feat(observability): honor the OpenTelemetry kill switch

[juliusmarminge]

Replaces #12925 by @yordis, which we can't push to because its fork is organization-owned. Their commits are kept as-is with authorship intact; the last commit is a cleanup on top.

A machine that sets OTEL_SDK_DISABLED=true for every process still got OTLP export from T3 Code, because we build exporters explicitly instead of through Effect's layerFromConfig, which is the only place that variable is read.

• OTEL_SDK_DISABLED and T3CODE_OTEL_SDK_DISABLED now clear every OTLP endpoint in the server and the desktop main process, including endpoints stored in Settings. Local trace files and stdout logs are unaffected.
• T3CODE_OTEL_SDK_DISABLED wins when set, so a machine that disables OTel globally can opt T3 Code back in. It accepts Config.Boolean's values, case-insensitively.
• OTEL_SDK_DISABLED follows the OpenTelemetry specification: only true (case-insensitive) disables. Anything else, such as 1, leaves export on and logs a warning instead of failing startup.
• The WSL backend receives both variables through WSLENV, so the switch reaches a server running in the distro.
• Cleanup commit: both variables are read by one Config.schema-based helper in packages/shared/src/otelEnvironment.ts (213 → 105 lines), tests are one table asserting exact warnings, and the docs section is trimmed to operator-facing behavior.

Co-authored-by: Yordis Prieto yordis.prieto@gmail.com

Done with Claude Opus 5.5 in Claude Code.

🤖 Generated with Claude Code

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Summary by CodeRabbit

• New Features
  • Added environment-variable controls to disable telemetry exports from the desktop and server, even when export endpoints are configured. Local trace files and stdout logs remain available.
  • The desktop backend forwards these controls into WSL environments. When telemetry is disabled, configured export endpoints are ignored.
• Documentation
  • Documented supported values, precedence, and startup warnings for unrecognized settings.

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	13.5 KiB	13.5 KiB	+29 B (+0.2%)	15.1 KiB	✅
Codex	Thread snapshot wire	7.1 KiB	7.1 KiB	0 B (0.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.4 KiB	6.5 KiB	+29 B (+0.4%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	56.2 KiB	56.3 KiB	+44 B (+0.1%)	66.4 KiB	✅
Codex	Live turn messages	9	10	+1 (+11.1%)	21	✅
Claude	Total thread wire	13.5 KiB	13.5 KiB	+17 B (+0.1%)	15.1 KiB	✅
Claude	Thread snapshot wire	7.1 KiB	7.1 KiB	+3 B (+0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.4 KiB	6.4 KiB	+14 B (+0.2%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	57.0 KiB	57.0 KiB	0 B (0.0%)	66.4 KiB	✅
Claude	Live turn messages	9	9	0 (0.0%)	21	✅

Baseline: 78af372 · PR result: b629870 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 113.9 KiB
• Claude decoded thread snapshot: 114.6 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This PR changes production OTLP export behavior across the server, desktop main process, and WSL, with an unresolved edge case around WSLENV direction flags. It also adds line-level static-analysis suppression directives in new tests, requiring human review.

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📥 Commits

Reviewing files that changed from the base of the PR and between 841ee8f and b629870.

📒 Files selected for processing (3)

• apps/desktop/src/app/DesktopObservability.test.ts
• apps/desktop/src/app/DesktopObservability.ts
• apps/server/src/observability/Layers/Observability.ts

🚧 Files skipped from review as they are similar to previous changes (3)

• apps/server/src/observability/Layers/Observability.ts
• apps/desktop/src/app/DesktopObservability.ts
• apps/desktop/src/app/DesktopObservability.test.ts

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📝 Walkthrough

Walkthrough

The change adds a shared loader for OpenTelemetry disable settings and applies its result to server and desktop OTLP endpoint configuration. The server and desktop observability layers log loader warnings. The desktop backend forwards both settings to WSL.

