manage_preferences

Instructions

Implementation Reference

• src/tools/manage-preferences.ts:42-117 (handler)

  The main handler function 'registerManagePreferences' which registers the 'manage_preferences' tool on the MCP server. It handles four actions: 'get' (reads all preferences), 'set' (updates defaults/styleNotes), 'add_favorite' (saves a prompt), and 'remove_favorite' (removes by index).

  export function registerManagePreferences(server: McpServer) {
    server.tool(
      'manage_preferences',
      'Read or update user preferences: default style, aspect ratio, model, style notes, and favorite prompts. Call with action "get" at conversation start to load preferences.',
      managePreferencesSchema,
      { readOnlyHint: false },
      async ({ action, style, aspectRatio, model, provider, styleNotes, prompt, index }) => {
        switch (action) {
          case 'get': {
            const prefs = loadPreferences()
            return {
              content: [{
                type: 'text' as const,
                text: JSON.stringify(prefs, null, 2),
              }],
            }
          }
  
          case 'set': {
            const updates: Record<string, string | undefined> = {}
            if (style !== undefined) updates.style = style
            if (aspectRatio !== undefined) updates.aspectRatio = aspectRatio
            if (model !== undefined) updates.model = model
            if (provider !== undefined) updates.provider = provider
  
            const prefs = updateDefaults(updates, styleNotes)
            return {
              content: [{
                type: 'text' as const,
                text: `Preferences updated.\n${JSON.stringify(prefs.defaults, null, 2)}` +
                  (styleNotes !== undefined ? `\nStyle notes: ${prefs.styleNotes}` : ''),
              }],
            }
          }
  
          case 'add_favorite': {
            if (!prompt) {
              return {
                content: [{ type: 'text' as const, text: 'Missing "prompt" parameter for add_favorite action.' }],
                isError: true,
              }
            }
            const prefs = addFavorite({ prompt, model, aspectRatio })
            return {
              content: [{
                type: 'text' as const,
                text: `Saved to favorites (${prefs.favorites.length} total).`,
              }],
            }
          }
  
          case 'remove_favorite': {
            if (index === undefined || index === null) {
              return {
                content: [{ type: 'text' as const, text: 'Missing "index" parameter for remove_favorite action.' }],
                isError: true,
              }
            }
            const prefs = removeFavorite(index)
            return {
              content: [{
                type: 'text' as const,
                text: `Favorite removed (${prefs.favorites.length} remaining).`,
              }],
            }
          }
  
          default:
            return {
              content: [{ type: 'text' as const, text: `Unknown action: ${action}` }],
              isError: true,
            }
        }
      }
    )
  }

• src/tools/manage-preferences.ts:17-40 (schema)

  The Zod schema 'managePreferencesSchema' defining the input parameters: action (enum of get/set/add_favorite/remove_favorite), style, aspectRatio, model, provider, styleNotes, prompt, and index.

  export const managePreferencesSchema = {
    action: z.enum(['get', 'set', 'add_favorite', 'remove_favorite'])
      .describe('Action to perform: "get" reads all preferences, "set" updates defaults/styleNotes, "add_favorite" saves a prompt, "remove_favorite" removes by index'),
  
    // For 'set' action
    style: z.string().optional()
      .describe('set: preferred default style (e.g. "realistic", "anime", "illustration")'),
    aspectRatio: z.string().optional()
      .describe('set: preferred default aspect ratio. Use "auto" (recommended) to let MeiGen infer per-prompt, or pin a value like "16:9", "1:1", "9:16".'),
    model: z.string().optional()
      .describe('set: preferred default model name'),
    provider: z.enum(['openai', 'meigen', 'comfyui']).optional()
      .describe('set: preferred default provider'),
    styleNotes: z.string().optional()
      .describe('set: free-text style notes (e.g. "cinematic lighting, shallow DOF, brand colors #1A1A2E")'),
  
    // For 'add_favorite' action
    prompt: z.string().optional()
      .describe('add_favorite: the prompt text to save'),
  
    // For 'remove_favorite' action
    index: z.number().optional()
      .describe('remove_favorite: 0-based index of the favorite to remove'),
  }

• src/server.ts:269-270 (registration)

  Registration call in the main server file that registers the 'manage_preferences' tool via 'registerManagePreferences(server)'.

  registerManagePreferences(server)

• src/server.ts:16-17 (registration)

  Import statement for 'registerManagePreferences' from the tool module.

  import { registerManagePreferences } from './tools/manage-preferences.js'

• src/lib/preferences.ts:1-147 (helper)

  Helper library providing low-level persistence functions: loadPreferences, savePreferences, updateDefaults, addFavorite, removeFavorite, and addRecentGeneration. Stores data at ~/.config/meigen/preferences.json.

