Claude Code

Claude Code emits structured telemetry for every developer session: prompts submitted, tools invoked, API calls made, and costs incurred. Routing this data to Last9 lets you analyze AI usage patterns, track per-user spend, audit tool decisions, and alert on error rates — all within your existing observability stack.

Claude Code exports three OpenTelemetry signal types:

• Logs — individual events per prompt, API call, tool execution, and error
• Metrics — aggregated counters for cost, tokens, sessions, and code edits
• Traces (beta) — span-based correlation linking a prompt to all its API calls and tool executions

What gets exported

Logs (events)

Claude Code exports five event types as OpenTelemetry log records. All share a prompt.id UUID that lets you reconstruct the full sequence for a single user interaction.

Metrics

Claude Code exports eight counters as OpenTelemetry metrics. These are aggregated — no per-prompt IDs — making them low-cardinality and suitable for dashboards and alerts.

Prerequisites

1. Last9 account — Sign up at app.last9.io
2. Claude Code — Installed and authenticated (claude --version should work)
3. OTLP credentials — Get your endpoint and auth header from Integrations → OpenTelemetry

Setup

1. Get your Last9 OTLP credentials

   Navigate to Integrations → OpenTelemetry in your Last9 dashboard. Copy:

   • OTLP Endpoint (e.g., https://otlp-aps1.last9.io:443)
   • Authorization header (e.g., Basic <base64-token>)

2. Set environment variables

   Add the following to your shell profile (~/.zshrc, ~/.bashrc, or equivalent):

   • Logs + Metrics (recommended)
   • Logs only
   • Metrics only

   # Required: enable Claude Code telemetry
   export CLAUDE_CODE_ENABLE_TELEMETRY=1
   
   # Export both logs and metrics to Last9
   export OTEL_LOGS_EXPORTER=otlp
   export OTEL_METRICS_EXPORTER=otlp
   
   # Last9 OTLP destination
   export OTEL_EXPORTER_OTLP_ENDPOINT="https://<your-last9-otlp-endpoint>"
   export OTEL_EXPORTER_OTLP_HEADERS="Authorization=Basic <your-last9-auth-token>"
   export OTEL_EXPORTER_OTLP_PROTOCOL=http/json
   
   # Required for metrics: Last9 expects cumulative counters
   export OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE=cumulative
   
   # Required for traces: currently in beta
   export CLAUDE_CODE_ENHANCED_TELEMETRY_BETA=1
   
   # Identify your sessions
   export OTEL_SERVICE_NAME="claude-code"
   export OTEL_RESOURCE_ATTRIBUTES="deployment.environment=local,team=<your-team>"

   Then reload your shell:

   source ~/.zshrc

3. Start a Claude Code session

   claude "summarize what this repo does"

   • Logs flush within 5 seconds of each event
   • Metrics flush every 60 seconds by default

4. Verify data is arriving

   • Logs — navigate to Logs in Last9, filter by service.name = claude-code
   • Metrics — navigate to Metrics, search for claude_code_cost_usage_total

Configuration reference

Core

Logs

Metrics

What you can do in Last9

Cost and spend tracking (metrics)

claude_code.cost.usage is a counter broken down by model and user.email. In Last9 Metrics, query the rate to get spend per minute, or sum it over a time window for daily/weekly totals:

• Dashboard total team spend across all models
• Break down by user.email to see per-developer cost
• Alert when cumulative cost crosses a budget threshold

Token efficiency (metrics)

claude_code.token.usage tracks input, output, cache read, and cache creation tokens separately. Compare cacheRead / input ratio to measure prompt cache efficiency — a high ratio means less spend per interaction.

Session replay via prompt.id (logs)

Every log event shares a prompt.id UUID. Filter Last9 Logs by a specific prompt.id to reconstruct the full sequence for one user interaction:

user_prompt → api_request → tool_decision → tool_result → api_request

Useful for debugging slow sessions or unexpected tool rejections.

Tool usage audit (logs)

claude_code.tool_decision events record every permission decision with tool.decision = accept | reject and decision.source. Surface which tools are most frequently rejected and whether your --allowedTools policies are working.

Code output tracking (metrics)

claude_code.lines_of_code.count and claude_code.commit.count let you measure developer output attributable to Claude Code sessions — useful for adoption reporting.

Error rate monitoring (logs + alerts)

claude_code.api_error events include http.status_code and retry_attempt. Create a Last9 alert on error rate spikes to catch Claude API degradation before users report it.

Team-level tagging

For organizations with multiple teams, use OTEL_RESOURCE_ATTRIBUTES to tag sessions by team or project:

export OTEL_RESOURCE_ATTRIBUTES="deployment.environment=production,team=platform,project=infra-agent"

All signals from that session carry team and project labels, enabling per-team cost breakdowns in Last9.

Troubleshooting

No logs in Last9 after running Claude Code

• Confirm CLAUDE_CODE_ENABLE_TELEMETRY=1 is set in the same shell session where you run claude — export does not persist across tabs or new sessions
• Set OTEL_EXPORTER_OTLP_PROTOCOL=http/json — Last9’s endpoint requires HTTP, not gRPC (the OTel SDK default)
• Check that OTEL_LOGS_EXPORTER=otlp (not none or console)
• Wait at least 10 seconds — the default export interval is 5s and there may be one flush delay

No metrics appearing

• Set OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE=cumulative — Claude Code defaults to delta temporality but Last9 requires cumulative counters
• Set OTEL_EXPORTER_OTLP_METRICS_PROTOCOL=http/json if the global protocol var is not being picked up
• Metrics flush every 60 seconds by default — wait at least 90 seconds before checking
• Metric names in Last9 use underscores: claude_code.cost.usage becomes claude_code_cost_usage_total

401 / authentication errors

• Verify the header format: Authorization=Basic <token> (no extra quotes, no Bearer prefix)
• Regenerate the token from Integrations → OpenTelemetry if it has expired

Events appear but user.email is missing

• user.email is only populated when authenticated with a user account (not API key only)
• Run claude --version to confirm you are logged in

Please get in touch with us on Discord or Email if you have any questions.