Gemini CLI Hook Support (PR #131 Part 3)

Cargo.toml

@@ -26,6 +26,7 @@ rusqlite = { version = "0.31", features = ["bundled"] }
 toml = "0.8"
 chrono = "0.4"
 thiserror = "1.0"
+which = "7"
 tempfile = "3"
 
 [dev-dependencies]

INSTALL.md

@@ -148,6 +148,37 @@ rtk init  # Creates ./CLAUDE.md with full RTK instructions (137 lines)
 
 **Token savings**: Instructions loaded only for this project
 
+### Gemini CLI Setup
+
+**Best for: Gemini CLI users wanting the same token optimization**
+
+```bash
+rtk init --gemini
+# → Registers "rtk hook gemini" in ~/.gemini/settings.json
+# → Prompts: "Patch settings.json? [y/N]"
+# → If yes: patches + creates backup (~/.gemini/settings.json.bak)
+
+# Automated alternatives:
+rtk init --gemini --auto-patch    # Patch without prompting
+rtk init --gemini --no-patch      # Print manual instructions instead
+
+# Verify installation
+rtk init --show  # Shows both Claude and Gemini hook status
+```
+
+**Manual setup** (if `rtk init --gemini` isn't available):
+```json
+// Add to ~/.gemini/settings.json
+{
+  "hooks": {
+    "BeforeTool": [{
+      "matcher": "run_shell_command",
+      "hooks": [{ "type": "command", "command": "rtk hook gemini" }]
+    }]
+  }
+}
+```
+
 ### Upgrading from Previous Version
 
 If you previously used `rtk init -g` with the old system (137-line injection):

README.md

@@ -6,7 +6,7 @@
 
 [Website](https://www.rtk-ai.app) | [GitHub](https://github.com/rtk-ai/rtk) | [Install](INSTALL.md)
 
-rtk filters and compresses command outputs before they reach your LLM context, saving 60-90% of tokens on common operations.
+rtk filters and compresses command outputs before they reach your LLM context, saving 60-90% of tokens on common operations. Works with **Claude Code** and **Gemini CLI**.
 
 ## ⚠️ Important: Name Collision Warning
 
@@ -684,19 +684,81 @@ chmod +x ~/.claude/hooks/rtk-suggest.sh
 
 The suggest hook detects the same commands as the rewrite hook but outputs a `systemMessage` instead of `updatedInput`, informing Claude Code that an rtk alternative exists.
 
+## Gemini CLI Integration
+
+RTK also supports [Gemini CLI](https://github.com/google-gemini/gemini-cli) via its **BeforeTool** hook protocol. The same safety engine that powers the Claude Code hook is used for Gemini, providing consistent command rewriting and blocking across both agents.
+
+### Quick Install (Automated)
+
+```bash
+rtk init --gemini
+# → Patches ~/.gemini/settings.json with BeforeTool hook
+# → Prompts: "Patch settings.json? [y/N]"
+# → Creates backup (~/.gemini/settings.json.bak) if file exists
+
+# Options:
+rtk init --gemini --auto-patch    # Patch without prompting (CI/CD)
+rtk init --gemini --no-patch      # Skip patching, print manual JSON snippet
+
+# Verify installation
+rtk init --show
+```
+
+### Manual Install
+
+Add the following to `~/.gemini/settings.json`:
+
+```json
+{
+  "hooks": {
+    "BeforeTool": [
+      {
+        "matcher": "run_shell_command",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "rtk hook gemini"
+          }
+        ]
+      }
+    ]
+  }
+}
+```
+
+### How It Works
+
+When Gemini CLI is about to execute a shell command, it sends a JSON payload to `rtk hook gemini` on stdin. RTK's safety engine evaluates the command and responds with:
+
+- **Allow + rewrite**: Rewrites the command to its `rtk run -c '...'` equivalent
+- **Block**: Returns `"deny"` with a reason explaining which native tool to use instead
+- **Passthrough**: Commands already using `rtk` pass through unchanged
+
+The `matcher` field (`run_shell_command`) identifies Gemini's shell execution tool (analogous to Claude Code's `Bash` matcher). Non-shell tool events pass through without inspection.
+
+### Uninstalling Gemini Hook
+
+```bash
+rtk init --gemini --uninstall
+# → Removes RTK hook entry from ~/.gemini/settings.json
+# → Preserves other hooks and settings
+```
+
+The global `rtk init -g --uninstall` also removes Gemini hooks alongside Claude Code hooks.
+
 ## Uninstalling RTK
 
