Using Downsizing with Junie

Prerequisites

Install the Downsizing CLI — see the CLI guide if you haven't already.

Link Junie (Recommended)

Link Junie to Downsizing:

ds link junie

The CLI writes a model profile to ~/.junie/models/downsizing.json with your Inference ID and API key pre-filled.

The CLI also sets Downsizing as the default model in ~/.junie/config.json, so you can run Junie without any extra flags:

junie --model custom:downsizing "your task"

Manual Setup

If you prefer to configure manually, create ~/.junie/models/downsizing.json:

{
  "baseUrl": "https://api.downsizing.dev/YOUR_INFERENCE_ID/anthropic/v1/messages",
  "id": "claude-sonnet-5",
  "apiType": "Anthropic",
  "apiKey": "dws_YOUR_API_KEY",
  "fasterModel": {
    "id": "claude-haiku-4-5"
  }
}

Find your Inference ID and API key in the Inference API page. Replace YOUR_INFERENCE_ID with the workspace UUID and dws_YOUR_API_KEY with your Downsizing API key.

Verify

Run a quick one-shot task to confirm traffic is routing through Downsizing:

junie --model custom:downsizing "What is 2+2? Reply in one word."

If Junie responds, Downsizing is set up correctly. You can also check your savings dashboard to see the request appear in your usage metrics.

Unlinking

To remove Downsizing from Junie and restore your original settings:

ds unlink junie