osgrep

name	osgrep
description	Semantic code search using natural language queries. Use when users ask "where is X implemented", "how does Y work", "find the logic for Z", or need to locate code by concept rather than exact text. Returns file paths with line numbers and code snippets.
allowed-tools	Bash(osgrep:*), Read
license	Apache-2.0

When to Use

Use this to find code by concept or behavior (e.g., "where is auth validated", "how are plugins loaded"). Note: This tool prioritizes finding the right files and locations in the code. Snippets are truncated (max 16 lines) and are often just previews.

Example:

osgrep "how are plugins loaded"
osgrep "how are plugins loaded" packages/transformers.js/src

Strategy for Different Query Types

For Architectural/System-Level Questions (auth, LSP integration, file watching)

1. Search Broadly First: Use a conceptual query to map the landscape.
   • osgrep "authentication authorization checks"
2. Survey the Results: Look for patterns across multiple files:
   • Are checks in middleware? Decorators? Multiple services?
   • Do file paths suggest different layers (gateway, handlers, utils)?
3. Read Strategically: Pick 2-4 files that represent different aspects:
   • Read the main entry point
   • Read representative middleware/util files
   • Follow imports if architecture is unclear
4. Refine with Specific Searches: If one aspect is unclear:
   • osgrep "session validation logic"
   • osgrep "API authentication middleware"

For Targeted Implementation Details (specific function, algorithm)

1. Search Specifically: Ask about the precise logic.
   • osgrep "logic for merging user and default configuration"
2. Evaluate the Semantic Match:
   • Does the snippet look relevant?
   • Crucial: If it ends in ... or cuts off mid-logic, read the file.
3. One Search, One Read: Use osgrep to pinpoint the best file, then read it fully.

Output Format

Returns: path/to/file:line [Tags] Code Snippet

• [Definition]: Semantic search detected a class/function here. High relevance.
• ...: Truncation Marker. Snippet is incomplete—use read_file for full context.

Tips

• Trust the Semantics: You don't need exact names. osgrep "how does the server start" works better than guessing osgrep "server.init".
• Watch for Distributed Patterns: If results span 5+ files in different directories, the feature is likely architectural—survey before diving deep.
• Scope When Possible: Use path constraints to focus: osgrep "auth" src/server/
• Don't Over-Rely on Snippets: For architectural questions, snippets are signposts, not answers. Read the key files.
• "Still Indexing...": If you see this, please stop, alert the user that the index is ongoing and ask them if they wish to proceed. Results will be partial until the index is complete.