Fastedit

FastEdit Setup

FastEdit 0.5.0+ adds cross-file caller-safety on deletes, AST-verified renames, signature-impact notes on edits, and a cross-file fast_move_to_file that rewrites importers.

When to Use

• "install fastedit", "set up fast edit", "configure fastedit"
• "add fastedit to claude code", "fastedit mcp", "fastedit cli"

Instructions

Ask user: MCP server (recommended — tools appear in Claude Code) or CLI (standalone commands)?

Install

# Mac (Apple Silicon)
pip install fastedits[mlx]

# Mac + MCP server
pip install fastedits[mlx,mcp]

# Linux GPU server
pip install fastedits[vllm]

Pull model (~3GB, one-time)

fastedit pull

74% of edits resolve deterministically (0 tokens, <1ms). Model handles the remaining 26%.

Option A: MCP Server (recommended)

Add to ~/.claude.json or project .claude.json:

{
  "mcpServers": {
    "fastedit": {
      "command": "python3",
      "args": ["-m", "fastedit.mcp_server"]
    }
  }
}

12 tools: fast_edit (replace=/after=), fast_batch_edit, fast_multi_edit, fast_read, fast_search, fast_delete, fast_move, fast_move_to_file, fast_rename, fast_rename_all, fast_diff, fast_undo

Optional — auto-redirect Edit → fast_edit (add to same .claude.json):

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Edit",
        "hooks": [{"type": "command", "command": "fastedit-hook"}]
      }
    ]
  }
}

Key patterns:

• replace='func_name' + context markers → AST-scoped edit (~1-2s)
• after='func_name' + new code → deterministic insert (0 tokens)
• fast_read first → learn symbol names → then edit

Option B: CLI

fastedit read src/app.py                              # structure map
fastedit edit src/app.py --replace fn --snippet '...'  # edit function
fastedit edit src/app.py --after fn --snippet '...'    # insert after
fastedit search "query" src/                           # find symbols
fastedit delete src/app.py old_func                    # remove symbol
fastedit rename src/app.py old_name new_name           # rename symbol
fastedit diff src/app.py                               # verify last edit
fastedit undo src/app.py                               # revert last edit

Remote / Local LLM Server (optional)

Any OpenAI-compatible server works: vLLM, LM Studio, llama.cpp, Ollama.

export FASTEDIT_BACKEND=llm
export FASTEDIT_LLM_API_BASE=http://localhost:1234/v1  # LM Studio default

Load the FastEdit GGUF/MLX model in your server, set the URL, done.