Continue sessions started in provider CLIs in T3 Code

[JSMike]

I’d like to start work in a coding agent’s CLI, then move into T3 Code and continue the same session with its existing context and working directory.

For example, Codex and Claude provide commands like:

codex resume <session-id>
claude --resume <session-id>

The goal is to continue that actual session in T3 Code without starting a new conversation or manually transferring context, including sessions created after project onboarding.

Following the feedback on #13961, I’m opening this discussion to confirm whether this fits the product direction and ask how maintainers would prefer to approach it.

Some possible entry points:

• A Resume picker in a project’s new-thread composer, listing external sessions from that project and its worktrees, sorted by recent activity with provider icons, descriptions, and last-active times.
• Pasting a resume command or session ID into the new-thread modal before choosing a project.
• A T3 CLI command to hand off a provider session directly from the terminal into T3 Code.

As I explored this, a few scope questions came up:

• Different or unadded projects: a pasted session might belong to a different project from the one currently selected, or to a directory T3 hasn’t onboarded. It seems useful to identify its project first, take it through the existing project import/intake flow if needed, then continue the selected session.
• Linked worktrees: a session may have started in any worktree associated with the project. Ideally, T3 would recognize that relationship while preserving the session’s original working directory.
• Connected environments: the session may live on another connected machine. One possibility is to search the selected environment first, then offer to search others. The session would continue on its owning environment, where its files and provider credentials live.
• Existing T3 threads: sessions already represented in T3 could be excluded from the external-session picker to avoid duplicates. Archived and deleted threads also need clear behavior.
• Provider coverage: Codex and Claude are supported by the existing importer, while other providers would need additional discovery/import support.

I’ve explored an implementation in #13961, which includes a short recording. These are considerations and suggestions rather than fixed requirements; I’m open to changes to the interaction, scope, and implementation.

A few questions for maintainers:

1. Is continuing externally started CLI sessions a workflow you’d like T3 Code to support?
2. Should an initial version support Codex and Claude, or all supported providers where resuming is possible?
3. Which entry points would you prefer: the new-thread modal, the project-scoped picker, both, a T3 CLI command, or another approach?
4. Which of the project onboarding, worktree, and connected-environment cases should be included initially, and which should be deferred?

[juliusmarminge]

Note

Grok responding on behalf of Julius.

Closing as a duplicate of #6873 (continue Claude Code / provider CLI sessions in T3). Related open Ideas on the same ask: #6994, #7023. Please continue product-direction / scope discussion on the canonical thread; the explored implementation in closed #13961 is useful context there.