Site Extension capabilities reference

Capabilities are a UI and runtime contract, not marketing metadata. Ophel only exposes controls that match the active pack’s capability set, and the runtime validator rejects packs that declare a capability without the required fields. The authoritative capability list lives in src/adapters/feature-capabilities.ts. The authoritative field requirements live in src/adapters/declarative/validate.ts.

Capability catalog

Capability	Required configuration	What it unlocks
`outline`	`selectors.responseContainer`	Conversation outline from assistant headings / structure
`outline-user-queries`	`outline` plus `selectors.userQuery`	User questions as top-level outline entries
`conversation-list`	`conversation`	Conversation list capture / navigation integration
`export-basic`	`export`	Basic conversation export
`model-lock`	`modelSwitcher`	Model lock controls for the pack site
`generation-detect`	`generating` or `networkMonitor`	Generating-state detection used by completion UI
`new-chat`	non-empty `selectors.newChatButton`	New conversation action
`stop-generation`	non-empty `selectors.stopButton`	Stop generation action
`width`	non-empty `widthSelectors`	Page width controls
`panel-avoidance`	`panelAvoidance`	Shrink host content into the safe area beside the Ophel panel
`zen`	`zenMode`	Zen mode hide rules / styles
`clean`	`cleanMode`	Clean mode hide rules / styles
`prompt-insert`	non-empty `selectors.textarea` plus `input`	Prompt insertion into the page input
`reading-history`	non-empty `selectors.chatContent`	Reading-history capture for the conversation surface

There is no capability id named theme-sync. Host theme sync is a separate config field, themeSync, and may imply supportsHostThemeSync.

Capability notes

Outline family

outline needs a conversation container so Ophel can scope scanning.
outline-user-queries cannot be declared alone; the validator requires outline as well.
Prefer stable message roots over translated visible text.

Prompt insertion

prompt-insert needs both:

one or more textarea / contenteditable selectors
an input block with mode (textarea or contenteditable) and submitKey (Enter or Ctrl+Enter)

Ophel uses the native value setter for textareas and a validated beforeinput / execCommand path for contenteditable editors. It does not silently fall back to assigning textContent.

Generation detection

Use whichever signal is reliable on the target site:

generating.existsSelectors — visible DOM markers while generating
networkMonitor — request URL / body rules when DOM state is insufficient

A pack may provide either or both. Declaring generation-detect without either is rejected.

Layout capabilities

Capability	Typical config	Caution
`width`	`widthSelectors[]` with selector + CSS property	Optional `extraCss` still passes the restricted CSS validator
`zen`	`zenMode.hide` and optional root class / styles	Do not hide the conversation or required input
`clean`	`cleanMode.hide` / styles	Keep rules narrow
`panel-avoidance`	`panelAvoidance.widthSelectors` plus optional obstacles / insets	Must be verified with the panel open at several viewport widths

Theme sync is not a capability id

Sites that switch light / dark mode by writing localStorage and optionally toggling a class on <html> can declare themeSync:

{
  "themeSync": {
    "storageKey": "theme",
    "values": { "dark": "dark", "light": "light", "system": "system" }
  }
}

Rules grounded in the current validator:

storageKey, values.dark, and values.light are required when themeSync is present
values.system is only for sites that store a distinct follow-system value
darkClass / lightClass are optional; both may be omitted when the site listens to storage events itself
nested object storage uses valuePath; flat JSON-encoded strings use valueFormat: "json"
valuePath and valueFormat cannot be combined
body class, data-theme, or click-simulation theme mechanisms are not supported by this field
declaring themeSync while also setting supportsHostThemeSync: false is rejected

Example: Duck.ai capability set

The published duck-ai pack currently declares:

[
  "outline",
  "outline-user-queries",
  "export-basic",
  "generation-detect",
  "new-chat",
  "stop-generation",
  "width",
  "zen",
  "prompt-insert"
]

It does not declare conversation-list, model-lock, clean, panel-avoidance, or reading-history. The product UI therefore does not present those pack-backed controls for Duck.ai. These groups are not capabilities themselves, but they often accompany capability declarations:

Group	Role
`selectors`	Shared page element roots
`input`	Input mode and submit key
`conversation`	Sidebar conversation items and navigation
`session`	Path-based session id / new-chat / share routes
`modelSwitcher`	Model menu selectors and timing
`export`	Message and turn selectors for export
`mermaidSupport` / `quickQuote`	Optional behavior switches
`theme`	Pack accent colors for UI presentation

Full field, length, regex, CSS, and size limits are defined by:

editor assist: registry/schema/site-pack.schema.json
runtime authority: src/adapters/declarative/validate.ts

When the two disagree, the runtime validator wins.

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Changelog

Site Extension capabilities reference

Capability catalog

Capability notes

Outline family

Prompt insertion

Generation detection

Layout capabilities

Theme sync is not a capability id

Example: Duck.ai capability set

​Capability catalog

​Capability notes

​Outline family

​Prompt insertion

​Generation detection

​Layout capabilities

​Theme sync is not a capability id

​Example: Duck.ai capability set

​Related configuration groups

​Related pages

Capability catalog

Capability notes

Outline family

Prompt insertion

Generation detection

Layout capabilities

Theme sync is not a capability id

Example: Duck.ai capability set

Related configuration groups

Related pages