feat: support .claude/rules/ directory for scoped Claude Code rules

src/cli.ts

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 
-import { existsSync, readFileSync, writeFileSync, appendFileSync, rmSync } from 'fs'
+import { existsSync, readFileSync, writeFileSync, appendFileSync, rmSync, statSync } from 'fs'
 import { join, resolve, dirname } from 'path'
 import { parseArgs } from 'util'
 import { importAll, importAgent, exportToAgent, exportAll, exportToCopilot, exportToCursor, exportToCline, exportToWindsurf, exportToZed, exportToCodex, exportToAider, exportToClaudeCode, exportToGemini, exportToQodo, importRoo, exportToRoo, exportToJunie, importOpenCode, exportToOpenCode } from './index.js'
@@ -107,6 +107,7 @@ async function main() {
           '.rules',
           'AGENTS.md',
           'CLAUDE.md',
+          '.claude/rules/*.md',
           'GEMINI.md',
           'best_practices.md'
         ]))
@@ -190,7 +191,7 @@ async function main() {
         { name: 'Zed (.rules)', value: 'zed' },
         { name: 'OpenAI Codex (AGENTS.md)', value: 'codex' },
         { name: 'Aider (CONVENTIONS.md)', value: 'aider' },
-        { name: 'Claude Code (CLAUDE.md)', value: 'claude' },
+        { name: 'Claude Code (CLAUDE.md + .claude/rules/)', value: 'claude' },
         { name: 'Gemini CLI (GEMINI.md)', value: 'gemini' },
         { name: 'Qodo Merge (best_practices.md)', value: 'qodo' },
         { name: 'Roo Code (.roo/rules/)', value: 'roo' },
@@ -246,6 +247,7 @@ async function main() {
             'AGENTS.md',
             'CONVENTIONS.md',
             'CLAUDE.md',
+            '.claude/rules/',
             'GEMINI.md',
             'best_practices.md'
           )
@@ -290,9 +292,9 @@ async function main() {
               exportedPaths.push('CONVENTIONS.md')
               break
             case 'claude':
-              exportPath = join(outputDir, 'CLAUDE.md')
-              if (!isDryRun) exportToClaudeCode(rules, exportPath, options)
-              exportedPaths.push('CLAUDE.md')
+              if (!isDryRun) exportToClaudeCode(rules, outputDir, options)
+              exportPath = join(outputDir, '.claude/rules/')
+              exportedPaths.push('CLAUDE.md', '.claude/rules/')
               break
             case 'gemini':
               exportPath = join(outputDir, 'GEMINI.md')
@@ -382,7 +384,7 @@ async function main() {
         else if (inputPath.includes('.windsurfrules')) format = 'windsurf'
         else if (inputPath.endsWith('.rules')) format = 'zed'
         else if (inputPath.endsWith('AGENTS.md')) format = 'codex'
-        else if (inputPath.endsWith('CLAUDE.md')) format = 'claude'
+        else if (inputPath.endsWith('CLAUDE.md') || inputPath.includes('.claude/rules')) format = 'claude'
         else if (inputPath.endsWith('GEMINI.md')) format = 'gemini'
         else if (inputPath.endsWith('CONVENTIONS.md')) format = 'aider'
         else if (inputPath.endsWith('best_practices.md')) format = 'qodo'
@@ -398,7 +400,7 @@ async function main() {
       console.log(`Input: ${color.path(inputPath)}`)
 
       // Import using appropriate importer
-      const { importCopilot, importCursor, importCline, importWindsurf, importZed, importCodex, importAider, importClaudeCode, importGemini, importQodo } = await import('./importers.js')
+      const { importCopilot, importCursor, importCline, importWindsurf, importZed, importCodex, importAider, importClaudeCode, importClaudeCodeRules, importGemini, importQodo } = await import('./importers.js')
 
       let result
       switch (format) {
@@ -424,7 +426,9 @@ async function main() {
           result = importAider(inputPath)
           break
         case 'claude':
-          result = importClaudeCode(inputPath)
+          result = statSync(inputPath).isDirectory()
+            ? importClaudeCodeRules(inputPath)
+            : importClaudeCode(inputPath)
           break
         case 'opencode':
           result = importOpenCode(inputPath)

src/exporters.ts

@@ -385,8 +385,68 @@ export function exportToAider(rules: RuleBlock[], outputPath: string, options?:
   writeFileSync(outputPath, fullContent, 'utf-8')
 }
 
