Serena - Semantic Code Understanding Skill

Serena - Semantic Code Understanding

IDE-like semantic code operations via CLI. Provides symbol-level code navigation, editing, and project memory.

Prerequisites

pip install serena-agent typer pyyaml

Quick Start

First-time setup: Launch the Web Dashboard to initialize and register the project:

python -m tools dashboard serve --open-browser

This will:

Initialize Serena configuration
Register the current project in ~/.serena/serena_config.yml
Open the Web Dashboard for monitoring and configuration

Configuration: Edit .env file in skills/serena/ directory:

SERENA_CONTEXT=claude-code
SERENA_MODES=interactive,editing,onboarding
SERENA_PROJECT=.

Usage

Basic Command Structure

python -m tools [GLOBAL OPTIONS] <command> [COMMAND OPTIONS]

Global Options (must be specified before the command):

-p, --project PATH - Project directory (default: current directory, env: SERENA_PROJECT)
-c, --context TEXT - Execution context (auto-detected if not specified, env: SERENA_CONTEXT)
-m, --mode TEXT - Operation modes (can be specified multiple times, env: SERENA_MODES)

Working with Different Projects

Important: When working with projects in different locations (especially cross-drive on Windows), use --project:

# Correct: Use --project for different project locations
python -m tools --project "/path/to/project" symbol find MyClass
python -m tools --project "E:\MyProject" file search "pattern"

# Incorrect: Don't use --path with absolute paths from different drives
python -m tools file search "pattern" --path "E:\MyProject"  # Will fail!

The --path option in subcommands expects relative paths within the project. Always use --project to set the project root first.

Common Operations

# Dashboard
python -m tools dashboard serve --open-browser
python -m tools dashboard info

# Symbol operations
python -m tools symbol find MyClass --body
python -m tools symbol overview src/main.py
python -m tools symbol refs MyClass/method
python -m tools symbol rename OldName NewName --path src/file.py

# Memory operations
python -m tools memory list
python -m tools memory read project_overview
python -m tools memory write api_notes --content "..."

# File operations
python -m tools file list --recursive
python -m tools file find "**/*.py"
python -m tools file search "TODO:.*" --path src

# Extended tools
python -m tools cmd run "git status"
python -m tools config read config.json

Tool Routing Policy

Prefer Serena Over Built-in Tools

| Task | Avoid | Use Serena CLI | |------|-------|----------------| | Find function | grep "def func" | symbol find func --body | | List file structure | cat file.py | symbol overview file.py | | Find usages | grep "func(" | symbol refs func | | Edit function | Edit tool | symbol replace func --path file.py | | Rename | Manual find/replace | symbol rename old new --path file.py |

When to Use Built-in Tools

Simple text search (non-code patterns)
Configuration files (JSON, YAML)
Documentation files (Markdown)

Command Reference

Dashboard Commands

| Command | Description | |---------|-------------| | dashboard serve [--open-browser] [--browser-cmd <path>] | Start Web Dashboard server | | dashboard info | Show current configuration | | dashboard tools | List active and available tools | | dashboard modes | List active and available modes | | dashboard contexts | List active and available contexts |

Symbol Commands

| Command | Description | |---------|-------------| | symbol find <name> [--body] [--depth N] [--path file] | Find symbols by name | | symbol overview <path> | List all symbols in file | | symbol refs <name> [--path file] | Find symbol references | | symbol replace <name> --path <file> --body <code> | Replace symbol body | | symbol insert-after <name> --path <file> --content <code> | Insert after symbol | | symbol insert-before <name> --path <file> --content <code> | Insert before symbol | | symbol rename <name> <new> --path <file> | Rename symbol |

Memory Commands

| Command | Description | |---------|-------------| | memory list | List all memories | | memory read <name> | Read memory content | | memory write <name> --content <text> | Create/update memory | | memory edit <name> --content <text> | Edit memory | | memory delete <name> | Delete memory |

File Commands

| Command | Description | |---------|-------------| | file list [--path dir] [--recursive] | List directory | | file find <pattern> | Find files by glob pattern | | file search <pattern> [--path dir] | Search for regex pattern |

Extended Commands

| Command | Description | |---------|-------------| | cmd run <command> [--cwd dir] [--timeout N] | Execute shell command | | cmd script <path> [--args "..."] | Execute script file | | config read <path> [--format json\|yaml] | Read config file | | config update <path> <key> <value> | Update config value |

Workflow Commands

| Command | Description | |---------|-------------| | workflow onboarding | Run project onboarding | | workflow check | Check onboarding status | | workflow tools [--scope all] | List available tools |

Workflow Examples

Phase 1: Exploration

python -m tools symbol overview src/main.py           # Understand file structure
python -m tools symbol find MyClass --depth 1         # Explore class members
python -m tools symbol find MyClass/method --body     # Get implementation details

Phase 2: Analysis

python -m tools symbol refs MyClass/method            # Impact analysis
python -m tools memory list                           # Check project knowledge
python -m tools memory read architecture              # Retrieve context

Phase 3: Modification

python -m tools symbol find target --body             # Verify target
python -m tools symbol replace target --path f --body "..."  # Edit
python -m tools symbol rename old new --path f        # Refactor

Error Handling

All CLI output is JSON:

// Success
{"result": <data>}

// Error
{"error": {"code": "ERROR_CODE", "message": "description"}}

| Error Code | Recovery | |------------|----------| | INVALID_ARGS | Check --help | | TOOL_NOT_FOUND | Use workflow tools | | INIT_FAILED | Check serena-agent installation | | RUNTIME_ERROR | Check error message |

Anti-Patterns

| Prohibited | Correct | |------------|---------| | Read entire file to find function | symbol find func --body | | Grep for function calls | symbol refs func | | Manual search-replace rename | symbol rename old new --path f | | Skip impact analysis | symbol refs before editing |

Agent Skills: Serena - Semantic Code Understanding

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Skill Files