openclaw-openclaw/docs/reference/rich-output-protocol.md

summary, read_when, title

summary	read_when	title
Rich output protocol for structured media, embeds, audio hints, and replies	Changing assistant output rendering in the Control UI Debugging `[embed ...]`, structured media, reply, or audio presentation directives	Rich output protocol

Assistant output carries delivery/render directives through a few dedicated channels:

• Structured mediaUrl / mediaUrls fields for attachment delivery.
• [[audio_as_voice]] for audio presentation hints.
• [[reply_to_current]] / [[reply_to:<id>]] for reply metadata.
• [embed ...] for Control UI rich rendering.

Structured media fields and [[...]] tags are delivery metadata. [embed ...] is the separate web-only rich-render path; it is not a media alias.

Media attachments

Remote attachments must be public https: URLs. http:, loopback, link-local, private, and internal hostnames are rejected as attachment directives; server-side media fetchers apply their own network guards on top.

Local attachments accept absolute paths, workspace-relative paths, or home-relative ~/ paths. They still pass the agent file-read policy and media type checks before delivery.

Do not emit text commands for attachments from tools, plugins, streaming blocks, browser output, or message actions. Use structured media fields instead:

{ "message": "Here is your image.", "mediaUrl": "/workspace/image.png" }

Legacy final-reply text may still be normalized for compatibility, but this is not a general plugin/tool protocol.

Plain Markdown image syntax (![alt](url)) stays text by default. Channels that want Markdown images treated as media replies opt in at their outbound adapter; Telegram does this so ![alt](url) becomes a media attachment.

When block streaming is enabled, media must ride on structured payload fields. If the same media URL appears in a streamed block and again in the final assistant payload, OpenClaw delivers it once and strips the duplicate from the final payload.

[embed ...]

[embed ...] is the only agent-facing rich-render syntax for the Control UI. Self-closing example:

[embed ref="cv_123" title="Status" /]

Rules:

• [view ...] is no longer valid for new output.
• Embed shortcodes render only in the assistant message surface.
• Only URL-backed embeds render; use ref="..." or url="...".
• Block-form inline HTML embed shortcodes do not render.
• The web UI strips the shortcode from visible text and renders the embed inline.

Stored rendering shape

The normalized/stored assistant content block is a structured canvas item:

{
  "type": "canvas",
  "preview": {
    "kind": "canvas",
    "surface": "assistant_message",
    "render": "url",
    "viewId": "cv_123",
    "url": "/__openclaw__/canvas/documents/cv_123/index.html",
    "title": "Status",
    "preferredHeight": 320
  }
}

present_view is not recognized; stored/rendered rich blocks always use this canvas shape.

Related

• RPC adapters
• Typebox