codex-transfer

A one-way handoff tool that moves the current Claude Code conversation, including its turn history, into Codex as a resumable thread.

In plain words
What is it for?
Use it to continue an existing Claude Code session in Codex. It accepts an optional session file and can return either a summary or raw JSON.
Why use it?
It removes the need to restart work or manually copy the conversation when switching from Claude Code to Codex.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/leejuoh/claude-code-zero/codex-transfer
Any agent
npx skills add LeeJuOh/claude-code-zero --skill codex-transfer
Clone the repo
git clone --depth 1 https://github.com/LeeJuOh/claude-code-zero

Made for: Claude Code, Codex.

Per session 86 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,496 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00086 $0.01496
Opus 5 $0.00043 $0.00748
Sonnet 5 $0.00017 $0.00299
Haiku 4.5 $0.00009 $0.00150

Measured 2d ago against content hash 6087728ddf87, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codex-transfer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/codex-advisor/skills/codex-transfer/SKILL.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Codex Session Transfer

One-way handoff. Unlike every other codex-advisor skill, there is no double-check phase — once the transfer completes, work continues in Codex outside Claude Code, so there is nothing left here to classify. The wrapper's job is whitelisting, error taxonomy, and disable-parity — not verification.

Phase 1: Analyze

Whitelist for this skill: --source <path>, --json. Nothing else — transfer has no prompt, so there is no focus text or model/effort to route.

  • --source <path> — explicit Claude session .jsonl to import. Optional; when omitted the companion falls back to the CODEX_COMPANION_TRANSCRIPT_PATH env var, which codex-advisor's own SessionStart hook (hooks/session-start.mjs) sets automatically — whether or not the Official plugin itself is enabled.
  • --json — when the user passes this, show them the raw JSON payload in Phase 3 instead of the friendly summary. This is independent of the --json codex-advisor always adds internally to the companion call (see Phase 2) — that one is for our own parsing, not the user's request.
  • Unrecognized token (any other flag, or free-standing text) → AskUserQuestion. Transfer has no positional argument — the companion silently discards anything it doesn't recognize as --source/--cwd/--json (handleTransfer destructures only options, never positionals), so passing it through would do nothing rather than corrupt a prompt. Still don't forward it: ask what the user meant. If it looks like a task description, suggest /codex-rescue instead — transfer moves the whole session, it doesn't run a task.

Phase 2: Invoke

Single synchronous call — no --wait/--background, no Pattern A/B. The companion's own import timeout is 2 minutes (EXTERNAL_AGENT_IMPORT_TIMEOUT_MS, lib/codex.mjs:52), so give the Bash tool call itself a timeout comfortably above that (e.g. 150000) — a shorter tool-side timeout could kill the process right at the companion's own deadline and mask its real error message.

Read the full file on GitHub · 89 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 89 lines · 86 tokens per session scan A 6087728ddf87

Subscribe to this mod's changes

codex-transfer is a skill published in the GitHub repository LeeJuOh/claude-code-zero (51 stars, last pushed 2d ago), licensed MIT. It adds 86 tokens to every session and 1,496 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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