Choose agents and models

Decide which AI harnesses a machine can run, which one handles each ticket state by default, and how a single ticket overrides that.

You need: bakers.build installed and signed in, at least one harness (Claude Code, Codex, Kimi, OpenCode, Pi or Grok) installed, on PATH, and logged in on this machine, and a project checkout. The herdr executor runs the harness through non-interactive sh, so a shell alias is not loaded.

1. See what the machine offers. Run this in the checkout:

   bakers agents

   The JSON lists each alias with its harness and model, plus enabled_agents, default_agent and routes. An alias is one selectable harness and model, such as opus or codex. bakers agents neither installs a harness nor checks its login.

2. Name your harnesses in ~/.bakers/machine.config.js. Keep the identity and capacity fields that bakers init wrote and edit addons and the agents object. A complete file that uses Codex for coding and Claude Opus for review:

   // @bakers-schema-version 3
   export default {
     schema_version: 3,
     machine_id: 'alex-laptop',
     user_id: 'alex',
     max_parallel: 1,
     addons: ['@bakers-build/addon-codex', '@bakers-build/addon-claude'],
     agents: {
       enabled: ['codex', 'opus'],
       default_agent: 'codex',
       routes: {
         default: { working: 'codex', review: 'opus', '*': 'codex' },
         careful: { '*': 'opus' },
       },
     },
   };

   addons supplies candidates (agent harnesses may be listed only in this file), enabled limits them, default_agent is the last fallback. A route maps workflow states to aliases, and '*' covers every state not named. The default route applies to every ticket without a label.

3. Override one ticket with a label, through the ticket's normal label editing:

   Label	Effect with the file above
   agent:careful	Route careful: Opus in every state
   agent:opus	Alias opus in every state
   agent:opus@working	Alias opus, only while the ticket is in working

   A direct alias beats a route, whatever the label order. The route must exist on the machine that actually runs the ticket. The full precedence list is in Machines.

4. Verify, then run one small ticket:

   bakers config check --scope machine
   bakers agents

   Inspect the run's recorded harness and model for the state. If coding and review use different agents, check both.

Done when: bakers agents shows your aliases, default_agent and routes, and a small ticket ran with the harness you chose for its state.

Ask your AI

"Show my installed harnesses with bakers agents, then propose the smallest agents change for Codex on coding and Opus on review."

When loading fails

The conductor and bakers agents fail with one of these messages; bakers config check does not inspect agents.

Message	Cause and fix
machine.config.js addons[] must resolve a non-empty catalog of aliased agents	No harness addon. Add one to addons of machine.config.js.
machine agents.addons is retired: …	An older machine file. Run bakers config upgrade --scope machine, which moves the entries into addons.
effective agent catalog is empty after agents filters	enabled or disabled removed every alias.
agents.default_agent names unavailable alias '<alias>'	default_agent is not among the enabled aliases.
agents.enabled names unknown alias '<alias>'	Typo, or the addon that publishes it is missing.

A label that names an unknown alias or route only logs a warning and falls back, so check the observed agent instead of trusting the label. Pins, options such as model and effort, catalog overlays and every field are in Machines.