> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zylon.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Adding custom instructions

> Provide project-specific instructions used in every chat in the project.

Each project can define **custom instructions** that the AI uses on **every interaction in that project**. These augment, rather than replace, the organization-wide company context.

Open **Project Settings**, write your instructions in the single **Instructions** field, and save the project settings.

Use this field for project-specific guidance such as:

* what this project is for
* who it serves
* important acronyms or domain context
* preferred response style or language

The maximum size of this field is controlled by your operator through `feature.maxInstructionsLength` in `/etc/zylon/zylon-conf.yaml`. The default limit is `4000`, and the same limit is enforced in both the Workspace UI and the API. For operator-side configuration, see [Project custom instructions](/en/operator-manual/configuration/features/feat-project-custom-instructions).

<img src="https://mintcdn.com/zylon/1MC3EkpeIBooYZ9J/images/project_context.png?fit=max&auto=format&n=1MC3EkpeIBooYZ9J&q=85&s=5a1320a1a0b7afc254b47e41f9548e48" alt="" width="1455" height="924" data-path="images/project_context.png" />

## Advanced Settings

Project settings also include two advanced toggles:

<img src="https://mintcdn.com/zylon/1MC3EkpeIBooYZ9J/images/advanced_settings.png?fit=max&auto=format&n=1MC3EkpeIBooYZ9J&q=85&s=2a74cf14eb4bd2263afcfb175bfe315a" alt="" width="855" height="294" data-path="images/advanced_settings.png" />

* **Citations**: Enables or disables citations in Zylon chat responses for that project.
* **System prompt**: Keeps or removes Zylon's default prompt layer. This prompt cannot be edited from the UI, only removed.

<Warning>
  These settings change how Zylon responds. Changing them can reduce answer quality, reduce traceability, or cause responses to fail, so use them carefully.
</Warning>

> **Behavior:** Custom instructions apply at the project level and shape how Zylon responds in that project together with the organization-wide company context.