codex-preserve

codex-preserve exports an OpenAI Codex session out of Codex into durable, human-readable files, and verifies that every manifest-attested member is present and byte-identical to the SHA-256 and size recorded in the manifest. It reads a Codex session; it never modifies one.

This is not codex archive. The built-in codex archive command changes a saved session's lifecycle state inside Codex. codex-preserve exports a durable copy outside Codex and verifies the exported package. It does not modify session state, and it is not a replacement for codex archive.

Not affiliated with OpenAI. codex-preserve is an independent, unofficial tool. It is not affiliated with, endorsed by, sponsored by, or certified by OpenAI, and it is not an OpenAI product or a first-party Codex component. It ships no OpenAI logo or other visual branding. It is named for the Codex sessions it reads.

Install

python -m pip install codex-preserve

Python 3.9 or newer. No runtime dependencies. Confirm the CLI surface with:

codex-preserve --help

Public project pages: PyPI · Releases · Issues

What it does

• Exports one already-persisted local Codex rollout into a per-session package: a readable conversation file, a machine receipt, input attachments and output files, and a manifest.
• Verifies an exported package against that manifest: every attested member must be present with the attested size and SHA-256. See What verification does and does not prove.
• Records provenance for exported artifacts and attachments, including which turn produced them and whether the payload is complete.
• Normalizes and redacts by default: home paths are normalized for readability, and credential-shaped values are removed before anything is written.
• Fails closed. What the tool cannot prove mechanically is reported as unknown rather than guessed, and a package that cannot be verified is never reported as intact.

What it does not do

• It does not modify, archive, unarchive, delete or move Codex sessions.
• It makes no model call and no network call. There is no daemon, no hook, no telemetry and no event database. It does run local read-only git queries by default — see What it reads.
• It does not decode opaque or encrypted reasoning. Such items are counted, never reconstructed.
• It does not sign anything. The manifest attests SHA-256 completeness and integrity; that is not a cryptographic signature and says nothing about who produced a package.

What verification does and does not prove

codex-preserve verify answers exactly one question: is every member the manifest attests present, and do its bytes still hash to the SHA-256 and size the manifest records?

That is worth having. It detects accidental loss, truncation, corruption in transit or storage, and edits made to a payload without also rewriting the manifest.

It is not tamper-proofing, and the following are outside the proof:

• The manifest is co-distributed and is not independently signed. It travels inside the package it describes. There is no signature, no certificate, no trust root and no transparency log, so the check is manifest-relative integrity, not authenticity. It says nothing about who produced the package.
• A coordinated rewrite is not detected. Anyone who edits a payload and recomputes its manifest row produces a package that verifies. Detecting that requires a trust anchor this tool does not have.
• Extra files are not part of the current check. Verification walks the members the manifest lists. A file added to the package directory that the manifest never mentions does not make verification fail, so "complete" means "nothing attested is missing", not "nothing else is present".

If you need authenticity rather than integrity, sign the exported package with a tool built for that. codex-preserve deliberately does not implement one.

What it reads

Export is local and read-only, but it is not limited to the one rollout file you name. On a normal run it may also:

• read ~/.codex/session_index.jsonl, read-only, to recover the session's display name. The lookup is filtered by session id and returns silently if the file is absent or unreadable. Nothing under ~/.codex is ever written.
• run local read-only git queries in the session's recorded workspace (rev-parse, branch --show-current, remote get-url, merge-base) to record where the work happened. These are local repository queries; they contact no network and no remote.
• include a normalized repository identity such as owner/repo in the exported provenance, in the receipt and in the human-readable file. The raw remote URL is discarded and never exported — but if you share an export, the owner/repo name goes with it.

Pass --no-git-probe to skip the live git queries entirely. That is the entire scope of the flag: it stops the export from asking the local repository anything. It does not erase repository identity that is already persisted in the rollout's own session metadata. A persisted identity is still normalized to owner/repo and may appear in the receipt, in the human-readable export, in the stable output basename, and in the output directory / bucket names. The raw remote URL is discarded and never exported, with or without the flag.

Try it in one command

You do not need a Codex session to see what this tool does. Three synthetic example packages and the runner script below live in the repository checkout, not in the installed wheel; from a clone of the repository they exercise the entire verification contract:

./examples/run_examples.sh

That prints one PASS, one FAIL and one UNVERIFIABLE verdict and checks that each exits 0, 1 and 2 respectively. See examples/README.md for what each one demonstrates and why. The same three packages are asserted by the test suite, so they stay honest.

Use

# See the surfaces.
codex-preserve --help

# List the sessions that could be exported (sanitized output).
codex-preserve --list-candidates

# Export one session by id.
codex-preserve --session-id <uuid> --output-dir ./exports

# The same export surface, named explicitly.
codex-preserve export --session-id <uuid> --output-dir ./exports

# Verify an exported package.
codex-preserve verify ./exports/<bucket>/<package-dir>

# Machine-readable verification receipt.
codex-preserve verify ./exports/<bucket>/<package-dir> --json

codex-preserve export --help lists the full export option set, including selection (--rollout, --session-id, --workspace, --since-hours), provenance (--artifact ROLE=PATH, --review-bundle, --no-git-probe) and policy (--no-normalize, --reasoning-cap, --max-package-bytes).

Sessions are discovered under ~/.codex/sessions and ~/.codex/archived_sessions only. The home directory is never scanned broadly.

Verify exit codes

The reason is always printed. --json emits the same verdict as a receipt with per-member reason codes.

Manifest-attested package members must be real files under the package tree; symlinked member paths are rejected.

Exit 2 also covers a manifest this build cannot interpret: an unrecognized or missing package_schema_version, or a manifest collection or row whose shape is not the expected JSON array/object. A verifier that cannot read the manifest reports UNVERIFIABLE rather than claiming the members it never looked at are fine.

Development

PYTHONPATH=src python3 -m unittest discover -t . -s tests
python3 tools/public_hygiene_scan.py .
./examples/run_examples.sh

The test suite is deterministic and entirely synthetic: it builds its own rollout fixtures in a temporary directory and never reads a real Codex session directory.

tools/public_hygiene_scan.py is a deterministic check that no private coordinate or credential-shaped literal has entered the tree.

Localization

Package member filenames and the default output directory are currently Simplified Chinese, because they are part of the already-proven package format this tool exports. Changing them is a package-format decision rather than a cosmetic one, and it is still open. Everything else — the CLI, the receipts, the manifest keys and this documentation — is English.

License

Apache License 2.0. See LICENSE for the full text.

SPDX-License-Identifier: Apache-2.0

Status

Version 0.1.0, first public release line. The export/verify contract described above — the three verdicts, the exit codes, and the limits of what the manifest proves — is what this version commits to. Package member filenames are still an open question; see Localization.

Not affiliated with OpenAI. codex-preserve is an independent, unofficial tool. It is not affiliated with, endorsed by, sponsored by, or certified by OpenAI, and it is not an OpenAI product or a first-party Codex component. It ships no OpenAI logo or other visual branding.