MCP Replicate FLUX

Implementation Reference

• index.js:17-33 (handler)

  Inline handler function for the 'generate-image' tool that calls the generateImage helper, handles errors, and returns MCP-formatted response content.

  async ({ prompt, filename }) => {
    try {
      const imageUrl = await generateImage({ prompt, filename })
      return {
        content: [
          { type: 'text', text: `Image successfully generated and uploaded to Cloudflare R2: ${imageUrl}` }
        ]
      }
    } catch (error) {
      console.error('Image generation failed:', error)
      return {
        content: [
          { type: 'text', text: `Image generation failed: ${error.message}` }
        ]
      }
    }
  }

• index.js:16-16 (schema)

  Zod input schema defining 'prompt' and 'filename' parameters for the generate-image tool.

  { prompt: z.string(), filename: z.string() },

• index.js:14-34 (registration)

  Registration of the 'generate-image' tool on the McpServer instance.

  server.tool(
    'generate-image',
    { prompt: z.string(), filename: z.string() },
    async ({ prompt, filename }) => {
      try {
        const imageUrl = await generateImage({ prompt, filename })
        return {
          content: [
            { type: 'text', text: `Image successfully generated and uploaded to Cloudflare R2: ${imageUrl}` }
          ]
        }
      } catch (error) {
        console.error('Image generation failed:', error)
        return {
          content: [
            { type: 'text', text: `Image generation failed: ${error.message}` }
          ]
        }
      }
    }
  )

• generateImage.js:15-79 (helper)

  Helper function implementing the core logic: generates image using Replicate Flux model, fetches the image, generates unique dated filename, and uploads to Cloudflare R2 via S3Client.

  module.exports = async ({ prompt, filename }) => {
    const replicate = new Replicate({
      auth: process.env.REPLICATE_API_TOKEN
    })
  
    try {
      // 生成唯一文件名，避免覆盖
      const timestamp = Date.now()
      const fileNameWithoutExt = path.basename(filename, path.extname(filename))
      const fileExt = path.extname(filename) || '.jpg'
      const uniqueFilename = `${fileNameWithoutExt}-${timestamp}${fileExt}`
      
      // 创建基于日期的文件夹结构
      const date = new Date()
      const year = date.getFullYear()
      const month = String(date.getMonth() + 1).padStart(2, '0') // 月份从0开始，需要+1
      const day = String(date.getDate()).padStart(2, '0')
      const folderPath = `${year}/${month}/${day}`
      
      // 完整的文件路径，包含日期文件夹
      const fullFilePath = `${folderPath}/${uniqueFilename}`
  
      // 使用 Replicate 生成图片
      const output = await replicate.run('black-forest-labs/flux-schnell', {
        input: {
          prompt,
          go_fast: true,
          num_outputs: 1,
          megapixels: '1',
          output_quality: 80,
          aspect_ratio: '16:9',
          output_format: 'jpg',
          num_inference_steps: 4
        }
      })
  
      if (!output || !output[0]) {
        throw new Error('No image generated')
      }
  
      const imageUrl = output[0]
      
      // 获取图片数据
      const response = await fetch(imageUrl)
      if (!response.ok) {
        throw new Error('Failed to fetch generated image')
      }
      const imageBuffer = await response.arrayBuffer()
  
      // 上传到 R2，使用包含日期文件夹的路径
      await s3Client.send(new PutObjectCommand({
        Bucket: process.env.STORAGE_BUCKET,
        Key: fullFilePath,
        Body: Buffer.from(imageBuffer),
        ContentType: 'image/jpeg'
      }))
  
      // 返回可访问的图片链接
      const r2ImageUrl = `https://${process.env.STORAGE_DOMAIN}/${fullFilePath}`
      return r2ImageUrl
    } catch (error) {
      console.error('Error in generateImage:', error)
      throw error
    }
  }