OpenTelemetry Tracing Support (Opt-In)

What: Comprehensive distributed tracing infrastructure for monitoring Claude Code's internal operations, API calls, and performance metrics. This feature is disabled by default and requires explicit opt-in.

How to use:

# Enable telemetry
export CLAUDE_CODE_ENABLE_TELEMETRY=true

# Configure where traces are exported (optional)
export OTEL_TRACES_EXPORTER=console  # or "otlp" for OpenTelemetry collectors

# Privacy controls (optional - both default to redacted)
export OTEL_LOG_USER_PROMPTS=true     # Log user prompts in traces
export OTEL_LOG_MODEL_RESPONSE=true   # Log model responses in traces

Details:

• Tracks user interactions, LLM API requests/responses, and tool executions
• Privacy-conscious by default: User prompts and model responses are redacted unless explicitly enabled via OTEL_LOG_USER_PROMPTS and OTEL_LOG_MODEL_RESPONSE
• Supports multiple export formats:
• console - Output traces to console for debugging
• otlp - Export to OpenTelemetry Protocol collectors (supports gRPC, HTTP/JSON, HTTP/Protobuf)
• Records detailed metrics: token counts (input, output, cache read, cache creation), latency, success/failure rates
• Full OpenTelemetry specification compliance with 15+ configuration environment variables
• Configurable sampling strategies via OTEL_TRACES_SAMPLER (defaults to parentbased_always_on)
• Batch span processor with tunable performance parameters
• Evidence: DiB() at line 2314, JiB() at line 2048, Jb0() at line 2087, cL5() at line 2277

Supported Environment Variables:

Telemetry Control:

• CLAUDE_CODE_ENABLE_TELEMETRY - Master switch (default: disabled)
• OTEL_LOG_USER_PROMPTS - Include user prompts in traces (default: redacted)
• OTEL_LOG_MODEL_RESPONSE - Include model responses in traces (default: redacted)

Export Configuration:

• OTEL_TRACES_EXPORTER - Exporters: "console", "otlp" (comma-separated)
• OTEL_EXPORTER_OTLP_TRACES_PROTOCOL - Protocol: "grpc", "http/json", "http/protobuf"
• OTEL_EXPORTER_OTLP_PROTOCOL - Default protocol for all signals

Sampling:

• OTEL_TRACES_SAMPLER - Sampler type (default: "parentbased_always_on")
• OTEL_TRACES_SAMPLER_ARG - Sampler configuration (e.g., ratio for TraceIdRatioBased)

Span Limits:

• OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT - Max attribute value length (unlimited by default)
• OTEL_ATTRIBUTE_COUNT_LIMIT - Max attributes per span (default: 128)
• OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT - Span-specific attribute value limit
• OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT - Span-specific attribute count (default: 128)
• OTEL_SPAN_LINK_COUNT_LIMIT - Max links per span (default: 128)
• OTEL_SPAN_EVENT_COUNT_LIMIT - Max events per span (default: 128)
• OTEL_SPAN_ATTRIBUTE_PER_EVENT_COUNT_LIMIT - Max attributes per event (default: 128)
• OTEL_SPAN_ATTRIBUTE_PER_LINK_COUNT_LIMIT - Max attributes per link (default: 128)

Batch Processor:

• OTEL_BSP_MAX_EXPORT_BATCH_SIZE - Batch size (default: 512)
• OTEL_BSP_MAX_QUEUE_SIZE - Queue size (default: 2048)
• OTEL_BSP_SCHEDULE_DELAY - Export delay in ms (default: 5000)
• OTEL_BSP_EXPORT_TIMEOUT - Timeout in ms (default: 30000)