Troubleshooting

Troubleshooting

rtk gain says “not a rtk command”

Symptom:

$ rtk gain
rtk: 'gain' is not a rtk command. See 'rtk --help'.

Cause: You installed Rust Type Kit (reachingforthejack/rtk) instead of Rust Token Killer (rtk-ai/rtk). They share the same binary name.

Fix:

cargo uninstall rtk
curl -fsSL https://raw.githubusercontent.com/rtk-ai/rtk/master/install.sh | sh
rtk gain    # should now show token savings stats

How to tell which rtk you have

If rtk gain…	You have
Shows token savings dashboard	Rust Token Killer ✅
Returns “not a rtk command”	Rust Type Kit ❌

AI assistant not using RTK

Symptom: Claude Code (or another agent) runs cargo test instead of rtk cargo test.

Checklist:

1. Verify RTK is installed:

   rtk --version
   rtk gain

2. Initialize the hook:

   rtk init --global    # Claude Code
   rtk init --global --agent cursor    # Cursor
   rtk init --global --opencode  # OpenCode

3. Restart your AI assistant.

4. Verify hook status:

   rtk init --show

5. Check settings.json has the hook registered (Claude Code):

   cat ~/.claude/settings.json | grep rtk

RTK not found after cargo install

Symptom:

$ rtk --version
zsh: command not found: rtk

Cause: ~/.cargo/bin is not in your PATH.

Fix:

For bash (~/.bashrc) or zsh (~/.zshrc):

export PATH="$HOME/.cargo/bin:$PATH"

For fish (~/.config/fish/config.fish):

set -gx PATH $HOME/.cargo/bin $PATH

Then reload:

source ~/.zshrc    # or ~/.bashrc
rtk --version

RTK on Windows

Double-clicking rtk.exe does nothing

Symptom: You double-click rtk.exe, a terminal flashes and closes instantly.

Cause: RTK is a command-line tool. With no arguments, it prints usage and exits. The console window opens and closes before you can read anything.

Fix: Open a terminal first, then run RTK from there:

• Press Win+R, type cmd, press Enter
• Or open PowerShell or Windows Terminal
• Then run: rtk --version

Hook not working (no auto-rewrite)

Symptom: On native Windows, commands are not auto-rewritten. An older rtk init -g printed “Falling back to —claude-md mode”.

Cause: Before v0.37.2, rtk init -g registered no hook on native Windows: it fell back to injecting the full RTK instructions into ~/.claude/CLAUDE.md. A setup made then still has no hook.

Fix: Upgrade to v0.37.2 or later, where rtk init -g registers the auto-rewrite hook on Windows as a native binary command (rtk hook claude). No Unix shell, bash, or jq is required. Re-run rtk init -g: it replaces the CLAUDE.md block with an @RTK.md reference and, once you confirm, adds rtk hook claude to settings.json. A legacy ~/.claude/hooks/rtk-rewrite.sh hook, if one exists, is deleted along with its .rtk-hook.sha256 and its settings.json entry.

Answer y when it asks to patch settings.json. Outside a terminal it cannot ask and defaults to N, so use --auto-patch there:

rtk init -g                # answer y at the settings.json prompt
rtk init -g --auto-patch   # or: patch settings.json without asking

The default N leaves no hook registered: any legacy rtk-rewrite.sh entry is removed and rtk hook claude is not added. The RTK hook registered (global). banner prints either way; the line that confirms the patch is settings.json: hook added (or settings.json: hook already present when an earlier run added it). Restart Claude Code, then confirm:

rtk init --show

It should report [ok] Hook: rtk hook claude (native binary command).

WSL also works and behaves like Linux if you prefer it.

Node.js tools not found

Symptom:

rtk vitest --run
Error: program not found

Cause: On Windows, Node.js tools are installed as .CMD/.BAT wrappers. Older RTK versions couldn’t find them.

Fix: Update to RTK v0.23.1+:

cargo install --git https://github.com/rtk-ai/rtk --branch master rtk
rtk --version    # should be 0.23.1+

Compilation error during installation

rustup update stable
rustup default stable
cargo clean
cargo build --release
cargo install --path . --force

Minimum required Rust version: 1.91 (edition 2024 needs Cargo 1.85 or newer).

OpenCode not using RTK

rtk init --global --opencode
# restart OpenCode
rtk init --show    # should show "OpenCode: plugin installed"

The plugin needs OpenCode 1.18.29 or newer. With an older version, rtk init installs nothing and prints the version it found, when it can read opencode --version. Upgrade OpenCode rather than looking for a rewrite setting.

If the plugin loads but nothing changes, check that rtk is on the PATH OpenCode itself sees. The plugin only resolves it from PATH, because OpenCode’s shell tool does not source .profile, .bashrc or .bash_profile and a binary found elsewhere cannot be spawned as a bare rtk. Set RTK_DISABLED=1 to confirm which way round the behaviour goes.

cargo install rtk installs the wrong package

If Rust Type Kit is published to crates.io under the name rtk, cargo install rtk may install the wrong one.

Always use the explicit URL, pinned to the release branch:

cargo install --git https://github.com/rtk-ai/rtk --branch master rtk

Does RTK break Claude’s prompt cache?

No. RTK filters command output once, at execution time. The filtered result is written into the conversation history and never changes afterwards, and prompt caching matches on a stable prefix — RTK does not rewrite anything the cache has already seen.

Smaller tool results also make caching cheaper: cache writes bill at 1.25x and cache reads at 0.1x the input rate, so fewer tokens in means less to write once and less to re-read every turn.

To see your own cache write and read volumes next to RTK’s savings:

rtk cc-economics

rtk gain reports token savings only; the cache breakdown lives in rtk cc-economics.

Run the diagnostic script

From the RTK repository root:

bash scripts/check-installation.sh

Checks:

• RTK installed and in PATH
• Correct version (Token Killer, not Type Kit)
• Available features
• Claude Code integration
• Hook status

Still stuck?

Open an issue: https://github.com/rtk-ai/rtk/issues