Resume a Codex session through Foundry

beta

Reattach to an earlier Codex session by ID or with --last, with Azure AI Foundry authentication injected transparently by the pks loopback passthrough.

Author: Poul Kjeldager

Usage: pks codex resume [ARGS] [options]

Category: infrastructure

Examples

$ pks codex resume --last

Resume the most recent Codex session through Foundry

$ pks codex resume 019f3e01-b0c1-7bf2-b1d8-d0befe7232fd

Resume a specific session by ID

Pick up an earlier Codex session on a Foundry deployment. pks codex resume forwards Codex's own resume feature through the loopback passthrough — the session lookup is native Codex behavior, and pks contributes only the authenticated endpoint.

1. Prerequisites

A Foundry login — pks foundry init, with a resource endpoint selected.
The upstream Codex CLI on PATH — npm i -g @openai/codex.
A session Codex itself can resume. pks keeps no session store of its own. If the local Codex CLI cannot find the session, neither can pks.

2. Resume the last session

pks codex resume --last

The passthrough starts, Codex reopens the most recent session, and the conversation continues against the resolved Foundry deployment.

3. Resume a specific session

pks codex resume 019f3e01-b0c1-7bf2-b1d8-d0befe7232fd

The session ID and any other native arguments are recovered from the raw process arguments, so a UUID-shaped or flag-shaped value reaches the real codex binary unmangled.

4. Override the deployment for this session

pks codex resume --last --model gpt-5.6-sol --reasoning-effort high

The same resolution order as a fresh launch applies: the flag wins, then the Foundry account default when it looks like a GPT or Codex model, then ~/.pks-cli/codex.json, then gpt-5-codex.

5. Verify

pks codex --print-env

The passthrough runs in the foreground and prints the launch command with the resolved deployment and port, confirming the environment a resume would use. Stop it with Ctrl-C.

6. Next steps

Run Codex non-interactively — resume plus a scripted instruction
How the Foundry passthrough works — the failure log and request sanitizing
Manage Codex sessions through Foundry — fork, archive, unarchive, and delete

Options

Flag	Default	Description
`-m, --model <name>`	Configured deployment, else `gpt-5-codex`	Foundry deployment name for this session.
`-e, --reasoning-effort <level>`	Configured value, else `medium`	Reasoning effort: `none`, `low`, `medium`, `high`, `xhigh`, or `default` (omits the `-c model_reasoning_effort` override and lets Codex use its own built-in default).
`-p, --port <port>`	Configured value, else `8788`	Loopback port for the passthrough.
`--print-env`	`false`	Run the passthrough in the foreground and print the launch command instead of starting Codex.
`--safe`	`false`	Keep Codex approval prompts and sandbox enabled.

The positional ARGS are native codex resume arguments, forwarded verbatim.

Troubleshooting

Codex reports no such session. The session store belongs to the Codex CLI. Confirm the ID with Codex directly; pks cannot list or recover sessions.

A native flag was consumed by pks instead of Codex. Put the pks flags first and the native arguments after them, as in the examples above.

Exit code 1 pointing at pks foundry init. Authentication or resource selection is missing. Every codex subcommand runs that check before doing anything else.

Exit code 127. The codex binary is not on PATH.