What is txviewer?

txviewer is a terminal-based viewer for Claude Code sessions. It lets you watch in real time what Claude is doing as it works through a task. The tool reads the transcript files that Claude Code automatically writes to your computer and displays them in a split-pane interface right in your terminal. The left pane shows a list of turns in the current session. The right pane shows details for the selected turn: which tools Claude called, what files it read or edited, what shell commands it ran, and a token usage breakdown for that turn. You can navigate through turns with arrow keys or vi-style shortcuts, toggle live mode to follow along as Claude works, or press "s" to see a session-wide summary with a bar chart of activity. Token tracking is a notable part of the display. Each turn shows how many tokens were served from Anthropic's prompt cache (the cheaper kind), how many were new uncached input, and how many output tokens Claude generated. A cache hit percentage gives a quick sense of how efficiently the session is using context. The session summary can show this data as token spend instead of step count when per-step data is available. The tool runs entirely on Python's standard library, so there is nothing to install beyond Python 3.8 or later. You run it with a single command and it attaches to the most recent active session. You can also pass a session ID or a full file path to open any past session. The README notes it was only tested with one specific version of Claude Code on a Mac, so behavior on other setups may vary.