This context describes how Codex users delegate work to ZCode while Codex remains the user-facing host.
Codex Host: The Codex session that receives the user's request and owns orchestration and result presentation. Avoid: Caller, frontend
ZCode Engine: The external coding agent to which the Codex Host delegates review or task work. Avoid: Backend, subagent
Skill:
A Codex-native reusable workflow invoked explicitly with a $zcode:<skill> name or selected automatically from its description.
Avoid: Command, slash command
Companion Run: One invocation of ZCode initiated by a Skill, producing either review findings or task output. Avoid: Command execution, request
Tracked Job: A persisted record of a Companion Run, including its ownership, lifecycle state, progress, and stored result. Avoid: Process, thread
Orphaned Job: A nonterminal Tracked Job whose exact worker-lifetime lease is no longer held, proving that its local executor has disappeared. Avoid: Stale job, dead session
Lifecycle Maintenance Principal: Internal authority derived only from a validated Orphaned Job's original owner and used to settle that job without transferring user-visible ownership. Avoid: Impersonated owner, adopted owner
Review: A read-only Companion Run that evaluates repository changes and returns findings without modifying the workspace. Avoid: Audit
Rescue: A delegated Companion Run in which ZCode investigates or changes the workspace to pursue a requested outcome. Avoid: Task, fix
Transfer: A handoff that creates a new ZCode session containing the ordered user and assistant turns converted from the current Codex conversation. Avoid: Session clone, seeded prompt
Headless Permission Policy: The rule by which the Codex Host answers ZCode operation requests when no person is attached to ZCode's permission prompt. Avoid: Sandbox, auto-approval
Caller Context: An opaque, turn-scoped capability created by a Codex hook that lets a Skill prove its originating Codex session, turn, workspace, and permission mode to the companion runtime. Avoid: Current session marker, thread environment