@glassypic/mcp-server

MCP server for GlassyPic. One tool that turns raw images into production-ready assets: upscaling, resizing and cropping, compression, file format conversion, and SEO filename and alt text generation. Describe the outcome you want in natural language.

Quick Start

Add to your MCP client config:

{
  "mcpServers": {
    "glassypic": {
      "command": "npx",
      "args": ["-y", "@glassypic/mcp-server@latest"]
    }
  }
}

No signup required. Works out of the box with 20 free daily credits.

Windows users: If the server doesn't appear after editing a JSON config, your client likely can't resolve npx from PATH (a common, silent failure). Wrap the command with cmd /c:

json

{
  "mcpServers": {
    "glassypic": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@glassypic/mcp-server@latest"]
    }
  }
}

This applies to the hand-edited JSON configs below (Claude Desktop, Cursor, Windsurf, Cline). The CLI commands (Claude Code, Gemini CLI, Codex CLI) are unaffected.

Client-Specific Setup

{
  "mcpServers": {
    "glassypic": {
      "command": "npx",
      "args": ["-y", "@glassypic/mcp-server@latest"]
    }
  }
}

claude mcp add glassypic -- npx -y @glassypic/mcp-server@latest

{
  "mcpServers": {
    "glassypic": {
      "command": "npx",
      "args": ["-y", "@glassypic/mcp-server@latest"]
    }
  }
}

{
  "mcpServers": {
    "glassypic": {
      "command": "npx",
      "args": ["-y", "@glassypic/mcp-server@latest"]
    }
  }
}

{
  "mcpServers": {
    "glassypic": {
      "command": "npx",
      "args": ["-y", "@glassypic/mcp-server@latest"]
    }
  }
}

gemini mcp add --transport stdio glassypic npx -y @glassypic/mcp-server@latest

{
  "mcpServers": {
    "glassypic": {
      "command": "npx",
      "args": ["-y", "@glassypic/mcp-server@latest"]
    }
  }
}

codex mcp add glassypic -- npx -y @glassypic/mcp-server@latest

[mcp_servers.glassypic]
command = "npx"
args = ["-y", "@glassypic/mcp-server@latest"]

Tool: optimize_image

One tool that turns a supplied image into a production-ready asset through a fixed server-side pipeline (typically 60-80% size reduction), with optional resize, upscale, format conversion, and SEO metadata generation. Inputs include JPEG, PNG, WebP, AVIF, GIF, SVG, ICO, HEIC, TIFF, and BMP. Outputs are JPEG, PNG, WebP, AVIF, GIF, SVG, and ICO. Accepts absolute local file paths or remote URLs.

Parameters

Resize Behavior

Examples

Basic compression — just compress, keep format and dimensions:

{ "input": "/Users/me/photos/hero.png" }

Convert to WebP:

{ "input": "/Users/me/hero.png", "output_format": "webp" }

Resize proportionally — set one dimension, the other scales:

{ "input": "/Users/me/hero.png", "output_width_px": 1200 }

Exact dimensions with padding — white bars fill the gap:

{ "input": "/Users/me/hero.png", "output_width_px": 1080, "output_height_px": 1080 }

Exact dimensions with smart crop:

{ "input": "/Users/me/hero.png", "output_width_px": 1080, "output_height_px": 1080, "output_resize_behavior": "crop" }

AI upscale 4x:

{ "input": "/Users/me/icon.png", "output_upscale_factor": 4 }

From URL, save to directory:

{ "input": "https://example.com/photo.jpg", "output_path": "/Users/me/assets/" }

Skip SEO to save 1 credit:

{ "input": "/Users/me/hero.png", "output_seo_tag_gen": false }

Output

Returns a text summary and structured metadata:

Optimized: /Users/me/photos/modern-office-workspace.webp
Size: 142.3 KB
Compression: 73%
Format: webp
Dimensions: 1920x1080
Alt text: Modern office workspace with laptop and coffee cup on wooden desk

Structured output fields:

{
  "output_path": "/Users/me/photos/modern-office-workspace.webp",
  "output_size_bytes": 145715,
  "output_width_px": 1920,
  "output_height_px": 1080,
  "output_format": "webp",
  "compression_ratio": 0.27,
  "seo_alt_text": "Modern office workspace with laptop and coffee cup on wooden desk",
  "seo_keywords": ["office", "workspace", "laptop", "desk", "modern"],
  "seo_filename": "modern-office-workspace"
}

Supported Formats

GlassyPic supports high-quality conversion between any input and output format combination. Converting an animated GIF to a non-GIF format (JPG, PNG, WebP, AVIF) preserves only the first frame. Converting an animated GIF to a GIF format supports upscaling/resizing while preserving the animation and quality. You may also reduce animated GIF file size by decreasing the number of output frames.

Max upload file size: 50 MB.

SVG & ICO Examples

# Optimize an SVG file (keeps as vector)
Optimize logo.svg and keep it as SVG

# Convert SVG to raster
Convert icon.svg to a 512x512 PNG

# Trace raster to vector SVG
Convert my logo.png to a vector SVG

# Generate favicon set from any image
Convert logo.png to an ICO favicon

# Generate single-size ICO
Convert logo.png to a 32x32 ICO

# Extract largest icon from ICO
Convert favicon.ico to PNG

How It Works

Local file or URL
  → Upload to GlassyPic API
    → Optional AI upscale (explicit, or automatic when a resize target exceeds the source by more than 1.2×)
    → Optional resize
    → Compression
    → Optional SEO metadata
  → Download optimized file
    → Save with the SEO filename slug, or a `.polished` suffix when SEO is off or returns no slug

All processing happens server-side via the GlassyPic API. The MCP server is a thin client that orchestrates the pipeline.

