github_copilot_vscode.md

GitHub Copilot (Coding Agent)

Copilot's coding agent supports preToolUse hooks, configured in .github/hooks/hooks.json on your default branch. youtube

{
  "version": 1,
  "hooks": {
    "preToolUse": [
      {
        "type": "command",
        "bash": ".github/hooks/omni-intercept.sh",
        "timeoutSec": 10
      }
    ]
  }
}

Create .github/hooks/omni-intercept.sh:

#!/usr/bin/env bash
set -euo pipefail

INPUT=$(cat)
TOOL_NAME=$(echo "$INPUT" | jq -r '.toolName // ""')
COMMAND=$(echo "$INPUT" | jq -r '.toolArgs' | jq -r '.command // ""')

# Only inspect shell/bash tool calls
if [ "$TOOL_NAME" != "bash" ] && [ "$TOOL_NAME" != "shell" ]; then
  exit 0
fi

# Intercept git commit → omni commit
if echo "$COMMAND" | grep -qE '^git\s+commit'; then
  echo "Use 'omni commit --yes --json' instead of git commit." >&2
  exit 2
fi

# Intercept gh pr create → omni pr
if echo "$COMMAND" | grep -qE '(gh\s+pr\s+create|git\s+push)'; then
  echo "Use 'omni pr --yes --json' instead of gh pr create / git push." >&2
  exit 2
fi

# Allow everything else
exit 0

Then make it executable:

chmod +x .github/hooks/omni-intercept.sh

How it works:

• The preToolUse hook fires before the agent executes any tool. youtube
• The stdin JSON contains toolName (e.g. "bash") and toolArgs as a JSON string that needs a second parse to extract .command. youtube
• Exit code 0 allows the command; exit code 2 blocks it and feeds stderr back to the agent as feedback. youtube
• Note: Copilot's coding agent already cannot run git push directly — it's restricted to pushing only to copilot/ branches through an internal mechanism. The main command to intercept is git commit. developers.openai

(Optional) Add custom instructions for reinforcement:

Create .github/copilot-instructions.md:

## Git Policy
- Never run `git commit` or `gh pr create` directly.
- Use `omni commit --yes --json` for commits.
- Use `omni pr --yes --json` for pull requests.

This gives you the same two-layer setup as Claude Code: custom instructions guide the agent, the preToolUse hook enforces it. developers.openai