How to debug Claude Code tool calls
Every tool call expanded — syntax-highlighted Read calls, inline Edit diffs, full Bash output, regex search matches, recursive subagent trees, and rendered Markdown / Mermaid.
In the terminal, Claude Code collapses tool calls into one-line summaries: Read 3 files, Edited 2 files, Ran bash command. You don't see which files, what changed, or what the output was.
claude-devtools expands every tool call with specialized viewers:
- Read calls show syntax-highlighted code with line numbers and the exact file path
- Edit calls show inline diffs with added/removed highlighting
- Bash calls show the full command and output
- Search calls (Grep / Glob) show the regex pattern, matching files, and matched lines
- Subagent (Task) calls show the full execution tree, expandable in-place
- Markdown / Mermaid content from assistant responses renders properly, not as raw text
The --verbose flag in Claude Code dumps raw JSON that includes internal system prompts and thousands of lines of noise. claude-devtools gives you the same information, structured and filterable. For a side-by-side comparison see claude --verbose vs claude-devtools.
Related
Reading Claude Code session transcripts
Claude Code records every session as JSONL in ~/.claude/. claude-devtools parses these transcripts into a chronological conversation with per-tool renderers and cross-session search.
How to view Claude Code token usage
Per-turn token attribution across 7 categories — CLAUDE.md, skills, @-mentions, tool I/O, thinking, team overhead, and user text. Actual numbers, not the opaque progress bar.