build: modularize codebase and improve type generation (#31)

Split monolithic skills-core.ts into focused modules (skills, agents,
commands, frontmatter, bootstrap, walk-dir). Remove skill-tool hook
system. Enable TypeScript declaration generation in build process.
Update all imports and tests accordingly.

Author: marcusrbrown

package.json

@@ -21,15 +21,15 @@
   ],
   "scripts": {
     "clean": "rimraf dist",
-    "build": "bun run clean && bun build src/index.ts src/cli.ts --outdir dist --target bun --splitting --packages external",
+    "build": "bun run clean && bun build src/index.ts src/cli.ts --outdir dist --target bun --splitting --packages external && tsc --emitDeclarationOnly",
     "dev": "bun --watch src/index.ts",
     "test": "bun test tests/unit",
     "test:integration": "bun test tests/integration",
     "test:all": "bun test",
     "typecheck": "tsc --noEmit",
     "lint": "biome check .",
     "fix": "bun run lint --fix",
-    "prepublishOnly": "bun run build && bun run test"
+    "prepublishOnly": "bun run build"
   },
   "keywords": [
     "opencode",

src/cli.ts

@@ -1,12 +1,15 @@
 #!/usr/bin/env node
 import fs from 'node:fs'
 import path from 'node:path'
+import * as agents from './lib/agents.js'
+import * as commands from './lib/commands.js'
+import { getConfigPaths } from './lib/config.js'
 import {
   type AgentMode,
   type ContentType,
   convertContent,
 } from './lib/converter.js'
-import * as skillsCore from './lib/skills-core.js'
+import * as skills from './lib/skills.js'
 
 const VERSION = '0.1.0'
 
@@ -37,46 +40,32 @@ Examples:
   systematic config show
 `
 
-function getUserConfigDir(): string {
-  return path.join(
-    process.env.HOME || process.env.USERPROFILE || '.',
-    '.config/opencode',
-  )
-}
-
-function getProjectConfigDir(): string {
-  return path.join(process.cwd(), '.opencode')
-}
-
 function listItems(type: string): void {
   const packageRoot = path.resolve(import.meta.dirname, '..')
   const bundledDir = packageRoot
 
-  let finder: (
-    dir: string,
-    sourceType: 'bundled',
-  ) => Array<{ name: string; sourceType: string }>
+  let finder: (dir: string) => Array<{ name: string }>
   let subdir: string
 
   switch (type) {
     case 'skills':
-      finder = skillsCore.findSkillsInDir
+      finder = skills.findSkillsInDir
       subdir = 'skills'
       break
     case 'agents':
-      finder = skillsCore.findAgentsInDir
+      finder = agents.findAgentsInDir
       subdir = 'agents'
       break
     case 'commands':
-      finder = skillsCore.findCommandsInDir
+      finder = commands.findCommandsInDir
       subdir = 'commands'
       break
     default:
       console.error(`Unknown type: ${type}. Use: skills, agents, commands`)
       process.exit(1)
   }
 
-  const items = finder(path.join(bundledDir, subdir), 'bundled')
+  const items = finder(path.join(bundledDir, subdir))
 
   if (items.length === 0) {
     console.log(`No ${type} found.`)
@@ -85,7 +74,7 @@ function listItems(type: string): void {
 
   console.log(`Available ${type}:\n`)
   for (const item of items.sort((a, b) => a.name.localeCompare(b.name))) {
-    console.log(`  ${item.name} (${item.sourceType})`)
+    console.log(`  ${item.name}`)
   }
 }
 
@@ -124,33 +113,29 @@ function runConvert(type: string, filePath: string, modeArg?: string): void {
 }
 
 function configShow(): void {
-  const userDir = getUserConfigDir()
-  const projectDir = getProjectConfigDir()
+  const paths = getConfigPaths(process.cwd())
 
   console.log('Configuration locations:\n')
-  console.log(`  User config:    ${path.join(userDir, 'systematic.json')}`)
-  console.log(`  Project config: ${path.join(projectDir, 'systematic.json')}`)
+  console.log(`  User config:    ${paths.userConfig}`)
+  console.log(`  Project config: ${paths.projectConfig}`)
 
-  const projectConfig = path.join(projectDir, 'systematic.json')
-  if (fs.existsSync(projectConfig)) {
+  if (fs.existsSync(paths.projectConfig)) {
     console.log('\nProject configuration:')
-    console.log(fs.readFileSync(projectConfig, 'utf-8'))
+    console.log(fs.readFileSync(paths.projectConfig, 'utf-8'))
   }
 