-export function exportToClaudeCode(rules: RuleBlock[], outputPath: string, options?: ExportOptions): void {
-  exportSingleFileWithHeaders(rules, outputPath, options)
+export function exportToClaudeCode(rules: RuleBlock[], outputDir: string, options?: ExportOptions): void {
+  const filteredRules = rules.filter(rule => !rule.metadata.private || options?.includePrivate)
+
+  const alwaysApplyRules = filteredRules.filter(r => r.metadata.alwaysApply !== false)
+  const scopedRules = filteredRules.filter(r => r.metadata.alwaysApply === false)
+
+  // Always-apply rules → CLAUDE.md
+  if (alwaysApplyRules.length > 0) {
+    const mainContent = alwaysApplyRules
+      .map(rule => {
+        const header = rule.metadata.description ? `# ${rule.metadata.description}\n\n` : ''
+        return header + rule.content
+      })
+      .join('\n\n')
+
+    const claudeMdPath = join(outputDir, 'CLAUDE.md')
+    ensureDirectoryExists(claudeMdPath)
+    writeFileSync(claudeMdPath, mainContent + '\n', 'utf-8')
+  }
+
+  // Scoped rules → .claude/rules/ as individual files with frontmatter
+  if (scopedRules.length > 0) {
+    const rulesDir = join(outputDir, '.claude', 'rules')
+    mkdirSync(rulesDir, { recursive: true })
+
+    for (const rule of scopedRules) {
+      let filePath: string
+
+      if (rule.metadata.id && rule.metadata.id.includes('/')) {
+        const parts = rule.metadata.id.split('/')
+        const fileName = parts.pop() + '.md'
+        const subDir = join(rulesDir, ...parts)
+        mkdirSync(subDir, { recursive: true })
+        filePath = join(subDir, fileName)
+      } else {
+        const filename = `${rule.metadata.id || 'rule'}.md`
+        filePath = join(rulesDir, filename)
+      }
+
+      // Claude Code frontmatter only supports description, globs, alwaysApply
+      const frontMatter: Record<string, unknown> = {}
+
+      if (rule.metadata.description !== undefined && rule.metadata.description !== null) {
+        frontMatter.description = rule.metadata.description
+      }
+
+      // Map scope → globs when globs is not already set
+      const globs = rule.metadata.globs ?? (
+        rule.metadata.scope
+          ? (Array.isArray(rule.metadata.scope) ? rule.metadata.scope : [rule.metadata.scope])
+          : undefined
+      )
+      if (globs !== undefined) {
+        frontMatter.globs = globs
+      }
+
+      frontMatter.alwaysApply = rule.metadata.alwaysApply ?? false
+
+      const mdContent = matter.stringify(rule.content, frontMatter, grayMatterOptions)
+      writeFileSync(filePath, mdContent, 'utf-8')
+    }
+  }
 }
 
 export function exportToOpenCode(rules: RuleBlock[], outputPath: string, options?: ExportOptions): void {
@@ -554,7 +614,7 @@ export function exportAll(rules: RuleBlock[], repoPath: string, dryRun = false,
     exportToZed(rules, join(repoPath, '.rules'), options)
     exportToCodex(rules, join(repoPath, 'AGENTS.md'), options)
     exportToAider(rules, join(repoPath, 'CONVENTIONS.md'), options)
-    exportToClaudeCode(rules, join(repoPath, 'CLAUDE.md'), options)
+    exportToClaudeCode(rules, repoPath, options)
     exportToOpenCode(rules, join(repoPath, 'AGENTS.md'), options)
     exportToGemini(rules, join(repoPath, 'GEMINI.md'), options)
     exportToQodo(rules, join(repoPath, 'best_practices.md'), options)

src/importers.ts

@@ -153,6 +153,16 @@ export async function importAll(repoPath: string): Promise<ImportResults> {
       errors.push({ file: claudeMd, error: String(e) })
     }
   }
+
+  // Check for Claude Code rules directory (.claude/rules/)
+  const claudeRulesDir = join(repoPath, '.claude', 'rules')
+  if (existsSync(claudeRulesDir)) {
+    try {
+      results.push(importClaudeCodeRules(claudeRulesDir))
+    } catch (e) {
+      errors.push({ file: claudeRulesDir, error: String(e) })
+    }
+  }
 
   // Check for AGENTS.md (OpenCode)
   const opencodeMd = join(repoPath, 'AGENTS.md')
@@ -668,6 +678,71 @@ export function importClaudeCode(filePath: string): ImportResult {
   }
 }
 
+export function importClaudeCodeRules(rulesDir: string): ImportResult {
+  const rules: RuleBlock[] = []
+
+  function findMdFiles(dir: string, relativePath = ''): void {
+    const entries = readdirSync(dir, { withFileTypes: true })
+
+    entries.sort((a: Dirent, b: Dirent) => {
+      if (a.isDirectory() && !b.isDirectory()) return -1
+      if (!a.isDirectory() && b.isDirectory()) return 1
+      return a.name.localeCompare(b.name)
+    })
+
+    for (const entry of entries) {
+      const fullPath = join(dir, entry.name)
+      const relPath = relativePath ? join(relativePath, entry.name) : entry.name
+
+      if (entry.isDirectory()) {
+        findMdFiles(fullPath, relPath)
+      } else if (entry.isFile() && entry.name.endsWith('.md')) {
+        const content = readFileSync(fullPath, 'utf-8')
+        const { data, content: body } = matter(content, grayMatterOptions)
+
+        let segments = relPath
+          .replace(/\.md$/, '')
+          .replace(/\\/g, '/')
+          .split('/')
+          .map((s: string) => s.replace(/^\d{2,}-/, '').replace(/\.local$/, ''))
+        if (segments[0] === 'private') segments = segments.slice(1)
+        const defaultId = segments.join('/')
+
+        const isPrivateFile = isPrivateRule(fullPath)
+
+        const metadata: any = {
+          id: data.id || defaultId,
+          description: data.description,
+          alwaysApply: data.alwaysApply ?? false,
+        }
+
+        // Map globs → scope for cross-format compatibility
+        if (data.globs) {
+          metadata.globs = data.globs
+          metadata.scope = data.globs
+        }
+
+        if (data.private === true || (data.private === undefined && isPrivateFile)) {
+          metadata.private = true
+        }
+
+        rules.push({
+          metadata,
+          content: body.trim()
+        })
+      }
+    }
+  }
+
+  findMdFiles(rulesDir)
+
+  return {
+    format: 'claude',
+    filePath: rulesDir,
+    rules
+  }
+}
+
 export function importOpenCode(filePath: string): ImportResult {
   const content = readFileSync(filePath, 'utf-8')
   const isPrivateFile = isPrivateRule(filePath)

src/index.ts

@@ -15,6 +15,7 @@ export {
   importCodex,
   importAider,
   importClaudeCode,
+  importClaudeCodeRules,
   importOpenCode,
   importGemini,
   importQodo,