LLM Analytics — Claude Code Setup

Help the user configure PostHog LLM Analytics for Claude Code session capture.

What this does

When enabled, every Claude Code session is automatically sent to PostHog's LLM Analytics as $ai_generation, $ai_span, and $ai_trace events — giving visibility into model usage, token consumption, tool calls, and costs.

Configuration

Both POSTHOG_LLMA_CC_ENABLED=true and POSTHOG_API_KEY are required. Set them via environment variables — either in your shell profile or in Claude Code's settings.json env block.

Required

• POSTHOG_LLMA_CC_ENABLED — Set to true to enable (must be explicitly opted in)
• POSTHOG_API_KEY — PostHog project API key (starts with phc_)

Optional

• POSTHOG_HOST — PostHog instance URL (default: https://us.i.posthog.com, use https://eu.i.posthog.com for EU)
• POSTHOG_LLMA_PRIVACY_MODE — Set to true to redact prompt/output content (tokens and costs still captured)
• POSTHOG_LLMA_DISTINCT_ID — Override the distinct_id (default: git user email)
• POSTHOG_LLMA_TRACE_GROUPING — session (default) or message
• POSTHOG_LLMA_CUSTOM_PROPERTIES — JSON object of custom properties added to all events (e.g. {"ai_product": "my-app"})

Steps

1. Check if the env vars are already set
2. If the user provided an API key as an argument ($ARGUMENTS), guide them to set it
3. Help them choose US or EU hosting
4. Offer them a choice of how to configure

Option 1: Claude Code settings.json (recommended)

For global setup, add to ~/.claude/settings.json:

{
  "env": {
    "POSTHOG_LLMA_CC_ENABLED": "true",
    "POSTHOG_API_KEY": "phc_...",
    "POSTHOG_HOST": "https://eu.i.posthog.com"
  }
}

For per-project setup, add to .claude/settings.local.json:

{
  "env": {
    "POSTHOG_LLMA_CC_ENABLED": "true",
    "POSTHOG_API_KEY": "phc_...",
    "POSTHOG_HOST": "https://eu.i.posthog.com"
  }
}

Custom properties

To tag all events with custom properties (e.g. for filtering in PostHog):

{
  "env": {
    "POSTHOG_LLMA_CC_ENABLED": "true",
    "POSTHOG_API_KEY": "phc_...",
    "POSTHOG_LLMA_CUSTOM_PROPERTIES": "{\"ai_product\": \"my-app\", \"team\": \"platform\"}"
  }
}

Option 2: Shell profile

export POSTHOG_LLMA_CC_ENABLED=true
export POSTHOG_API_KEY="phc_..."
export POSTHOG_HOST="https://eu.i.posthog.com"  # for EU, omit for US
export POSTHOG_LLMA_CUSTOM_PROPERTIES='{"ai_product": "my-app"}'  # optional

Check current status

echo "POSTHOG_LLMA_CC_ENABLED=${POSTHOG_LLMA_CC_ENABLED:-(not set, defaults to false)}"
echo "POSTHOG_API_KEY=${POSTHOG_API_KEY:-(not set)}"
echo "POSTHOG_HOST=${POSTHOG_HOST:-(not set, defaults to US)}"
echo "POSTHOG_LLMA_PRIVACY_MODE=${POSTHOG_LLMA_PRIVACY_MODE:-(not set, defaults to false)}"
echo "POSTHOG_LLMA_CUSTOM_PROPERTIES=${POSTHOG_LLMA_CUSTOM_PROPERTIES:-(not set)}"