sbx/codex-sessions repository overview

⁠Codex host sessions for Docker Sandboxes

This v3 mixin Kit retains Codex conversation state on the host across sandbox removal. It composes with either the Codex workload or its agent mixin.

This Kit is built on Docker Hardened Images.

⁠Run

sbx run sbx/codex:latest --kit sbx/codex-sessions:latest /path/to/workspace

⁠Kit arguments

This kit has no create-time kit arguments.

To configure the composed agent, set arguments on its workload or agent mixin, such as --kit-arg codex.model=gpt-5. This mixin does not declare model or effort arguments.

⁠Authentication and configuration

The runtime mounts host storage at /home/agent/codex-history. Each sandbox uses a subdirectory named after that sandbox, so simultaneous sandboxes do not share one writable session store. Reuse the sandbox name to reconnect to its retained state.

The kit retains the declared session data, not account credentials or the agent's complete configuration directory. Conversation history can contain workspace content and tool output. Authentication stays with the composed agent kit.

The install hook refuses to replace existing nonempty session state or unexpected symlinks. Move existing state into the host-backed directory before adding this mixin to an existing environment.

⁠Related kits

• sbx/codex⁠ provides the complete agent workload.
• sbx/codex-acp⁠ provides the ACP adapter for the composed agent.
• sbx/codex-mixin⁠ provides the agent overlay for a compatible workload.

⁠Source and security

For the Kit format and capability contracts, see the Sandbox Kit v3 specification⁠.

For runtime setup, see the Docker Sandboxes documentation⁠. For provenance, SBOM, VEX, and image verification, see the Docker Hardened Images documentation⁠.

Codex and OpenAI are trademarks of OpenAI, L.L.C. Product names and logos do not imply sponsorship or endorsement.