oh-my-opencode-slim/docs/preset-switching.md

Preset Switching

Switch agent model presets at runtime without restarting OpenCode using the /preset slash command.

Controls

Command	Description
/preset	List available presets (highlights the active one)
/preset <name>	Switch to the named preset immediately

How It Works

1. Define named presets in oh-my-opencode-slim.jsonc under the presets field
2. Run /preset <name> to switch. The plugin calls the OpenCode SDK's config.update() method, which triggers a server-side cache invalidation
3. The next LLM call uses the new models and settings

Example Configuration

{
  "presets": {
    "cheap": {
      "orchestrator": { "model": "anthropic/claude-3.5-haiku" },
      "explorer": { "model": "openai/gpt-5.4-mini" },
      "oracle": { "model": "anthropic/claude-sonnet-4-6" }
    },
    "powerful": {
      "orchestrator": { "model": "openai/gpt-5.5" },
      "oracle": { "model": "anthropic/claude-opus-4-6" },
      "librarian": { "model": "anthropic/claude-sonnet-4-6" }
    },
    "thinking": {
      "oracle": {
        "model": "anthropic/claude-sonnet-4-6",
        "variant": "thinking",
        "options": { "thinking": { "type": "enabled", "budgetTokens": 10000 } }
      }
    }
  }
}

Supported Fields

The following fields are forwarded to the OpenCode SDK at runtime:

Field	Description
model	Model ID in provider/model format. Array form (fallback chains) is resolved to the first entry
temperature	Inference temperature (0-2)
variant	Model variant (e.g. "thinking")
options	Provider-specific options (e.g. thinking budget)

Fields not forwarded (require restart): prompt, skills, mcps, displayName.

Startup Preset vs Runtime Switching

There are two ways to activate a preset:

Method	How	Persists?
Config file	Set "preset": "cheap" in oh-my-opencode-slim.jsonc	Yes, across restarts
/preset command	Run /preset cheap during a session	No, reverts on restart

On restart, the plugin's config() hook re-applies the preset from the config file, overwriting any runtime switch. To make a runtime switch permanent, update the "preset" field in your config file.

Example Output

/preset

Available presets:
  cheap ← active
    orchestrator → anthropic/claude-3.5-haiku
    explorer → openai/gpt-5.4-mini
    oracle → anthropic/claude-sonnet-4-6
  powerful
    orchestrator → openai/gpt-5.5
    oracle → anthropic/claude-opus-4-6

Usage: /preset <name> to switch.

/preset powerful

Switched to preset "powerful":
orchestrator → model: openai/gpt-5.5
oracle → model: anthropic/claude-opus-4-6

See Configuration for the full preset option reference.