mcp-digger

mcp-digger

Code context for AI coding agents. Progressive, on-demand access to your internal .NET / NuGet package source — agents browse, search, and read private C# libraries autonomously, with zero workspace pollution.

⚠ Scope: .NET / C# only. mcp-digger indexes NuGet-style repos containing .csproj packages and .cs source files. It is not a general-purpose source indexer — other languages (TypeScript, Python, Java, Go, etc.) are out of scope.

✨ Why

Public NuGet packages have documentation ecosystems — API references, tutorials, community Q&A. Tools like context7 serve that well.

Internal .NET packages often have source code as their primary documentation. mcp-digger turns that source into structured, searchable, token-efficient context that any MCP-compatible agent can consume — bridging the documentation gap in private C# library ecosystems.

Without it:

• 🐢 Slow context gathering — git clone + find + grep + cat chains burn tokens on infrastructure before useful context is retrieved.
• 🔍 No semantic search — file system tools find text, not API surfaces. "Every type implementing this interface" means writing extraction scripts on demand.
• 💸 Token waste — agents read whole files when a single method signature would do.
• 🖱 Permission click fatigue — dozens of shell-command approvals per session.
• 🧹 Workspace noise — referenced repos pollute file search, git status, and the agent's context window.

With it:

• ✅ Correct code on the first try — real signatures, generic constraints, interface contracts, base class patterns.
• ⚡ Self-service context — point the agent at your NuGet repos once; it browses, searches, and reads autonomously.
• 🪙 Progressive disclosure — 200-token overview before 5,000 tokens of source. Most questions resolve at L1 or L2.
• 🧼 Zero workspace pollution — managed clones live outside your project tree.
• 🌐 Any Git host — GitHub, GitLab, Azure DevOps, Bitbucket, self-hosted — HTTPS or SSH.

🛠 How it works

Ten purpose-built tools, escalating from broad to deep. The agent picks the cheapest tool that answers its question.

                                                           ┌─→ 📦 dig_package_overview ─┐
                                                           │   (docs, key types)        │
   🩺 dig_status  →  📋 dig_list  →  📖 dig_repo_overview  ┤                            ├─→  🔎 dig_lookup     →  📄 dig_file
   (health)          (discover)      (README + summaries)  │                            │   (symbol → file)       (full source)
                                                           ├─→ 📁 dig_package_files ────┤
                                                           │   (file listing)           │
                                                           └────────────────────────────┴─→  📝 dig_signatures
                                                                                            (stripped API)

   Operational:  🔄 dig_refresh   (force cache invalidation, on demand)
   Bootstrap:    🌱 dig_init      (only when no config exists)

🧰 Tools (10)

Search modes for dig_lookup:

🚀 Quick start

Install

npm install -g mcp-digger
# or run directly
npx mcp-digger

Requires Node.js 20+, git on PATH, and a .NET / C# source repo (NuGet packages with .csproj + .cs sources).

Minimal config

Create .digger/config.json in your workspace root:

{
  "repos": [
    {
      "name": "my-libraries",
      "url": "https://github.com/org/shared-libs.git",
      "packageFilter": "MyCompany.*",
      "auth": {
        "strategy": "pat",
        "PAT-EnvVarName": "GIT_PAT"
      }
    }
  ]
}

Don't have a config yet? Start the server, then call dig_init to scaffold one.

Agent setup

{
  "mcpServers": {
    "digger": {
      "command": "npx",
      "args": ["-y", "mcp-digger"]
    }
  }
}

[mcp_servers.mcp-digger]
command = "npx"
args = ["-y", "mcp-digger"]

{
  "mcpServers": {
    "digger": {
      "command": "npx",
      "args": ["-y", "mcp-digger"]
    }
  }
}

{
  "servers": {
    "digger": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "mcp-digger"]
    }
  }
}

{
  "mcpServers": {
    "digger": {
      "command": "npx",
      "args": ["-y", "mcp-digger"]
    }
  }
}

Verify

Once connected, ask your agent to call dig_status — it reports config validation, per-repo connectivity, and index health.

⚙ Configuration

Repos & packages

A repos[] entry has three ways to declare packages:

sourceRoot defaults to "src" — set it to whichever directory holds your package folders. The walk is recursive, so nested layouts like src/Group/Foo/Foo.csproj are picked up.

{
  "repos": [
    {
      "name": "my-libraries",
      "url": "https://github.com/org/shared-libs.git",
      "branch": "develop"
    }
  ]
}

{
  "localRepos": {
    "my-libraries": "C:/repos/shared-libs"
  },
  "repos": [
    {
      "name": "my-libraries",
      "sourceRoot": "src"
    }
  ]
}

🩺 Diagnostics & recovery

Debug log

Enable debug logging in your config:

{ "debug": true, "repos": [...] }

Logs go to .digger/debug.log (capped at 5 MB, auto-truncated). Critical errors and crash output land in .digger/error.log.

💬 Feedback

Tried mcp-digger on your codebase? Share what worked, what broke, what's missing in GitHub Discussions. Bug reports go in Issues.

📜 License

MIT License — see LICENSE.