rtk
rtk is a Rust CLI proxy that filters and compresses command output before it reaches a coding agent's context, cutting the bash output an agent has to read across more than 100 supported commands.
Hook-based agents rewrite a bash command, such as turning "git status" into "rtk git status", before it runs, while plugin-based agents rewrite commands through their own plugin API; either way the agent gets compact output without calling rtk directly. The hook only covers Bash tool calls, so an agent's built-in read, search or file-listing tools are not automatically rewritten unless invoked as shell commands instead.
Four strategies produce the savings: filtering out noise such as comments and whitespace, grouping similar items like files by directory or errors by type, truncating output while keeping relevant context, and deduplicating repeated log lines with counts. It ships as a single Rust binary with no dependencies, and running it does not interfere with an LLM provider's prompt caching.
Rust, Apache-2.0.