trace-claude-code

Trace Claude Code to Braintrust

Automatically send Claude Code conversations to Braintrust for tracing and observability. Get full visibility into your AI coding sessions with hierarchical traces showing sessions, turns, and every tool call.

What you get

Claude Code Session (root trace)
├── Turn 1: "Add error handling"
│   ├── Read: src/app.ts
│   ├── Edit: src/app.ts
│   └── Response: "I've added try-catch..."
├── Turn 2: "Now run the tests"
│   ├── Terminal: npm test
│   └── Response: "All tests pass..."
└── Turn 3: "Great, commit this"
    ├── Terminal: git add .
    ├── Terminal: git commit -m "..."
    └── Response: "Changes committed..."

How it works

Four hooks capture the complete workflow:

Hook	What it captures
SessionStart	Creates root trace when you start Claude Code
PostToolUse	Captures every tool call (file reads, edits, terminal commands)
Stop	Captures conversation turns (your message + Claude's response)
SessionEnd	Logs session summary when you exit

Quick setup

Run the setup script in any project directory where you want tracing:

bash /path/to/skills/trace-claude-code/setup.sh

The script prompts for your API key and project name, then configures all hooks automatically.

Manual setup

Prerequisites

• Claude Code CLI installed
• Braintrust API key
• jq command-line tool (brew install jq on macOS)

Configuration

Create .claude/settings.local.json in your project directory:

{
  "hooks": {
    "SessionStart": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "bash /path/to/hooks/session_start.sh"
          }
        ]
      }
    ],
    "PostToolUse": [
      {
        "matcher": "*",
        "hooks": [
          {
            "type": "command",
            "command": "bash /path/to/hooks/post_tool_use.sh"
          }
        ]
      }
    ],
    "Stop": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "bash /path/to/hooks/stop_hook.sh"
          }
        ]
      }
    ],
    "SessionEnd": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "bash /path/to/hooks/session_end.sh"
          }
        ]
      }
    ]
  },
  "env": {
    "TRACE_TO_BRAINTRUST": "true",
    "BRAINTRUST_API_KEY": "sk-...",
    "BRAINTRUST_CC_PROJECT": "my-project"
  }
}