OTEL_LOG_RAW_API_BODIES silently no-ops on Claude Desktop 1.5354 / embedded SDK 2.1.121

Claude cowork team plan (team customers)

Summary

Setting OTEL_LOG_RAW_API_BODIES=1 on Claude Desktop 1.5354.0 (instrumentation scope com.anthropic.claude_code.events v2.1.121) produces claude_code.api_request log records with no request/response body attributes. The same env var works correctly on:

• Claude Desktop 1.3883 (SDK 2.1.111) — bodies emitted ✅
• Claude Code CLI 2.1.123 — bodies emitted ✅

So this is a regression in the desktop bundle between SDK 2.1.111 → 2.1.121.

Reproduction

1. Run a local OTLP collector on :4318 with max_request_body_size: 0 and a file exporter for ground-truth inspection.
2. Launch Claude Desktop 1.5354.0 from a shell with:

``
OTEL_LOG_RAW_API_BODIES=1
OTEL_LOGS_EXPORTER=otlp
OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf
OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318 (exposed via ngrok)
``

1. Send any prompt. Inspect the captured OTLP claude_code.api_request log records (file exporter dump or downstream backend).

Observed

claude_code.api_request records contain only:

model, input_tokens, output_tokens, cache_read_tokens,
cache_creation_tokens, cost_usd, duration_ms,
request_id, speed, query_source, effort

No request_body, response_body, or any body-shaped attribute. Verified directly from the collector's raw OTLP file capture — i.e. the desktop app is not emitting bodies at the OTLP wire; it is not a downstream filter or size-limit issue.

Expected

Body attributes present on api_request records when OTEL_LOG_RAW_API_BODIES=1, as on CLI 2.1.123 and the older 1.3883 desktop build.

Environment

• macOS 26.4.1, arm64
• Claude Desktop 1.5354.0
• Embedded scope com.anthropic.claude_code.events 2.1.121

Related

• #50567 — OTEL_METRICS_EXPORTER=otlp silently no-ops in 2.1.113. Likely same root cause class (dynamic OTLP package require failing silently in the Bun-compiled binary).
• #55269 — confirms bodies are being emitted in CLI 2.1.126 (just missing trace_id/span_id), suggesting the gap is desktop-bundle-specific, not a global removal.
• #33301, #25389 — earlier "OTEL works in CLI, no-ops in non-CLI surface" reports.