Write Validation Events

Overview

Use a validation event to prove Beacon can write a known-good endpoint event to the local runtime JSONL log before you rely on real agent activity. This guide covers the default validation event, JSON output for automation, custom log paths, and system-mode validation.

Setup

Confirm endpoint telemetry is configured:

Check endpoint status

beacon endpoint status

1. Write A Test Event

Run beacon endpoint test-event with the default per-user endpoint paths:

Write a validation event

beacon endpoint test-event

Sample output

$ beacon endpoint test-event

checking runtime log: ok
writing validation event: ok
event action: endpoint.validation
runtime log: ~/.beacon/endpoint/logs/runtime.jsonl

The command checks that the configured runtime log is writable, appends a synthetic Beacon endpoint event, and reports validation stages. beacon endpoint validate-pipeline is an alias for the same local validation path.

Alias for the same validation path

beacon endpoint validate-pipeline

2. Print Validation Stages As JSON

Use JSON output when capturing evidence for support, scripts, or rollout checks:

Print validation event result as JSON

beacon endpoint test-event --json

Sample JSON output

{
  "runtimeLogWritable": true,
  "eventWritten": true,
  "eventAction": "endpoint.validation",
  "logPath": "~/.beacon/endpoint/logs/runtime.jsonl"
}

3. Validate A Specific Log Path

If you are testing a non-default runtime log, pass the path explicitly:

Write to a custom runtime log

beacon endpoint test-event --log-path /path/to/runtime.jsonl

For a system-mode deployment, use the system endpoint paths:

Write a system-mode validation event

sudo beacon endpoint test-event --system

4. Test GitHub Copilot CLI Telemetry

After beacon endpoint install has started the local collector, run a real Copilot CLI prompt with OTLP export enabled:

Generate Copilot CLI telemetry

COPILOT_OTEL_ENABLED=true \
OTEL_EXPORTER_OTLP_ENDPOINT=http://127.0.0.1:4318 \
OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT=true \
copilot -p "Tell me about this repo."

Use OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT=true only when prompt content capture is intended for the test. Confirm the Copilot event with status or the local dashboard:

Confirm telemetry

beacon endpoint status
beacon endpoint dashboard --open

Verify Results

After writing the event, confirm it with status or the local dashboard:

Verify validation event

beacon endpoint status
beacon endpoint dashboard --open

The status output should include a recent last Beacon event when the runtime log has been written successfully. The dashboard should show the validation event in Log Search.

Troubleshooting

If the write fails, check runtime log path and permissions.
If JSON output shows the log is not writable, run beacon endpoint doctor --fix when safe.
If system-mode writes work but user-mode checks look empty, confirm the dashboard is pointed at the system log.
If Copilot telemetry is missing, confirm the OTLP endpoint and environment variables are set for the Copilot process.

beacon endpoint test-event

Review all flags and examples for synthetic validation events.

Test the Local Dashboard

Confirm validation events through the local read-only dashboard.

Inspect Runtime Logs

Inspect runtime JSONL paths and last-event freshness.

Log forwarding

Move from local validation to destination-specific forwarding checks.

​Overview

​Setup

​1. Write A Test Event

​2. Print Validation Stages As JSON

​3. Validate A Specific Log Path

​4. Test GitHub Copilot CLI Telemetry

​Verify Results

​Troubleshooting

​Related