[BUG] Log/events exporter emits nothing while metrics work fine (Windows native v2.1.159)

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?

With telemetry enabled, metrics export normally but log/events are never emitted at all — not even to the console exporter.

• OTEL_METRICS_EXPORTER=console correctly prints claude_code.session.count, cost.usage, token.usage, active_time.total.
• OTEL_LOGS_EXPORTER=console (with metrics off) prints zero log records — no severityText / body / event.name output.
• Therefore no claude_code.user_prompt / api_request / tool_result events are produced, and nothing reaches our OTLP backend (CloudWatch Logs).

Because it fails at the console exporter (no network involved), this is not a network/firewall/endpoint/auth problem — events are simply never generated or flushed. A manual OTLP POST from PowerShell to the same CloudWatch endpoint/token returns HTTP 200, confirming the backend is fine.

Reproduced identically on both the native installer build and the npm package at v2.1.159, so it is not install-method-specific — it points to a core regression in the log/events pipeline.

What Should Happen?

With OTEL_LOGS_EXPORTER set, Claude Code should emit log/events (at minimum user_prompt and api_request, per the docs) to the configured exporter, just as metrics are emitted. With console, these records should print to the console.

Error Messages/Logs

# OTEL_METRICS_EXPORTER=console  → metrics DO print (excerpt):
{
  descriptor: { name: "claude_code.session.count", type: "COUNTER", ... },
  dataPoints: [ { attributes: { ... }, value: 1 } ],
}
{ descriptor: { name: "claude_code.token.usage", ... }, dataPoints: [ ... ] }
# (cost.usage, active_time.total also printed)

# OTEL_LOGS_EXPORTER=console, OTEL_METRICS_EXPORTER=none  → NOTHING printed:
# 0 log records. No severityText / body / event.name lines at all.
# Reproduced with: claude -p, interactive session, and
# OTEL_LOGS_EXPORT_INTERVAL=500 + a multi-second prompt.
# Same result on both native installer and npm package.

Steps to Reproduce

1. Configure telemetry (shell env or settings.json):

CLAUDE_CODE_ENABLE_TELEMETRY=1
OTEL_LOGS_EXPORTER=console
OTEL_METRICS_EXPORTER=none
OTEL_LOGS_EXPORT_INTERVAL=500

1. Run: claude -p "Explain why the sky is blue in 200 words."

(a multi-second prompt so several export windows elapse)

1. Observe console output.

Expected: log records (user_prompt, api_request, ...) printed by the console exporter.
Actual: zero log records — only the assistant's reply is printed.

Cross-checks:

• Switching OTEL_METRICS_EXPORTER=console shows metrics print fine (so telemetry init works).
• With OTEL_LOGS_EXPORTER=otlp to a CloudWatch Logs endpoint, nothing arrives, while a manual PowerShell OTLP POST to the same endpoint returns HTTP 200.
• Reproduced on both native installer (~/.local/bin/claude.exe) and npm (@anthropic-ai/claude-code).

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

~~Unknown exact version; telemetry was confirmed working around 2026-05-11.~~
regression introduced somewhere between
2.1.132 and 2.1.159.

Claude Code Version

2.1.159 — reproduced on BOTH native installer build and npm package (@anthropic-ai/claude-code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

• Auth: organization SSO (OAuth) account.
• Backend: CloudWatch Logs OTLP endpoint (/v1/logs), verified independently working via a manual PowerShell OTLP POST (HTTP 200).
• Metrics export fine; only log/events are dead, in both install methods.
• Possibly related: #39471 (events not emitted), but that one is Cowork/macOS and loses all signals; here metrics work and only logs are dead.