Level 6: Harness Builder — Build a Safe Working Environment

Level 6 designs a harness for reliable Codex work. A harness combines rules, skills, checks, and permissions into a controlled working environment.

Harness Components

Component	Purpose
Rules	Define editing policy, protected areas, and constraints
Skills	Reuse task-specific procedures and quality standards
Checks	Detect failures through tests and static analysis
Permissions	Limit read, write, and external operations
Approvals	Stop builds, publication, or deletion for human review

Completion Standard

Consequential actions pause for approval, routine changes follow reproducible procedures, and policy violations are detected by checks.

To practice this level, continue to Level 6 Practice: Turn Permissions and Validation into a Harness. To design each component in detail, use Codex Harness.

Next Level

To work with evidence beyond files and the shell, continue to Level 7: Tool Operator — Use MCP, Browsers, and Connectors.