Serena Usage

<purpose> Provide patterns for effective use of Serena MCP tools for semantic code operations. </purpose> <tools> <tool name="get_symbols_overview"> <description>Get high-level view of symbols in a file</description> <param name="relative_path">Path to file (required)</param> <param name="depth">Descendant depth, 0 for top-level only</param> <use_case>First step when exploring a new file</use_case> </tool> <tool name="find_symbol"> <description>Find symbols by name path pattern</description> <param name="name_path_pattern">Symbol name or path (e.g., "MyClass/myMethod")</param> <param name="relative_path">Restrict to file or directory</param> <param name="include_body">Include source code</param> <param name="depth">Include descendants</param> <param name="substring_matching">Match partial names</param> <use_case>Locate specific functions, classes, or methods</use_case> </tool> <tool name="find_referencing_symbols"> <description>Find all references to a symbol</description> <param name="name_path">Symbol to find references for</param> <param name="relative_path">File containing the symbol</param> <use_case>Dependency analysis, impact assessment</use_case> </tool> <tool name="search_for_pattern"> <description>Regex search across codebase</description> <param name="substring_pattern">Regex pattern</param> <param name="relative_path">Restrict search scope</param> <param name="context_lines_before">Lines before match</param> <param name="context_lines_after">Lines after match</param> <param name="restrict_search_to_code_files">Search only code files or all files</param> <param name="paths_include_glob">Glob pattern for files to include</param> <param name="paths_exclude_glob">Glob pattern for files to exclude</param> <use_case>Find patterns, non-code files, complex searches</use_case> </tool> <tool name="replace_symbol_body"> <description>Replace entire symbol definition</description> <param name="name_path">Symbol to replace</param> <param name="relative_path">File containing symbol</param> <param name="body">New symbol body</param> <use_case>Refactoring entire functions or classes</use_case> </tool> <tool name="insert_before_symbol"> <description>Insert content before a symbol</description> <param name="name_path">Symbol to insert before</param> <param name="relative_path">File containing symbol</param> <param name="body">Content to insert</param> <use_case>Add imports, decorators, comments</use_case> </tool> <tool name="insert_after_symbol"> <description>Insert content after a symbol</description> <param name="name_path">Symbol to insert after</param> <param name="relative_path">File containing symbol</param> <param name="body">Content to insert</param> <use_case>Add new functions, classes</use_case> </tool> <tool name="rename_symbol"> <description>Rename symbol across codebase</description> <param name="name_path">Symbol to rename</param> <param name="relative_path">File containing symbol</param> <param name="new_name">New symbol name</param> <use_case>Consistent renaming with reference updates</use_case> </tool> <tool name="list_memories"> <description>List all available memory files</description> <use_case>Check existing patterns before implementation</use_case> </tool> <tool name="read_memory"> <description>Read content of a memory file</description> <param name="memory_file_name">Name of memory file to read</param> <use_case>Load project patterns and conventions</use_case> </tool> <tool name="write_memory"> <description>Write information to a memory file</description> <param name="memory_file_name">Name of memory file to write</param> <param name="content">Content to write</param> <use_case>Record new patterns and conventions</use_case> </tool> <tool name="delete_memory"> <description>Delete a memory file</description> <param name="memory_file_name">Name of memory file to delete</param> <use_case>Remove obsolete or incorrect patterns</use_case> </tool> <tool name="edit_memory"> <description>Replace content in a memory file using regex or literal matching</description> <param name="memory_file_name">Name of memory file to edit</param> <param name="needle">Pattern to search for</param> <param name="repl">Replacement string</param> <param name="mode">Either "literal" or "regex"</param> <use_case>Update specific parts of memory files</use_case> </tool> </tools> <concepts> <concept name="memory_files"> <description>Persistent storage for project patterns, conventions, and architectural decisions</description> <example> list_memories # Check existing patterns read_memory "nix-conventions" # Load Nix patterns write_memory "api-patterns" "REST API conventions..." # Record new pattern delete_memory "outdated-pattern" # Remove obsolete info </example> </concept> <concept name="memory_naming"> <description>Consistent naming conventions for memory files</description> <example> {project}-conventions # Project-wide conventions {feature}-patterns # Feature-specific patterns {domain}-patterns # Domain-specific patterns architecture-{decision} # Architecture decisions </example> </concept> <concept name="symbol_path"> <description>Path to symbol within a file (e.g., MyClass/myMethod)</description> <example> find_symbol "MyClass/myMethod" # Find specific method find_symbol "get*" substring_matching=true # Find all getter methods </example> </concept> <concept name="reflection_tools"> <description>Meta-cognitive tools for ensuring search quality and task alignment</description> <example> <note>After searching multiple files</note> think_about_collected_information

