Bittensor Subnet 75:Hippius

Hippius extends Bittensor by offering:

Decentralized data storage: A network of storage nodes (miners) store and serve data, ensuring no single point of failure​. This benefits Bittensor by giving AI models and services a place to persist datasets, model checkpoints, or outputs in a distributed way.

On-chain transparency and incentives: Usage of Hippius is metered and logged on its Substrate blockchain, with a crypto-economic model rewarding those who provide storage resources​. This aligns with Bittensor’s broader tokenomics, using blockchain incentives (in $TAO and subnet-specific tokens) to sustain the service.

Integration with Bittensor’s network: Hippius is not a standalone Layer-1 but a Bittensor subnet (network ID 75) that connects to the Bittensor metagraph (main chain)​. Its validators report performance metrics (so-called “weights”) back to the main Bittensor chain, allowing Hippius to participate in Bittensor’s consensus-based reward distribution (Dynamic TAO)​. This means a portion of Bittensor’s TAO token emissions is allocated to Hippius’s contributors based on the quality and usage of the storage service they provide​.

By fulfilling these roles, Hippius aims to become the decentralized storage layer for all Bittensor applications, and eventually a general-purpose decentralized cloud (including computation). Community members have emphasized that Hippius brings “true decentralized storage with a bulletproof economic model” to the $TAO ecosystem​, akin to how Filecoin or Arweave provide decentralized storage but with the key difference of being natively integrated into Bittensor’s AI-driven network.

Technical Architecture and Functioning

Hippius is built on a custom Substrate blockchain (a standalone chain) that operates as Subnet 75 within Bittensor​. This design gives Hippius its own ledger, consensus, and token, while still linking it to Bittensor’s main chain through a bridge and shared incentive model. Below are key technical aspects of how the subnet functions:

Consensus and NPoS: Hippius uses the Blind Assignment for Blockchain Extension (BABE) consensus algorithm for block production​, and Nominated Proof-of-Stake (NPoS) for security​. This means a set of validators produce blocks and finalize the Hippius chain, and token holders (nominators) can stake to elect/secure these validators. The validator set in Hippius maintains the chain and also coordinates storage tasks. Validators earn rewards for block production and for faithfully reporting storage performance to Bittensor’s main chain​.

Native Token (“Alpha”) and Dynamic TAO: The native currency on the Hippius chain is informally called Alpha (α)​. Under Bittensor’s Dynamic TAO system, each subnet has its own token that is backed by and convertible to TAO through a reserve pool. In Hippius’s case, users obtain Alpha by staking TAO into Hippius’s reserve (via the bridge) and can convert back by redeeming Alpha for TAO​. The on-chain automated market maker determines the price of Alpha based on the ratio of TAO staked vs. Alpha in circulation​. This dynamic token design allows Hippius’s value to be directly tied to the broader TAO economy, and it enables cross-chain transfers. (Phase 4 of the launch is enabling this Alpha–TAO bridge, allowing Alpha to move between Hippius and the main Bittensor chain​.)

Storage Services (IPFS and S3): Hippius provides two types of storage for clients​:

1. IPFS Pinning: Fully decentralized content-addressable storage. IPFS miners in the Hippius network host content on the IPFS network; Hippius’s blockchain manages the pinning and persistence by incentivizing multiple replicas.​ This ensures data is permanent and distributed. Users can store files and get an IPFS hash; Hippius miners will keep that content alive on IPFS.
2. S3-Compatible Object Storage: A more traditional file storage interface where data is addressed by buckets/keys (like Amazon S3) but stored on decentralized volumes. S3 miners provide this service, offering authenticated read/write access to stored objects via an S3 API compatibility layer​. This is aimed at enterprise use – applications can integrate with Hippius as if it were an S3 cloud storage endpoint. Data is redundantly stored across miners’ hardware.

Both storage systems run in parallel, giving users a choice between content-addressed IPFS (useful for public or static content) and bucketed object storage (useful for private or mutable data). In both cases, data is encrypted and anonymized; the network supports end-to-end encryption so that miners cannot read user data, and user identity is handled via cryptographic keys (mnemonics) rather than accounts/passwords​.

Miner and Validator Roles: Hippius nodes can take on specialized roles, each with off-chain workers that integrate with on-chain logic​:

Storage Miners: These are subdivided into IPFS miners and S3 miners as described. They run the storage infrastructure – for IPFS, running go-ipfs nodes; for S3, running storage servers – and continuously report their capacity and performance. Off-chain worker processes on miners handle tasks like monitoring file health, ensuring replication (making multiple copies across nodes), and responding to read/write requests from clients​. Miners must also prove uptime and reliability; if they go offline or lose data, the network can detect this (through validators) and apply penalties (slashing)​.

