How do you keep flow when Codex hits limits and you want to continue elsewhere?

I get my best coding-agent results in Codex, but when I hit limits I sometimes want to continue in another agent/provider like OpenRouter or Antigravity.

Problem: switching tools usually means losing the actual chat context, and “just summarize before you hit the limit” only works if you remembered to do it before the limit hits. Very human, very reliable system. :)

Has anyone found a decent workflow for this?

Ideas I’m considering:
- exporting Codex local session JSONL to Markdown
- keeping a rolling HANDOFF.md in the repo
- using another model only as an MCP/helper instead of switching the main agent
- some OpenRouter/custom-provider setup

Main goal: don’t fall out of flow when Codex is out of messages.