  /**
   * User preferences persistence
   * Storage: ~/.config/meigen/preferences.json
   *
   * Completely independent from config.ts (which handles provider credentials).
   * All functions are safe — read errors return defaults, write errors are silently ignored.
   */
  
  import { readFileSync, writeFileSync, mkdirSync } from 'fs'
  import { join } from 'path'
  import { homedir } from 'os'
  
  // ── Types ──────────────────────────────────────────────────────
  
  export interface UserPreferences {
    version: number
    defaults: {
      style?: string
      aspectRatio?: string
      model?: string
      provider?: string
    }
    styleNotes: string
    favorites: FavoriteEntry[]
    recentSuccessful: RecentEntry[]
  }
  
  export interface FavoriteEntry {
    prompt: string
    model?: string
    aspectRatio?: string
    savedAt: string
  }
  
  export interface RecentEntry {
    prompt: string
    provider: string
    model?: string
    aspectRatio?: string
    generatedAt: string
  }
  
  // ── Constants ──────────────────────────────────────────────────
  
  const MAX_FAVORITES = 20
  const MAX_RECENT = 10
  
  function prefsPath(): string {
    return join(homedir(), '.config', 'meigen', 'preferences.json')
  }
  
  function emptyPreferences(): UserPreferences {
    return {
      version: 1,
      defaults: {},
      styleNotes: '',
      favorites: [],
      recentSuccessful: [],
    }
  }
  
  // ── Read / Write ───────────────────────────────────────────────
  
  export function loadPreferences(): UserPreferences {
    try {
      const raw = readFileSync(prefsPath(), 'utf-8')
      const parsed = JSON.parse(raw) as Partial<UserPreferences>
      // Merge with defaults to ensure all fields exist
      return {
        ...emptyPreferences(),
        ...parsed,
        defaults: { ...emptyPreferences().defaults, ...parsed.defaults },
      }
    } catch {
      return emptyPreferences()
    }
  }
  
  export function savePreferences(prefs: UserPreferences): void {
    const filePath = prefsPath()
    mkdirSync(join(homedir(), '.config', 'meigen'), { recursive: true })
    writeFileSync(filePath, JSON.stringify(prefs, null, 2) + '\n')
  }
  
  // ── Mutations (used by the tool) ───────────────────────────────
  
  export function updateDefaults(
    updates: Partial<UserPreferences['defaults']>,
    styleNotes?: string,
  ): UserPreferences {
    const prefs = loadPreferences()
    for (const [key, value] of Object.entries(updates)) {
      if (value !== undefined) {
        (prefs.defaults as Record<string, string | undefined>)[key] = value || undefined
      }
    }
    if (styleNotes !== undefined) {
      prefs.styleNotes = styleNotes
    }
    savePreferences(prefs)
    return prefs
  }
  
  export function addFavorite(entry: Omit<FavoriteEntry, 'savedAt'>): UserPreferences {
    const prefs = loadPreferences()
    prefs.favorites.unshift({
      ...entry,
      savedAt: new Date().toISOString(),
    })
    if (prefs.favorites.length > MAX_FAVORITES) {
      prefs.favorites = prefs.favorites.slice(0, MAX_FAVORITES)
    }
    savePreferences(prefs)
    return prefs
  }
  
  export function removeFavorite(index: number): UserPreferences {
    const prefs = loadPreferences()
    if (index >= 0 && index < prefs.favorites.length) {
      prefs.favorites.splice(index, 1)
    }
    savePreferences(prefs)
    return prefs
  }
  
  // ── Auto-save (fire-and-forget, called from generate-image.ts) ─
  
  export function addRecentGeneration(entry: {
    prompt: string
    provider: string
    model?: string
    aspectRatio?: string
  }): void {
    try {
      const prefs = loadPreferences()
      prefs.recentSuccessful.unshift({
        ...entry,
        generatedAt: new Date().toISOString(),
      })
      if (prefs.recentSuccessful.length > MAX_RECENT) {
        prefs.recentSuccessful = prefs.recentSuccessful.slice(0, MAX_RECENT)
      }
      savePreferences(prefs)
    } catch {
      // Never fail — this is a background enhancement
    }
  }