Credits

Session data is stored locally at ~/.glassypic/session.json and persists across invocations.

Automatic upscaling

When a resize target exceeds the source image by more than 1.2×, GlassyPic automatically runs an AI upscale before resizing, so enlargements ship sharp instead of blurred. This happens without output_upscale_factor being set and adds 2 credits.

A resize-only call therefore costs the same as a full pipeline when the source is smaller than the target:

Animated GIFs are billed per frame — see the confirm_gif_cost parameter.

Account & Credits

Log in to unlock more credits and share them across the web app and MCP server:

Use the login tool to sign in.
Use the status tool to check your current credits.
Use the upgrade tool to open the pricing page.
Use the logout tool to sign out.

login

Opens a browser window to complete login (Google, Facebook, or email/magic link). After approval, your account is linked and credits are shared with the web app.

Login complete: user@example.com (Pro tier, 3,150 of 3,300 credits remaining)

status

Check your current account status and credits before batch processing:

Logged in as user@example.com (Pro tier)
Credits: 3,150 of 3,300 remaining
Resets: 03/01/2026, 12:00 AM PST

logout

Revokes the session and reverts to guest mode (20 credits/day).

upgrade

Opens glassypic.com/pricing in your browser.

Tips for AI Agents

Paste this into your CLAUDE.md or system prompt to help agents use the tool effectively:

## GlassyPic MCP

Tools: optimize_image, login, logout, status, upgrade

- Use status to check credits before batch processing
- Credits: 3 to compress (always), +1 if width/height is set, +2 to upscale, +1 for SEO tags (default). A full pipeline is 7 credits. SVG/ICO output is a flat 1 credit.
- Resizing up past 1.2x the source triggers an automatic AI upscale (+2 credits) even without output_upscale_factor set — a resize-only call on a small image can cost 7, not 5.
- Guest: 20 credits/day. Free account: 30/day. Pro: 3,300/month.
- Always use absolute file paths, not relative.
- Set only width OR height for proportional resize. Set both for exact dimensions.
- When both dimensions are set, use output_resize_behavior: "crop" for photos, "pad" for logos/icons.
- output_seo_tag_gen (default true) renames the file to an SEO slug and generates alt text + keywords.
- Set output_seo_tag_gen: false to save 1 credit when SEO metadata is not needed.
- GIF is supported for both input and output; animated GIFs stay animated when output_format is "gif".
- Converting an animated GIF to jpg/png/webp/avif preserves only the first frame.
- HEIC, TIFF, BMP inputs are auto-converted to JPG.
- For batch processing, call optimize_image once per file.
- If credits run out, use login to sign in or upgrade to open pricing.

Troubleshooting

Server not appearing in tool list:

• Restart your MCP client after editing the config
• Ensure Node.js >= 18 is installed: node --version
• Try running directly: npx -y @glassypic/mcp-server@latest (should start without errors)
• On Windows: if the server silently never loads, wrap the command with cmd /c ("command": "cmd", "args": ["/c", "npx", "-y", "@glassypic/mcp-server@latest"]) — see the Windows note under Quick Start

"Insufficient credits" error:

• Use the status tool to check remaining credits
• Use the login tool to sign in for more credits (free accounts get 30/day)
• Use the upgrade tool to open the pricing page and compare plans
• Disable SEO tags (output_seo_tag_gen: false) to save 1 credit; note that resizing up past 1.2× the source still adds an automatic 2-credit upscale regardless

Login browser window doesn't open:

• Open this URL manually: https://glassypic.com/mcp/authorize and enter the code shown in the terminal
• Ensure a browser is installed and accessible

Session token issues:

• Session data is stored at ~/.glassypic/session.json
• Delete this file to reset and start fresh
• Use logout then login to re-authenticate

File not found:

• Use absolute paths for local files
• For URLs, ensure the image is publicly accessible

Timeout errors:

• Large images or AI upscaling can take 30-60 seconds
• The server has a 60-second timeout per job

Privacy Policy

Full policy: https://glassypic.com/privacy/

What is transmitted. Images you optimize are uploaded to the GlassyPic API (https://api.glassypic.com) for processing, along with your authentication token. Images are retained according to your account tier and then deleted — both the original upload and the processed version. See the policy for the retention schedule.

When you pass a remote URL to the tool, the GlassyPic API fetches it server-side; the URL itself is sent to GlassyPic, and the request to the image host originates from GlassyPic's servers rather than from your machine.

What is stored locally. When you use the login tool, your access token and account email are written to ~/.glassypic/session.json with file mode 0600 (owner read/write only). If you optimize an image without logging in, the first upload mints a guest session token, which is written to that same file so subsequent calls stay attached to the same guest session's credits — no account, email, or personal information is attached to it. Running the logout tool removes the file's token. See also Account & Credits and Troubleshooting.

What is not collected. When run as a local connector, this server sends no telemetry and makes no network call other than to the GlassyPic API. (The remote HTTP transport additionally calls Supabase for authentication.)

Configuration

The value must be an https URL. Plain http is accepted only for localhost and 127.0.0.1, because your images and Bearer token are sent to this host. An invalid value produces a clear error naming the variable rather than a silent request to the wrong endpoint.

Requirements

• Node.js >= 18
• An MCP-compatible client (Claude Desktop, Claude Code, Cursor, Windsurf, Cline, OpenAI Codex CLI, Gemini CLI, etc.)

Security

Report vulnerabilities privately. See SECURITY.md. Do not file a public issue for an unfixed security report.

License

MIT - see LICENSE.