Settings

Celestial can be customized through a .celestial/settings.json file in your workspace root. This file allows you to configure the editor’s appearance, AI assistant, and asset handling.

Settings File Location

Create a .celestial/settings.json file in your workspace root:

your-project/
├── .celestial/
│   └── settings.json
├── docs/
└── other-files/

Then tell Celestial to open that directory and your settings.json file will be automatically loaded.

Complete Example

./celestial/settings.json

{
  "appearance": {
    "template": "path/to/template.html",
    "theme": "path/to/theme.css"
  },
  "assets": {
    "previewBaseUrl": "http://localhost:4321"
  },
  "llm": {
    "provider": "ollama",
    "model": "llama2"
  }
}

Appearance

Custom HTML Template

Provide a custom HTML template to wrap your editor content, perfect for matching your blog or documentation site’s styling. See Astro integration for use with an Astro blog.

{
  "appearance": {
    "template": "templates/editor.html"
  }
}

Custom CSS Theme

Custom HTML templates are primarily intended to match your editor content to a blog/website. Separately, you may wish to just apply a “theme” to Celestial — e.g. tweak colors, fonts etc. Celestial supports this via the theme property:

{
  "appearance": {
    "theme": "themes/dark.css"
  }
}

Celestial’s default theme.css:

@layer celestialUI {
  :root {
    --shadow-body-height: 95vh;
    --shadow-body-width: 100%;
    --shadow-body-overflow-y: auto;

    /* Fonts */
    --base-font-size: 16px;
    --xs-text: 0.5rem; /* 8px */
    --sm-text: 0.75rem; /* 12px */
    --xlsm-text: 0.875rem; /* 14px */
    --md-text: 1rem; /* 16px */
    --lg-text: 1.5rem; /* 24px */
    --xl-text: 2rem; /* 32px */
    --2xl-text: 3rem; /* 48px */

    --font-family: system-ui, sans-serif;
    --font-family-header: var(--font-family);
    --font-family-mono: var(--font-family);

    /* Spacing */
    --xxs-space: 0.25rem; /* 4px */
    --xs-space: 0.5rem; /* 8px */
    --sm-space: 0.75rem; /* 12px */
    --md-space: 1rem; /* 16px */
    --lg-space: 1.5rem; /* 24px */
    --xl-space: 2rem; /* 32px */
    --2xl-space: 3rem; /* 48px */

    /* Icons */
    --xs-icon: 8px;
    --sm-icon: 16px;
    --md-icon: 24px;
    --lg-icon: 32px;

    /* Colors */
    --surface-color: oklch(27.4% 0.006 286.033);
    --surface-color-secondary: oklch(25% 0.006 286.033);
    --surface-color-secondary-hover: oklch(35% 0.006 286.033);
    --on-surface-color-secondary-hover: oklch(40% 0.006 286.033);

    --background: rgb(20, 20, 20);
    --background-secondary: rgb(25, 25, 25);

    --primary-color: oklch(0.65 0.27 250); /* Cosmic purple */
    --primary-color-light: oklch(0.75 0.2 250); /* Lighter purple */
    --primary-color-dark: oklch(0.55 0.27 250); /* Darker purple */
    --on-primary-color: oklch(0.98 0.005 0); /* White text on primary */

    --accent-color: oklch(0.7 0.2 200); /* Nebula teal */
    --accent-color-light: oklch(0.8 0.15 200); /* Lighter teal */
    --accent-color-dark: oklch(0.6 0.2 200); /* Darker teal */
    --on-accent-color: oklch(0.1 0.02 270); /* Dark text on accent */

    /* Alert/status colors */
    --success-color: oklch(0.65 0.2 150); /* Green nebula */
    --warning-color: oklch(0.7 0.2 80); /* Solar flare orange */
    --error-color: oklch(0.65 0.25 30); /* Red giant */
    --info-color: oklch(0.7 0.2 230); /* Blue star */

    --border-color: rgb(40, 40, 40);
    --divider-color: rgb(70, 70, 70);

    --on-surface-color: oklch(0.8607 0 0);
    --on-surface-color-muted: oklch(0.7692 0.0145 248.02);
    --on-surface-color-disabled: oklch(
      from var(--on-surface-color-muted) l c h / 0.5
    );

    --lg-shadow: 0px 3px 5px rgba(0, 0, 0, 0.15);
    --md-shadow: 0px 2px 3px 3px rgba(0, 0, 0, 0.3);
    --sm-shadow: 0px 1px 2px rgba(0, 0, 0, 0.3);

    /* Layout */
    --container-width: 720px;
  }

  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    font-family: var(--font-family-header);
    font-weight: 600;
  }

  h1 {
    font-size: var(--2xl-text);
    margin: var(--xl-space) 0 0;
  }

  h2 {
    font-size: var(--xl-text);
    line-height: 1.25;
    margin: var(--lg-space) 0;
  }

  h3 {
    font-size: var(--lg-text);
    line-height: 1.33;
    margin: var(--lg-space) 0;
  }

  h4 {
    font-size: var(--md-text);
  }

  h5 {
    font-size: var(--md-text);
  }

  h6 {
    font-size: var(--md-text);
  }

  hr {
    margin: var(--md-space) 0;
  }

  p {
    margin: var(--md-space) 0;
    padding: 0;
    font-size: var(--md-text);
    line-height: 1.5;
    font-weight: 400;
    font-family: var(--font-family);
  }

  ul,
  ol {
    margin: var(--md-space) 0 var(--md-space) var(--lg-space);
    padding: 0;
    font-family: var(--font-family);
  }

  li {
    margin: var(--xs-space) 0;
    padding: 0;

    p {
      margin: 0;
    }
  }

  a {
    color: var(--primary-color);
  }

  code {
    background: var(--surface-color);
    padding: 2px var(--xs-space);
    border-radius: var(--xs-space);
    font-family: var(--font-family-mono);
  }

  .editor {
    outline: none;
    border: none;
    padding: var(--lg-space);
    margin: 0 auto;
    position: relative;
    max-width: var(--container-width);

    p.empty {
      position: relative;

      &::after {
        content: "Enter text";
        display: inline-block;
        pointer-events: none;
        font-style: italic;
        color: var(--on-surface-color-muted);
        position: absolute;
        left: 0px;
        top: 0px;
      }
    }
  }
}

Assets

Configure how assets (images, etc.) are handled:

{
  "assets": {
    "previewBaseUrl": "http://localhost:4321"
  }
}

Preview Base URL

The previewBaseUrl setting helps preview images and other assets correctly during development without modifying the actual file paths in your documents.

Use cases:

• Local development servers
• Testing with different CDN configurations
• Previewing assets from a staging environment

Example:

![My Image](./images/screenshot.png)

With previewBaseUrl: "http://localhost:4321", the image will preview as: http://localhost:4321/images/screenshot.png

But when saved, the file will still contain the original relative path: ./images/screenshot.png

AI Assistant Settings

Configure your AI writing assistant powered by Ollama:

{
  "llm": {
    "provider": "ollama",
    "model": "llama2"
  }
}

See ai docs for more details.