What is Claude-devtools?
Claude-devtools is a debugging tool designed for Claude Code that restores visibility into session logs hidden by the terminal. Since Claude Code v2.1.20, detailed output was replaced with opaque summaries, sparking community backlash. This tool reads session logs from `~/.claude/` on your machine, revealing everything Claude Code does behind the scenes—without modifying the tool or acting as a wrapper.
Key features include per-turn token attribution across seven categories: CLAUDE.md (global, project, directory), skill activations, @-mentioned files, tool I/O, thinking, team overhead, and user text. It visualizes context filling, compression during compaction, and refilling, allowing you to see exactly what was in the window at any point. The tool also provides exact inputs and outputs for every Read, Edit, Bash, and Grep call, along with per-agent tool traces showing tokens, duration, and cost.
Benefits include the ability to inspect reasoning steps that the terminal hides, which often contain surprising decisions. You can track how sub-agents hand off work and what each one sees, view actual file diffs, and see what filled the context—CLAUDE.md, @-mentions, skills, and tool output. The built-in `--verbose` option dumps raw JSON noise, but claude-devtools presents data cleanly with syntax highlighting for Read calls, inline Edit diffs, Bash output, and subagent execution trees.
Use cases include debugging complex Claude Code sessions, optimizing token usage, understanding context limits, and auditing agent behavior. It works on macOS, Linux, and Windows, and supports every session you've ever run. Copying from the terminal is awkward due to selection wrapping and ANSI codes, but claude-devtools renders messages, tool calls, and outputs as real selectable text—one click copies code blocks, file paths, or entire responses. Per-project Claude memory is also accessible via a dedicated pane, showing MEMORY.md and layer files for working style and architecture notes.
Use Cases
Key Features
session log visibility per turn token attribution context visualization tool I/O inspection sub agent trace tracking file diff viewing reasoning step inspectionWho is it for?
Claude Code users, AI developers, debugging engineers, software engineers, prompt engineers, technical leads
