Observability with OpenTelemetry

Learn how to enable and setup OpenTelemetry for Gemini CLI.

Observability with OpenTelemetry

Key Benefits

🔍 Usage Analytics: Understand interaction patterns and feature adoption across your team
⚡ Performance Monitoring: Track response times, token consumption, and resource utilization
🐛 Real-time Debugging: Identify bottlenecks, failures, and error patterns as they occur
📊 Workflow Optimization: Make informed decisions to improve configurations and processes
🏢 Enterprise Governance: Monitor usage across teams, track costs, ensure compliance, and integrate with existing monitoring infrastructure

OpenTelemetry Integration

Built on OpenTelemetry — the vendor-neutral, industry-standard observability framework — Gemini CLI’s observability system provides:

Universal Compatibility: Export to any OpenTelemetry backend (Google Cloud, Jaeger, Prometheus, Datadog, etc.)
Standardized Data: Use consistent formats and collection methods across your toolchain
Future-Proof Integration: Connect with existing and future observability infrastructure
No Vendor Lock-in: Switch between backends without changing your instrumentation

Configuration

All telemetry behavior is controlled through your .gemini/settings.json file. These settings can be overridden by environment variables or CLI flags.

Setting	Environment Variable	CLI Flag	Description	Values	Default
`enabled`	`GEMINI_TELEMETRY_ENABLED`	`--telemetry` / `--no-telemetry`	Enable or disable telemetry	`true`/`false`	`false`
`target`	`GEMINI_TELEMETRY_TARGET`	`--telemetry-target <local\|gcp>`	Where to send telemetry data	`"gcp"`/`"local"`	`"local"`
`otlpEndpoint`	`GEMINI_TELEMETRY_OTLP_ENDPOINT`	`--telemetry-otlp-endpoint <URL>`	OTLP collector endpoint	URL string	`http://localhost:4317`
`otlpProtocol`	`GEMINI_TELEMETRY_OTLP_PROTOCOL`	`--telemetry-otlp-protocol <grpc\|http>`	OTLP transport protocol	`"grpc"`/`"http"`	`"grpc"`
`outfile`	`GEMINI_TELEMETRY_OUTFILE`	`--telemetry-outfile <path>`	Save telemetry to file (overrides `otlpEndpoint`)	file path	-
`logPrompts`	`GEMINI_TELEMETRY_LOG_PROMPTS`	`--telemetry-log-prompts` / `--no-telemetry-log-prompts`	Include prompts in telemetry logs	`true`/`false`	`true`
`useCollector`	`GEMINI_TELEMETRY_USE_COLLECTOR`	-	Use external OTLP collector (advanced)	`true`/`false`	`false`

Note on boolean environment variables: For the boolean settings (enabled, logPrompts, useCollector), setting the corresponding environment variable to true or 1 will enable the feature. Any other value will disable it.

For detailed information about all configuration options, see the Configuration Guide.

Google Cloud Telemetry

Prerequisites

Before using either method below, complete these steps:

Set your Google Cloud project ID:
- For telemetry in a separate project from inference:
  Terminal window
```
export OTLP_GOOGLE_CLOUD_PROJECT="your-telemetry-project-id"
```
- For telemetry in the same project as inference:
  Terminal window
```
export GOOGLE_CLOUD_PROJECT="your-project-id"
```

Authenticate with Google Cloud:

If using a user account:
Terminal window
```
gcloud auth application-default login
```

If using a service account:

export GOOGLE_APPLICATION_CREDENTIALS="/path/to/your/service-account.json"

Make sure your account or service account has these IAM roles:
- Cloud Trace Agent
- Monitoring Metric Writer
- Logs Writer

Enable the required Google Cloud APIs (if not already enabled):

gcloud services enable \
  cloudtrace.googleapis.com \
  monitoring.googleapis.com \
  logging.googleapis.com \
  --project="$OTLP_GOOGLE_CLOUD_PROJECT"

Direct Export (Recommended)

Sends telemetry directly to Google Cloud services. No collector needed.

Enable telemetry in your .gemini/settings.json:

{
  "telemetry": {
    "enabled": true,
    "target": "gcp"
  }
}

Run Gemini CLI and send prompts.
View logs and metrics:
- Open the Google Cloud Console in your browser after sending prompts:
  - Logs: https://console.cloud.google.com/logs/
  - Metrics: https://console.cloud.google.com/monitoring/metrics-explorer
  - Traces: https://console.cloud.google.com/traces/list

Collector-Based Export (Advanced)

For custom processing, filtering, or routing, use an OpenTelemetry collector to forward data to Google Cloud.

