pi-model-switch

A Pi coding agent extension that gives the agent the ability to list, search, and switch models on its own.

With this extension, you can tell the agent things like "switch to a cheaper model" or "use Claude for this task" and it will handle the model change itself, without you needing to use /model or keyboard shortcuts.

Installation

``bash
pi install npm:pi-model-switch
`

Restart Pi to load the extension.

$3

After restarting Pi, the switch_model tool should be available. Ask the agent to "list available models" to confirm.

$3

If you used curl:
`bash
curl -o ~/.pi/agent/extensions/model-switch/index.ts \
https://raw.githubusercontent.com/nicobailon/pi-model-switch/main/index.ts
`

If you cloned:
`bash
cd ~/.pi/agent/extensions/model-switch && git pull
`

Restart Pi after updating.

Configuration

$3

Create aliases.json in the extension directory to define shortcuts:

`bash
~/.pi/agent/extensions/model-switch/aliases.json
`

`json
{
"cheap": "google/gemini-2.5-flash",
"fast": "google/gemini-2.5-flash",
"coding": "anthropic/claude-opus-4-5",
"budget": ["openai/gpt-5-mini", "google/gemini-2.5-flash", "anthropic/claude-3-5-haiku-latest"]
}
`

- String value: Must be an available model or returns an error
- Array value: Uses first available model in the list (fallback chain)

Then just say "switch to cheap" or "use coding model".

$3

Add model switching preferences to your AGENTS.md for contextual decisions:

`markdown


Model preferences


- Simple file ops / quick questions: switch to "cheap"
- Complex refactoring / architecture: switch to "coding"
- Default to budget-friendly models unless quality is needed
`

The agent will use aliases when appropriate based on your guidance.

Usage

Once installed, the agent gains a switch_model tool. Just ask naturally:

- "List available models"
- "Switch to GPT-5.2"
- "Use Opus 4.5"
- "Change to a model with vision capabilities"
- "Use a cheaper model for this task"

The agent will list models or switch as appropriate.

Tool Reference

The extension registers a single tool:

switch_model

| Parameter | Type | Description |
|-----------|------|-------------|
| action | "list" \| "search" \| "switch" | List all models, search/filter models, or switch to one |
| search | string (optional) | For search/switch: term to match model by provider, id, or name |
| provider | string (optional) | Filter to a specific provider (e.g. 'anthropic', 'openai', 'google') |

$3

Returns all models you have API keys configured for, showing:
- Provider and model ID
- Model name
- Context window and max output tokens
- Capabilities (reasoning, vision)
- Cost per 1M tokens (input/output)
- Which model is currently active

$3

Filters models by partial match on provider, id, or name. Returns all matching models with full details.

$3

Matches models by:
1. Alias lookup (if defined in aliases.json)
2. Exact provider/id match
3. Exact id` match
4. Partial match on id, name, or provider

If multiple models match, it asks you to be more specific.

Requirements

- Pi coding agent
- API keys configured for the models you want to use

License

MIT