 **Complete Removal (Global Only)**:
 ```bash
 rtk init -g --uninstall
 
 # Removes:
-#   - ~/.claude/hooks/rtk-rewrite.sh
+#   - RTK hook from ~/.claude/settings.json
+#   - RTK hook from ~/.gemini/settings.json
 #   - ~/.claude/RTK.md
 #   - @RTK.md reference from ~/.claude/CLAUDE.md
-#   - RTK hook entry from ~/.claude/settings.json
 
-# Restart Claude Code after uninstall
+# Restart Claude Code / Gemini CLI after uninstall
 ```
 
 **Restore from Backup** (if needed):

hooks/rtk-rewrite.sh

@@ -1,209 +1,4 @@
-#!/bin/bash
-# RTK auto-rewrite hook for Claude Code PreToolUse:Bash
-# Transparently rewrites raw commands to their rtk equivalents.
-# Outputs JSON with updatedInput to modify the command before execution.
-
-# Guards: skip silently if dependencies missing
-if ! command -v rtk &>/dev/null || ! command -v jq &>/dev/null; then
-  exit 0
-fi
-
-set -euo pipefail
-
-INPUT=$(cat)
-CMD=$(echo "$INPUT" | jq -r '.tool_input.command // empty')
-
-if [ -z "$CMD" ]; then
-  exit 0
-fi
-
-# Extract the first meaningful command (before pipes, &&, etc.)
-# We only rewrite if the FIRST command in a chain matches.
-FIRST_CMD="$CMD"
-
-# Skip if already using rtk
-case "$FIRST_CMD" in
-  rtk\ *|*/rtk\ *) exit 0 ;;
-esac
-
-# Skip commands with heredocs, variable assignments as the whole command, etc.
-case "$FIRST_CMD" in
-  *'<<'*) exit 0 ;;
-esac
-
-# Strip leading env var assignments for pattern matching
-# e.g., "TEST_SESSION_ID=2 npx playwright test" → match against "npx playwright test"
-# but preserve them in the rewritten command for execution.
-ENV_PREFIX=$(echo "$FIRST_CMD" | grep -oE '^([A-Za-z_][A-Za-z0-9_]*=[^ ]* +)+' || echo "")
-if [ -n "$ENV_PREFIX" ]; then
-  MATCH_CMD="${FIRST_CMD:${#ENV_PREFIX}}"
-  CMD_BODY="${CMD:${#ENV_PREFIX}}"
-else
-  MATCH_CMD="$FIRST_CMD"
-  CMD_BODY="$CMD"
-fi
-
-REWRITTEN=""
-
-# --- Git commands ---
-if echo "$MATCH_CMD" | grep -qE '^git[[:space:]]'; then
-  GIT_SUBCMD=$(echo "$MATCH_CMD" | sed -E \
-    -e 's/^git[[:space:]]+//' \
-    -e 's/(-C|-c)[[:space:]]+[^[:space:]]+[[:space:]]*//g' \
-    -e 's/--[a-z-]+=[^[:space:]]+[[:space:]]*//g' \
-    -e 's/--(no-pager|no-optional-locks|bare|literal-pathspecs)[[:space:]]*//g' \
-    -e 's/^[[:space:]]+//')
-  case "$GIT_SUBCMD" in
-    status|status\ *|diff|diff\ *|log|log\ *|add|add\ *|commit|commit\ *|push|push\ *|pull|pull\ *|branch|branch\ *|fetch|fetch\ *|stash|stash\ *|show|show\ *)
-      REWRITTEN="${ENV_PREFIX}rtk $CMD_BODY"
-      ;;
-  esac
-
-# --- GitHub CLI (added: api, release) ---
-elif echo "$MATCH_CMD" | grep -qE '^gh[[:space:]]+(pr|issue|run|api|release)([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^gh /rtk gh /')"
-
-# --- Cargo ---
-elif echo "$MATCH_CMD" | grep -qE '^cargo[[:space:]]'; then
-  CARGO_SUBCMD=$(echo "$MATCH_CMD" | sed -E 's/^cargo[[:space:]]+(\+[^[:space:]]+[[:space:]]+)?//')
-  case "$CARGO_SUBCMD" in
-    test|test\ *|build|build\ *|clippy|clippy\ *|check|check\ *|install|install\ *|fmt|fmt\ *)
-      REWRITTEN="${ENV_PREFIX}rtk $CMD_BODY"
-      ;;
-  esac
-
-# --- File operations ---
-elif echo "$MATCH_CMD" | grep -qE '^cat[[:space:]]+'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^cat /rtk read /')"
-elif echo "$MATCH_CMD" | grep -qE '^(rg|grep)[[:space:]]+'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed -E 's/^(rg|grep) /rtk grep /')"
-elif echo "$MATCH_CMD" | grep -qE '^ls([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^ls/rtk ls/')"
-elif echo "$MATCH_CMD" | grep -qE '^tree([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^tree/rtk tree/')"
