Rule
Use the Assets app when a workflow needs reusable brand media, a human picker, or generated image/video assets that another app can reference by ID and URL.
Choose The Path
- Use
generate-assetwhen a person should get newly generated, on-brand image candidates and choose the winner in the inline picker. It matches a library whenlibraryIdis omitted, generates candidates, returns the picker filtered to those run IDs, and works in in-app chat plus external MCP hosts. - Use
open-asset-pickerwhen a person should browse, search, or select an existing asset inside an embedded picker, or when you want the picker to handle generation itself. It still opens/librarywith the iframe/bridge contract. The normal human Library workspace is/libraryand/library/:id. PassmediaType: "image"by default, ormediaType: "video"for video libraries. - Use unattended actions when the agent already knows what to do:
search-assets,list-assets,generate-image,generate-image-batch,generate-video,refresh-generation-run, andexport-asset. - In chat, consume composer
@references as structured generation inputs:brand-kitmaps tolibraryId,presetmaps topresetId, andmedia-typechooses image generation versus video generation. If no mention is available, useview-screen,list-libraries, andlist-generation-presetsto choose explicit args. - Use generation presets when the user asks for a repeatable output format
like social image, blog hero, or diagram. Call
list-generation-presetsfor the library and passpresetIdthrough generation/refinement actions. - Use generation sessions when another person needs to continue improving a candidate. Sessions carry the brief, preset, active asset, feedback, and run IDs without requiring the original chat thread.
- Use chat-driven
restyle-imageandedit-imagefor preserving subjects, applying library style, and making targeted changes. Do not surface separate restyle, edit, or quality-tier buttons in host UIs. - Use browser/deep-link fallback when the host cannot render MCP Apps inline (CLIs and code editors like Claude Code and Codex). Surface the returned picker link. When the user opens it, they can either click an asset — the page auto-copies a short handoff summary for them to paste back into chat — or simply tell you which one in words (e.g. "use image A" / "the second one"). Both are first-class; don't insist on the paste-back if they just name the pick.
Image Workflows
- For human-in-the-loop generation, call
generate-assetfirst and preserve the returned picker/candidate metadata. For unattended generation, pick or match the library withlist-librariesormatch-library. If the user wants a default look rather than a brand library, calllist-library-presetsand thencreate-library-from-preset; the resulting library is editable and reusable like any other library. - For one asset, call
generate-image; for multiple independent slots, callgenerate-image-batchwith stableslotIdvalues. - Image generation actions are synchronous. After
generate-imageorgenerate-image-batchreturns, use its returnedimages/ asset fields directly; do not callget-generation-run,refresh-generation-run, or regenerate just to verify image runs. - For preset-backed work, pass a mentioned or selected
presetId; for handoff work, passsessionId. - Let the server choose a small deterministic reference set unless the user
named exact assets. Canonical style anchors come from
assetLibraries.settings.canonicalStyleAssetIdsandassets.metadata.isStyleAnchor. - Pass
tier: "fast"for exploration,tier: "best"for final/high-value output, ortier: "auto"when there is no clear preference.- Model/ratio compatibility: Gemini image models accept any
aspectRatio, butgpt-image-2supports only1:1,2:3, and3:2. When the user needs another ratio (16:9, 9:16, 4:5, 21:9, …), pick a Gemini model rather thangpt-image-2— an unsupported pairing is rejected upstream. Source of truth issupportedAspectRatiosForModel/MODEL_ASPECT_RATIOSinshared/api.ts.
- Model/ratio compatibility: Gemini image models accept any
- Preserve returned
assetId,runId,previewUrl, anddownloadUrl. - Use
refine-imagefor feedback on an existing asset,edit-imagefor targeted changes, andrestyle-imagewithsubjectAssetIdandstyleStrengthfor subject-preserving brand restyles. - If a designer will take over, call
create-generation-sessionorupdate-generation-session, thenprepare-generation-session-continuationwhen they want a chat preloaded with the session context.
For short vague prompts, enhance conservatively with library style context while
preserving the user's original prompt in run metadata. Use
analyze-collection-style when a collection needs upgraded vision brand
analysis before generation. Brand QA scoring and best-of-N selection are
deferred.
Video Workflows
- Call
generate-videowith16:9or9:16and relevant image references. - Poll
refresh-generation-rununtil the run completes and returns a video asset. - Use
export-assetwhen another app needs a download URL or artifact type.
Cross-App Use
- Hosted default: connect
https://assets.agent-native.com/_agent-native/mcp. Do not put shared secrets in skill files. - Local customization: run
npx @agent-native/core@latest app-skill launch --localfrom the Assets app-skill manifest, or pass--into <path>for editable source. - For MCP callers,
generate-assetis the portable first choice because the same MCP App picker renders inline in Agent-Native chat, ChatGPT, and Claude when the host supports MCP Apps. Include exactassetId,runId, media type, and URLs in the final response so the caller can attach or embed the media. IncludepresetIdandsessionIdwhen present.
Don't
- Do not call image/video providers directly from another app.
- Do not treat
imagesas the app identity; the app id isassets. - Do not use picker UI for unattended generation when direct actions are enough.
- Do not use copyrighted screenshots or named studio/brand image sets as preset references. Use broad textual guidance and user-provided references instead.