CDX-004: Unknown Config Key - Codex CLI

Summary

• Rule ID: CDX-004
• Severity: MEDIUM
• Category: Codex CLI
• Normative Level: SHOULD
• Auto-Fix: Yes (safe)
• Verified On: 2026-09-14

Applicability

• Tool: codex
• Version Range: unspecified
• Spec Revision: unspecified

Evidence Sources

• https://developers.openai.com/codex/
• https://github.com/openai/codex/blob/rust-v0.154.0/codex-rs/core/config.schema.json

Test Coverage Metadata

• Unit tests: true
• Fixture tests: true
• E2E tests: false

Examples

The following examples demonstrate what triggers this rule and how to fix it.

Invalid

unknownKey = true

Valid

model = "o4-mini"
approvalMode = "suggest"