Kontor Protocol Brings Permanent File Storage to Bitcoin NFTs
Horizon Market to integrate pay-once, store-forever file persistence for Counterparty assets and Ordinals
Dover, DE, April 16, 2026 (GLOBE NEWSWIRE) — Unspendable Labs today announced that Kontor, its next-generation Bitcoin metaprotocol, has launched a file storage system on Bitcoin’s signet test network. The system allows anyone to store files permanently with a single payment, verified by cryptographic proofs recorded and executed on the Bitcoin blockchain. Horizon Market, the Bitcoin NFT marketplace for Counterparty assets and Ordinals, will be the first platform to integrate the technology.
Kontor Network
Most NFT image and metadata files today are stored on centralized servers. When those servers go down, the data disappears. An NFT that sold for thousands of dollars can end up pointing to a dead link. Storing data directly on the Bitcoin blockchain is one option, but it forces every full node on the network to download and store that data forever. The network bears the cost indefinitely, and it’s simply impossible to store large amounts of data in this way.
Kontor’s file persistence protocol takes a different approach. File contents not simply stored off-chain, but are in fact guaranteed to be kept available permanenly by economic incentives enforced on the Bitcoin blockchain. by storage nodes who are economically incentivized to maintain them permanently. The result: large-scale data storage at a fraction of on-chain costs, with availability guarantees that match on-chain storage.
“We’re not simply storing hashes on Bitcoin—we’re providing availability guarantees that are economically enforced on-chain by the Kontor Bitcoin metaprotocol. Storing that data directly on Bitcoin is too expensive and burdens the entire network. Kontor gives Bitcoin users permanent storage without either compromise: the data lives off-chain, but the proof that it exists and is being maintained lives on Bitcoin.” said Adam Krellenstein, Kontor founder. “Horizon Market will be the first place where users can actually use this.”
Horizon Market Integration
Horizon Market is a Bitcoin NFT marketplace for Counterparty assets and Ordinals inscriptions. Kontor’s file storage will allow Horizon Market users to upload artwork and metadata with a single payment and a guarantee that the data will remain available as long as the Bitcoin network exists. No subscription renewals. No reliance on a centralized host that could shut down.
How the Storage Protocol Works
When a file is uploaded through Kontor, the data is prepared with Reed-Solomon erasure coding for fault tolerance and committed via a Merkle tree. The Merkle root is recorded on the Bitcoin blockchain as part of a file agreement signed by the user and a set of storage nodes.
Each Bitcoin block, the protocol uses the block hash to select files for auditing. A challenged storage node must produce a cryptographic proof that it still holds specific, randomly chosen sectors of the file. The proof is approximately 10 kilobytes regardless of file size and can be verified by any Kontor indexer. Nodes that fail to respond are slashed: they lose staked capital, a portion of which is distributed to the other nodes storing that file.
The detection math makes cheating a bad bet. A storage node that has lost 10% of a file’s data has a 99.997% chance of being caught in a single challenge. With 12 challenges per year, expected time to detection is measured in weeks.
Pay Once, Store Forever
The user’s one-time storage fee is burned entirely. Storage nodes are compensated through ongoing KOR token emissions, calibrated so that the present value of future emissions exceeds storage costs for rational operators. If replication of a file drops below safe levels, emissions increase automatically to attract additional capacity.
Cost scales logarithmically with file size. A 1 GB file costs roughly twice as much as a 1 MB file. This keeps small but critical files, like NFT images and metadata, affordable to store while ensuring storage nodes find files of all sizes worth maintaining.
Why Not IPFS, Arweave, or Filecoin?
IPFS, widely used for NFT file hosting, provides no availability guarantees. Files disappear when nodes decide to prune them. There is no economic incentive for anyone to keep hosting data.
Filecoin, Sia, and Chia require continuous deal renewal. When the paying user stops renewing, the data goes away. That model breaks for blockchain assets that may sit dormant for years before resurfacing in value.
Arweave aims for permanent storage but operates as a separate blockchain. Bitcoin users must acquire a different token and use separate tooling. Its own documentation does not guarantee the network will continue producing blocks indefinitely. Storage nodes face no penalties for dropping data they committed to store.
Kontor’s file storage runs directly on Bitcoin. Users pay with KOR, a token on the Bitcoin blockchain, with no separate blockchain. The protocol uses Nova recursive SNARKs to make proofs compact and efficient, and penalizes nodes that fail to store committed data, ensuring data are kept available permanently.
Availability
The file storage system is live on Bitcoin’s signet test network. Protocol documentation is available at docs.kontor.network. The Kontor whitepaper, including the full technical specification for the file persistence protocol, is available at kontor.network
About Unspendable Labs
Unspendable Labs is developing a suite of innovative protocols and applications to build a deeper and richer economy for digitally native assets. Unspendable Labs is dedicated to advancing the greater Bitcoin ecosystem through the construction and maintenance of critical infrastructure for peer-to-peer markets.
Press Inquiries
contact [at] unspendablelabs.com
https://unspendablelabs.com
Disclaimer: The above press release comes to you under an arrangement with GlobeNewswire. NYnewscast.com takes no editorial responsibility for the same.
