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  2. Models and runtimes

Models and runtimes

This page shows you how to choose what a ticket’s agent runs with: which machine it runs on, which coding tool, which model and how hard it thinks. By the end you’ll know how to change those for one ticket, and how to set the defaults every new ticket in a project or in the whole organization starts from.

A ticket’s run config has four settings:

  • Machine: the remote agent the ticket runs on, or Auto to let By Dawn pick.
  • Runtime: the coding tool the agent runs. By Dawn runs Claude Code, Codex and Grok.
  • Model: the model the runtime uses, such as Opus or Sonnet for Claude Code.
  • Effort: how much reasoning the model puts into each step. More effort is slower and uses more of your plan, but helps on hard work.

Each setting is decided in layers, and the first layer that sets it wins:

  1. The ticket itself, if someone changed it there.
  2. The project’s run defaults.
  3. The organization’s run defaults.
  4. By Dawn’s built-in default for the runtime.

So most tickets need no choice at all. A team sets the organization’s defaults once, a project overrides them where its work is different, and a person changes a single ticket only when that ticket needs it.

Open the ticket. Its header has a Run config line that shows the machine, model and effort it will run with. Open it to see four settings, Machine, Runtime, Model and Effort, and choose any one to change it.

Each menu starts with Follow project, followed by the value the project gives right now. A setting you’ve changed for this ticket is marked with a dot, and Reset to project defaults puts every setting back in one go.

Choice Where the ticket runs
Auto · least busy The least busy machine that can run the ticket’s runtime. By Dawn picks it when the run starts.
Follow project The project’s Default agent.
Local · this machine The machine running the By Dawn desktop app. Only offered in the desktop app.
A machine by name That machine, and only that one.

A machine that can’t take the ticket says why beside its name: offline, personal (it only runs another member’s work, see Whose work a machine runs), unknown (it hasn’t reported yet), or no followed by the runtime it lacks. The list also shows how busy each machine is.

Auto is the best choice for most tickets, because it spreads work across your machines and skips one that’s full, strained or signed out. Pin a machine only when a ticket needs something only that machine has.

The Model menu lists the models your machines report for the ticket’s runtime, so it matches what they can really run. If no machine has reported any, the menu shows By Dawn’s built-in list and says built-in list · no machine reported models. A model you picked earlier that no machine reports now stays in the list, marked unavailable?, because the machine that has it may just be offline.

The efforts you can pick depend on the runtime:

Runtime Efforts Built-in default
Claude Code Low, Medium, High, Extra high, Max High
Codex Minimal, Low, Medium, High Medium
Grok Low, Medium, High, Extra high High

A model and an effort belong to one runtime. So when you switch a ticket’s runtime, By Dawn clears a model or effort the new runtime doesn’t offer, rather than handing a Claude model to Codex.

Once the agent is running, the ticket’s worker pane shows the model it’s using. Choose it to switch. While a run is live, the menu says Pushed to the running worker · applies to the next run too, because By Dawn passes the change to the running agent as well. Otherwise it says Applies to the next run.

Run defaults are the two layers under the ticket: one page for each project, and one for the whole organization. A project’s page only needs to name what’s different, because anything it leaves alone follows the organization’s.

Settings, then This project, then Run defaults holds where every new ticket in the project starts. Project admins and org admins can change it.

  • Default agent is the machine that Follow project means. Choose Auto · least busy to spread the project’s tickets across your machines with no per-ticket choice at all.
  • Default model, Default effort and Default runtime each show the value in force and where it comes from: Inherited from organization or Built-in default. Choose Override to set the project’s own value, and Revert to organization default to go back. View org default opens the organization’s setting.

Changes apply to tickets that start afterwards. A ticket that’s already running keeps what it started with.

Settings, then Organization, then Run defaults is the top layer: every project that sets nothing, and every ticket in it, runs with these. Owners and admins can change them.

Setting What it does
Default runtime The runtime new tickets run on.
Default model The model new tickets launch with. Built-in default follows By Dawn’s default for the runtime.
Default effort The effort new tickets use. Built-in default follows By Dawn’s default for the runtime.
Questions model The model Questions are answered on. Questions always run on Claude Code.
Members can choose a model for Questions Off pins every question to the Questions model.
Agent briefing Text added at the start of every agent session in the organization’s projects, such as house rules. Choose Save briefing to keep it.

In the desktop app, Advanced on Settings, then You, then This computer lists the runtimes By Dawn can run, each with its default model and effort. A runtime only works on machines that have it installed. Each machine’s row in Settings, then Organization, then Remote Agents shows the runtimes it reported. A machine that reports none shows Runtimes unknown and gets no work until its agent is updated and a runtime is installed there.

Claude Code runs on the Claude account the machine is signed in to (see Claude accounts, sign-in and seats). Codex runs on the machine’s own codex login. Grok needs the setup below.

Grok is xAI’s Grok Build coding tool. You can pick it as a ticket’s runtime and install it on your machines now, but By Dawn can’t run any work on it yet (see the note below). Setting a machine up ahead of time means it’s ready when Grok sessions arrive, and By Dawn only sends a Grok ticket to a machine that has Grok installed.

  1. Install Grok Build on the machine from xAI’s Grok Build page. It installs to ~/.grok/bin/grok. If By Dawn can’t find it, set SAW_GROK_BIN (or GROK_BIN) in the agent’s environment to the path of the grok executable.
  2. Sign Grok in by running grok login on the machine. It signs you in through your browser and keeps the sign-in on the machine. On a machine with no browser, run grok login --device-auth instead.
  3. Run saw-agent doctor on the machine. It says whether Grok is installed and whether it’s signed in. Once Grok is installed, the machine lists Grok among its runtimes.

Grok’s built-in model is grok-4.7. You can also pick grok-4.6, grok-4.5 or grok-build-0.1.

Why isn't the model I want in the list?

The list shows the models your machines report for the ticket’s runtime. Check that the ticket’s Runtime is the one the model belongs to, and that a machine with that model is online.

I changed the project's default model. Why does a running ticket still use the old one?

Defaults apply when a ticket starts. To change a running ticket, switch its model in the worker pane.

Why did my ticket's model reset when I changed its runtime?

A model belongs to one runtime, so By Dawn clears a model the new runtime doesn’t offer. Pick one from the new runtime’s list.

Why did my Grok ticket stop as soon as it started?

Grok can’t run a ticket’s interactive session yet, so a ticket set to Grok fails to start. Switch the ticket to Claude Code or Codex (see Set up Grok on a machine).