Configure your .gemini/settings.json:

{
  "telemetry": {
    "enabled": true,
    "target": "gcp",
    "useCollector": true
  }
}

Run the automation script:
Terminal window
```
npm run telemetry -- --target=gcp
```
This will:
- Start a local OTEL collector that forwards to Google Cloud
- Configure your workspace
- Provide links to view traces, metrics, and logs in Google Cloud Console
- Save collector logs to ~/.gemini/tmp/<projectHash>/otel/collector-gcp.log
- Stop collector on exit (e.g. Ctrl+C)
Run Gemini CLI and send prompts.
View logs and metrics:
- Open the Google Cloud Console in your browser after sending prompts:
  - Logs: https://console.cloud.google.com/logs/
  - Metrics: https://console.cloud.google.com/monitoring/metrics-explorer
  - Traces: https://console.cloud.google.com/traces/list
- Open ~/.gemini/tmp/<projectHash>/otel/collector-gcp.log to view local collector logs.

Local Telemetry

For local development and debugging, you can capture telemetry data locally:

File-based Output (Recommended)

Enable telemetry in your .gemini/settings.json:

{
  "telemetry": {
    "enabled": true,
    "target": "local",
    "otlpEndpoint": "",
    "outfile": ".gemini/telemetry.log"
  }
}

Run Gemini CLI and send prompts.
View logs and metrics in the specified file (e.g., .gemini/telemetry.log).

Collector-Based Export (Advanced)

Run the automation script:
Terminal window
```
npm run telemetry -- --target=local
```
This will:
- Download and start Jaeger and OTEL collector
- Configure your workspace for local telemetry
- Provide a Jaeger UI at http://localhost:16686
- Save logs/metrics to ~/.gemini/tmp/<projectHash>/otel/collector.log
- Stop collector on exit (e.g. Ctrl+C)
Run Gemini CLI and send prompts.
View traces at http://localhost:16686 and logs/metrics in the collector log file.

Logs and Metrics

The following section describes the structure of logs and metrics generated for Gemini CLI.

A sessionId is included as a common attribute on all logs and metrics.

Logs

Logs are timestamped records of specific events. The following events are logged for Gemini CLI:

gemini_cli.config: This event occurs once at startup with the CLI’s configuration.
- Attributes:
  - model (string)
  - embedding_model (string)
  - sandbox_enabled (boolean)
  - core_tools_enabled (string)
  - approval_mode (string)
  - api_key_enabled (boolean)
  - vertex_ai_enabled (boolean)
  - code_assist_enabled (boolean)
  - log_prompts_enabled (boolean)
  - file_filtering_respect_git_ignore (boolean)
  - debug_mode (boolean)
  - mcp_servers (string)
  - output_format (string: “text” or “json”)
gemini_cli.user_prompt: This event occurs when a user submits a prompt.
- Attributes:
  - prompt_length (int)
  - prompt_id (string)
  - prompt (string, this attribute is excluded if log_prompts_enabled is configured to be false)
  - auth_type (string)
gemini_cli.tool_call: This event occurs for each function call.
- Attributes:
  - function_name
  - function_args
  - duration_ms
  - success (boolean)
  - decision (string: “accept”, “reject”, “auto_accept”, or “modify”, if applicable)
  - error (if applicable)
  - error_type (if applicable)
  - content_length (int, if applicable)
  - metadata (if applicable, dictionary of string -> any)
gemini_cli.file_operation: This event occurs for each file operation.
- Attributes:
  - tool_name (string)
  - operation (string: “create”, “read”, “update”)
  - lines (int, if applicable)
  - mimetype (string, if applicable)
  - extension (string, if applicable)
  - programming_language (string, if applicable)
  - diff_stat (json string, if applicable): A JSON string with the following members:
    - ai_added_lines (int)
    - ai_removed_lines (int)
    - user_added_lines (int)
    - user_removed_lines (int)
gemini_cli.api_request: This event occurs when making a request to Gemini API.
- Attributes:
  - model
  - request_text (if applicable)
gemini_cli.api_error: This event occurs if the API request fails.
- Attributes:
  - model
  - error
  - error_type
  - status_code
  - duration_ms
  - auth_type
gemini_cli.api_response: This event occurs upon receiving a response from Gemini API.
- Attributes:
  - model
  - status_code
  - duration_ms
  - error (optional)
  - input_token_count
  - output_token_count
  - cached_content_token_count
  - thoughts_token_count
  - tool_token_count
  - response_text (if applicable)
  - auth_type
gemini_cli.tool_output_truncated: This event occurs when the output of a tool call is too large and gets truncated.
- Attributes:
  - tool_name (string)
  - original_content_length (int)
  - truncated_content_length (int)
  - threshold (int)
  - lines (int)
  - prompt_id (string)
gemini_cli.malformed_json_response: This event occurs when a generateJson response from Gemini API cannot be parsed as a json.
- Attributes:
  - model
gemini_cli.flash_fallback: This event occurs when Gemini CLI switches to flash as fallback.
- Attributes:
  - auth_type
gemini_cli.slash_command: This event occurs when a user executes a slash command.
- Attributes:
  - command (string)
  - subcommand (string, if applicable)
gemini_cli.extension_enable: This event occurs when an extension is enabled
gemini_cli.extension_install: This event occurs when an extension is installed
- Attributes:
  - extension_name (string)
  - extension_version (string)
  - extension_source (string)
  - status (string)
gemini_cli.extension_uninstall: This event occurs when an extension is uninstalled

