Use Modellix LLM with Junie CLI

Configure Junie CLI by JetBrains to call the Modellix LLM gateway. Junie does not ship a built-in Modellix BYOK provider, so add a custom LLM profile that points at Chat Completions on POST /v1/chat/completions.

This page covers LLM text only (https://llm.modellix.ai).Modellix model IDs are provider/name (for example openai/gpt-5.5). Put that full string in the profile id field. Junie requires baseUrl to be the full Chat Completions URL (including /v1/chat/completions), not a host-only or /v1 base. See Models & Pricing.

Set Up Junie

Get a Modellix API Key

Create a Modellix API key in the console and export it so the profile can resolve ${MODELLIX_API_KEY}:

export MODELLIX_API_KEY="mdlx-xxxxxxxx"

Add the same line to your shell profile (for example ~/.zshrc) for persistent use.

Add a Custom Model Profile

Create ~/.junie/models/modellix.json (or .junie/models/modellix.json in a project):

{
  "id": "openai/gpt-5.5",
  "baseUrl": "https://llm.modellix.ai/v1/chat/completions",
  "apiType": "OpenAICompletion",
  "apiKey": "${MODELLIX_API_KEY}"
}

The filename without .json is the profile ID (modellix). Junie discovers profiles from $JUNIE_HOME/models/*.json (default ~/.junie/models/) and project-level .junie/models/*.json.

Field	Value
`id`	Exact Modellix Model ID (`provider/name`)
`baseUrl`	`https://llm.modellix.ai/v1/chat/completions`
`apiType`	`OpenAICompletion`
`apiKey`	`${MODELLIX_API_KEY}` (resolved from the environment)

Use the full Chat Completions URL. A host-only value or https://llm.modellix.ai/v1 without /chat/completions will fail. Do not point baseUrl at the media API host (https://api.modellix.ai).

Optionally add a cheaper helper model for Junie’s internal tasks:

{
  "id": "openai/gpt-5.5",
  "baseUrl": "https://llm.modellix.ai/v1/chat/completions",
  "apiType": "OpenAICompletion",
  "apiKey": "${MODELLIX_API_KEY}",
  "fasterModel": {
    "id": "google/gemini-3.6-flash"
  }
}

Change id (and fasterModel.id) to any Modellix catalog ID. Full list: Models & Pricing.

Select the Modellix Profile

Start Junie with the custom profile:

junie --model custom:modellix

Custom models use the custom: prefix plus the profile filename (without .json). In the interactive TUI, pick the Modellix profile from the model list or use /model.

Do not use built-in BYOK flags such as --openrouter-api-key or JUNIE_OPENAI_API_KEY for Modellix. Those route to vendor providers, not your custom profile.

Start Junie

From your project directory:

cd /path/to/your/project
junie --model custom:modellix

For a one-shot (headless) task:

junie --model custom:modellix "Review and fix any code quality issues in the latest commit"

Troubleshooting

Symptom	Check
401 / missing API key	`MODELLIX_API_KEY` is set in the environment; profile uses `${MODELLIX_API_KEY}` (unset vars fail profile load)
Model not found / 404	Profile `id` is a full ID like `openai/gpt-5.5`, not bare `gpt-5.5`; ID is in the live catalog
Wrong path / URL errors	`baseUrl` is `https://llm.modellix.ai/v1/chat/completions` (include `/chat/completions`), not the media API host
Profile missing from model list	File is under `~/.junie/models/` or `.junie/models/`; selection uses `custom:` + filename without `.json`

Junie Custom LLMs — profile schema and discovery
Models & Pricing — Model IDs and rates
LLM API guide — protocols and curl examples
Hermes · OpenClaw — other OpenAI-compatible custom setups

Get Started

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Use Modellix LLM with Junie CLI

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