BuildGist

Can you resume a coding agent session in a different tool?

Kayvan Zahiri ·

No coding agent can open another agent's session. Claude Code, Cursor and Codex each resume only their own. What you can carry into the other tool is the code, which is already in the folder, and the task, which you write down or pass with Continue on the BuildGist card.

How each agent resumes its own

Each one keeps its history in its own place and its own format. None of them reads the others'.

Why a transcript does not move

Claude Code keeps each session as a JSONL file under ~/.claude/projects/. Its documentation says that format is internal and changes between versions. There is no import for it in Cursor or Codex.

Pasting a whole transcript is rarely worth it even when you can. It is long, mostly tool output, and it records what was said, not what the code is now. A message can say a file was fixed when the fix landed elsewhere. The next agent spends its context reading an argument you already settled.

If you want part of it, /export in Claude Code saves the conversation as readable text. Copy the request and the decisions, not the whole thing. A summary written by the old agent is shorter, but it is still that agent's account of its own work. Check it against the diff.

What to carry instead

Three things, and the first is already there.

  1. The code. Open the other agent on the same folder. It reads the files, including uncommitted ones. Run git status and git diff --stat so you know what is in it.
  2. The task. What you asked for and the next step.
  3. The decisions. What you tried and dropped, and why. These never show up in the code, so no agent can rediscover them.
Task: Add login with Google.
Done so far: the sign-in button, where Google sends you back, and the browser's signed-in
status. See the diff.
Tried and dropped: storing passwords ourselves.
Next step: check that a deleted note belongs to the signed-in user.

Paste it as the first message of a new chat, and ask the agent to say the task and the next step back before it edits. The note follows the BuildGist home page's example. For Codex, the steps are in how to switch from Claude Code to Codex. For Cursor, they are in how to hand off a task from Claude Code to Cursor.

Continue on the BuildGist card

BuildGist works with Claude Code, Cursor and Codex. When you start a new chat in another of them in the same project, a BuildGist card at the bottom right of your screen offers the earlier agent's task. Choose Continue and the new chat starts with that task's context. Choose Start fresh and nothing is handed over.

That is not a resumed session either. The context is your own words, the task and the constraints you typed, plus, when the last run's files are still as it left them, how many files it changed, whether a test failed, and up to three paths. The transcript stays where it was. By default the card offers a task active in the last 12 hours. Cursor's handling of the context is best effort, so paste the note if the task does not show.

Going back

When you return to the first agent, its old session is still there, and still out of date. It does not know what the other agent did. The same is true the other way: a Codex chat you resume has not seen what Claude Code did since. Read the new diff, then give it the note again, or choose Continue when you start a new session. Where Claude Code keeps sessions, and for how long, is in where Claude Code keeps session history.

BuildGist writes a plain-English explanation after each meaningful run, in whichever agent ran it, so you can read what happened while you were in the other tool. It is written by AI, so check important behavior against the code and tests.

What you need

Codex needs you to approve BuildGist once, in Codex. BuildGist shows the steps. Setup is in Getting started.

To explain a run, your computer sends BuildGist what that run needs, and BuildGist passes it to Anthropic. BuildGist does not keep this material. It does not send your whole repository, files the run did not change, or files named like secrets, such as .env files and keys. It keeps the explanation and short cited excerpts of changed code, at most 12 lines each. Secret masking is best-effort. Privacy has the full list.

Every account gets 7 days of BuildGist Pro free, with no card. The 7 days start at your first explanation or Continue handoff. Nobody is charged when the trial ends. After that, BuildGist Pro is $12 per month, plus any applicable tax shown at checkout. See pricing.

Try BuildGist

Apple silicon, macOS 12 or later. United States, 18 or older.

Related

Questions: kayvanandre@gmail.com.