Slide files use the following structure:

{
    "schema_version": 1,
    "config": {
        "colors": {
            "default": { "start": "#333333", "end": "#222222", "degrees": 145 },
            "events": { "start": "#1a4a6e", "end": "#234d6e", "degrees": 145 },
            "seasonal": {
                "start": "#781E32", "end": "#641E64", "degrees": 145,
                "steps": ["#781E32", "#8C5014", "#327832", "#1E5A82", "#3C2882", "#641E64"]
            }
        },
        "types": {
            "events": { "randomized": false, "maxdisplay": 0, "only": false },
            "tips": { "randomized": true, "maxdisplay": 3 }
        }
    },
    "slides": [
        {
            "type": "events",
            "tag": "Conference",
            "title": "SharkFest'26 US",
            "description": "Nashville, Tennessee",
            "description_sub": "July 18-23, 2026",
            "body_text": "Join the annual Wireshark developer...",
            "button_label": "Learn More",
            "url": "https://sharkfest.wireshark.org/sfus/",
            "image": "sharkfestus.png",
            "date_from": "2025-12-01",
            "date_until": "2026-07-23"
        }
    ]
}

A formal JSON Schema is available at resources/json/slides.schema.json for editor-based and CI validation.

The type, title, description, and url fields are required per slide. Slides missing any of these are skipped with a warning. The type must be one of "events", "sponsorship", "tips", or "seasonal". Note that "sponsorship" and "seasonal" are reserved for the predefined slides.json and cannot be used in custom slide files. All other slide fields are optional and default to empty strings.

The image field is a filename resolved at runtime under :/json/banners/. If empty or missing, a generic semi-transparent overlay is shown instead.

The application field filters a slide to either "wireshark" or "stratoshark". If omitted, the slide is shown in both applications.

The date_from and date_until fields use ISO 8601 format (YYYY-MM-DD). Slides are hidden before date_from and after date_until. Omitting either field removes that constraint.

date_month (1-12) and date_day (1-31) specify the exact day the slide should be shown each year. date_from and date_until will be ignored if these fields are present. For example, date_month=12 and date_day=25 will show the slide only on December 25th of each year.

The optional config section controls slide display behavior and colors.

Colors (config.colors): Per-type gradient color overrides with "start" and "end" fields in #RRGGBB format. The "default" entry provides fallback colors for types without explicit colors. Available keys: "default", "events", "sponsorship", "tips", "seasonal".

Each color entry also supports the optional fields "degrees" (integer, 0-360) for the gradient angle and "steps" (array of #RRGGBB hex strings) for intermediate gradient color stops. When "steps" is provided, the colors are distributed evenly across the gradient from 0.0 to 1.0 instead of using a simple start/end pair.

Type settings (config.types): Per-type display settings. Available keys: "events", "sponsorship", "tips", "seasonal". Each entry supports:

All config fields are optional. Missing values use defaults. Config from a custom file merges over the predefined config on a per-type basis.

Distributors can inject additional slides without modifying the source tree using the CUSTOM_SLIDES_JSON CMake variable:

cmake -DCUSTOM_SLIDES_JSON=/path/to/my_slides.json ..

The custom file uses the same JSON schema. Custom slides are merged with predefined slides per type, respecting only and hidden flags. If the path does not exist, it is silently ignored.

Custom file restrictions:

See also doc/README.slides for a standalone reference.