Github copilot cli does not seems to use rtk ai

[MathieuThauvoye]

Hi. I installed both rtk and github copilot cli but and initalized rtk with rtk init -g and rtk init -g --copilot.
But after prompting in github copilot cli i can see no gain with rtk gain --graph.
Github copilot cli seems to use build in tools like read to parse files and folders...then rtk proxy is never used.

Any ideas what i've done wrong ?

Thank you.

[mocasus]

The issue is that GitHub Copilot CLI has its own built-in tools that bypass RTK's proxy. Copilot uses internal 'read' tool implementations that don't go through the shell where RTK intercepts commands. Solution: Instead of relying on Copilot's built-in tools, force it to use shell commands by prefixing with 'rtk': rtk cat path/to/file.rs, rtk ls -la, rtk git diff. Or use RTK with Claude Code or other CLI tools that respect shell execution: rtk claude. The 'rtk gain' command shows savings only for commands that went through RTK's proxy - Copilot's internal tools bypass this entirely.

[Ruchika-dev07]

The README notes GitHub Copilot CLI has a known limitation, it uses a "PreToolUse deny-with-suggestion" method rather than a full transparent rewrite (unlike the VS Code Copilot extension, which does rewrite transparently). I believe it's worth mentioning that distinction since it explains the issue to some extend.

[Ruchika-dev07]

Following up with more detail on the deny-with-suggestion point, since that's the actual root cause here:
RTK integrates with different tools in different ways depending on what each one allows. The VS Code Copilot extension supports a transparent rewrite, meaning when Copilot calls a built-in tool like read, RTK can intercept and rewrite that call under the hood, so you get gains automatically without changing your workflow.
GitHub Copilot CLI doesn't support that. It only supports a "PreToolUse deny-with-suggestion" hook, RTK can detect when Copilot CLI is about to use its internal read/ls-style tools and suggest an RTK-equivalent command instead, but it can't silently intercept and reroute the call the way the VS Code extension can. That's why rtk init -g --copilot completes fine, but rtk gain --graph shows nothing: Copilot's internal tools are still doing the actual file reads, RTK is just standing next to them.
Practical fix: in your prompts to Copilot CLI, explicitly ask it to use shell commands (e.g., "read this file using cat" or "list files using ls") rather than letting it default to its internal tools, that will route through RTK where the deny-with-suggestion hook can catch it. Worth checking your Copilot CLI version too, since older builds may not surface RTK's suggestion at all.
Hope that clarifies the CLI vs. VS Code extension gap! If this resolves it, marking it accepted would help others hit the same issue find it faster, happy to dig into your specific Copilot CLI version/config if it's still not routing through.