Changes

OpenTelemetry export kill switch

Layer / File(s)	Summary
Define and parse telemetry settings packages/shared/src/otelEnvironment.ts, packages/shared/src/otelEnvironment.test.ts, packages/shared/package.json, docs/operations/observability.md	The shared package exports a loader that parses T3CODE_OTEL_SDK_DISABLED and OTEL_SDK_DISABLED, applies precedence, and reports warnings for unrecognized values. Tests and operations documentation describe the settings and behavior.
Apply the setting in server configuration apps/server/src/config.ts, apps/server/src/cli/config.ts, apps/server/src/cli/config.test.ts, apps/server/src/observability/Layers/Observability.ts, apps/server/src/cli/pair.ts, apps/server/src/bin.test.ts, apps/server/src/environment/ServerEnvironment.test.ts, apps/server/src/server.test.ts, apps/server/src/serverLogger.test.ts	Server configuration includes the loaded environment and unsets trace, metrics, and logs URLs when disabled. The observability layer logs loader warnings. Server tests and configuration fixtures provide the new field.
Apply the setting in desktop configuration apps/desktop/src/app/DesktopObservability.ts, apps/desktop/src/app/DesktopObservability.test.ts, apps/desktop/src/backend/DesktopBackendConfiguration.ts, apps/desktop/src/backend/DesktopBackendConfiguration.test.ts	Desktop endpoint resolution returns no endpoints when telemetry is disabled and logs loader warnings through installed loggers. The WSL backend configuration forwards both disable settings, and tests cover endpoint suppression and forwarding.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant ProcessEnvironment
  participant OtelEnvironment
  participant resolveServerConfig
  participant ObservabilityLive
  ProcessEnvironment->>OtelEnvironment: Provide disable settings
  resolveServerConfig->>OtelEnvironment: Load environment configuration
  OtelEnvironment-->>resolveServerConfig: Return disabled flag and warnings
  resolveServerConfig->>ObservabilityLive: Provide server configuration
  ObservabilityLive->>ObservabilityLive: Log configured warnings

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Merge Risk: 🔵 Low · up to b6298

The kill switch may not reach the WSL backend when WSLENV already contains a directional entry for it. The change is otherwise mergeable with explicit acceptance or correction of this edge case.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely identifies the main change: honoring the OpenTelemetry kill switch.
Description check	✅ Passed	The description explains what changed and why, including variable precedence, endpoint behavior, WSL forwarding, tests, and documentation. It omits the template headings and checklist, but the require…
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 1…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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Actionable comments posted: 2

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• 🪄 Fix CodeRabbit comments on this PR

🤖 Prompt to fix review comments

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only still-valid issues, skip the rest with a brief reason, keep changes
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Inline comments:
In `@apps/desktop/src/backend/DesktopBackendConfiguration.ts`:
- Around line 100-101: Update mergeWslEnv to normalize existing entries for
names in WSL_FORWARDED_ENV_NAMES that have the incompatible /w flag to /u before
checking membership and building the result. Preserve valid /u entries and all
unrelated entries unchanged, and apply this to every forwarded name rather than
only the OTEL variables.

In `@apps/server/src/observability/Layers/Observability.ts`:
- Around line 24-25: Move the startup-warning loop in ObservabilityLive out of
layer construction and into an effect that runs after ServerLoggerLive is
installed. Preserve logging each config.otelEnvironment.warnings entry with
Effect.logWarning.

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📥 Commits

Reviewing files that changed from the base of the PR and between 78af372 and 841ee8f.

📒 Files selected for processing (17)

• apps/desktop/src/app/DesktopObservability.test.ts
• apps/desktop/src/app/DesktopObservability.ts
• apps/desktop/src/backend/DesktopBackendConfiguration.test.ts
• apps/desktop/src/backend/DesktopBackendConfiguration.ts
• apps/server/src/bin.test.ts
• apps/server/src/cli/config.test.ts
• apps/server/src/cli/config.ts
• apps/server/src/cli/pair.ts
• apps/server/src/config.ts
• apps/server/src/environment/ServerEnvironment.test.ts
• apps/server/src/observability/Layers/Observability.ts
• apps/server/src/server.test.ts
• apps/server/src/serverLogger.test.ts
• docs/operations/observability.md
• packages/shared/package.json
• packages/shared/src/otelEnvironment.test.ts
• packages/shared/src/otelEnvironment.ts

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