LlamaIndex with idapt

OpenAILike against idapt's compatible API for indexes, query engines, and agents.

Last reviewed 2026-07-17

Install

bash

pip install llama-index llama-index-llms-openai-like

Point it at idapt

python

from llama_index.llms.openai_like import OpenAILike

llm = OpenAILike(
    model="openai/gpt-5.6-luna",
    api_base="https://idapt.app/api/openai/v1",
    api_key=os.environ["IDAPT_API_KEY"],
    is_chat_model=True,
)

is_chat_model=True routes calls to /chat/completions instead of the legacy completions path.

Pitfalls

Use OpenAILike, not the OpenAI class

LlamaIndex's OpenAI class validates model names against OpenAI's list and rejects catalog slugs. OpenAILike passes them through.

References

More quickstarts

LangChain (Python)OpenAI SDK (Python)