manage_preferences

Read or update default style, aspect ratio, model, style notes, and favorite prompts. Use 'get' at conversation start to load preferences.

Instructions

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.

Input Schema

TableJSON Schema

Name	Required	Description
`action`	Yes	Action to perform: "get" reads all preferences, "set" updates defaults/styleNotes, "add_favorite" saves a prompt, "remove_favorite" removes by index
`style`	No	set: preferred default style (e.g. "realistic", "anime", "illustration")
`aspectRatio`	No	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`	No	set: preferred default model name
`provider`	No	set: preferred default provider
`styleNotes`	No	set: free-text style notes (e.g. "cinematic lighting, shallow DOF, brand colors #1A1A2E")
`prompt`	No	add_favorite: the prompt text to save
`index`	No	remove_favorite: 0-based index of the favorite to remove

Implementation Reference

src/tools/manage-preferences.ts:1-117 (handler)

Main tool implementation: exports schema (managePreferencesSchema) and handler function (registerManagePreferences) that registers a 'manage_preferences' tool with 4 actions (get, set, add_favorite, remove_favorite) for reading/writing user preferences.

/**
 * manage_preferences Tool — read/write user preferences
 *
 * Single tool with action parameter to keep context footprint small (~600 tokens).
 * Storage: ~/.config/meigen/preferences.json (separate from provider config).
 */

import { z } from 'zod'
import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
import {
  loadPreferences,
  updateDefaults,
  addFavorite,
  removeFavorite,
} from '../lib/preferences.js'

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'),
}

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)

Zod schema defining the tool's input: action enum (get/set/add_favorite/remove_favorite) with optional parameters style, aspectRatio, model, provider, styleNotes, prompt, 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:16-16 (registration)
Import of registerManagePreferences from the tool module.
```
import { registerManagePreferences } from './tools/manage-preferences.js'
```
src/server.ts:269-269 (registration)
Registration call to registerManagePreferences(server) in the createServer() function.
```
registerManagePreferences(server)
```

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

Helper module with persistence logic: loadPreferences, savePreferences, updateDefaults, addFavorite, removeFavorite, addRecentGeneration. Stores/reads from ~/.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
  }
}

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