Use JetBrains (AI Assistant, Junie) with llmapi.cheap

Run JetBrains (AI Assistant, Junie) on Gemini 3.8 Flash, Claude Sonnet 4.6, Claude Opus 4.6 or GPT-OSS with a single llmapi.cheap key. Plans start at $2 a month, and there is a free one-hour trial.

Protocol: OpenAI Chat

Setup

AI Assistant: Settings → Tools → AI Assistant → Models → Third-party providers → OpenAI-compatible.

URL:     https://llmapi.cheap/v1
API key: YOUR_API_KEY

Junie CLI: the setup command writes ~/.junie/models/llmapi-<model>.json for each model. Then:

junie --model custom:llmapi-gemini-3.8-flash-high

Endpoints

Use the base URL that matches the protocol your tool speaks.

OpenAI: https://llmapi.cheap/v1
Anthropic: https://llmapi.cheap
Gemini: https://llmapi.cheap/v1beta
Models: https://llmapi.cheap/v1/models

Model IDs

Any of these work wherever JetBrains (AI Assistant, Junie) asks for a model name. Gemini 3.8 Flash (high) is the default the setup command picks.

Model ID	Model
`gemini-3.8-flash-high`	Gemini 3.8 Flash, high reasoning (default)
`gemini-3.8-flash`	Gemini 3.8 Flash, medium reasoning
`gemini-3.8-flash-low`	Gemini 3.8 Flash, low reasoning
`gemini-3.1-pro-high`	Gemini 3.1 Pro, high reasoning
`gemini-3.1-pro-low`	Gemini 3.1 Pro, low reasoning
`gemini-3-flash`	Gemini 3 Flash
`claude-sonnet-4-6`	Claude Sonnet 4.6
`claude-opus-4-6`	Claude Opus 4.6
`gpt-oss-120b`	GPT-OSS 120B

Troubleshooting

401 / invalid key: check the key starts with sk-llm- and has no extra spaces. Create a new one under Dashboard → API keys if needed.
Model not allowed: the free trial covers the Gemini models; Claude and GPT-OSS come with any paid plan.
404 on requests: OpenAI-style tools need https://llmapi.cheap/v1; Anthropic-style tools need https://llmapi.cheap without /v1.