feat(init): add Cursor support (rtk init --cursor)

CHANGELOG.md

@@ -5,6 +5,16 @@ All notable changes to rtk (Rust Token Killer) will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Features
+
+* **init:** add Cursor support (`rtk init --cursor`) ([#213](https://github.com/rtk-ai/rtk/issues/213))
+  * Hook script supports both Claude Code and Cursor preToolUse (auto-detect payload)
+  * Installs hook + rules (rtk.mdc) + hooks.json for global (~/.cursor) or project (.cursor)
+  * `rtk init --cursor --show` and `rtk init --cursor -g --uninstall`
+* **init:** refactor for multi-agent: `InitTarget` enum, shared `patch_json_registry`, `ensure_agent_hook_installed` (enables adding Codex, OpenCode, etc.)
+
 ## [0.22.2](https://github.com/rtk-ai/rtk/compare/v0.22.1...v0.22.2) (2026-02-20)
 
 

CLAUDE.md

@@ -128,9 +128,10 @@ main.rs (CLI entry)
   - Priority: env var > config file > default location
 
 **4. Configuration System** (src/config.rs, src/init.rs)
-- Manages CLAUDE.md initialization (global vs local)
+- Manages CLAUDE.md initialization (global vs local) and Cursor (hooks + rules)
 - Reads ~/.config/rtk/config.toml for user preferences
-- `rtk init` command bootstraps LLM integration
+- `rtk init` bootstraps Claude Code; `rtk init --cursor` bootstraps Cursor (hooks.json + rtk.mdc)
+- **Adding a new agent (Codex, OpenCode, etc.)**: Add an `InitTarget` variant in init.rs, implement `run_<agent>_mode` (reuse `ensure_agent_hook_installed`, `patch_json_registry` with agent-specific is_present/insert), and branch in `show_config`/`uninstall`. See doc comment on `InitTarget` in src/init.rs.
 - **New**: `tracking.database_path` field for custom DB location
 
 **5. Tee Output Recovery** (src/tee.rs)

README.md

@@ -373,6 +373,8 @@ Four strategies applied per command type:
 | `rtk init -g --claude-md` | Global | ❌ | ❌ | Full (137 lines) | ~2000 | Legacy compatibility |
 | `rtk init -g --hook-only` | Global | ✅ | ❌ | Nothing | 0 | Minimal setup, hook-only |
 | `rtk init` | Local | ❌ | ❌ | Full (137 lines) | ~2000 | Single project, no hook |
+| `rtk init --cursor` | Project | Cursor hook | rtk.mdc | .cursor/hooks.json | 0 | Cursor Agent (preToolUse) |
+| `rtk init --cursor -g` | Global | Cursor hook | rtk.mdc | ~/.cursor/hooks.json | 0 | Cursor Agent, all projects |
 
 ```bash
 rtk init --show         # Show current configuration
@@ -401,6 +403,15 @@ rtk init -g --hook-only     # Hook only, no RTK.md
 rtk init -g --uninstall     # Remove all RTK artifacts
 ```
 
+**Cursor** (Agent / Cmd+K):
+```bash
+rtk init --cursor           # Project: .cursor/hooks + .cursor/rules/rtk.mdc + .cursor/hooks.json
+rtk init --cursor -g        # Global: ~/.cursor/ (same layout)
+rtk init --cursor --show    # Show Cursor RTK status (global + project)
+rtk init --cursor -g --uninstall   # Remove global Cursor RTK
+```
+Uses the same rewrite hook (preToolUse for Shell); Cursor runs it via `hooks.json` and gets rules from `rtk.mdc`. Restart Cursor after init.
+
 **What is settings.json?**
 Claude Code configuration file that registers the RTK hook. The hook transparently rewrites commands (e.g., `git status` → `rtk git status`) before execution. Without this registration, Claude won't use the hook.
 

