feat: add transparent hook support for Mistral Vibe (BeforeTool)

[ousamabenyounes]

Context

rtk init --agent vibe is already implemented and installs:

• ~/.vibe/prompts/rtk.md — system prompt instructing Vibe to use rtk commands
• Patches ~/.vibe/config.toml — sets system_prompt_id = "rtk" and adds rtk to bash allowlist

Problem

Vibe currently has no hook mechanism to intercept bash commands before execution (unlike Claude Code's PreToolUse and Gemini's BeforeTool). This means RTK integration relies on the model following the system prompt — which is less reliable than a real hook.

We opened a feature request on the Vibe repo to add this: mistralai/mistral-vibe#531

Current State (prompt-only approach)

What	Status
rtk init --agent vibe	✅ Implemented
System prompt (~/.vibe/prompts/rtk.md)	✅ Installed
Config patch (system_prompt_id, allowlist)	✅ Patched
Transparent hook (BeforeTool)	❌ Blocked on mistralai/mistral-vibe#531

Plan

Once mistralai/mistral-vibe#531 is implemented:

1. Add ~/.vibe/hooks/rtk-hook-vibe.sh (rewrite bash commands to rtk)
2. Update run_vibe_mode() to also install the hook and patch [hooks] section in config.toml
3. Same pattern as the existing Gemini hook (hooks/rtk-hook-gemini.sh)

References

• Gemini hook implementation: hooks/rtk-hook-gemini.sh + src/init.rs::run_gemini()
• Vibe feature request: feat: add BeforeTool hook to intercept bash commands before execution mistralai/mistral-vibe#531

[pszymkowiak]

[w] wshm · Automated triage by AI

🔍 Automated Triage

✨ Category	feature
🟢 Priority	low
🎯 Confidence	92%

Summary

Tracking issue for adding BeforeTool hook support for Mistral Vibe, currently blocked on upstream feature request (mistralai/mistral-vibe#531)

📁 Relevant files

• hooks/rtk-hook-gemini.sh
• src/init.rs

---

Triaged automatically by wshm · This is an automated analysis, not a human review.

[ousamabenyounes]

Update: Blocked on mistralai/mistral-vibe#531

After testing, the prompt-only approach (system_prompt_id = "rtk" + ~/.vibe/prompts/rtk.md) is not reliable — Vibe ignores the system prompt and still calls raw ls -la, git status, etc. instead of rtk ls, rtk git status.

Without a BeforeTool hook to intercept commands before execution, there is no way to guarantee RTK is used. The feature is therefore blocked until mistralai/mistral-vibe#531 is resolved.

The branch feat/vibe-agent-support will not be merged until Vibe implements hook support.

[ousamabenyounes]

Update: PR submitted to Mistral Vibe 🎉

A pull request implementing the BeforeToolCallback hook has been submitted upstream:

mistralai/mistral-vibe#533 — feat(hooks): add BeforeToolCallback to intercept tool calls before execution

What the PR adds

async def rtk_rewrite(tool_name: str, args: dict) -> dict | None:
    if tool_name == "bash":
        cmd = args.get("command", "")
        return {**args, "command": rewrite_to_rtk(cmd)}
    return None

agent_loop.set_before_tool_callback(rtk_rewrite)

• BeforeToolCallback type alias in types.py
• before_tool_callback field on InvokeContext
• set_before_tool_callback() public method on AgentLoop (mirrors set_approval_callback)
• 5 new tests, 0 regressions on 345 existing tests

Current status of RTK Vibe support

The rtk init --agent vibe command already works (installs prompt + patches config). Once mistralai/mistral-vibe#533 is merged, we can replace the prompt-only approach with a proper hook that guarantees command rewriting.