Metadata & Storage

While the Smart Contract manages ownership and authenticity verification, the visual and descriptive representation of the physical object relies on Metadata.

Tokentagged uses the ERC-1155 Metadata Standard and prioritizes permanent, decentralized storage to ensure the "Digital Twin" lasts as long as the physical object.

Permanent Storage (Arweave)

Unlike centralized servers or temporary IPFS pinning services, we utilize Arweave for metadata storage.

• Permaweb: Data stored on Arweave is backed by a sustainable endowment, guaranteeing storage for hundreds of years.
• Immutability: Once the metadata JSON is uploaded and the URI is written to the blockchain, the content cannot be altered. This guarantees that the description of a physical artwork or collectible remains authentic forever.

Immutability

Once a Tokentag is minted and the metadata is frozen, it is impossible to change the image, description, or attributes. This protects the collector, ensuring the digital asset always matches the physical condition at the time of minting.

Token Metadata (ERC-1155)

Each Tokentag (NFT) points to a specific JSON file via its tokenURI. This file describes the individual physical item.

Example Structure

{
  "name": "Blockchain",
  "description": "Oil and egg tempera on canvas, 91 × 153,5 cm.",
  "external_url": "https://tokentagged.com/tag/eth/0x2fdfa8ab84bfbe658827a51af399531371cab86a/0x323951715310843b94e257b01b31c31db3ffbef4",
  "image": "https://arweave.net/0JuocasTJR-KUn5k5jDV6gLgY8I58GfnBuSirB9jc9E",
  "attributes": null,
  "animation_url": "https://arweave.net/RxwvIPXXaeF_D6KDnoijPdKMZpN9NwOL1Usgyepa-nk"
}

Properties Breakdown

Property	Description
name	The title of the artwork or object.
description	A text description. Supports Markdown. Should include physical details (dimensions, material) and delivery notes.
image	URL to the primary static image (Arweave). Used in wallet previews and marketplace grids.
external_url	A deep link to the Tokentagged verification page for this specific item. Alternatively, creators can provide a custom URL (e.g., their homepage or project site).
animation_url	(Optional) URL to a multimedia file (Video/MP4 or 3D Model/GLB). Marketplaces render this for the detailed view.
attributes	(Optional) Array of traits (e.g., "Material": "Gold", "Year": "2023") for filtering on marketplaces.

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Contract Metadata (Collection Level)

To ensure the collection appears correctly on marketplaces like OpenSea (with a logo, banner, and description), the smart contract itself has a contractURI. This defines the branding for the entire group of tokens.

Example Structure

{
    "name": "Akira's Friends",
    "symbol": "AKIRA",
    "description": "Deep in the hollow earth of your fantasy live Akira's friends. \nThey know neither one another nor themselves. \nAnd yet, they struggle bravely, building new hope for those who will come after us. \n~Akira",
    "image": "https://arweave.net/85FoUBhbGGFzD0ezlTCIPPcwS6M1QWsmWXNYzttwcfM",
    "banner_image": "https://arweave.net/5p2C9WHtbzoOS94iiGMuAh1jkCGLrjswbbdhznduh5o",
    "featured_image": "https://arweave.net/xGsbFjrljLxVTohB3sCTcm5oNcvQqIptZPW-rhyzR5M",
    "external_link": "https://akira.energy"
}

Properties Breakdown

Property	Description	Marketplace Usage
name	Collection Name.	Headline of the collection page.
symbol	Collection Symbol / Ticker.	Shown as the short identifier on marketplaces.
description	Description of the brand/creator.	Appears below the header.
image	Collection Logo / Avatar.	Circular icon (e.g., 350x350px).
banner_image	Large header background.	Top of the page (e.g., 1400x350px).
featured_image	Promotional Tile.	Used on the marketplace homepage/recommendations (e.g., 600x400px).
external_link	Website URL.	Button linking to the creator's site.

---

Media Recommendations

To ensure your physical assets look professional on all platforms (OpenSea, Rarible, MetaMask, Tokentagged App), we recommend the following specs for media files uploaded to Arweave.

1. Token Image (image)

The image property represents the static cover image of the token. It is shown in wallet previews and marketplace grids.

Input Recommendation:

• Resolution: We recommend high-resolution photos (min. 1000px on the shortest side).
• Format: JPG or PNG.
• Aspect Ratio: Rectangular images are fully supported.

Platform Processing (Interactive Cropping): During the setup process, the Tokentagged App provides an interactive cropping tool. You don't need to prepare a square image beforehand; instead, you can manually position and scale the 1:1 selection window over your uploaded photo to define the perfect frame.

Output Standard: The final image is saved as a normalized 960 x 960 px file to ensure consistency across the ecosystem.

Interactive Assets (animation_url)

Currently, Tokentagged normalizes all interactive content into a standardized MP4 video format. This ensures maximum compatibility across wallets and marketplaces.

The platform automatically generates this asset based on your source material:

1. From 3D Scans: If you create a 3D model using the Tokentagged tools, the platform automatically renders a 6-second "turntable" trailer (the object rotating) as an MP4 video.
2. From Video Uploads:
   • Short Videos (≤ 10s): The video is optimized and used directly.
   • Long Videos (> 10s): The platform automatically generates a 6-second trailer/teaser from the footage.

Future Roadmap

Native support for interactive GLB files (3D models) and full-length video streaming via the animation_url is planned for future protocol updates. Currently, these assets are strictly formatted as MP4 trailers.

Output Standards:

• Format: MP4
• Codec: H.264 / AAC Audio
• Duration: Max. 10 seconds (standardized to ~6s for generated trailers)

Collection Branding

• Logo (image): OpenSea recommends a minimum of 350 x 350 px. Best practice: 600 x 600 px or 1000 x 1000 px. Format: PNG, JPG, GIF. Usually displayed circularly, so keep important details away from the corners.
• Featured Image (featured_image): OpenSea uses 600 x 400 px. Used when the collection is featured on the homepage or in categories. If missing, OpenSea often uses a random NFT which can look inconsistent.
• Banner (banner_image): OpenSea uses 1400 x 350 px. Format: PNG, JPG, GIF. Keep logos/text in the center safe zone to avoid cropping on mobile.