fossil-mcp

Overview

Fossil MCP is a specialized static analysis tool designed for AI-assisted codebases, addressing problems that traditional linters miss. It works both as a CLI tool and as an MCP server that provides AI agents with a code graph instead of text search capabilities. The tool detects dead code accumulating when AI rewrites functions, structural duplication across modules, scaffolding markers like TODO comments and placeholder functions, and temporary files that persist across sessions.

Try asking AI

After installing, here are 7 things you can ask your AI assistant:

• scan_all

  Run all analyses (dead code + clones + scaffolding) on a project

  Try:Scan my entire project for code quality issuesTry:Find all dead code, clones, and scaffolding in the current directory
• analyze_dead_code

  Detect unreachable code with configurable confidence

  Try:Find dead code in my TypeScript filesTry:Show me unreachable functions with high confidence
• detect_clones

  Find duplicated code (Type 1/2/3 clones)

  Try:Find duplicate code in my Python filesTry:Show me structural code clones across the project
• fossil_refresh

  Incremental re-analysis after file changes (fast)

  Try:Refresh analysis after these file changesTry:Update code graph after recent commits
• fossil_inspect

  Inspect call graph, data flow, control flow, or blast radius for any function

  Try:Inspect the call graph for this functionTry:Show blast radius of this function
• fossil_trace

  Find call paths between two functions — understand how code connects

  Try:Trace path between these two functionsTry:How do these functions connect?
• fossil_explain_finding

  Get rich context about a specific finding

  Try:Explain this dead code findingTry:Show context for this clone detection
• fossil_detect_scaffolding

  Find AI scaffolding: phased comments, TODOs, placeholders, and temp files

  Try:Find scaffolding markers in my codeTry:Show me TODO comments and placeholder functions

Comparable tools

Installation

curl -fsSL fossil-mcp.com/install.sh | sh

irm fossil-mcp.com/install.ps1 | iex

{
  "mcpServers": {
    "fossil": {
      "command": "fossil-mcp"
    }
  }
}

FAQ

How does Fossil differ from traditional linters?

Fossil is specifically designed for artifacts accumulated in AI-assisted coding, such as dead code from forgotten helper functions, structural duplication across modules, and scaffolding markers left by AI. It uses call graphs rather than text search to understand code connectivity.

What languages does Fossil support?

Fossil works across 16 programming languages including JavaScript/TypeScript, Python, Java, C/C++, Rust, Go, Ruby, PHP, C#, Swift, Kotlin, and more. It automatically detects and adapts to different language ecosystems.

On Hacker News

Recent discussion from the developer community.

• Fossil MCP – Dead code detection for vibe-coded projects▲ 2💬 2
  Story by yfedoseev · 2026-02-10

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