Coding mode
A lean, per-session mode for working on code — a short system prompt, only the tools coding needs, a fresh worktree on request, and the pull request's status in the chat header.
Coding mode turns a session into a focused coding agent. It sends a much shorter system prompt (about 2,400 characters instead of about 17,000) and only the session tools that coding work needs, so every turn costs fewer tokens and the model stays on your code. Your preferences, the project's context and the repository's CLAUDE.md / AGENTS.md still apply.
Turning it on
| Where | How |
|---|---|
| One session | Click the Coding chip next to the folder chip in the composer, before the first message. |
| Every new session | Settings → Workspace → Start new sessions in Coding mode. |
| CLI | fabric-cli run --coding "fix the failing test" |
The mode is fixed once the conversation starts. Clicking the chip in a session that has started offers to continue in a new session with the mode switched; the new session starts with a summary of the conversation so far.
Coding sessions show a </> glyph in the session list.
Where the session works
Turning Coding mode on asks where the session should work:
- Use existing folder opens the folder picker.
- Create new worktree lists your repositories: those in your recent folders, those in the workspace's default folder, and your GitHub repositories (through the GitHub CLI). Pick one and Fabric creates a new branch, by default
fabric/<session id>, from the latest default branch in a folder of its own, and makes that folder the session's working directory. A GitHub repository that isn't on your computer yet is cloned first.
A bare repository with many worktrees appears as one entry.
Pull request status in the header
When a Coding session's folder is a git repository with an open pull request, the chat header shows the PR next to the folder name: its number, its state (open, draft, merged or closed) and one status mark:
| Mark | Meaning |
|---|---|
| Merge conflicts | The branch can't merge cleanly. |
| Conversations | Review threads are still open. |
| Failing checks | At least one check failed. |
| Running | Checks are still running. |
| Tick (orange) | All good on GitHub, but you have uncommitted changes or unpushed commits. |
| Tick (green) | All good. |
Hover the chip, or click it to keep it open, for the last commit, the checks, reviewers, open conversations and the merge state. One button sends a ready-made prompt to the agent: Resolve merge conflicts, Fix review comments or Fix CI. The agent works locally; it doesn't push or reply on GitHub unless you ask it to.
The status refreshes after each agent turn and when you commit, switch branches or push, and otherwise every 15 seconds to 2 minutes. It pauses while the window is hidden. It uses a connected GitHub source or your GitHub CLI sign-in; no AI model is involved.
In Coding sessions the header shows one label chip plus "+N", so the PR status has room.
Related
- Working directory — how the session's folder is used by tools.
- CLI —
fabric-cli run --coding. - Agents — subagents and the subagent model setting.
Workflow Mode
Design / Code / Mixed session mode in Fabric Agents — visual sidebar identification, manual override, and per-session system-prompt budgeting that drops ~600 tokens for coding-only sessions.
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