_error": "escalate",
  "escalate_without_ask": "block",
  "escalation_model": "anthropic/claude-haiku-4.5",
  "spend_cap_usd": 2.5
}

Every setting and its default is in autoguard/policy.py.

Every decision is appended to ~/.autoguard/decisions.jsonl, or to the path in AUTOGUARD_LOG. Once the logged spend reaches spend_cap_usd, escalations stop calling the LLM.

Commands

Command	Does
autoguard install [--agent NAME] [--user]	Adds the hook to your agent's config. Existing settings are kept, and running it twice is safe.
autoguard check	Runs two sample calls to check your key
autoguard console	Opens the live decision dashboard
autoguard demo [block|escalate|all]	Runs the demo calls through the real guard
autoguard eval	Scores the policy on the labeled test calls (run it from a clone of this repo)

Results

On a held-out set of 20 calls that was never used for tuning (evals/holdout.jsonl):

	Safe allowed	Dangerous caught	Ambiguous escalated	Median latency	Cost per check
Auto-Guard (Jev)	8/8	8/8	4/4	428ms	$0.000025
Claude Haiku 4.5 as the guard	8/8	8/8	3/4	823ms	$0.00012
Claude Sonnet 5 as the guard	7/8	5/8	1/4	1,992ms	$0.00032

On the 61-call set the thresholds were tuned on, it allowed 26/26 safe calls and caught 25/25 dangerous ones.

Latency was measured from a laptop through OpenRouter with a new connection per call, which is how the hooks run. Calling guard() repeatedly in one process reuses the connection and brings the median down to about 310–360ms.

Limits

Auto-Guard is a filter and will sometimes miss things, so keep backups, scoped credentials and sandboxing.

Jev's "in scope" answer is its weakest signal and sometimes misjudges requests with several parts. Scope only counts toward a block when the risk is also high.

It can block something you asked for. "Delete my old AWS config" gets blocked because deleting credentials is high-risk, so run commands like that yourself.

Each check adds about 0.3–0.6s. Next to an agent's own model calls that's hard to notice.

Development

python3 -m unittest discover tests      # offline tests, no API calls
python3 -m autoguard eval               # re-score with cached Jev answers (free)
cd demo && npm install && npm run video # rebuild the demo videos from recorded Jev responses

autoguard/   guard(), policy, Jev client, agent hooks, CLI, live console
evals/       labeled test calls and cached Jev answers
tests/       unit tests
demo/        demo scenes and the video pipeline (Playwright and Remotion)

License

MIT. See LICENSE.