[BUG] Claude Code OTel spans should emit standard gen_ai.usage.* token attributes

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Follow-up to #50776, which was closed as stale/not planned. The closing bot comment says to open a new issue if the problem is still relevant.

Summary

Claude Code telemetry currently emits token usage on claude_code.llm_request spans using flat, non-standard attributes such as:

• input_tokens
• output_tokens
• cache_read_tokens
• cache_creation_tokens

But OpenTelemetry GenAI semantic conventions expect usage data under the standard gen_ai.usage.* namespace, for example:

• gen_ai.usage.input_tokens
• gen_ai.usage.output_tokens
• cached-token fields according to the current GenAI/Anthropic semantic convention guidance

The original issue reported that downstream OTel-native observability tools such as Langfuse, Datadog, and Honeycomb render zero tokens/cost for Claude Code spans because they read the standard attributes and do not recognize the flat Claude Code-specific keys.

What Should Happen?

Requested change

Please emit the standard OpenTelemetry GenAI usage attributes alongside the existing flat attributes, so the change is additive and backwards-compatible:

• gen_ai.usage.input_tokens
• gen_ai.usage.output_tokens
• appropriate cached-token attributes according to the current OTel GenAI semantic conventions

Keeping the current input_tokens, output_tokens, and cache_*_tokens fields in parallel would avoid breaking existing consumers.

Error Messages/Logs

Steps to Reproduce

Using the settings.json

{
  "env": {
    "CLAUDE_CODE_ENABLE_TELEMETRY": "1",
    "OTEL_METRICS_EXPORTER": "otlp",
    "OTEL_LOGS_EXPORTER": "none",
    "OTEL_EXPORTER_OTLP_PROTOCOL": "grpc",
    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://localhost:4317",
    "OTEL_METRIC_EXPORT_INTERVAL": "5000",
    "OTEL_LOGS_EXPORT_INTERVAL": "5000",
    "CLAUDE_CODE_ENHANCED_TELEMETRY_BETA": "1",
    "OTEL_TRACES_EXPORTER": "otlp",
    "OTEL_LOG_TOOL_DETAILS": "1",
    "OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE": "delta",
    "OTEL_RESOURCE_ATTRIBUTES": "service.name=claude-code",
    "OTEL_METRICS_INCLUDE_VERSION": "true",
    "OTEL_METRICS_INCLUDE_ENTRYPOINT": "true",
    "OTEL_LOG_LEVEL": "debug"
  }
}

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude 1.11187.4 (584005) 2026-06-05T20:15:04.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Reference

Original issue: #50776

Related comment in the original issue:
https://github.com/anthropics/claude-code/issues/50776#issuecomment-4276300754

The stale close comment:
https://github.com/anthropics/claude-code/issues/50776#issuecomment-4554065190