-elif echo "$MATCH_CMD" | grep -qE '^find[[:space:]]+'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^find /rtk find /')"
-elif echo "$MATCH_CMD" | grep -qE '^diff[[:space:]]+'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^diff /rtk diff /')"
-elif echo "$MATCH_CMD" | grep -qE '^head[[:space:]]+'; then
-  # Transform: head -N file → rtk read file --max-lines N
-  # Also handle: head --lines=N file
-  if echo "$MATCH_CMD" | grep -qE '^head[[:space:]]+-[0-9]+[[:space:]]+'; then
-    LINES=$(echo "$MATCH_CMD" | sed -E 's/^head +-([0-9]+) +.+$/\1/')
-    FILE=$(echo "$MATCH_CMD" | sed -E 's/^head +-[0-9]+ +(.+)$/\1/')
-    REWRITTEN="${ENV_PREFIX}rtk read $FILE --max-lines $LINES"
-  elif echo "$MATCH_CMD" | grep -qE '^head[[:space:]]+--lines=[0-9]+[[:space:]]+'; then
-    LINES=$(echo "$MATCH_CMD" | sed -E 's/^head +--lines=([0-9]+) +.+$/\1/')
-    FILE=$(echo "$MATCH_CMD" | sed -E 's/^head +--lines=[0-9]+ +(.+)$/\1/')
-    REWRITTEN="${ENV_PREFIX}rtk read $FILE --max-lines $LINES"
-  fi
-
-# --- JS/TS tooling (added: npm run, npm test, vue-tsc) ---
-elif echo "$MATCH_CMD" | grep -qE '^(pnpm[[:space:]]+)?(npx[[:space:]]+)?vitest([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed -E 's/^(pnpm )?(npx )?vitest( run)?/rtk vitest run/')"
-elif echo "$MATCH_CMD" | grep -qE '^pnpm[[:space:]]+test([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^pnpm test/rtk vitest run/')"
-elif echo "$MATCH_CMD" | grep -qE '^npm[[:space:]]+test([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^npm test/rtk npm test/')"
-elif echo "$MATCH_CMD" | grep -qE '^npm[[:space:]]+run[[:space:]]+'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^npm run /rtk npm /')"
-elif echo "$MATCH_CMD" | grep -qE '^(npx[[:space:]]+)?vue-tsc([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed -E 's/^(npx )?vue-tsc/rtk tsc/')"
-elif echo "$MATCH_CMD" | grep -qE '^pnpm[[:space:]]+tsc([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^pnpm tsc/rtk tsc/')"
-elif echo "$MATCH_CMD" | grep -qE '^(npx[[:space:]]+)?tsc([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed -E 's/^(npx )?tsc/rtk tsc/')"
-elif echo "$MATCH_CMD" | grep -qE '^pnpm[[:space:]]+lint([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^pnpm lint/rtk lint/')"
-elif echo "$MATCH_CMD" | grep -qE '^(npx[[:space:]]+)?eslint([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed -E 's/^(npx )?eslint/rtk lint/')"
-elif echo "$MATCH_CMD" | grep -qE '^(npx[[:space:]]+)?prettier([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed -E 's/^(npx )?prettier/rtk prettier/')"
-elif echo "$MATCH_CMD" | grep -qE '^(npx[[:space:]]+)?playwright([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed -E 's/^(npx )?playwright/rtk playwright/')"
-elif echo "$MATCH_CMD" | grep -qE '^pnpm[[:space:]]+playwright([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^pnpm playwright/rtk playwright/')"
-elif echo "$MATCH_CMD" | grep -qE '^(npx[[:space:]]+)?prisma([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed -E 's/^(npx )?prisma/rtk prisma/')"
-
-# --- Containers (added: docker compose, docker run/build/exec, kubectl describe/apply) ---
-elif echo "$MATCH_CMD" | grep -qE '^docker[[:space:]]'; then
-  if echo "$MATCH_CMD" | grep -qE '^docker[[:space:]]+compose([[:space:]]|$)'; then
-    REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^docker /rtk docker /')"
-  else
-    DOCKER_SUBCMD=$(echo "$MATCH_CMD" | sed -E \
-      -e 's/^docker[[:space:]]+//' \
