Analytics & Telemetry

How Claude Code collects usage data, evaluates feature flags, and exports observability signals.

Feature Flags (GrowthBook)

Claude Code uses GrowthBook for feature flag evaluation:

🏷️

GrowthBook Service

🚩

90+ Feature Flags

Build-time or Runtime?

Build-time: bun:bundle feature() — dead code elimination

Runtime: GrowthBook SDK evaluation

Build-Time Flags

The majority of flags are resolved at build time via Bun's feature() API:

import { feature } from 'bun:bundle'

// Replaced with true/false at build time
// Dead branch eliminated from bundle
if (feature('COORDINATOR_MODE')) {
  // This entire block is removed in the public build
}

Runtime Flags

Some flags are evaluated at runtime via the GrowthBook SDK, allowing A/B testing and gradual rollouts without rebuilding.

Flag Categories

Category	Examples	Default (Public Build)
Core features	BUILTIN_EXPLORE_PLAN_AGENTS, TOKEN_BUDGET, MCP_SKILLS	true
Internal features	COORDINATOR_MODE, KAIROS, DAEMON	false
Experimental	VOICE_MODE, WEB_BROWSER_TOOL, BRIDGE_MODE	false
Ablation	ABLATION_BASELINE	false

See the Feature Flags Appendix for the complete list.

Event Pipeline

⚡

User/System Action

📊

logEvent()

Event Sink

First-Party Analytics

📊

Datadog

OpenTelemetry Export

Traces

Metrics

Logs

What's Tracked

Event Type	Examples
Session events	Session start, end, duration
Tool usage	Tool name, execution time, success/failure
Model usage	Tokens consumed, model used, cache hits
Command usage	Which slash commands are used
Error events	Error types, stack traces

Event Metadata

Each event includes:

• Session ID
• User context (anonymous)
• Tool names and outcomes
• Token counts
• Timestamps

OpenTelemetry

Claude Code has comprehensive OpenTelemetry instrumentation:

Exporters

Signal	Supported Exporters
Traces	OTLP (gRPC, HTTP, Proto)
Metrics	OTLP (gRPC, HTTP, Proto), Prometheus
Logs	OTLP (gRPC, HTTP, Proto)

What's Instrumented

• API call latency and token usage
• Tool execution timing
• MCP server connection lifecycle
• Session duration and message count

Killswitch

Telemetry can be disabled:

• Environment variable: CLAUDE_CODE_DISABLE_TELEMETRY=1
• Settings: telemetry disabled in settings.json
• Enterprise policy: admin can disable telemetry fleet-wide

When disabled, no events are collected or transmitted.

Key Source Files

File	Purpose
src/services/analytics/	GrowthBook, event pipeline, telemetry
src/services/analytics/growthbook.ts	Feature flag evaluation
src/services/analytics/telemetry.ts	OpenTelemetry setup