tail

tail-claude-plugin

Run applications in background sub-processes and stream their logs back to Claude.

Features

• start_process -- launch any shell command in the background (supports cwd and env)
• tail_logs -- show the last N lines of output (optional regex pattern filter)
• read_logs -- stream new output since last read (optional regex pattern filter)
• wait_for -- block until output matches a pattern, goes idle, exits, or times out
• kill_process -- send a signal to stop a process and its child tree
• restart_process -- stop (waiting for full exit) and re-launch a process
• list_processes -- show all managed processes
• remove_process -- clean up finished processes

Install

Add the Fingerskier marketplace and install:

claude plugin marketplace add fingerskier/claude-plugins
claude plugin install tail@fingerskier-plugins

Or install directly via npm:

claude mcp add tail -- npx -y tail-claude-plugin

Usage

Once installed, Claude has access to the tail: tools. Examples:

> Start a dev server and show me the logs

Claude will call tail:start_process with command "npm run dev",
then tail:read_logs to show the startup output.

> Restart the server and tail the last 100 lines

Claude will call tail:restart_process, then tail:tail_logs with lines=100.

How It Works

The plugin runs an MCP server that manages child processes. Each process's stdout and stderr are decoded line-by-line (partial lines buffered, CRLF and ANSI color codes stripped) into an in-memory ring buffer (up to 10,000 lines). Claude can then query those logs at any time using tail_logs (last N lines), read_logs (streaming cursor), or block on wait_for until something interesting happens.

Processes (and their child trees) persist for the lifetime of the MCP server session. When the session ends -- the client disconnects or the server receives SIGINT/SIGTERM -- all managed processes are stopped, so nothing is left orphaned.

License

MIT