Metrics

Metrics are numerical measurements of behavior over time.

Custom

gemini_cli.session.count (Counter, Int): Incremented once per CLI startup.
gemini_cli.tool.call.count (Counter, Int): Counts tool calls.
- Attributes:
  - function_name
  - success (boolean)
  - decision (string: “accept”, “reject”, or “modify”, if applicable)
  - tool_type (string: “mcp”, or “native”, if applicable)
gemini_cli.tool.call.latency (Histogram, ms): Measures tool call latency.
- Attributes:
  - function_name
  - decision (string: “accept”, “reject”, or “modify”, if applicable)
gemini_cli.api.request.count (Counter, Int): Counts all API requests.
- Attributes:
  - model
  - status_code
  - error_type (if applicable)
gemini_cli.api.request.latency (Histogram, ms): Measures API request latency.
- Attributes:
  - model
- Note: This metric overlaps with gen_ai.client.operation.duration below that’s compliant with GenAI Semantic Conventions.
gemini_cli.token.usage (Counter, Int): Counts the number of tokens used.
- Attributes:
  - model
  - type (string: “input”, “output”, “thought”, “cache”, or “tool”)
- Note: This metric overlaps with gen_ai.client.token.usage below for input/output token types that’s compliant with GenAI Semantic Conventions.
gemini_cli.file.operation.count (Counter, Int): Counts file operations.
- Attributes:
  - operation (string: “create”, “read”, “update”): The type of file operation.
  - lines (Int, if applicable): Number of lines in the file.
  - mimetype (string, if applicable): Mimetype of the file.
  - extension (string, if applicable): File extension of the file.
  - model_added_lines (Int, if applicable): Number of lines added/changed by the model.
  - model_removed_lines (Int, if applicable): Number of lines removed/changed by the model.
  - user_added_lines (Int, if applicable): Number of lines added/changed by user in AI proposed changes.
  - user_removed_lines (Int, if applicable): Number of lines removed/changed by user in AI proposed changes.
  - programming_language (string, if applicable): The programming language of the file.
gemini_cli.chat_compression (Counter, Int): Counts chat compression operations
- Attributes:
  - tokens_before: (Int): Number of tokens in context prior to compression
  - tokens_after: (Int): Number of tokens in context after compression

GenAI Semantic Convention

The following metrics comply with OpenTelemetry GenAI semantic conventions for standardized observability across GenAI applications:

gen_ai.client.token.usage (Histogram, token): Number of input and output tokens used per operation.
- Attributes:
  - gen_ai.operation.name (string): The operation type (e.g., “generate_content”, “chat”)
  - gen_ai.provider.name (string): The GenAI provider (“gcp.gen_ai” or “gcp.vertex_ai”)
  - gen_ai.token.type (string): The token type (“input” or “output”)
  - gen_ai.request.model (string, optional): The model name used for the request
  - gen_ai.response.model (string, optional): The model name that generated the response
  - server.address (string, optional): GenAI server address
  - server.port (int, optional): GenAI server port
gen_ai.client.operation.duration (Histogram, s): GenAI operation duration in seconds.
- Attributes:
  - gen_ai.operation.name (string): The operation type (e.g., “generate_content”, “chat”)
  - gen_ai.provider.name (string): The GenAI provider (“gcp.gen_ai” or “gcp.vertex_ai”)
  - gen_ai.request.model (string, optional): The model name used for the request
  - gen_ai.response.model (string, optional): The model name that generated the response
  - server.address (string, optional): GenAI server address
  - server.port (int, optional): GenAI server port
  - error.type (string, optional): Error type if the operation failed