feat(telemetry): add OpenTelemetry integration for AI SDK monitoring

[junmediatek]

Summary

Implement complete OpenTelemetry monitoring integration allowing users to send AI call traces to Jaeger, Grafana Tempo, and other OTLP-compatible backends.

Changes

Core Implementation

• Add OpenTelemetry SDK dependencies (@opentelemetry/sdk-node, @opentelemetry/exporter-trace-otlp-http, etc.)
• Create telemetry module (config.ts, provider.ts) for SDK management
• Initialize telemetry in InstanceBootstrap with automatic shutdown on exit

Configuration

• Extend experimental.openTelemetry from boolean to full configuration object
• Support both simple (boolean) and detailed configuration
• Add environment variable support (OTEL_EXPORTER_OTLP_ENDPOINT, OTEL_SERVICE_NAME)
• Auto-append /v1/traces to endpoint URLs for user convenience

Integration

• Integrate tracer into LLM stream calls (llm.ts) with session metadata
• Integrate tracer into Agent generation (agent.ts) with user metadata
• Pass functionId and metadata to distinguish different call types
• Add LOC (Lines of Code) statistics tracking for file modification tools

Configuration Example

{
  "experimental": {
    "openTelemetry": {
      "enabled": true,
      "endpoint": "http://localhost:4318",
      "serviceName": "opencode",
      "sampleRate": 1.0,
      "recordInputs": true,
      "recordOutputs": true
    }
  }
}

Tracked Data

AI Operations

• Model ID, provider, operation type
• Token usage (prompt/completion)
• Session ID, agent name, user ID
• Tool calls with arguments
• Request duration and spans

File Modifications (LOC Tracking)

• File path and tool name (edit/write/apply_patch)
• Lines added, deleted, and net change
• Change type (add/update/delete/move)
• Batch operations with aggregated statistics

Test Plan

• Type checking passes
• Telemetry initializes correctly
• Endpoint URL normalization works
• Configuration parsing handles both boolean and object forms
• Related tests passed (edit, write, apply_patch)

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

I found potential duplicate PRs related to OpenTelemetry integration:

Related PRs:

1. PR feat: integrate OpenTelemetry #5245 - feat: integrate OpenTelemetry

   • General OpenTelemetry integration work that may overlap with the current monitoring implementation

2. PR feat(telemetry): add OpenTelemetry instrumentation with Aspire Dashboard support #6629 - feat(telemetry): add OpenTelemetry instrumentation with Aspire Dashboard support

   • Similar telemetry feature with OpenTelemetry but targeting Aspire Dashboard instead of Jaeger/Tempo. May have overlapping implementation or configuration logic.

These PRs should be reviewed to determine if they:

• Cover the same functionality (OTLP endpoint configuration, trace initialization, etc.)
• Have been merged already and this is a duplicate effort
• Address different deployment targets that should be consolidated

[junmediatek]

hi Hi @thdxr, @adamdotdevin, and @rekram1-node
Could help to review this PR?