claude-output-cache

A Claude Code plugin that caches full Bash command outputs and lets you retrieve them via MCP tools.

The problem

Claude Code truncates long command outputs to fit its context window — often appending | tail or only showing the last few hundred lines. When you later need the beginning of that output (where errors often are), the only option is to re-run the command.

This plugin fixes that by caching every Bash command's complete output and exposing MCP tools to selectively re-read it: paginated, grepped, or in full.

How it works

[Claude Code] --PostToolUse hook--> [cache writer] --> /tmp/claude-output-cache/*.json
[Claude Code] --MCP tools-------> [cache reader]  --> /tmp/claude-output-cache/*.json

1. A PostToolUse hook fires after every Bash command, capturing the full output to a JSON file
2. An MCP server exposes tools to list, read, grep, and inspect cached outputs
3. Claude can use these tools to revisit any output without re-running commands

Quick start

# Install
git clone https://github.com/youruser/claude-output-cache ~/Projects/claude-output-cache
cd ~/Projects/claude-output-cache
uv tool install -e .

# Setup (adds hook + registers MCP server)
claude-output-cache setup

# Restart Claude Code

MCP tools

Tool	Description
list_cached_outputs	Browse recent cached command outputs (metadata only)
read_cached_output	Read full or partial output with line-based pagination
grep_cached_output	Search cached outputs with regex, with context lines
cache_status	Cache stats: entry count, total size, age range

Configuration

Environment variables (all optional):

Variable	Default	Description
CLAUDE_OUTPUT_CACHE_DIR	/tmp/claude-output-cache	Cache directory path
CLAUDE_OUTPUT_CACHE_MAX_AGE_HOURS	4	Auto-evict entries older than this
CLAUDE_OUTPUT_CACHE_MAX_SIZE_MB	100	Max total cache size before eviction
CLAUDE_OUTPUT_CACHE_MAX_OUTPUT_BYTES	5242880 (5MB)	Max single output size (truncates)

CLI commands

claude-output-cache setup    # Install hook + MCP server
claude-output-cache status   # Show cache stats
claude-output-cache clean    # Force eviction
claude-output-cache remove   # Uninstall hook + MCP server

Uninstall

claude-output-cache remove
uv tool uninstall claude-output-cache

License

MIT