Open-source guardrail
A flag that explicitly accepts data loss
AgentTrail Guard blocks this by default: the call never runs, and your coding agent is told which guardrail stopped it.
- Default action
- Block
- Severity
- Critical severity
- Library version
- 0.2.1 · Sep 29, 2026
What it does
What it catches, and what it misses
Written into the rule itself, next to what it matches, so you can judge it before you trust it.
Matches the flags whose own names admit the consequence — --accept-data-loss (Prisma), --force-reset, and prisma db push --force. A tool that makes you type those words has already decided a human should be in the loop. Does NOT match prisma db push without a flag, which is the ordinary spelling, and it cannot tell a scratch database from a real one because no connection string reaches the guard. A quoted MENTION is not a use: a search, a git commit -m message, an echo or a curl --data body that only names this command is left alone. That holds only while every shell metacharacter stays inside the quotes, so git commit -m "x" && … is still caught; and the carrier must be the first word, so sudo grep … is not exempt.
Examples
Tested on every build
The rule must match every command on the left and none on the right, or the library does not build. Catching the real thing is easy; staying quiet on the near-miss is the hard part.
Catches (3)
- npx prisma db push --accept-data-loss
- npx prisma migrate reset --force-reset
- npx prisma db push --force
Stays quiet on (8)
- git commit -m "docs: explain npx prisma db push --accept-data-loss"
- grep -rn "npx prisma db push --accept-data-loss" docs/
- echo "never run npx prisma db push --accept-data-loss"
- curl --data "we ran npx prisma db push --accept-data-loss" https://api.example.com/comments
- npx prisma db push
- npx prisma generate
- pnpm db:push
- npx prisma studio
In your agent
What "block" means in each app
The guard runs as a hook in each app, and each app gives a hook different powers. Here is what this rule's default action does in each one.
- Claude Code
- The call never runs, and the agent is told which guardrail stopped it.
- Cursor
- The call never runs. Cursor shows no reason of its own, so the agent retells the guardrail's message in its own words.
- Codex CLI
- The command never runs, and Codex prints the guard's reason on screen.
Each app hands the guard a different set of calls: in a Cursor sandbox run mode, for one, some terminal commands run without reaching the guard at all. Read the notes for Cursor and for Codex CLI before you rely on a rule there.
Make it yours
Change what it does in one command
Turn it off, change its action, or silence it on one command shape. The narrow one is allow: the rule keeps catching everything else.
Run it locally
Put these guardrails in front of your agent.
AgentTrail Guard is free and open source. It checks every command and file change against the whole library before your agent runs it, on your machine, with no account.
npm i -g @agenttrail/guard