Claude DevTools

Claude DevTools is a companion application for Claude Code that lets you inspect, analyze, and compare your AI coding sessions in a graphical interface. While Claude Code runs in the terminal and produces a stream of actions (file reads, code edits, command executions), Claude DevTools presents that session data visually—conversation threads, tool call trees, token usage breakdowns, and side-by-side session comparisons. The core use case is understanding how Claude approached a task. After Claude Code finishes refactoring a module, Claude DevTools shows you the full session: what files Claude read first, what questions it asked itself, which tool calls it made, where it backtracked, and how many tokens each step consumed. This visibility helps you write better prompts—if Claude spent 60% of tokens reading irrelevant files, you know to narrow the context next time. The conversation inspector shows the full message exchange between you and Claude, including system prompts, user messages, assistant responses, and tool calls. Each tool call (file read, file write, bash command) is expandable with input/output details. You can see exactly what Claude saw when it read a file, what it wrote, and what command output it processed. For debugging unexpected behavior ('why did Claude modify that file?'), the conversation inspector provides the answer. Token usage analytics break down consumption by category: input tokens (context sent to Claude), output tokens (Claude's responses), and tool call tokens. Bar charts show which messages consumed the most tokens—often the initial codebase read is the biggest cost. Understanding token distribution helps optimize prompts: if context is the dominant cost, you can exclude irrelevant files; if output is the dominant cost, you can ask for shorter responses. Session comparison lets you run the same task with different prompts and compare the results side by side. Did prompt A produce better code than prompt B? Did it use fewer tokens? Did it take fewer steps? For developers refining their AI workflow, this is prompt engineering with actual data instead of guessing. Claude DevTools reads local session data from Claude Code—it doesn't make API calls, doesn't need your Anthropic API key, and doesn't send your code anywhere. It's a local analysis tool for understanding and improving how you work with Claude.