  <note>Before making changes</note>
  think_about_task_adherence

  <note>When task seems complete</note>
  think_about_whether_you_are_done
</example>

</concept> </concepts> <patterns> <pattern name="explore_file"> <description>Systematically explore file structure from high-level to detailed</description> <example> <step>Step 1: Get top-level overview</step> get_symbols_overview relative_path="src/main.ts" depth=0

  <step>Step 2: Explore class members</step>
  get_symbols_overview relative_path="src/main.ts" depth=1

  <step>Step 3: Get specific implementation</step>
  find_symbol name_path_pattern="MyClass/myMethod" include_body=true
</example>

</pattern> <pattern name="trace_dependencies"> <description>Trace symbol dependencies and callers</description> <example> <step>Step 1: Locate the symbol</step> find_symbol name_path_pattern="processData" relative_path="src/processor.ts"

  <step>Step 2: Find all callers</step>
  find_referencing_symbols name_path="processData" relative_path="src/processor.ts"

  <step>Step 3: Recursively trace for full dependency graph</step>
  <note>Repeat steps 1-2 for each caller to build complete dependency tree</note>
</example>

</pattern> <pattern name="safe_refactoring"> <description>Refactor with full impact analysis</description> <example> <step>Step 1: Understand current implementation</step> find_symbol name_path_pattern="MyClass/oldMethod" include_body=true

  <step>Step 2: Identify all usages</step>
  find_referencing_symbols name_path="MyClass/oldMethod" relative_path="src/myclass.ts"

  <step>Step 3: Perform the change</step>
  replace_symbol_body name_path="MyClass/oldMethod" relative_path="src/myclass.ts" body="..."

  <step>Step 4: Update references if interface changed</step>
  <note>If method signature changed, update all calling sites identified in step 2</note>
</example>

</pattern> <pattern name="pattern_search"> <description>Search for patterns with appropriate scope</description> <example> <note>Search only in code files</note> search_for_pattern substring_pattern="TODO:" restrict_search_to_code_files=true

  <note>Search in all files including configs</note>
  search_for_pattern substring_pattern="api-key" restrict_search_to_code_files=false

  <note>Include context around matches</note>
  search_for_pattern substring_pattern="function.\*async" context_lines_before=2 context_lines_after=3
</example>

</pattern> <pattern name="memory_workflow"> <description>Use memories to maintain consistency across tasks</description> <example> <note>Before implementation</note> list_memories # Check what patterns exist read_memory "typescript-patterns" # Load relevant patterns

  <note>During implementation</note>
  <note>Follow the patterns loaded from memory</note>

  <note>After implementation</note>
  write_memory "api-client-pattern" "HTTP client pattern using fetch with retry logic..."
</example>

</pattern>

<decision_tree name="tool_selection"> <question>What type of operation is needed?</question> <branch condition="Symbol lookup">Use find_symbol with name_path_pattern</branch> <branch condition="File structure overview">Use get_symbols_overview with appropriate depth</branch> <branch condition="Find references">Use find_referencing_symbols</branch> <branch condition="Pattern search">Use search_for_pattern with regex</branch> <branch condition="Refactor symbol">Use replace_symbol_body</branch> <branch condition="Rename symbol">Use rename_symbol for consistent updates</branch> <branch condition="Add code">Use insert_before_symbol or insert_after_symbol</branch> <branch condition="Check patterns">Use list_memories then read_memory</branch> <branch condition="Record patterns">Use write_memory</branch> </decision_tree> </patterns>

<anti_patterns> <avoid name="reading_entire_files"> <description>Reading entire files when only specific symbols are needed</description> <instead>Use get_symbols_overview for file structure and find_symbol with include_body for specific implementations</instead> </avoid>

