Epic: Codex migration strategy and compatibility matrix

[ethanolivertroy]

Context

This repository was forked from GRCEngClub/claude-grc-engineering to become the Codex-oriented GRC Engineering toolkit. The fork is only the starting point: Claude Code plugin workflows, slash commands, marketplace manifests, and Anthropic-specific deployment assumptions will not map 1:1 into the Codex app/harness.

Initial triage found:

• 778 Claude references across 242 files.
• 55 Anthropic references across 9 files.
• 0 Codex references.
• 64 .claude-plugin/plugin.json manifests.
• Primary docs still point to GRCEngClub/claude-grc-engineering and Claude Code /plugin commands.

Goal

Create a migration strategy that clearly separates:

1. Workflows that can run unchanged in Codex.
2. Workflows that need Codex-oriented runbooks/adapters.
3. Claude-specific workflows that should remain Claude-only or be removed from this fork.
4. Capabilities that differ by harness and need documented fallback behavior.

Tasks

• Define target user journey for Codex app users.
• Inventory every plugin/command category and mark Codex support level: native, adapter-needed, manual-runbook, unsupported, or deferred.
• Document differences between Claude Code plugin marketplace semantics and Codex app repository/harness semantics.
• Decide whether this repo remains a fork long-term or becomes an independent Codex-native repo.
• Create a migration roadmap with phases: bootstrapping, compatibility, docs, validation, release.
• Link all child migration issues from this epic.

Acceptance Criteria

• A committed docs/CODEX-MIGRATION.md or equivalent exists.
• It contains a compatibility matrix covering docs, commands, skills, connectors, MCP, workflows, and enterprise deployment.
• The README points Codex users to the correct migration/onboarding path.

Child Issues

• Add Codex-native onboarding docs and replace Claude Code install path #2
• Create AGENTS.md for Codex repo instructions #3
• Design Codex command/runbook adapter for former Claude slash commands #4
• Define Codex-compatible manifest format or marketplace replacement #5
• Rename and compatibility-plan claude-grc paths, caches, config, and env vars #6
• Audit enterprise deployment docs for Anthropic/Claude assumptions and add Codex/OpenAI guidance #7
• Validate connector workflows under Codex app/harness constraints #8
• Update CI, tests, badges, and repository links for codex-grc-engineering #9
• Create Codex migration smoke-test suite for top GRC workflows #10
• Decide what to do with Claude Cowork, MCP, and vouch workflows in the Codex fork #11