ch - Claude History CLI

A memory-efficient Go CLI tool for viewing Claude Code conversation history, including subagent conversations.

Why ch?

Claude Code's UI shows history for humans. ch exposes it for agentic systems:

• JSON output for programmatic access (--json flag on all commands)
• Memory-efficient streaming handles thousands of conversations without OOM
• Foundation for MCP server wrappers - designed for AI-to-AI context retrieval
• Cross-project search and filtering across all your Claude Code sessions

Disclaimer

This tool accesses Claude Code's local conversation cache (~/.claude/projects/). This is undocumented, unofficial, and not supported by Anthropic. The data format may change without notice. Use at your own risk.

Installation

go install github.com/dmora/ch/cmd/ch@latest

Or build from source:

git clone https://github.com/dmora/ch.git
cd ch
go build -o ch ./cmd/ch

Commands

Command	Description
ch list	List conversations (table format)
ch show <id>	Show specific conversation
ch search <query>	Search across conversations
ch resume <id>	Resume conversation in Claude Code
ch agents <id>	List agents spawned by a conversation
ch projects	List all projects
ch stats	Show usage statistics

Flags

list

• -a, --agents - Include agent/subagent conversations
• -p, --project <name> - Filter by project
• -n, --limit <num> - Limit results (default 50)
• -g, --global - All projects (default: current dir's project)
• --json - JSON output

show

• --thinking - Include thinking blocks
• --tools - Include tool calls
• --json - JSON output
• --raw - Raw JSONL output

search

• -a, --agents - Include agent conversations
• -p, --project <name> - Filter by project
• -n, --limit <num> - Limit results (default 20)
• -g, --global - Search all projects
• -c, --case-sensitive - Case-sensitive search
• --json - JSON output

Examples

# List recent 50 conversations in current project
ch list

# List all conversations including agents
ch list -a

# List from all projects globally
ch list -g -n 100

# Show specific conversation with thinking blocks
ch show abc123 --thinking

# Search for "docker" in all projects
ch search "docker" -g

# Resume a conversation
ch resume abc123

# List agents for a conversation
ch agents abc123

# List projects
ch projects

# Show stats
ch stats

Memory Efficiency

Unlike tools that load entire conversation files into memory, ch uses:

• Streaming JSONL parsing - Only parses one line at a time
• Lazy content loading - Only loads full content when displaying specific conversations
• Worker pool with bounded concurrency - Parallel processing without memory explosion
• Byte-level quick checks - Avoids JSON parsing when possible

This allows ch to handle conversation histories with thousands of files totaling gigabytes of data without running out of memory.

Environment Variables

• CLAUDE_PROJECTS_DIR - Override the default projects directory (~/.claude/projects)
• CLAUDE_BIN - Override the Claude CLI binary path (default: claude)

Testing

# Run all tests
go test ./...

# Run with coverage
go test ./... -cover

# Run e2e tests
go test -v -run TestE2E

License

MIT