Compute Miners (Future): The architecture anticipates compute miners​, which will provide virtual machine environments and possibly GPU-accelerated compute in the future. These miners would act as decentralized cloud “VM” providers, running sandboxed computations or hosting applications. (Support for compute is planned but not active at initial launch – see Roadmap below.)

Validators: Validators form the backbone of the Hippius blockchain and also coordinate the marketplace. A validator’s duties include verifying blocks and transactions, maintaining consensus, and critically, assigning storage tasks and evaluating miners’ performance​. When users make storage requests, validators receive these requests (via the marketplace) and decide which miners will serve the data or store new data. They gather metrics from miners (e.g. response times, uptime) and compute “weights” – a performance score for each miner over time​. These weights are reported to the Bittensor main chain as part of the Yuma consensus, which in turn influences how much TAO emission Hippius miners and validators earn from the network​. Validators are also responsible for enforcing rules (they can blacklist/ban misbehaving nodes and trigger slashing if a miner loses data or cheats)​.

Marketplace and Usage Flow: Hippius features a built-in marketplace system that intermediates between clients (users) and the storage miners​. When a client uses the Hippius dashboard or API to purchase storage, the process is as follows​:

1. The user chooses a storage service (IPFS or S3) and pays for it either in fiat or crypto (TAO/Alpha) via the Hippius web dashboard​. Payments in fiat are converted behind the scenes into credits, which correspond to a certain amount of Alpha deposited on-chain​. (Thus every purchase results in an on-chain deposit of Alpha tokens representing the pre-paid storage credit​.)
2. The marketplace (a component of the Hippius chain runtime or associated off-chain service) records the purchase and “credits” the user with storage capacity. It then submits a request to the network’s validators: e.g. “allocate X GB of storage for user Y’s file”​.
3. Validators receive the request and assign it to miners. For a new file upload, a validator will pick one or more S3/IPFS miners (depending on service) to store the file, aiming to balance load and maintain redundancy​. For a download request, validators route it to the nearest/fastest miners holding the data. This assignment happens in a decentralized way, possibly using on-chain information and off-chain worker communication.
4. Miners then fulfill the request: storing the data or retrieving it for the user. Off-chain, the miner will interact with the user’s client (through the IPFS network or via an S3 HTTP endpoint) to transfer the data. Miners also update the blockchain (or inform validators) about the new data stored (e.g., registering the content hash, size, etc., on-chain for accounting).
5. Reward Distribution: As users consume storage (using up their credits), the payments made are periodically distributed to the network participants. Hippius’s economic split is 60% of revenue to the storage miners (as compensation for providing disk space and bandwidth), 30% to validators and nominators (for securing the chain and coordinating the service), and 10% to a treasury (for ongoing development of Hippius)​. These rewards are paid in the Hippius Alpha token, which miners/validators can later convert to TAO via the bridge if desired​. All of this occurs on-chain, ensuring transparency in who earned what. In addition to usage revenue, miners and validators also gain TAO emissions from Bittensor’s consensus (based on the performance weights as noted), effectively earning two streams of reward: one in Alpha from user fees, and one in TAO from the Bittensor network​.

Security and Reliability: Hippius is designed with multiple security measures. Identities are secured by Bittensor’s mnemonic authentication (wallet seed-phrases serve as both identity and encryption keys for users)​, meaning users do not rely on passwords or third-party accounts – losing your secret key means losing access, enforcing self-custody of credentials. All data can be encrypted client-side using those keys, providing end-to-end security​. On the network side, communication between validators and miners is secured (they likely use encrypted channels and handshakes to prevent tampering)​. The chain implements slashing of misbehaving nodes – for example, if a validator detects that a miner who was supposed to store a file is unreachable or has lost the file, that miner’s stake can be slashed as a penalty​. There are also reputational mechanisms: validators can ban or blacklist miners that repeatedly fail or provide poor service​, ensuring the storage remains reliable for users. By having multiple miners replicate the same data, Hippius provides redundancy: even if some nodes go offline, data is not lost. This distributed design naturally protects against censorship and server outages, as no single miner controls the availability of content.

In practical terms, the Hippius network has quickly grown to significant capacity. Within a couple of weeks of launch, it reached its initial limit of 256 registered miner seats (UIDs) and achieved nearly 900 TB of aggregate storage provided by the community’s miners​. This demonstrates a high supply of storage ready to be utilized. All operations (storage deals, node performance, etc.) can be monitored via Bittensor’s block explorer and the Hippius dashboard, giving a clear view into the subnet’s functioning. Overall, the technical architecture of Hippius combines a blockchain (for consensus, accounting, and coordination) with off-chain storage tech (IPFS, S3 servers) and clever incentive alignment to create a decentralized storage cloud that is both useful and economically sustainable.