Every thread leaves a line.
Threadlines is a local desktop workspace that runs Claude Code and Codex in parallel threads, with real source control at the center and nothing hidden. Bring the subscriptions you already pay for.
Free and open source (MIT) · No account · Your code never leaves your machine
Project files, first-class
The project is part of the conversation
The project-file popover is a real file surface: tabs, browsing, and syntax highlighting. Open a file, edit it, save it, without leaving the thread. Then select the lines that matter and attach them to the chat as exact context.
One thread, two providers
Hit a usage limit? Switch, don't stop.
Switch a running conversation between Claude and Codex in place. The recap and your working tree carry over. Live meters show both providers' five-hour and weekly windows with reset countdowns, so you see the wall before you hit it and keep shipping when you do.
Steer, don't re-prompt
Reply to the exact lines you mean
Select a sentence of the agent's answer, a range of code, or lines of terminal output, and attach exactly that to your next message. Add a note when you attach it, then reopen or edit the note from the composer before you send. Course-correct in seconds instead of writing paragraphs of follow-up.
Nothing runs invisibly
Every task, subagent, and background run. Visible, labeled, stoppable.
The activity header shows what your agents are actually doing: a task list with live states, each subagent's goal with the model and effort it runs on, and background processes with a Stop button. And when a subagent finishes, its findings land in the conversation the way you saw at the top of this page, not as a collapsed spinner line.
This capture follows the site theme — try the toggle in the top bar.
Built to be boring
Reliability is the feature
Survives restarts
Sessions resume across app and server restarts via event replay. Close the lid mid-turn and pick it back up.
Fork from anywhere
Fork any message into a parallel thread with context, attachments, and working tree included.
Worktrees per thread
Give each agent its own isolated checkout, or share one. Your call, per thread.
Always within reach
Glanceable agent status from the macOS menu bar: running threads, one click away.
Source control, not a diff drawer
From agent diff to opened PR
A real source-control panel sits beside every thread: changes grouped per file and folder with staged and unstaged state, per-file review and actions, and a one-button generate, commit, and push flow with your hooks' output shown, not hidden. GitHub, GitLab, Bitbucket, and Azure DevOps.
01 Changes, file by file
Step through each changed file's own diff, review and act on it, then return to the grouped tree without losing your place.
02 History you can see
The Git graph shows branches and tags where they actually point. Hover a commit for a preview, or click through commits in a detail card that stays put while you read, without losing the agent conversation beside it.
How we build
We don't compete with the frontier. We keep up with it.
OpenAI and Anthropic have giant teams shipping new agent capabilities every month. Threadlines doesn't reinvent that work: it keeps pace with it.
Core first
No pile of gimmick features. The daily loop, threads, diffs, commits, reviews, gets the attention.
Native parity, fast
When Codex or Claude ships a new capability, Threadlines fits it in. In days, not months.
No lock-in
Every feature works across providers. Switching is a feature here, not a betrayal.
Open source
MIT-licensed, history and all
Threadlines began as a fork of T3 Code and grew into the safety and endurance layer for agent work: visibility, recovery, and source-control depth. The full git history is public: refactors, lessons, and all.
github.com/Threadlines/threadlines · macOS + Windows + Linux