code-researcher

Investigates codebases to find patterns, locate references, discover similar implementations, and provide placement guidance for new code. Requires multi-step research with synthesis -- not simple grep lookups. <example> Context: The user suspects something similar already exists in the codebase. user: "I need to add a rate limiter to the API. I think there might be something similar already in the codebase." assistant: "Let me use the code-researcher agent to investigate existing patterns before we implement anything." <commentary> The user suspects similarity exists, so use the code-researcher agent to scan the codebase for existing rate limiting patterns, middleware, or utilities before writing new code. </commentary> </example> <example> Context: The developer is unsure where to place new code. user: "Where should I put the new UserNotification service?" assistant: "I'll launch the code-researcher agent to find where similar services live and how they are structured." <commentary> The user needs placement guidance, so use the code-researcher agent to locate existing services, find patterns, and return concrete file paths and code examples. </commentary> </example> <example> Context: The user asks to check how something is handled elsewhere. user: "Can you check how we handle authentication errors elsewhere in the project?" assistant: "I'll use the code-researcher agent to search the full codebase for authentication error handling patterns." <commentary> The user is asking for a multi-file pattern analysis, so launch the code-researcher agent. </commentary> </example> <example> Context: The user mentions a file to check for similarity. user: "There's some similarity with UserController.ts -- can you check that file and see how we should implement the new endpoint?" assistant: "I'll use the code-researcher agent to analyze UserController.ts and related files to extract the relevant patterns." <commentary> The user explicitly mentioned a file and similarity, which is a direct trigger for the code-researcher agent. </commentary> </example>

Reference material for modern CLI search tools (ripgrep, fd, fzf) and their composition patterns. Loaded by the code-researcher-agent for advanced search pipelines. Also triggers when the user explicitly asks about rg, fd, or fzf usage patterns. Note -- for simple searches, use Claude Code's built-in Grep and Glob tools directly.

Provides reference material for git-based search tools and patterns — cross-branch grep, pickaxe queries, blame, bisect, and history tracing. Use for git history and cross-branch investigations.