SRC-721 Recursive NFT Protocol
The SRC-721 Recursive NFT Protocol enables advanced non-fungible tokens with layered, composable artwork stored directly on Bitcoin. Unlike traditional NFTs, SRC-721 tokens reference multiple on-chain layers to create high-resolution, cost-effective NFTs.
Protocol Founder: DerpHerpstein - Community founder and architect of the SRC-721 Non-Fungible Token Standard, pioneering unique Bitcoin Stamps NFT functionality.
Key Features
- Recursive Composition: NFTs built from multiple pre-stored layer assets
- Cost Efficient: Store artwork layers once, reference in multiple NFTs
- High Resolution: Support for detailed, multi-layer compositions
- On-Chain Metadata: All data permanently stored on Bitcoin
- Flexible Minting: Multiple mint modes and trait allocation systems
- Counterparty Integration: Uses stable Counterparty asset IDs
Creating SRC-721 Collections
Simple Collection Creation Process:
Visit Stampchain.io → for SRC-721 creation tools
Step-by-Step Collection Building:
- Design Layers: Create individual artwork components (backgrounds, characters, accessories)
- Upload Layers: Store each layer as a separate Bitcoin Stamp
- Deploy Collection: Define collection parameters and pricing using web tools
- Set Traits: Configure how layers combine to create unique NFTs
- Enable Minting: Allow users to mint composed NFTs from your layers
Benefits for Artists:
- Lower Costs: Store layers once, use in multiple NFTs
- Higher Quality: Support detailed, layered artwork
- Flexible Design: Mix and match layers for infinite variety
- Permanent Storage: All artwork stored forever on Bitcoin
- Revenue Streams: Earn from both individual sales and royalties
Example Collection Structure:
- Background Layer: Sky, forest, city (3 options)
- Character Layer: Different characters (10 options)
- Accessory Layer: Hats, glasses, jewelry (5 options)
- Total Combinations: 3 × 10 × 5 = 150 unique NFTs
Technical Implementation
For developers implementing SRC-721 programmatically:
Collection Deployment Structure
The protocol uses JSON-formatted data with operations for deploy, reveal, mint, and transfer. Each operation requires specific parameters for collection management and NFT creation.
Key Technical Features
- Recursive Composition: NFTs reference multiple pre-stored stamp layers
- Cost Efficiency: Store common elements once, reference multiple times
- Unlimited Scale: No file size limits through layer composition
- Asset Stability: Uses Counterparty asset IDs for consistency
Development Resources
- OpenStamp Documentation → - Complete SRC-721 implementation guide
- GitHub Examples → - Code samples and templates
- TX-Builder SDK → - Technical integration tools
Minting Modes
Public vs Whitelist
- Public: Anyone can mint tokens
- Whitelist: Only approved addresses can mint
- Hybrid: Whitelist period followed by public sale
Trait Allocation
- Random: Traits assigned randomly using seed
- Authorized: Collection owner assigns specific traits
- Mixed: Combination of random and manual allocation
Pricing Models
- Fixed Price: Set price per NFT
- Dynamic: Price changes based on demand
- Free: No cost (only network fees)
Protocol Benefits
For Collectors
- Unique Compositions: Each NFT combines multiple artistic layers
- Verifiable Rarity: On-chain trait verification and scarcity
- True Ownership: Complete NFT data stored on Bitcoin
- Unlimited Scale: No file size limits through recursive composition
For Developers
- Efficient Storage: Reuse layers across multiple NFTs
- Rich Metadata: Support for complex attribute systems
- Scalable Architecture: Bypass single-transaction size limits
- Cost Optimization: Shared layers reduce per-NFT costs
Real-World Applications
Gaming Assets:
- Character customization systems
- Equipment and upgrade components
- Achievement badges and collectibles
Digital Art Collections:
- Generative art with trait variations
- Collaborative artwork projects
- Limited edition releases
Utility NFTs:
- Access tokens with visual representation
- Membership badges with customization
- Event tickets with unique designs
Network Integration
SRC-721 integrates with Bitcoin Stamps infrastructure:
- Counterparty Protocol: Stable asset ID system
- Stamps Indexer: Tracks NFT mints and transfers
- Layer Storage: Individual stamps store artwork layers
- API Access: Query collections and NFT data via stampchain.io APIs
Permanence Guarantee
Bitcoin Stamps, including all SRC-721 NFT layers and compositions, achieve a level of data permanence that is architecturally superior to other Bitcoin-based protocols. This guarantee stems from how Stamps data is stored on the Bitcoin network.
Why SRC-721 Data Cannot Be Pruned
SRC-721 artwork layers and collection metadata are encoded directly into the unspent transaction output (UTXO) set -- the core dataset that every fully validating Bitcoin node must retain in order to verify new transactions. Because this data resides within outputs that nodes are required to keep, it cannot be discarded without breaking consensus. Any Bitcoin full node, at any point in the future, will hold the complete record of every SRC-721 layer, collection deployment, and NFT composition. Since SRC-721 uses recursive references to on-chain layers, every component of a composed NFT is independently permanent -- there are no off-chain dependencies that could break over time.
Contrast with Ordinals and Witness Data
Ordinals inscriptions store their data in the witness (SegWit) portion of Bitcoin transactions. While witness data is included in blocks, Bitcoin's protocol explicitly allows nodes to prune witness data after validation. A pruned node can discard witness sections entirely and still function as a valid participant in the network. This means Ordinals data availability depends on archival nodes choosing to retain that data -- it is not structurally guaranteed.
Bitcoin Stamps take the opposite approach. By embedding data in the UTXO set rather than witness data, Stamps ensure that every full node -- whether archival or pruned -- retains the data as a mandatory part of consensus operations.
Practical Implication
Any SRC-721 NFT and its constituent layers can be retrieved and fully reconstructed from any Bitcoin full node, indefinitely. Unlike NFT systems that store artwork on IPFS or external servers, SRC-721 artwork layers live directly in Bitcoin's UTXO set. There is no reliance on pinning services, CDNs, or third-party data availability layers -- the Bitcoin network itself guarantees that every layer of your NFT remains accessible forever.
Getting Started
For Creators:
- OpenStamp Documentation → - Complete SRC-721 guide
- TX-Builder SDK → - Technical integration
- Layer Creation Tutorial → - Learn stamp creation
For Developers:
- SRC-721 Examples → - Code samples
- API Integration → - Query NFT collections
- SDK Integration → - Build applications
SRC-721 brings advanced NFT functionality to Bitcoin, enabling composable, high-resolution digital collectibles with permanent on-chain storage and flexible trait systems.