-  const userConfig = path.join(userDir, 'systematic.json')
-  if (fs.existsSync(userConfig)) {
+  if (fs.existsSync(paths.userConfig)) {
     console.log('\nUser configuration:')
-    console.log(fs.readFileSync(userConfig, 'utf-8'))
+    console.log(fs.readFileSync(paths.userConfig, 'utf-8'))
   }
 }
 
 function configPath(): void {
-  const userDir = getUserConfigDir()
-  const projectDir = getProjectConfigDir()
+  const paths = getConfigPaths(process.cwd())
 
   console.log('Config file paths:')
-  console.log(`  User:    ${path.join(userDir, 'systematic.json')}`)
-  console.log(`  Project: ${path.join(projectDir, 'systematic.json')}`)
+  console.log(`  User:    ${paths.userConfig}`)
+  console.log(`  Project: ${paths.projectConfig}`)
 }
 
 const args = process.argv.slice(2)

src/index.ts

@@ -1,12 +1,11 @@
 import fs from 'node:fs'
-import os from 'node:os'
 import path from 'node:path'
 import { fileURLToPath } from 'node:url'
 import type { Plugin } from '@opencode-ai/plugin'
-import { loadConfig, type SystematicConfig } from './lib/config.js'
+import { getBootstrapContent } from './lib/bootstrap.js'
+import { loadConfig } from './lib/config.js'
 import { createConfigHandler } from './lib/config-handler.js'
 import { createSkillTool } from './lib/skill-tool.js'
-import * as skillsCore from './lib/skills-core.js'
 
 const __dirname = path.dirname(fileURLToPath(import.meta.url))
 
@@ -28,57 +27,6 @@ const getPackageVersion = (): string => {
   }
 }
 
-const getBootstrapContent = (config: SystematicConfig): string | null => {
-  if (!config.bootstrap.enabled) return null
-
-  if (config.bootstrap.file) {
-    const customPath = config.bootstrap.file.startsWith('~/')
-      ? path.join(os.homedir(), config.bootstrap.file.slice(2))
-      : config.bootstrap.file
-    if (fs.existsSync(customPath)) {
-      return fs.readFileSync(customPath, 'utf8')
-    }
-  }
-
-  const usingSystematicPath = path.join(
-    bundledSkillsDir,
-    'using-systematic/SKILL.md',
-  )
-  if (!fs.existsSync(usingSystematicPath)) return null
-
-  const fullContent = fs.readFileSync(usingSystematicPath, 'utf8')
-  const content = skillsCore.stripFrontmatter(fullContent)
-
-  const toolMapping = `**Tool Mapping for OpenCode:**
-When skills reference tools you don't have, substitute OpenCode equivalents:
-- \`TodoWrite\` → \`update_plan\`
-- \`Task\` tool with subagents → Use OpenCode's subagent system (@mention)
-- \`Skill\` tool → OpenCode's native \`skill\` tool
-- \`SystematicSkill\` tool → \`systematic_skill\` (Systematic plugin skills)
-- \`Read\`, \`Write\`, \`Edit\`, \`Bash\` → Your native tools
-
-**Skills naming:**
-- Bundled skills use the \`systematic:\` prefix (e.g., \`systematic:brainstorming\`)
-- Skills can also be invoked without prefix if unambiguous
-
-**Skills usage:**
-- Use \`systematic_skill\` to load Systematic bundled skills
-- Use the native \`skill\` tool for non-Systematic skills
-
-**Skills location:**
-Bundled skills are in \`${bundledSkillsDir}/\``
-
-  return `<SYSTEMATIC_WORKFLOWS>
-You have access to structured engineering workflows via the systematic plugin.
-
-**IMPORTANT: The using-systematic skill content is included below. It is ALREADY LOADED - you are currently following it. Do NOT use the systematic_skill tool to load "using-systematic" again - that would be redundant.**
-
-${content}
-
-${toolMapping}
-</SYSTEMATIC_WORKFLOWS>`
-}
-
 export const SystematicPlugin: Plugin = async ({ client, directory }) => {
   const config = loadConfig(directory)
 
