Voidleap Code is a desktop agentic IDE from Voidleap that runs on your own machine, with every agent, skill, hook, and security rule left editable. You can change model in the middle of a thread, planning on one, implementing on another, and reviewing on a third without starting over, then read back the tokens, cost, latency, and cache hit rate for each. Opper ships inside the app as a provider rather than a base URL override, so you add your key once in settings and pick Opper models per turn.
Voidleap CodeoninIn Voidleap Code, go to Settings → Providers → Add Provider, choose Opper, and paste your API key. Then pick GPT-5.4 Mini.
GPT-5.4 Mini runs on the routes below. Route only to EU providers when your data has to stay in Europe.
GPT-5.4 Mini is OpenAI's strongest small model, improving over GPT-5 Mini in coding and reasoning while running more than 2x faster, with a 400k context window.
Anthropic's terminal coding agent. Run it on any model on Opper, not just Claude.
opper launch claude
OpenAI's open-source coding CLI. Run it on any model on Opper.
opper launch codex
DeepSeek's open-source coding agent. Add Opper as a custom provider to run it on any model, not just DeepSeek's.
OpenAI-compatible