Claude Code

Claude Code is a transparent client: sqz init installs hooks that route shell commands through sqz on their own, and registers the sqz MCP server.

Setup

1. Run sqz init

sqz init            # this project: .claude/settings.local.json
sqz init --global   # every project: ~/.claude/settings.json

The settings file gets these hooks:

• PreToolUse (Bash and PowerShell): sqz hook claude rewrites the command so its output is piped through sqz compress.
• PostToolUse (Bash): sqz hook claude-post compresses the stdout and stderr of a successful command the PreToolUse hook left alone, through updatedToolOutput. Output Claude Code already cut to a preview (BASH_MAX_OUTPUT_LENGTH), images and interrupted commands are left as they are. It always answers with the compressed text, never a §ref: with the hook installed twice, a reference from the second run pointed at output the model never saw. The original is still stored, so an sqz expand hint in the output works.
• PreCompact: sqz hook precompact marks cached references stale when Claude Code compacts.
• SessionStart (after compaction): sqz resume re-injects the session context.

It also adds two allow rules to permissions.allow, Bash(set -o pipefail) and Bash(sqz compress --cmd *), which cover only the parts the rewrite adds. The hook does not approve commands: Claude Code’s own permission rules still decide whether a command runs or asks first. When Claude Code asks, or denies a command, its message quotes the rewritten command, such as set -o pipefail; git tag v0 2>&1 for git tag v0. Until both rules are there the hook leaves commands alone. Outside bypass mode, pipelines, loops and heredocs are left as written. In every mode, so is a list where one of the piped commands could stop the shell on a failed expansion (${DEST:?}, $((1/0)), and unless $SHELL is bash an unquoted glob that matches nothing, =cmd or ~user) and more commands follow after ;, || or a newline: piped on its own, the failing command would stop only its pipe and the rest would run. Bypass mode pipes pipelines and loops as one group, and leaves one as written when the group could run different commands than the original: when its leading cd dir && is followed by ;, || or another line, or, with bash as $SHELL, when lines follow one with an expansion such as $((...)), since bash would still run them if it failed.

Your existing settings are kept; sqz merges its entries. If ~/.claude/settings.json already has the sqz hooks, sqz init at project scope leaves them out of .claude/settings.local.json; sqz doctor flags a project copy, and sqz doctor --fix removes it and keeps the file’s permissions.

2. MCP server

sqz init adds the server to ~/.claude.json (user scope, with or without --global):

{
  "mcpServers": {
    "sqz": {
      "command": "sqz-mcp",
      "args": ["--transport", "stdio"]
    }
  }
}

It also writes a guidance block to CLAUDE.md in the project.

3. Verify

sqz doctor

Claude Code should show as configured, transparent. Doctor also flags an older install without the allow rules and an outdated CLAUDE.md block (sqz doctor --fix adds the rules and replaces the block).

What you get

• Shell output compressed before it reaches the context window
• Repeated output replaced by a short §ref:HASH§ reference, re-sent in full after compaction
• sqz_read_file, sqz_grep and sqz_list_dir for reads the hook cannot see: Claude Code’s built-in Read tool does not go through Bash, and sqz does not rewrite its results

Uninstall

sqz uninstall

Removes sqz’s hooks and allow rules from the settings file, the guidance block from CLAUDE.md and the sqz entry from ~/.claude.json, leaving everything else.