[BUG] OTEL metrics not exported on Claude Code ≥ v2.1.113 (confirmed with mTLS configuration)

Preflight Checklist

• [ ] 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?

Since v2.1.113, Claude Code no longer exports OTEL metrics to a configured OTLP endpoint. No metrics reach the backend despite a
correct configuration that worked on v2.1.112. The issue persists through the latest v2.1.118.
This appears to be a duplicate of #50567. We can confirm the same silent failure with an mTLS configuration (OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE / OTEL_EXPORTER_OTLP_CLIENT_KEY). Pinning to v2.1.112 restores metrics export as a workaround

What Should Happen?

Metrics should be exported to the configured OTLP endpoint as they were on ≤ v2.1.112.

Steps to Reproduce

1. Configure the following environment variables (in ~/.zshrc or ~/.claude/settings.json):

CLAUDE_CODE_ENABLE_TELEMETRY=1
OTEL_METRICS_EXPORTER=otlp
OTEL_LOGS_EXPORTER=otlp
OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
OTEL_EXPORTER_OTLP_ENDPOINT=https://<collector>
OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE=~/.claude/claude-metrics-certs/client.crt
OTEL_EXPORTER_OTLP_CLIENT_KEY=~/.claude/claude-metrics-certs/client.key
OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE=delta

1. Install v2.1.112: npm install -g @anthropic-ai/claude-code@2.1.112 --registry https://registry.npmjs.org
2. Start a session and send a few messages → metrics appear in backend ✅
3. Upgrade to v2.1.113+: npm install -g @anthropic-ai/claude-code@2.1.118 --registry https://registry.npmjs.org
4. Start a session and send a few messages → no metrics appear ❌

Also tried switching to the metrics-specific cert vars — no change:

OTEL_EXPORTER_OTLP_METRICS_CLIENT_CERTIFICATE=~/.claude/claude-metrics-certs/client.crt
OTEL_EXPORTER_OTLP_METRICS_CLIENT_KEY=~/.claude/claude-metrics-certs/client.key

Claude Model

claude-sonnet-latest

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.112

Claude Code Version

2.1.118

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)