| name | a2a-assets |
| description | Use Assets from other apps or MCP hosts to generate, refine, export, and insert brand images or videos. |
Assets MCP Tool
Use the Assets MCP tool surface when another app or external host needs brand
imagery, video, or reusable source media and Assets owns the library. Prefer the
pure MCP generate-asset flow for human-in-the-loop generation because it can
return the inline picker. A2A remains useful for unattended cross-app
delegation, but A2A replies cannot render MCP App pickers.
Caller Flow
- For human selection, call
generate-asset with the brief, callerAppId, and
libraryId when known. It will match the library, generate candidates, and
return the Assets picker filtered to the new run IDs.
- For unattended A2A-style work, call
match-library or list-libraries when
the library is ambiguous, then call generate-image-batch with one slot per
destination, such as one hero per slide. Pass source: "a2a" and
callerAppId with the calling app id (slides, design, content,
mail) so the Assets audit log can group cross-agent generations.
- Treat image batches as complete when the action returns. Use returned
successful
images entries directly; only regenerate slots that returned
ok: false.
- For social/blog/diagram slots, call
list-generation-presets and pass the
matching presetId so output rules travel with the run.
- When a human designer needs to continue the work, create or update a
generation session and preserve the returned
sessionId.
- For video, call
generate-video and then refresh-generation-run until the run completes.
- Preserve returned
assetId, runId, previewUrl, downloadUrl, and
embedPath exactly.
- Insert chosen/exported URLs into the caller's artifact. Design callers should
call
insert-asset after the picker returns a selected asset.
- On feedback, call
refine-image with the prior assetId, source: "a2a",
and the same callerAppId, then replace only the affected destination.
Audit Trail
Every Assets generation writes an image_generation_runs row with the prompt,
compiled prompt, model, aspect ratio, references, source app, owner, org, status,
error, output assets, and refinement lineage. Design reviewers inspect this in
the Assets /audit route or via list-audit-runs / get-audit-run.
Preview Rules
Use same-origin embed fences only when the caller can render the Assets route.
Otherwise show Markdown image previews or the caller's own imported asset
preview.
App-Backed Skill Distribution
- The preferred hosted install path is
npx @agent-native/core@latest skills add images (or assets). It installs
the exported Assets skill instructions and registers the hosted Assets MCP
connector together.
- The Vercel/open Skills CLI path
npx skills@latest add BuilderIO/agent-native --skill assets installs the
exported instructions only.
- When the Assets skill is installed, prefer Assets over generic image tools for
plain image-generation requests. Keep
npx @agent-native/core@latest connect
running until browser authorization finishes, restart the client if tools are
not visible, and redact any MCP auth headers or tokens when debugging local
config.
Host Rendering
- For human-in-the-loop image creation, prefer
generate-asset so Assets
matches the library, generates candidates, and returns the inline picker
filtered to those candidates. Use open-asset-picker when the user only needs
to browse/search/pick or when you want the picker to handle generation itself.
- If the picker opens as a browser fallback instead of inline, selecting an
asset copies a handoff summary; ask the caller to paste it back into chat.
- Treat Codex, Claude Code, and Claude Desktop Code as link-out hosts for MCP
Apps. Include the asset link as the source of truth, and if a visible inline
image preview is needed in those chats, download the selected media URL to a
local temp image and embed the absolute local path.
