In order to achieve this objective, we can extract a pattern from the [filter](https://github.com/stac-utils/stac-fastapi/blob/main/stac_fastapi/extensions/stac_fastapi/extensions/core/filter/filter.py) in STAC-FASTAPI extensions, which will provide the functionality of [collection search](https://github.com/stac-api-extensions/collection-search) in the STAC API. If the functionality performs effectively in the production environment of Cat4KIT, it can be merged into the main repository of STAC-FastAPI.