feat: Add option to disable backup file creation in agents and CLI

.claude/settings.local.json

@@ -0,0 +1,11 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(gh pr view:*)",
+      "Bash(npm run lint)",
+      "Bash(npm install)",
+      "Bash(git add:*)"
+    ],
+    "deny": []
+  }
+}

README.md

@@ -151,7 +151,7 @@ The `apply` command looks for `.ruler/` in the current directory tree, reading t
 | Option                         | Description                                                                                                                                                |
 | ------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `--project-root <path>`        | Path to your project's root (default: current directory)                                                                                                   |
-| `--agents <agent1,agent2,...>` | Comma-separated list of agent names to target (amp, copilot, claude, codex, cursor, windsurf, cline, aider, firebase, gemini-cli, junie, augmentcode, kilocode) |
+| `--agents <agent1,agent2,...>` | Comma-separated list of agent names to target (amp, copilot, claude, codex, cursor, windsurf, cline, aider, firebase, gemini-cli, junie, augmentcode, kilocode, opencode, crush, goose) |
 | `--config <path>`              | Path to a custom `ruler.toml` configuration file                                                                                                           |
 | `--mcp` / `--with-mcp`         | Enable applying MCP server configurations (default: true)                                                                                                  |
 | `--no-mcp`                     | Disable applying MCP server configurations                                                                                                                 |
@@ -160,6 +160,7 @@ The `apply` command looks for `.ruler/` in the current directory tree, reading t
 | `--no-gitignore`               | Disable automatic .gitignore updates                                                                                                                       |
 | `--local-only`                 | Do not look for configuration in `$XDG_CONFIG_HOME`                                                                                                        |
 | `--verbose` / `-v`             | Display detailed output during execution                                                                                                                   |
+| `--disable-backup`             | Disable creation of `.bak` backup files when applying rules (default: false)                                                                              |
 