<avoid name="unscoped_searches"> <description>Searching entire codebase when scope is known</description> <instead>Use relative_path parameter to restrict search to known files or directories</instead> </avoid> <avoid name="ignoring_memories"> <description>Implementing features without checking existing patterns</description> <instead>Always check list_memories and read_memory before implementation</instead> </avoid> <avoid name="manual_refactoring"> <description>Manually updating symbol references across files</description> <instead>Use rename_symbol for consistent renaming with automatic reference updates</instead> </avoid> <avoid name="excessive_depth"> <description>Using high depth values unnecessarily in get_symbols_overview</description> <instead>Start with depth=0, then incrementally increase if needed</instead> </avoid> </anti_patterns> <workflow> <phase name="prepare"> <objective>Prepare for effective Serena tool usage</objective> <step>1. Check list_memories for existing patterns</step> <step>2. Identify target symbols or files</step> <step>3. Choose appropriate tool based on decision_tree</step> </phase> <phase name="execute"> <objective>Execute Serena operations efficiently</objective> <step>1. Start with get_symbols_overview for file structure</step> <step>2. Use find_symbol with include_body for details</step> <step>3. Use find_referencing_symbols for dependencies</step> </phase> <phase name="verify"> <objective>Verify results and record patterns</objective> <step>1. Call think_about_collected_information after searches</step> <step>2. Record new patterns with write_memory</step> <step>3. Call think_about_whether_you_are_done when complete</step> </phase> </workflow>

<best_practices> <practice priority="critical">Always check memories with list_memories and read_memory before implementing new features</practice> <practice priority="critical">Use symbol operations (get_symbols_overview, find_symbol) over reading entire files</practice> <practice priority="high">Restrict searches by relative_path when scope is known to improve performance</practice> <practice priority="high">Use substring_matching for uncertain symbol names to broaden search results</practice> <practice priority="high">Record new patterns and conventions with write_memory for future reference</practice> <practice priority="medium">Use context_lines parameters in search_for_pattern to understand surrounding code</practice> <practice priority="medium">Verify symbol changes with find_referencing_symbols before refactoring</practice> </best_practices>

<rules priority="critical"> <rule>Always check memories before implementing new features</rule> <rule>Use symbol operations over reading entire files</rule> <rule>Call think_about_collected_information after non-trivial search sequences</rule> <rule>Call think_about_task_adherence before making code changes</rule> </rules> <rules priority="standard"> <rule>Restrict searches by relative_path when scope is known</rule> <rule>Use substring_matching for uncertain symbol names</rule> <rule>Record new patterns with write_memory</rule> <rule>Call think_about_whether_you_are_done when task appears complete</rule> </rules>

<related_agents> <agent name="design">Uses Serena for architecture analysis and pattern discovery</agent> <agent name="code-quality">Uses Serena for complexity analysis and refactoring</agent> <agent name="bug">Uses Serena for tracing dependencies and impact analysis</agent> <agent name="execute">Uses Serena for symbol-level operations and memory management</agent> <agent name="security">Uses Serena for vulnerability detection and security pattern analysis</agent> <agent name="database">Uses Serena for schema analysis and query optimization</agent> <agent name="performance">Uses Serena for performance bottleneck identification and optimization</agent> <agent name="test">Uses Serena for test coverage analysis and test generation</agent> </related_agents>

<error_escalation> <level severity="low"> <example>Symbol not found with exact match</example> <action>Note in report, proceed</action> </level> <level severity="medium"> <example>Memory file not found</example> <action>Document issue, use AskUserQuestion for clarification</action> </level> <level severity="high"> <example>Conflicting information in memories</example> <action>STOP, present options to user</action> </level> <level severity="critical"> <example>Memory corruption or invalid state</example> <action>BLOCK operation, require explicit user acknowledgment</action> </level> </error_escalation>

<related_skills> <skill name="investigation-patterns">Investigation methodology using Serena tools</skill> <skill name="nix-ecosystem">Nix patterns stored in Serena memories</skill> <skill name="typescript-ecosystem">TypeScript patterns stored in Serena memories</skill> <skill name="golang-ecosystem">Go patterns stored in Serena memories</skill> <skill name="rust-ecosystem">Rust patterns stored in Serena memories</skill> <skill name="common-lisp-ecosystem">Common Lisp patterns stored in Serena memories</skill> <skill name="emacs-ecosystem">Emacs patterns stored in Serena memories</skill> </related_skills>

<constraints> <must>Check memories before implementing new features</must> <must>Use symbol operations over reading entire files</must> <must>Restrict searches by relative_path when scope is known</must> <avoid>Reading entire files when symbol operations suffice</avoid> <avoid>Unscoped searches across entire codebase</avoid> <avoid>Ignoring existing memory patterns</avoid> </constraints>