-      -e 's/(-H|--context|--config)[[:space:]]+[^[:space:]]+[[:space:]]*//g' \
-      -e 's/--[a-z-]+=[^[:space:]]+[[:space:]]*//g' \
-      -e 's/^[[:space:]]+//')
-    case "$DOCKER_SUBCMD" in
-      ps|ps\ *|images|images\ *|logs|logs\ *|run|run\ *|build|build\ *|exec|exec\ *)
-        REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^docker /rtk docker /')"
-        ;;
-    esac
-  fi
-elif echo "$MATCH_CMD" | grep -qE '^kubectl[[:space:]]'; then
-  KUBE_SUBCMD=$(echo "$MATCH_CMD" | sed -E \
-    -e 's/^kubectl[[:space:]]+//' \
-    -e 's/(--context|--kubeconfig|--namespace|-n)[[:space:]]+[^[:space:]]+[[:space:]]*//g' \
-    -e 's/--[a-z-]+=[^[:space:]]+[[:space:]]*//g' \
-    -e 's/^[[:space:]]+//')
-  case "$KUBE_SUBCMD" in
-    get|get\ *|logs|logs\ *|describe|describe\ *|apply|apply\ *)
-      REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^kubectl /rtk kubectl /')"
-      ;;
-  esac
-
-# --- Network ---
-elif echo "$MATCH_CMD" | grep -qE '^curl[[:space:]]+'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^curl /rtk curl /')"
-elif echo "$MATCH_CMD" | grep -qE '^wget[[:space:]]+'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^wget /rtk wget /')"
-
-# --- pnpm package management ---
-elif echo "$MATCH_CMD" | grep -qE '^pnpm[[:space:]]+(list|ls|outdated)([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^pnpm /rtk pnpm /')"
-
-# --- Python tooling ---
-elif echo "$MATCH_CMD" | grep -qE '^pytest([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^pytest/rtk pytest/')"
-elif echo "$MATCH_CMD" | grep -qE '^python[[:space:]]+-m[[:space:]]+pytest([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^python -m pytest/rtk pytest/')"
-elif echo "$MATCH_CMD" | grep -qE '^ruff[[:space:]]+(check|format)([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^ruff /rtk ruff /')"
-elif echo "$MATCH_CMD" | grep -qE '^pip[[:space:]]+(list|outdated|install|show)([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^pip /rtk pip /')"
-elif echo "$MATCH_CMD" | grep -qE '^uv[[:space:]]+pip[[:space:]]+(list|outdated|install|show)([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^uv pip /rtk pip /')"
-
-# --- Go tooling ---
-elif echo "$MATCH_CMD" | grep -qE '^go[[:space:]]+test([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^go test/rtk go test/')"
-elif echo "$MATCH_CMD" | grep -qE '^go[[:space:]]+build([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^go build/rtk go build/')"
-elif echo "$MATCH_CMD" | grep -qE '^go[[:space:]]+vet([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^go vet/rtk go vet/')"
-elif echo "$MATCH_CMD" | grep -qE '^golangci-lint([[:space:]]|$)'; then
-  REWRITTEN="${ENV_PREFIX}$(echo "$CMD_BODY" | sed 's/^golangci-lint/rtk golangci-lint/')"
-fi
-
-# If no rewrite needed, approve as-is
-if [ -z "$REWRITTEN" ]; then
-  exit 0
-fi
-
-# Build the updated tool_input with all original fields preserved, only command changed
-ORIGINAL_INPUT=$(echo "$INPUT" | jq -c '.tool_input')
-UPDATED_INPUT=$(echo "$ORIGINAL_INPUT" | jq --arg cmd "$REWRITTEN" '.command = $cmd')
-
-# Output the rewrite instruction
-jq -n \
-  --argjson updated "$UPDATED_INPUT" \
-  '{
-    "hookSpecificOutput": {
-      "hookEventName": "PreToolUse",
-      "permissionDecision": "allow",
-      "permissionDecisionReason": "RTK auto-rewrite",
-      "updatedInput": $updated
-    }
-  }'
+#!/bin/sh
+# Legacy shim — actual hook logic is in the rtk binary.
+# Direct usage: rtk hook claude (reads JSON from stdin)
+exec rtk hook claude