@@ -131,7 +79,7 @@ export const SystematicPlugin: Plugin = async ({ client, directory }) => {
       ) {
         return
       }
-      const content = getBootstrapContent(config)
+      const content = getBootstrapContent(config, { bundledSkillsDir })
       if (content) {
         if (!output.system) {
           output.system = []

src/lib/agents.ts

@@ -0,0 +1,54 @@
+import { walkDir } from './walk-dir.js'
+import { stripFrontmatter } from './frontmatter.js'
+
+export interface AgentFrontmatter {
+  name: string
+  description: string
+  prompt: string
+}
+
+export interface AgentInfo {
+  name: string
+  file: string
+  category?: string
+}
+
+export function findAgentsInDir(dir: string, maxDepth = 2): AgentInfo[] {
+  const entries = walkDir(dir, {
+    maxDepth,
+    filter: (e) => !e.isDirectory && e.name.endsWith('.md'),
+  })
+
+  return entries.map((entry) => ({
+    name: entry.name.replace(/\.md$/, ''),
+    file: entry.path,
+    category: entry.category,
+  }))
+}
+
+export function extractAgentFrontmatter(content: string): AgentFrontmatter {
+  const lines = content.split('\n')
+
+  let inFrontmatter = false
+  let name = ''
+  let description = ''
+
+  for (const line of lines) {
+    if (line.trim() === '---') {
+      if (inFrontmatter) break
+      inFrontmatter = true
+      continue
+    }
+
+    if (inFrontmatter) {
+      const match = line.match(/^(\w+(?:-\w+)*):\s*(.*)$/)
+      if (match) {
+        const [, key, value] = match
+        if (key === 'name') name = value.trim()
+        if (key === 'description') description = value.trim()
+      }
+    }
+  }
+
+  return { name, description, prompt: stripFrontmatter(content) }
+}

src/lib/bootstrap.ts

@@ -0,0 +1,68 @@
+import fs from 'node:fs'
+import os from 'node:os'
+import path from 'node:path'
+import type { SystematicConfig } from './config.js'
+import { stripFrontmatter } from './frontmatter.js'
+
+export interface BootstrapDeps {
+  bundledSkillsDir: string
+}
+
+function getToolMappingTemplate(bundledSkillsDir: string): string {
+  return `**Tool Mapping for OpenCode:**
+When skills reference tools you don't have, substitute OpenCode equivalents:
+- \`TodoWrite\` → \`update_plan\`
+- \`Task\` tool with subagents → Use OpenCode's subagent system (@mention)
+- \`Skill\` tool → OpenCode's native \`skill\` tool
+- \`SystematicSkill\` tool → \`systematic_skill\` (Systematic plugin skills)
+- \`Read\`, \`Write\`, \`Edit\`, \`Bash\` → Your native tools
+
+**Skills naming:**
+- Bundled skills use the \`systematic:\` prefix (e.g., \`systematic:brainstorming\`)
+- Skills can also be invoked without prefix if unambiguous
+
+**Skills usage:**
+- Use \`systematic_skill\` to load Systematic bundled skills
+- Use the native \`skill\` tool for non-Systematic skills
+
+**Skills location:**
+Bundled skills are in \`${bundledSkillsDir}/\``
+}
+
+export function getBootstrapContent(
+  config: SystematicConfig,
+  deps: BootstrapDeps,
+): string | null {
+  const { bundledSkillsDir } = deps
+
+  if (!config.bootstrap.enabled) return null
+
+  if (config.bootstrap.file) {
+    const customPath = config.bootstrap.file.startsWith('~/')
+      ? path.join(os.homedir(), config.bootstrap.file.slice(2))
+      : config.bootstrap.file
+    if (fs.existsSync(customPath)) {
+      return fs.readFileSync(customPath, 'utf8')
+    }
+  }
+
+  const usingSystematicPath = path.join(
+    bundledSkillsDir,
+    'using-systematic/SKILL.md',
+  )
+  if (!fs.existsSync(usingSystematicPath)) return null
+
+  const fullContent = fs.readFileSync(usingSystematicPath, 'utf8')
+  const content = stripFrontmatter(fullContent)
+  const toolMapping = getToolMappingTemplate(bundledSkillsDir)
+
+  return `<SYSTEMATIC_WORKFLOWS>
+You have access to structured engineering workflows via the systematic plugin.
+
+**IMPORTANT: The using-systematic skill content is included below. It is ALREADY LOADED - you are currently following it. Do NOT use the systematic_skill tool to load "using-systematic" again - that would be redundant.**
+
+${content}
+
+${toolMapping}
+</SYSTEMATIC_WORKFLOWS>`
+}