Observability for OpenAI Codex with Opik

OpenAI Codex supports opt-in OpenTelemetry export through Codex configuration files.

When this guide applies

Use this guide if you run Codex (CLI/IDE/app) and want its OTEL trace exporter to send telemetry to Opik.

Where to configure Codex

Codex reads configuration from:

• user config: ~/.codex/config.toml
• project config: .codex/config.toml

See Codex config basics.

Opik OTLP trace endpoint modes

For Opik OTEL endpoint behavior, see Opik OpenTelemetry overview.

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[otel]
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# Optional environment label in Codex telemetry
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trace_exporter = "otlp-http"
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environment = "prod"
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log_user_prompt = false
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[otel.trace_exporter.otlp-http]
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endpoint = "https://www.comet.com/opik/api/v1/private/otel/v1/traces"
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protocol = "binary"
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headers = { "Authorization" = "<your-api-key>", "Comet-Workspace" = "<your-workspace>", "projectName" = "<your-project-name>" }

Example intent and minimal valid setup

Intent: Route Codex OTEL trace export to Opik with project/workspace attribution.

Applies when: You have enabled Codex OTEL export and selected OTLP/HTTP exporter in config.

Required fields:

• trace_exporter = "otlp-http" under [otel]
• otel.trace_exporter exporter block (otlp-http)
• endpoint
• protocol (binary or json, binary recommended)

Optional fields:

• headers (projectName strongly recommended)
• otel.environment
• otel.log_user_prompt (keep false unless policy allows prompt export)

Minimal valid config:

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[otel]
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trace_exporter = "otlp-http"
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log_user_prompt = false
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[otel.trace_exporter.otlp-http]
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endpoint = "https://www.comet.com/opik/api/v1/private/otel/v1/traces"
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protocol = "binary"
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headers = { "Authorization" = "<your-api-key>", "Comet-Workspace" = "<your-workspace>", "projectName" = "<your-project-name>" }

Validation

1. Run a Codex session after updating config.toml.
2. Confirm OTLP HTTP requests are sent to /otel/v1/traces.
3. Verify traces appear in the expected Opik workspace/project.

Notes

• Codex telemetry export is opt-in.
• Keep log_user_prompt = false unless your policy explicitly allows prompt text export.
• If your Codex build uses a different exporter key path, align with your installed version’s config reference.

Source references

• Codex security and OTEL opt-in
• Codex config basics
• Codex config reference
• Opik OpenTelemetry overview