hooks/rtk-cursor-rules.mdc

@@ -0,0 +1,39 @@
+---
+description: Use rtk (Rust Token Killer) to wrap CLI commands for token-optimized output (60-90% savings)
+globs: ["**/*"]
+alwaysApply: true
+---
+
+# RTK Command Proxy
+
+When running shell commands, prefer `rtk <cmd>` over raw commands for token-optimized output. rtk is a CLI proxy that reduces LLM token consumption by 60-90% through smart filtering.
+
+Leading env var assignments should be preserved (e.g., `FOO=bar cargo test` → `FOO=bar rtk cargo test`).
+
+## Custom Rules (rtk err — errors-only wrapper)
+
+These commands have no native rtk filter. Wrap with `rtk err` to show only stderr/errors:
+
+- `pre-commit ...` → `rtk err pre-commit ...`
+- `make ...` → `rtk err make ...`
+- `go generate ...` → `rtk err go generate ...`
+- `pnpm run <script>` → `rtk err pnpm run <script>`
+
+## Native RTK Rewrites
+
+- **Git**: `git <subcmd>` → `rtk git <subcmd>` (all subcommands)
+- **GitHub CLI**: `gh pr|issue|run|api|release ...` → `rtk gh ...`
+- **Cargo**: `cargo test|build|clippy|check|install|fmt` → `rtk cargo ...`
+- **File ops**: `cat` → `rtk read`, `rg|grep` → `rtk grep`, `ls` → `rtk ls`, `tree` → `rtk tree`, `find|diff` → `rtk find|diff`
+- **JS/TS**: `vitest|tsc|eslint|prettier|playwright|prisma|pnpm list|outdated` → `rtk vitest|tsc|lint|prettier|playwright|prisma|pnpm ...`
+- **Python**: `pytest|ruff check|format|pip|uv pip` → `rtk pytest|ruff|pip ...`
+- **Go**: `go test|build|vet` → `rtk go ...`, `golangci-lint` → `rtk golangci-lint`
+- **Containers**: `docker compose|docker ps|images|logs|...` → `rtk docker ...`, `kubectl get|logs|...` → `rtk kubectl ...`
+- **Network**: `curl|wget` → `rtk curl|wget`
+
+## Exceptions — Do NOT wrap with rtk
+
+- Commands already prefixed with `rtk`
+- Commands with heredocs (`<<`)
+- Interactive commands (e.g., `git rebase -i`)
+- Commands that must produce exact raw output for parsing by other tools

hooks/rtk-rewrite.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
-# RTK auto-rewrite hook for Claude Code PreToolUse:Bash
+# RTK auto-rewrite hook for Claude Code PreToolUse:Bash and Cursor preToolUse (Shell).
 # Transparently rewrites raw commands to their rtk equivalents.
-# Outputs JSON with updatedInput to modify the command before execution.
+# Outputs JSON: Claude = hookSpecificOutput.updatedInput; Cursor = decision + updated_input.
 
 # Guards: skip silently if dependencies missing
 if ! command -v rtk &>/dev/null || ! command -v jq &>/dev/null; then
@@ -11,6 +11,19 @@ fi
 set -euo pipefail
 
 INPUT=$(cat)
+# Detect Cursor vs Claude Code from payload shape.
+# Cursor payloads include "hook_event_name" or "cursor_version" as top-level strings.
+# Claude Code payloads have none of these; they nest event info inside hookSpecificOutput.
+# If both agents add overlapping fields in the future, set RTK_HOOK_MODE=cursor|claude to override.
+CURSOR_MODE=
+if [ "${RTK_HOOK_MODE:-}" = "cursor" ]; then
+  CURSOR_MODE=1
+elif [ "${RTK_HOOK_MODE:-}" = "claude" ]; then
+  CURSOR_MODE=
+elif echo "$INPUT" | jq -e '.hook_event_name // .cursor_version | type == "string"' &>/dev/null; then
+  CURSOR_MODE=1
+fi
+
 CMD=$(echo "$INPUT" | jq -r '.tool_input.command // empty')
 
 if [ -z "$CMD" ]; then
@@ -196,14 +209,22 @@ fi
 ORIGINAL_INPUT=$(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": $updated
-    }
-  }'
+# Output the rewrite instruction (format depends on host)
+if [ -n "$CURSOR_MODE" ]; then
+  # Cursor preToolUse: https://cursor.com/docs/agent/hooks
+  jq -n \
+    --argjson updated "$UPDATED_INPUT" \
+    '{ "decision": "allow", "updated_input": $updated }'
+else
+  # Claude Code PreToolUse
+  jq -n \
+    --argjson updated "$UPDATED_INPUT" \
+    '{
+      "hookSpecificOutput": {
+        "hookEventName": "PreToolUse",
+        "permissionDecision": "allow",
+        "permissionDecisionReason": "RTK auto-rewrite",
+        "updatedInput": $updated
+      }
+    }'
+fi