taxi-blackbox

taxi-blackbox records every tool call Claude Code makes, like a car dashcam (a “black box” in Korea). When a call fails or is denied, /blackbox replays the calls that led up to it, so you can see what Claude was doing just before the accident. The README and the interface are in Korean.

It is one of four mods in devbrothers’ taxi pack, with a fare meter (taxi-meter), a navigation display (taxi-navi) and a speed camera for risky commands (taxi-speedcam). Each one installs on its own.

What it does

• A ● REC line above the prompt shows the date and time, how long the session has run, how many calls it has recorded and, in yellow, the number of incidents. The REC badge blinks while Claude is responding.
• /blackbox opens a pane on the latest incident: a timeline of the session with incidents in red, the five calls before it, and a red card with the failed call and its error or denial message. p and n step to the previous and next incident.
• With no incidents yet, the pane shows the most recent calls instead.
• Each call has a badge coloured by tool: Bash orange, Edit and Write blue, Read and search grey, web tools teal, anything else purple. Calls made by subagents are marked ↳.
• The before setting in /config sets how many calls to show before an incident, from 1 to 20 (default 5).

The labels you will meet: 사고 is an incident, 기록 the recorded calls, 오류 an error and 거부 a denial.

Install

Needs Claude Code 2.1.287 or later.

claude plugin marketplace add devbrother2024/devbrothers-mods
claude plugin install taxi-blackbox@devbrothers-mods

Run /reload-plugins or restart Claude Code, and the REC line appears above the prompt. Type /blackbox for the replay. With the fullscreen renderer ("tui": "fullscreen") and a terminal 110 columns or wider, the pane docks on the right; otherwise it opens above the prompt.

Mods run in the order you install them, so if you also use taxi-speedcam, install taxi-blackbox first and the commands the camera stops are recorded as incidents.

How it works

The mod wraps every tool call, subagents’ included, and keeps one frame per call: the time, the tool, one line describing the call (the command, file path, pattern, URL, query or prompt, cut to 90 characters) and whether it succeeded, failed or was denied, with the error or denial text cut to 160 characters. Values that look like secrets (token=, password=, api_key=, Bearer headers, and keys starting with sk-, ghp_, xoxb- or AKIA) become ••• before the frame is stored.

Frames live only in memory, up to the last 500 calls of the session. Nothing is written to disk and nothing goes over the network: the hooks module uses only the clock, command and interface methods, which the calls: line of claude plugin validate shows. Tool results pass through untouched, so Claude sees nothing different and the mod costs no tokens.

Limitations

• The recording ends with the session and there is no export. Past 500 calls the oldest frames are dropped, though the counter still counts them.
• Masking only catches the patterns above. A secret in any other shape is kept as written, in memory.
• The author documents the terminal and the Desktop Code tab for local sessions. Desktop has no raster graphics, so the pane loses its timeline there. The VS Code extension chat, claude -p and the Agent SDK draw nothing.
• The author built and tested it on Claude Code 2.1.289 and warns that the mods API can change between releases.