Compatibility history

Claude Code and Codex Version Support History

Reinstate RC8 currently accepts stable Claude Code versions 2.1.219–2.1.220 and Codex CLI versions 0.133.0–0.145.0. Those inclusive ranges were documented in RC3 and did not change in RC4, RC5, or RC8; later candidates changed path portability and setup validation instead.

Published
Last verified
Current release
v0.1.0-rc.8
Release status
pre-1.0 release candidate

Current tested stable ranges

AgentInclusive rangeResume modeEvidence reviewed
Claude Code2.1.2192.1.220Claude Code to Claude Code
Immutable test source
OpenAI Codex CLI0.133.00.145.0Codex to Codex
Immutable test source

The matrix is rendered from the same committed compatibility data asthe public compatibility page. Ranges cover stable three-component versions only. A prerelease, malformed version, or version below or above the inclusive endpoints is not silently accepted.

What happens outside a tested range

A recognizable installed agent outside the tested range is UNTESTED.rein setup check exits with compatibility code 5, and the Phase 1 CLI blocks session export and restore. There is no public unsafe override in the current CLI.UNSUPPORTED and NOT_INSTALLED also prevent mutation.

This source-level gate is necessary but does not certify every operating system. Native Windows, macOS amd64, WSL2, and the complete RC8 two-device matrix retain separate physical acceptance evidence on the current matrix.

Release-by-release compatibility tracker

Reinstate releaseDateAgent-version rangeRelated compatibility change
v0.1.0-rc.8No agent-version range change documented.Restore liveness no longer depends on an open file handle. Claude Code closes its session file between appends, so a live session held no handle and RC7 treated it as free. Detection now also matches an agent naming the exact session on its command line, or working inside the session’s mapped project. Tagged implementation.
v0.1.0-rc.7No agent-version range change documented.Restore liveness detection became session-scoped. A restore now checks whether the exact target session file is held open, using operating-system file handles, instead of asking whether any Claude Code or Codex process is running. A session that is genuinely in use is restored alongside the live one rather than refused. Tagged implementation.
v0.1.0-rc.6No agent-version range change documented.Codex working directories resolve to canonical project IDs. Additional-device init changed from RC5’s metadata-only manifest probe to reading the complete remote ciphertext; init still does not decrypt it or validate the passphrase. Tagged implementation.
v0.1.0-rc.5No agent-version range change documented.Additional-device init required a metadata-only existence probe for the remote manifest before saving local setup; it did not read or decrypt the ciphertext. Tagged implementation.
v0.1.0-rc.4No agent-version range change documented.Claude restore paths became destination-aware, legacy unmapped snapshots fail closed, and exact native restore locations are verified.
v0.1.0-rc.3Introduced the current inclusive ranges: Claude Code 2.1.219–2.1.220 and Codex CLI 0.133.0–0.145.0.Installed versions outside a tested stable range become UNTESTED and setup check exits with compatibility code 5.
v0.1.0-rc.2No agent-version range change documented.Release CI corrected signed-tag verification; no adapter compatibility change is recorded.
v0.1.0-rc.1Claude Code and Codex adapters launched with fixture-backed checks, but this changelog does not publish an exact historical version range.Established fail-closed adapter compatibility states and same-vendor session restore.

“No change documented” is intentional. It means the tagged changelog does not claim a range change; it does not reconstruct private test history or guess what an earlier binary accepted. RC1 and RC2 do not publish exact historical endpoints in the current release evidence, so this tracker leaves them unstated.

How a range changes

  1. A vendor version is exercised against deterministic synthetic adapter fixtures.
  2. Discovery, structural path handling, export, restore, exclusions, and failure behavior are reviewed.
  3. The adapter constants and tests change together.
  4. compatibility.json, documentation, and release notes cite the exact evidence.
  5. Physical platform results remain separately qualified until their acceptance rows pass.

A new vendor release is not supported merely because its version number is close to the current range. The range expands only after evidence is committed and released.

Before upgrading an agent

  • Check this tracker and the current compatibility matrix.
  • Keep the existing agent and Reinstate installers or another recovery path.
  • Run rein setup check before any push or pull.
  • Use a synthetic, non-sensitive session for a newly accepted version.
  • Report the exact agent version, Reinstate version, operating system, and redacted failure.