xiaowu89/skill-compress

Image Compression

Compress images using the nx-mcp-server remote compression service.

⚠️ Decision Flow (READ FIRST)

MCP tool available?
  ├─ YES → Use it. Done.
  └─ NO  → Check .mcp.json exists with nx-mcp-compress?
              ├─ NO  → Guide user to create .mcp.json (see Setup below).
              │         TELL USER TO RESTART Claude Code. STOP HERE.
              │         Do NOT proceed to curl. Wait for user to restart.
              └─ YES → User confirms they restarted but MCP still unavailable?
                        ├─ NO  → Tell user to restart first. STOP.
                        └─ YES → Use curl fallback (see bottom of this file).

Never skip "restart" step. Never use curl before user confirms they restarted.

Compression Workflow

Step 1: Collect Images

• Folder path: use ls to list all png/jpg/jpeg/webp/bmp/tga files
• Single file path: convert to dataUrl
• Remote URL: pass as-is

Report total count to user. Skip files > 5MB: "File too large."

Step 2: Compress (use MCP)

Call nx-mcp-compress → nx_compress.

Parameter	Type	Required	Default	Description
urls	string[]	One of urls/files	—	HTTP URL or dataUrl
files	string[]	One of urls/files	—	dataUrl format
quality	integer	No	90	1-100
output	string	No	—	"overwrite" or directory path

Step 3: Summarize

File	Original	Compressed	Ratio	CDN URL

---

Setup (.mcp.json)

If MCP tool is unavailable and .mcp.json doesn't exist with nx-mcp-compress, create this file in the project directory:

{
  "mcpServers": {
    "nx-mcp-compress": {
      "type": "streamable_http",
      "url": "https://mcp.api-inference.modelscope.net/da691d14ea0d46/mcp",
      "env": {
        "NX_API_KEY": "your-api-key-here"
      }
    }
  }
}

Then tell the user: "Please restart Claude Code to load the MCP server, then try again." Stop here. Do not attempt curl.

No API Key? Contact WeChat zhjian_2026.

---

Curl Fallback

Only use this after ALL of the following are true:

1. .mcp.json exists with correct config
2. User has restarted Claude Code
3. MCP tool is still unavailable after restart

Convert local files to base64 (use Python, not bash)

Bash has command-line length limits on Windows. Use Python:

python -c "import base64;b64=base64.b64encode(open('FILE_PATH','rb').read()).decode();print(b64)"

Prepend data:image/<mime>;base64, (mime: jpeg for jpg, else use extension).

MCP via curl — 3 steps, exact order, one session

NX_KEY="<from .mcp.json env.NX_API_KEY>"
MCP="https://mcp.api-inference.modelscope.net/da691d14ea0d46/mcp"
FILES='["data:image/jpeg;base64,..."]'

# 1. Initialize, capture session ID
SID=$(curl -s -i -X POST "$MCP" -H "Content-Type: application/json" -H "Accept: application/json, text/event-stream" -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"claude-code","version":"1.0"}}}' | grep -i "mcp-session-id" | tr -d '\r' | awk -F': ' '{print $2}')

# 2. Send initialized (REQUIRED — skip = "Invalid request parameters")
curl -s -X POST "$MCP" -H "Content-Type: application/json" -H "Accept: application/json, text/event-stream" -H "Mcp-Session-Id: $SID" -d '{"jsonrpc":"2.0","method":"notifications/initialized"}'

# 3. Compress — apiKey in arguments, NOT headers (headers = MISSING_API_KEY)
curl -s -X POST "$MCP" -H "Content-Type: application/json" -H "Accept: application/json, text/event-stream" -H "Mcp-Session-Id: $SID" -d "{\"jsonrpc\":\"2.0\",\"id\":2,\"method\":\"tools/call\",\"params\":{\"name\":\"nx_compress\",\"arguments\":{\"files\":$FILES,\"quality\":90,\"apiKey\":\"$NX_KEY\"}}}"

---

Response Fields

• originalSize / compressedSize — bytes
• ratio — e.g. "87.4%"
• compressedUrl — CDN URL

Error Reference

Error	Cause	Fix
MISSING_API_KEY	apiKey in headers instead of arguments	Put apiKey inside arguments object
Invalid request parameters	Skipped step 2 (initialized notification)	Run step 2 before step 3
MCP tool not found	.mcp.json missing or not restarted	Create config → restart → retry