MCP Service Integration - Context7, ACE Tool, Fast-Context

CCG’s installer provides one-click configuration of multiple MCP (Model Context Protocol) services, giving Claude Code powerful code retrieval and documentation query capabilities.

Supported MCP Services

fast-context (Recommended)

Semantic code retrieval service powered by Windsurf Fast Context.

Features:

Natural language search across your codebase
Supports both Chinese and English queries
API key optional (enhances results when provided)
FC_INCLUDE_SNIPPETS parameter returns code snippets inline

Configuration:

{
  "mcpServers": {
    "fast-context": {
      "command": "npx",
      "args": ["fast-context-mcp"],
      "env": {
        "FC_API_KEY": "your-key-here"
      }
    }
  }
}

ace-tool

Code retrieval MCP tool offering search_context and enhance_prompt capabilities.

Features:

Semantic code search
Prompt enhancement
Relay endpoint available: https://acemcp.heroman.wtf/

context7

Free library documentation query MCP — no API key required. Automatically configured during installation.

Features:

Query the latest docs for any library or framework
Supports React, Next.js, Prisma, and other popular libraries
No API key needed, works out of the box

Configuration:

{
  "mcpServers": {
    "context7": {
      "command": "npx",
      "args": ["-y", "@context7/mcp"]
    }
  }
}

Cross-Model MCP Sync

The CCG installer synchronizes MCP configuration across all model CLI config files:

Target	Config File	Sync Method
Claude Code	`~/.claude.json`	Written during install
Codex CLI	`~/.codex/config.toml`	`syncMcpToCodex()`
Gemini CLI	`~/.gemini/settings.json`	`syncMcpToGemini()`

This ensures all three model CLIs have access to the same MCP toolset.

Configuration During Install

When running npx ccg-workflow, MCP tool selection appears at Step 3:

Step 3/4: MCP Tool Configuration

Select MCP services to install:
  [1] fast-context (recommended) — Semantic code retrieval
  [2] ace-tool — Code retrieval + prompt enhancement
  [3] context7 — Free library doc queries (auto-installed)
  [4] Skip MCP configuration

Diagnostics

If MCP tools are not working, run the diagnostic command:

npx ccg-workflow diagnose-mcp

This command checks:

Whether MCP service configurations exist
Whether the corresponding npm packages are installed
Whether services are reachable
Whether API keys are valid (when required)