Codex Skill

Migrate to Codex

Migrate supported instruction files, skills, agents, and MCP config into Codex project and global files.

Editor's Note

Migrate supported instruction files, skills, agents, and MCP config into Codex project and global files. Covers autonomy, migration order, self-healing loop.

Install

npx skills add https://github.com/openai/skills --skill migrate-to-codex

Page Outline

AutonomyMigration OrderSelf-Healing LoopCommands

Source Content

Normalized top-level metadata comes from the directory layer. The body below is the upstream source content for this item.

Migrate to Codex

Autonomy

Keep going until the selected migration is completely done: run the migrator, inspect the report, fix migrated Codex instructions/skills/agents/MCP config, and re-run checks without stopping to ask for confirmation of the next step. If the user has selected a target, do not ask before creating, editing, replacing, or deleting generated Codex artifacts in that target (`AGENTS.md`, `.codex/`, `.agents/`, or `~/.codex/`). Preserve unrelated existing Codex config entries in `.codex/config.toml` or `~/.codex/config.toml`, such as `notify`, `projects`, `marketplaces`, or unrelated MCP servers; do not ask about them unless they fail validation or directly conflict with the migration. Do not edit source Claude Code files (`.claude/`, `~/.claude/`, `.mcp.json`, or `.claude.json`), unrelated project code, secrets, or another repository.

Migration Order

Run the migration in this order for each selected global or project source:

  • Start by using Codex's built-in TODO/task list tool. Do not create `MIGRATION_TODOS.md` or any TODO file unless the user explicitly asks. The TODO list input has a `plan` array whose items each have `step` and `status`; use statuses `pending`, `in_progress`, and `completed`. Make the TODOs specific to the selected artifacts. Use literal source → Codex target labels, for example:
  • Inspect `.claude/commands` → Codex skills/prompts
  • Inspect `.claude/agents` → `.codex/agents`
  • Inspect `.mcp.json` → `.codex/config.toml` MCP servers
  • Inspect `.claude/settings.json` hooks → `.codex/hooks.json`
  • Migrate safe selected artifacts → Codex files
  • Validate generated `.codex/config.toml`
  • Validate generated `.codex/agents`
  • Report migrated artifacts and manual-review items
  • Read `references/differences.md` (and refresh Codex docs if its `Docs last checked` date is old).
  • Scan and inspect before writing:
  • `--scan-only` lists active and inactive source surfaces.
  • `--plan` prints staged Codex artifact paths and report rows.
  • `--doctor` summarizes readiness, manual-review work, and validation risks.
  • Convert surfaces in the same order the CLI uses:
  • instructions: `CLAUDE.md` / `AGENTS.md` to `AGENTS.md`
  • plugins: report Claude plugin trees and marketplaces as manual migration work
  • hooks: rewrite supported Claude hooks into `.codex/hooks.json` and enable `[features].codex_hooks = true`
  • skills and commands: write Codex skills under `.agents/skills/`
  • config: write `.codex/config.toml` from Claude model/sandbox settings and MCP servers, including `personality = "friendly"` when config is generated
  • subagents: write Codex custom agents under `.codex/agents/`
  • Dry-run, then write the selected target. Use `--replace` only when orphan generated skills or agents should be deleted.
  • Inspect the terminal output and `.codex/migrate-to-codex-report.txt` after real runs.
  • Review generated artifacts in this order: `AGENTS.md`, `.agents/skills/`, `.codex/config.toml`, `.codex/hooks.json`, `.codex/agents/`, then report-only plugin items.
  • Run `--validate-target` against each target after edits.
  • Re-run checks and `--dry-run` after edits.
  • Return the final migration report as one markdown table per scope that has rows. The tables cover only the non-native follow-up migration work you performed, such as skills created from slash commands, subagents, MCP servers, hooks, unsupported/local plugin notes, and manual-review caveats. Include programmatic native import rows for config, instructions, skills, or supported plugins only if you personally migrated them in this follow-up run.

