> For the complete documentation index, see [llms.txt](https://docs.caterpillarproject.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.caterpillarproject.org/faq.md).

# FAQ

## Should I contact a Caterpillar core member to use the data?

For using the merger tree and halo catalogs, no, you now no longer need to contact a core member. That being said however, we do encourage you to contact a core member as certain efforts may have been undertaken by groups either internally and externally and we can put you in direct contact with them to coordinate efforts.

## Why aren't the particle snapshots public?

This is primarily because unlink many other simulation suites, the particle resolution and snapshot resolution make it expensive to 100% host on public servers (e.g. Google Cloud Platform). Should you want more than the z = 0 snapshot, please get in touch so we can find the best path forward for your project.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.caterpillarproject.org/faq.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.