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

# Capability Taxonomy

> Standard namespaces and naming conventions for ABP capabilities

## Overview

ABP uses **dot-notation namespaces** to organize capabilities:

```
namespace.action
```

**Examples:**

* `export.pdf` -- Export as PDF
* `convert.markdownToHtml` -- Convert markdown to HTML
* `ai.summarize` -- Summarize text using AI
* `render.html` -- Render HTML with CSS

## Standard Namespaces

### `export.*` -- Export Operations

| Capability        | Description                      | Input                   | Output                                                                                                                         |
| ----------------- | -------------------------------- | ----------------------- | ------------------------------------------------------------------------------------------------------------------------------ |
| `export.pdf`      | Generate PDF from HTML content   | `{ html, options }`     | `BinaryData` (inline `{ document: BinaryData }`, or the client generates a PDF from HTML returned by a `convert.*` capability) |
| `export.image`    | Export as image (PNG, JPEG, SVG) | `{ selector?, format }` | `{ image: BinaryData }`                                                                                                        |
| `export.html`     | Export rendered HTML             | `{ content, options }`  | `{ document: BinaryData }`                                                                                                     |
| `export.markdown` | Export as Markdown               | `{ content }`           | `{ markdown: string }`                                                                                                         |

### `convert.*` -- Format Conversion

| Capability               | Description              | Input                   | Output                  |
| ------------------------ | ------------------------ | ----------------------- | ----------------------- |
| `convert.markdownToHtml` | Convert Markdown to HTML | `{ markdown, options }` | `{ html }`              |
| `convert.htmlToMarkdown` | Convert HTML to Markdown | `{ html }`              | `{ markdown }`          |
| `convert.htmlToImage`    | Render HTML as image     | `{ html, options }`     | `{ image: BinaryData }` |
| `convert.csvToJson`      | Convert CSV to JSON      | `{ csv, options }`      | `{ json }`              |

### `render.*` -- Rendering Operations

| Capability      | Description          |
| --------------- | -------------------- |
| `render.html`   | Render HTML with CSS |
| `render.canvas` | Render to canvas     |
| `render.svg`    | Render SVG           |

### `ai.*` -- AI Operations

| Capability     | Description     | Input                  | Output           |
| -------------- | --------------- | ---------------------- | ---------------- |
| `ai.summarize` | Summarize text  | `{ text, maxLength? }` | `{ summary }`    |
| `ai.translate` | Translate text  | `{ text, from, to }`   | `{ translated }` |
| `ai.complete`  | Text completion | `{ text, style }`      | `{ rewritten }`  |

### `storage.*` -- Browser Storage

| Capability       | Description                           |
| ---------------- | ------------------------------------- |
| `storage.read`   | Read from localStorage/sessionStorage |
| `storage.write`  | Write to localStorage/sessionStorage  |
| `storage.delete` | Delete from storage                   |

### `auth.*` -- Authentication

| Capability      | Description                         |
| --------------- | ----------------------------------- |
| `auth.getToken` | Get auth token from browser session |
| `auth.getUser`  | Get current user info               |

### Forbidden Capabilities: Delivery and Input-Acquisition Mechanisms

<Warning>
  Apps MUST NOT declare capabilities that wrap browser delivery mechanisms or input-acquisition APIs. These are browser features that route content to an OS-level destination (clipboard, share sheet, file dialog, notification) or acquire input through OS-level UI (file picker, camera prompt). An ABP capability should produce or consume **data** -- the agent handles routing and acquisition on the host side.
</Warning>

For a decision test to identify these mechanisms, see the [Implementation Guide -- How to Recognize a Delivery Mechanism](/guides/implementation-guide#how-to-recognize-a-delivery-mechanism).

The primary example is `clipboard.*`: apps MUST NOT declare `clipboard.*` capabilities. The browser Clipboard API requires user gestures that automated agents cannot provide, and clipboard is a host-side delivery mechanism -- agents can write to the system clipboard directly using host tools (`pbcopy`, `xclip`, `clip`). Instead, expose the underlying content-producing capability (e.g., `convert.markdownToHtml`) and let the agent handle clipboard operations on the host side. The same principle applies to `navigator.share()`, `showSaveFilePicker()` / `showOpenFilePicker()`, `new Notification()`, and any future browser API that triggers OS-level UI.

See the [Protocol Overview](/concepts/protocol-overview) for additional context on forbidden capabilities.

## Vendor Namespaces

Vendors can use reverse-domain notation for custom capabilities:

```
vendorDomain.namespace.action
```

**Examples:**

* `com.acme.imageFilter.blur`
* `io.github.username.customTool`

## Naming Conventions

### Action Verbs

Use consistent action verbs:

* **Create/Generate:** `export.pdf`, `generate.thumbnail`
* **Read/Get:** `storage.read`, `auth.getToken`
* **Write/Set:** `storage.write`, `storage.set`
* **Convert/Transform:** `convert.markdownToHtml`
* **Delete/Remove:** `storage.delete`

### Case Convention

* Use `camelCase` for multi-word names
* Namespace and action are separated by `.`
* Examples: `convert.markdownToHtml`, `auth.getToken`

## Capability Lifecycle

Capabilities progress through three stages:

```
Experimental → Stable → Deprecated → Removed
```

### Experimental

* Marked with `experimental: true` in the manifest
* May change without notice between versions
* Agents SHOULD warn users when calling experimental capabilities

### Stable

* The default state (no `experimental` or `deprecated` flag)
* Follow semantic versioning
* Breaking changes only in major protocol versions

### Deprecated

* Marked with `deprecated: true` and optionally `deprecationMessage`
* **Deprecated capabilities MUST remain functional for at least one major version**
* The `alternatives` field SHOULD suggest replacement capabilities
* Agents SHOULD warn users when calling deprecated capabilities

See the [Protocol Overview](/concepts/protocol-overview) for the full lifecycle details.

## Next Steps

<CardGroup cols={3}>
  <Card title="Examples & Tutorials" icon="graduation-cap" href="/guides/examples">
    See capabilities in action
  </Card>

  <Card title="Building ABP Apps" icon="hammer" href="/guides/building-web-apps">
    Build your own app with capabilities
  </Card>

  <Card title="Protocol Overview" icon="diagram-project" href="/concepts/protocol-overview">
    Full specification details
  </Card>
</CardGroup>