If only one scope has rows, render only the table with no heading. If multiple scopes have rows, render one heading before each table. Use `**User Config**` for user-scope rows. For project-scope rows, use the actual project folder name as the heading, for example `**northstar-support-portal**`; do not use `Current Project` as the heading. Do not add prose before or after the table output.

Use exactly these columns:

**northstar-support-portal**

| Status | Item | Notes | | --- | --- | --- | | `Added` | `Slash command` pr-review | Converted into a Codex skill | | `Added` | `Subagent` release-lead | Added as a Codex subagent | | `Check before using` | `Hook` PreToolUse | Converted, but some Claude hook behavior differs in Codex | | `Not Added` | `Hook` Notification | Codex does not have an equivalent notification hook | | `Not Added` | `Plugin` team-macros | Plugin needs manual setup |

`Status` must be `Added`, `Check before using`, or `Not Added`. Use `Added` when a Codex-facing artifact was created or changed and needs no special review. Use `Check before using` when a Codex-facing artifact was created or changed but the migration changed semantics, inferred behavior, preserved tool rules as guidance, or dropped unsupported behavior. Use `Not Added` when a source artifact was detected but no Codex-facing artifact was created. `Item` combines the artifact type and concrete item name in one cell. Artifact type must be singular: `Skill`, `Slash command`, `Subagent`, `MCP`, `Hook`, or `Plugin`. Wrap the artifact type in inline code; write the item name as plain text after it. `Notes` is always required; never leave it empty. Keep notes short, plain, and literal. Avoid internal implementation terms such as runtime expansion. Prefer phrases like `Converted into a Codex skill`, `Added as a Codex subagent`, `Added to Codex config`, `Converted into a Codex hook`, `Converted, but some Claude hook behavior differs in Codex`, `Codex does not have an equivalent notification hook`, `Plugin needs manual setup`, or `Plugin marketplace needs manual setup`.

Self-Healing Loop

Keep looping until the selected migration is complete:

  • Run `--plan` or `--doctor`.
  • Run the migration with `--dry-run`.
  • Run the migration for real.
  • Fix every generated `## MANUAL MIGRATION REQUIRED` block and every `manual_fix_required` or `skipped` report row that can be resolved inside Codex artifacts.
  • Run `--validate-target`.
  • Re-run the migrator and validator until the report and validator have no actionable generated-artifact fixes left.

Do not edit source Claude Code files, unrelated project code, secrets, or another repository during this loop. If a report row requires source-provider changes or product judgment, leave the generated Codex artifact with clear manual guidance instead of changing the source.

Commands

Choose the migrator command.

   MIGRATE_TO_CODEX='python3 .codex/skills/migrate-to-codex/scripts/migrate-to-codex.py'

Inspect the migration before writing.

   $MIGRATE_TO_CODEX --source ~/.claude/ --scan-only
   $MIGRATE_TO_CODEX --source ~/.claude/ --target ~/.codex/ --plan
   $MIGRATE_TO_CODEX --source ~/.claude/ --target ~/.codex/ --doctor

Dry-run, then run without `--dry-run`, for global and project.

   $MIGRATE_TO_CODEX --source ~/.claude/ --target ~/.codex/ --dry-run
   $MIGRATE_TO_CODEX --source ~/.claude/ --target ~/.codex/
   $MIGRATE_TO_CODEX --source ./.claude/ --target ./.codex/ --dry-run
   $MIGRATE_TO_CODEX --source ./.claude/ --target ./.codex/

Run the post-migration validator against each target after edits.

   $MIGRATE_TO_CODEX --validate-target ~/.codex/
   $MIGRATE_TO_CODEX --validate-target ./.codex/

Run `$MIGRATE_TO_CODEX --help` for flags (`--scan-only`, `--plan`, `--doctor`, `--validate-target`, defaults, and so on). Deep tables and more links are in `references/differences.md`.

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