 ### Common Examples
 
@@ -199,6 +200,12 @@ ruler apply --verbose
 ruler apply --no-mcp --no-gitignore
 ```
 
+**Apply rules without creating backup files:**
+
+```bash
+ruler apply --disable-backup
+```
+
 ## Usage: The `revert` Command
 
 The `revert` command safely undoes all changes made by `ruler apply`, restoring your project to its pre-ruler state. It intelligently restores files from backups (`.bak` files) when available, or removes generated files that didn't exist before.

src/agents/AiderAgent.ts

@@ -25,7 +25,9 @@ export class AiderAgent implements IAgent {
     const mdPath =
       agentConfig?.outputPathInstructions ??
       this.getDefaultOutputPath(projectRoot).instructions;
-    await backupFile(mdPath);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(mdPath);
+    }
     await writeGeneratedFile(mdPath, concatenatedRules);
 
     const cfgPath =
@@ -38,7 +40,9 @@ export class AiderAgent implements IAgent {
     let doc: AiderConfig = {} as AiderConfig;
     try {
       await fs.access(cfgPath);
-      await backupFile(cfgPath);
+      if (!agentConfig?.disableBackup) {
+        await backupFile(cfgPath);
+      }
       const raw = await fs.readFile(cfgPath, 'utf8');
       doc = (yaml.load(raw) || {}) as AiderConfig;
     } catch {

src/agents/AugmentCodeAgent.ts

@@ -30,12 +30,16 @@ export class AugmentCodeAgent implements IAgent {
   ): Promise<void> {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
 
     if (rulerMcpJson) {
       const settingsPath = getVSCodeSettingsPath(projectRoot);
-      await backupFile(settingsPath);
+      if (!agentConfig?.disableBackup) {
+        await backupFile(settingsPath);
+      }
 
       const existingSettings = await readVSCodeSettings(settingsPath);
       const augmentServers = transformRulerToAugmentMcp(rulerMcpJson);

src/agents/ClaudeAgent.ts

@@ -22,7 +22,9 @@ export class ClaudeAgent implements IAgent {
   ): Promise<void> {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
   }
   getDefaultOutputPath(projectRoot: string): string {

src/agents/ClineAgent.ts

@@ -22,7 +22,9 @@ export class ClineAgent implements IAgent {
   ): Promise<void> {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
   }
   getDefaultOutputPath(projectRoot: string): string {

src/agents/CodexCliAgent.ts

@@ -34,7 +34,9 @@ export class CodexCliAgent implements IAgent {
       defaults.instructions;
 
     // Write the instructions file
-    await backupFile(instructionsPath);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(instructionsPath);
+    }
     await writeGeneratedFile(instructionsPath, concatenatedRules);
 
     // Handle MCP configuration if enabled

src/agents/CopilotAgent.ts

@@ -27,7 +27,9 @@ export class CopilotAgent implements IAgent {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
     await ensureDirExists(path.dirname(output));
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
   }
   getDefaultOutputPath(projectRoot: string): string {

src/agents/CursorAgent.ts

@@ -33,7 +33,9 @@ export class CursorAgent implements IAgent {
     const content = `${frontMatter}${concatenatedRules.trimStart()}`;
 
     await ensureDirExists(path.dirname(output));
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, content);
   }
   getDefaultOutputPath(projectRoot: string): string {

src/agents/FirebaseAgent.ts

@@ -22,7 +22,9 @@ export class FirebaseAgent implements IAgent {
   ): Promise<void> {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
   }
 

src/agents/IAgent.ts

@@ -16,6 +16,8 @@ export interface IAgentConfig {
   outputPathConfig?: string;
   /** MCP propagation config for this agent. */
   mcp?: McpConfig;
+  /** Disable backup file creation for this agent */
+  disableBackup?: boolean;
 }
 
 export interface IAgent {

src/agents/JunieAgent.ts

@@ -27,7 +27,9 @@ export class JunieAgent implements IAgent {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
     await ensureDirExists(path.dirname(output));
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
   }
   getDefaultOutputPath(projectRoot: string): string {

src/agents/KiloCodeAgent.ts

@@ -28,7 +28,9 @@ export class KiloCodeAgent implements IAgent {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
     await ensureDirExists(path.dirname(output));
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
   }
 

src/agents/OpenHandsAgent.ts

@@ -22,7 +22,9 @@ export class OpenHandsAgent implements IAgent {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
     await ensureDirExists(path.dirname(output));
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
   }
   getDefaultOutputPath(projectRoot: string): string {

src/agents/WindsurfAgent.ts

@@ -27,7 +27,9 @@ export class WindsurfAgent implements IAgent {
     const output =
       agentConfig?.outputPath ?? this.getDefaultOutputPath(projectRoot);
     await ensureDirExists(path.dirname(output));
-    await backupFile(output);
+    if (!agentConfig?.disableBackup) {
+      await backupFile(output);
+    }
     await writeGeneratedFile(output, concatenatedRules);
   }
   getDefaultOutputPath(projectRoot: string): string {

src/cli/commands.ts

@@ -65,6 +65,12 @@ export function run(): void {
             'Only search for local .ruler directories, ignore global config',
           default: false,
         });
+        y.option('disable-backup', {
+          type: 'boolean',
+          description:
+            'Disable creation of backup files before applying changes',
+          default: false,
+        });
       },
       async (argv) => {
         const projectRoot = argv['project-root'] as string;
@@ -79,6 +85,7 @@ export function run(): void {
         const verbose = argv.verbose as boolean;
         const dryRun = argv['dry-run'] as boolean;
         const localOnly = argv['local-only'] as boolean;
+        const disableBackup = argv['disable-backup'] as boolean;
 
         // Determine gitignore preference: CLI > TOML > Default (enabled)
         // yargs handles --no-gitignore by setting gitignore to false
@@ -99,6 +106,7 @@ export function run(): void {
             verbose,
             dryRun,
             localOnly,
+            disableBackup,
           );
           console.log('Ruler apply completed successfully.');
         } catch (err: unknown) {

src/lib.ts

@@ -116,6 +116,7 @@ export async function applyAllAgentConfigs(
   verbose = false,
   dryRun = false,
   localOnly = false,
+  disableBackup = false,
 ): Promise<void> {
   // Load configuration (default_agents, per-agent overrides, CLI filters)
   logVerbose(
@@ -312,7 +313,8 @@ export async function applyAllAgentConfigs(
         }
         agentsMdWritten = true;
       }
-      let finalAgentConfig = agentConfig;
+      // Propagate disableBackup to agent config
+      let finalAgentConfig = { ...agentConfig, disableBackup };
       if (agent.getIdentifier() === 'augmentcode' && rulerMcpJson) {
         const resolvedStrategy =
           cliMcpStrategy ??
@@ -321,7 +323,7 @@ export async function applyAllAgentConfigs(
           'merge';
 
         finalAgentConfig = {
-          ...agentConfig,
+          ...finalAgentConfig,
           mcp: {
             ...agentConfig?.mcp,
             strategy: resolvedStrategy,