You started a long debugging session in Claude. Two hundred messages in, you hit a wall — Claude's context window is straining, and you want a fresh perspective from Codex. But the session is in Claude. You'd have to copy-paste the relevant parts, re-explain the background, re-establish the context. Most of the time you just keep going with the same agent, even when a different one would do better.

The same friction showed up whenever you needed a second opinion. "What would Gemini say about this architecture?" means starting from scratch, manually summarizing what you've already built up over the last hour.

Resume Any Session in Any Agent

You no longer have to stay locked to the agent that started a conversation. In the Resume dialog, you now pick not just which session to continue — but which AI agent to continue it in. Claude session → Codex. Gemini thread → Amp. Any past conversation → any agent you've configured.

The resumed agent gets the full prior chat as context, so it picks up exactly where the previous one left off.

How It Works in Practice

Choose a target agent when resuming

Open the Resume panel, find the session you want to continue, and the agent picker now lists every AI agent you have configured — Claude, Codex, Gemini CLI, Amp, and any custom AI commands you've set up. Each agent shows its icon and color so you can spot the right one at a glance.

The "second opinion" flow is one click

If you select a single session to resume, 1DevTool defaults the target to a different agent than the one that originally ran it. The most common reason to resume is to get a fresh take — so the default now matches that intent. You don't have to actively deselect the original agent to get a new one.

Resuming two or more sessions together still defaults to the most common agent in the selection, which keeps the multi-session "combine and continue" flow consistent.

The resumed agent gets clean context

The generated context prompt adapts to what you're doing. Resuming a single session produces "Here is the chat from a previous session for context." Combining multiple sessions produces "Here are the combined chats from previous sessions for context." A small thing, but it matters: the resumed agent receives language that matches the structure of what it's being handed, so it orients faster.

Every agent now understands where it's picking up

1DevTool has always let you resume sessions in the same agent. Cross-agent resume extends the same mechanics — the chat history is passed in as structured context, the resumed terminal opens directly in the target agent's native mode, and the handoff is invisible from the inside.

Before vs After

Task	Before	After
Get a second opinion from a different AI	Copy transcript, open new terminal, re-explain context	Resume → pick target agent → one click
Continue a Claude session in Codex	Not possible without manual paste	Resume → select Codex from picker
Combine two sessions for a fresh agent	Not possible	Multi-select → combine → pick any agent
Resume with same agent (existing flow)	Works as before	Still works, unchanged

Who Benefits Most

Developers working across multiple AI tools — If you regularly use Claude for architecture and Codex for implementation, cross-agent resume means those two workflows can now share context without you being the copy-paste bridge.

Anyone hitting context limits — When a session gets long enough that the current agent is starting to lose the thread, resuming in a fresh instance of a different agent gives you a clean context window with the full history pre-loaded.

Teams comparing AI outputs — Resuming the same session in multiple agents and comparing their responses on the same codebase context is now a defined workflow, not an improvised one.

Try It

Open the Resume dialog (Cmd+Shift+R), pick any past session, and look at the agent picker below the session list. Select a different agent than the one shown, hit Resume, and the new terminal opens mid-conversation. Your next prompt lands in Codex, Gemini, or whichever agent you chose — with full context from everything that happened before.