ide-index-mcp

name

ide-index-mcp

description

Guide for using JetBrains IDE Index MCP tools for code navigation, refactoring, and analysis. TRIGGER: When ANY of these MCP tools are available in the current session: ide_find_references, ide_find_definition, ide_find_class, ide_find_file, ide_search_text, ide_diagnostics, ide_index_status, ide_sync_files, ide_refactor_rename, ide_move_file, ide_type_hierarchy, ide_call_hierarchy, ide_find_implementations, ide_find_symbol, ide_find_super_methods, ide_file_structure, ide_refactor_safe_delete, ide_reformat_code, ide_build_project, ide_read_file, ide_get_active_file, ide_open_file. Use when performing code navigation (find usages, go to definition, find class), code analysis (diagnostics, type hierarchy, call hierarchy), refactoring (rename, move, safe delete, reformat), or searching code (text search, symbol search, file search). Prefer IDE tools over grep/find/sed for ALL semantic code operations.

IDE Index MCP - Agent Guide

The IDE Index MCP server exposes JetBrains IDE indexing and refactoring capabilities. These tools provide semantic code understanding superior to text-based search/replace.

Core Rule

Always prefer IDE MCP tools over built-in tools (grep, find, sed, read) for semantic code operations. IDE tools understand code structure, types, inheritance, and references. Built-in tools only see text.

When to Use IDE Tools vs Built-In Tools

Task	Use IDE Tool	Use Built-In Tool
Find all usages of a method/class/variable	ide_find_references	Never - grep misses renamed imports, aliases, overrides
Go to a symbol's definition	ide_find_definition	Never - grep can't resolve through imports/generics
Find a class by name	ide_find_class	Only if IDE unavailable
Find a file by name	ide_find_file	Glob is fine for simple patterns
Search for text in code	ide_search_text	Grep is fine when IDE context filtering is unnecessary
Rename a symbol across project	ide_refactor_rename	Never - sed/replace breaks code
Move a file to another directory	ide_move_file	Never - mv/git mv bypasses IDE move semantics
Check for errors in a file	ide_diagnostics	Never - no equivalent
Understand class hierarchy	ide_type_hierarchy	Never - no equivalent
Find who calls a method	ide_call_hierarchy	Never - grep misses indirect calls
Find interface implementations	ide_find_implementations	Never - grep can't resolve type relationships
Delete a symbol safely	ide_refactor_safe_delete	Never - manual deletion misses usages
Find what a method overrides	ide_find_super_methods	Never - no equivalent
Read file content	Built-in Read tool	ide_read_file only for library/jar sources
Find text with regex	ide_search_text	Use Grep when you do not need IDE context filtering

Pre-Flight Check

Before using any IDE tool that requires smart mode, check IDE readiness:

ide_index_status -> if isDumbMode: true, wait a few seconds and retry

Most tools require smart mode (IDE finished indexing). Tools that work in dumb mode: ide_index_status, ide_sync_files, ide_reformat_code, ide_open_file, ide_get_active_file.

File Sync Rule

If you created or modified files outside the IDE (via Write/Edit tools) and an IDE search tool returns incomplete/missing results, call ide_sync_files first, then retry.

{ "paths": ["src/new_file.java", "src/modified_file.java"] }

Omit paths to sync the entire project.

Parameter Rules

1. Line and column are 1-based (first line = 1, first column = 1)
2. Project file paths are relative to project root (e.g., src/main/java/App.java, NOT absolute paths). If an IDE tool returns a dependency/library file, keep the returned absolute path or jar:// URL unchanged when passing it back to read-only navigation tools or ide_read_file
3. Column must point to the symbol name, not whitespace or punctuation. For public void myMethod(), column should land on m of myMethod. For dotted expressions like json.dumps() or os.path.join(), put the column on the member token (dumps, join) when you want the member definition rather than the module/package.
4. project_path is only needed for multi-project workspaces. Omit for single-project setups. When needed, use the absolute path to the project root.
5. Use built-in search scope intentionally: ide_find_references, ide_find_implementations, ide_type_hierarchy, ide_call_hierarchy, ide_find_class, ide_find_file, and ide_find_symbol accept scope. Use project_files for the default project-only view, project_and_libraries when dependency code matters, project_production_files to stay out of tests, and project_test_files when you want test-only results.

Tool Selection by Task

"I need to understand how X is used"

1. ide_find_references - all call sites, field accesses, imports
2. ide_call_hierarchy with direction: "callers" - full call chain upward

"I need to understand what X is"

1. ide_find_definition - jump to source
2. ide_type_hierarchy - inheritance chain
3. ide_find_super_methods - what interface/base method it implements

"I need to find a class/file/symbol"

1. ide_find_class - classes by name (CamelCase: USvc finds UserService)
2. ide_find_file - files by name
3. ide_search_text - exact word occurrences across project

"I need to refactor"

1. ide_refactor_rename - rename symbol + all references atomically
2. ide_move_file - move file and let the IDE apply semantic updates when that language/backend supports them
3. ide_refactor_safe_delete - delete with usage checking (Java/Kotlin only)
4. ide_reformat_code - apply project code style (disabled by default)

"I need to check for problems"

1. ide_diagnostics - compiler errors, warnings, quick fixes

"I need to find implementations of an interface"

1. ide_find_implementations - cursor on interface/abstract class/method

"I need to trace call chains"

1. ide_call_hierarchy with direction: "callers" - who calls this?
2. ide_call_hierarchy with direction: "callees" - what does this call?

Common Mistakes to Avoid

1. Using grep instead of ide_find_references: Grep finds text, not semantic usages. Misses aliased imports, includes false positives from comments/strings.

2. Using sed/replace instead of ide_refactor_rename: Text replacement breaks code. IDE rename updates all references, getters/setters, overrides, test classes, imports.

3. Using mv/git mv instead of ide_move_file: File system moves bypass IDE move semantics. ide_move_file can preserve IDE-managed package/namespace/reference updates when the active language backend supports them.

4. Forgetting to check index status: If IDE is indexing (dumb mode), most tools error. Check ide_index_status first if a tool fails unexpectedly.

5. Using 0-based line/column: All IDE tools use 1-based. Line 5 in file = line: 5.

6. Passing absolute project file paths: Use relative paths for project files. src/main/App.java, not /Users/me/project/src/main/App.java.

7. Rewriting plugin-returned library paths: If a search or read tool returns an absolute path or jar:// URL for a dependency/library file, pass that path back unchanged to read-only navigation tools or ide_read_file.

8. Not syncing after external file changes: After creating files via Write tool, call ide_sync_files before searching.

9. Assuming regex is the default in ide_search_text: Regex requires "regex": true; otherwise the tool uses the faster exact-word index.

10. Using ide_find_class for methods/functions: It searches classes only. Use ide_search_text for a quick word lookup.

Disabled-by-Default Tools

These tools exist but are disabled by default. If you get "tool not found", they need to be enabled in IDE settings (Settings > Tools > Index MCP Server):

ide_build_project, ide_file_structure, ide_find_symbol, ide_read_file, ide_get_active_file, ide_open_file, ide_reformat_code

Detailed Tool Parameters

For complete parameter reference with types, defaults, and return formats, see tools-reference.md.