Capture the history of a pane.
AI agents call capture_history to retrieve information from TmuxControlLib MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves historical data from a tmux pane's scrollback buffer. It performs a read-only query operation with no side effects—it does not modify, delete, or execute commands. The worst-case misuse would be unauthorized access to sensitive terminal history, which is a data exposure risk rather than a destructive or execution risk.
From the tool's definition Tool name 'capture_history' and description 'Capture the history of a pane' indicate data retrieval without modification. The action is to read/extract terminal output history, analogous to the sibling tool 'capture_pane' which retrieves pane content.
Attacks that exploit this kind of access
Capture the history of a pane. It is categorised as a Read tool in the TmuxControlLib MCP Server MCP Server, which means it retrieves data without modifying state.
Register the TmuxControlLib MCP Server MCP server in PolicyLayer and add a rule for capture_history: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches TmuxControlLib MCP Server. Nothing to install.
capture_history is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the capture_history rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for capture_history. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
capture_history is provided by the TmuxControlLib MCP Server MCP server (jbwinters/tmuxcontrollib). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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