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

# Runtime

These guides cover Urbit's runtime and Nock interpreter, which is called Vere.

* [U3 Overview](/build-on-urbit/runtime/u3.md) - An overview of the noun-wrangling part of the runtime, U3.
* [Conn.c Guide](/build-on-urbit/runtime/conn.md) - Using `conn.c` to interact with a running ship from the outside.
* [How to Write a Jet](/build-on-urbit/runtime/jetting.md) - A jetting guide by for new Urbit developers.
* [C3: C in Urbit](/build-on-urbit/runtime/c.md) - Under u3 is the simple c3 layer, which is just how we write C in Urbit.
* [U3: Land of Nouns](/build-on-urbit/runtime/nouns.md) - The division between c3 and u3 is that you could theoretically imagine using c3 as just a generic C environment. Anything to do with nouns is in u3.
* [U3: API Overview](/build-on-urbit/runtime/api.md) - A walkthrough of each of the u3 modules.
* [Cryptography](/build-on-urbit/runtime/cryptography.md) - References on the cryptography libraries utilized by jets.

## Additional Resources <a href="#additional-resources" id="additional-resources"></a>

* [User Reference](/user-manual/running/vere.md) - Reference for the utilities and options the runtime takes from the terminal.
* [The Vere Repo](https://github.com/urbit/vere) - Github repository for the Urbit runtime.


---

# 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.urbit.org/build-on-urbit/runtime.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.
