Docs — International Shiba Station

At a glance

Chain

Ethereum mainnet

Supply cap

2,000

Combinatorics

9,600 unique

Native sprite

64×64 px

Mint mechanic

V4 afterSwap

Storage

100% on-chain

Deployment model

Shibanaut is a fully on-chain generative collection on Ethereum mainnet. SVGs render directly from tokenURI() — no IPFS, no Arweave, no server. Mints are gated by a Uniswap V4 afterSwap hook on the canonical $ISS pool.

Chain choice rationale. Post-Pectra/Fusaka, sustained mainnet gas at ~0.1 gwei makes the swap+mint mechanic economically comparable to L2 alternatives (~$0.12 per mint at $3,000 ETH). Mainnet wins on durability, decentralization, and collector prestige for a permanent fully-on-chain collection. Testnet: Sepolia.

Trait catalog

Six trait categories. Body is mandatory; the other five overlay onto a canonical sprite that already bakes in the bubble dome, the white suit baseline, the happy face, and a small utility tool in the right paw.

Body

5 variants · always present · derived as palette swaps from one canonical sprite

ID	Name	Weight	Notes
0	Cream	25%	Palette swap
1	Red	30%	Canonical sprite
2	Sesame	25%	Palette swap
3	Black & Tan	15%	Palette swap
4	White	5%	Palette swap · rarest body

Suit

4 variants · Standard White is the baked-in baseline (no overlay)

ID	Name	Weight	Notes
0	Standard White	45%	No overlay — baked into body
1	Mission Red	25%	GPT generation
2	Steel Gray	20%	Palette-snapped from Deep Blue
3	Cargo Yellow	10%	Palette-snapped from Cargo Orange

Glasses

6 variants · Gold Aviators is founder-locked (tokenIds 1–100 only)

ID	Name	Weight	Notes
0	None	35%	No overlay
1	Round Spectacles	20%
2	Aviators	15%
3	Visor Shades	15%
4	Monocle	10%
5	Gold Aviators	5%	Founder-locked · re-rolls for tokenId ≥ 101

Emblem

4 variants · paints into the chest patch on the suit

ID	Name	Weight	Notes
0	None	40%	No overlay
1	Mission Patch	30%
2	Star	20%
3	Skull	10%

Accessory

5 variants · overrides the baked-in utility tool in the right paw

ID	Name	Weight	Notes
0	None	40%	Baked utility tool remains visible
1	Coffee Mug	25%
2	Wrench	15%
3	Flag	12%
4	Bone	8%

Backpack

4 variants · drawn behind the body so it visibly extends past the silhouette

ID	Name	Weight	Notes
0	None	50%	No overlay
1	O2 Tank	25%
2	Solar Panels	15%
3	Jetpack	10%

Combinatorics: 5 × 4 × 6 × 4 × 5 × 4 = 9,600 unique combinations across a 2,000-supply collection. Expected duplicate trait sets: ~420. Mint block timestamps in metadata distinguish otherwise-identical mints.

Layer stack

Render order is back-to-front. Body is always present. Backpack is the only layer drawn behind it; everything else stacks on top.

L0Backpack overlayOptional · behind

L1Body base — fur + suit baseline + dome + face + utility toolRequired

L2Suit overlay (replaces white torso/arms/legs)Optional

L3Emblem overlay (chest patch)Optional

L4Glasses overlay (visible through dome)Optional

L5Accessory overlay (replaces baked-in tool)Optional

Contract suite

Five contracts. The Descriptor is forked from Nouns and holds all the RLE trait bytes; the rest are project-specific.

Token

ERC-20 $ISS. The token traded in the gated V4 pool. Holding it does not mint — only swapping into it through the hook does.

Seeder

Pure function. Maps the mint block hash and token ID to a 6-field trait seed via weighted bit-slicing. Re-rolls Gold Aviators outside the founder window.

Descriptor

Nouns-forked. Stores RLE-encoded trait bytes, decodes & renders SVG, returns base64 metadata data URI. ~15–16 KB.

NFT

ERC-721. The mint entry point is restricted to the hook contract. tokenURI() defers to the Descriptor.

Hook

V4 afterSwap hook. The single entry point that triggers a mint. See the Hook page for the full flow.

Metadata schema

tokenURI(uint256) returns a base64-encoded JSON data URI. The image is itself a base64-encoded SVG inlined in the JSON — no external resource is ever required to render a Shibanaut.

// tokenURI(1337) → data:application/json;base64,...  decoded:
{
  "name":        "Shibanaut #1337",
  "description": "Resident of the International Shiba Station...",
  "image":       "data:image/svg+xml;base64,PHN2Zy4uLg==",
  "attributes": [
    { "trait_type": "Body",       "value": "Sesame"       },
    { "trait_type": "Suit",       "value": "Cargo Yellow" },
    { "trait_type": "Glasses",    "value": "Aviators"     },
    { "trait_type": "Emblem",     "value": "Star"         },
    { "trait_type": "Accessory",  "value": "Wrench"       },
    { "trait_type": "Backpack",   "value": "Solar Panels" },
    { "trait_type": "Mint Block", "display_type": "number", "value": 18742019 }
  ]
}

Placement system

Each token gets a permanent slot on the station the moment it mints. Placement is sequential: tokenId N takes slot N in the canonical manifest. The manifest is published off-chain alongside the frontend, read once at load time, and never mutated.

Slots are partitioned into five modules so the station feels like a crewed habitat instead of a uniform grid.

Module	Slots	Notes
Command Deck	100	Tokens 1–100 (founder window)
Habitat	200	Largest cluster · general crew
Observatory	60
Hydroponics	60
Cargo Dock	80
Total	500	Sized for v1 supply at realistic adoption

Capacity scales by adding new wings to the station, not by inflating existing modules.

Open decisions

These do not block contract work but must be resolved before mainnet launch.