Subnet 5: Hone

Hone is a Bittensor subnet operated by Manifold where miners compete to solve ARC-AGI-2 abstract reasoning problems; solutions run in a secure GPU sandbox and are scored by exact-match accuracy.

Subnet 5: Hone

Hone is Bittensor’s fifth subnet (netuid 5), operated by Manifold. Its purpose is to benchmark and advance AI reasoning by pitting miners against ARC-AGI-2 — a suite of novel abstract reasoning tasks designed to resist pattern-memorisation and measure genuine general intelligence. Miners don’t run solvers inside the validator workflow directly; instead they publish a git repository containing their solution, which a centralised GPU sandbox clones, builds, and executes in isolation.

References: manifold-inc/hone (GitHub), taostats.io/subnets/5

How the Mechanism Works

Each miner hosts a lightweight HTTP server that exposes a /info endpoint. When queried, this endpoint returns a pointer to the miner’s solution repository — an owner, repository name, branch, and commit hash.

Validators collect these pointers and submit jobs to a managed Sandbox Runner — a cluster of H200 GPUs operated by Manifold. The Sandbox Runner:

  1. Clones the miner’s repository and builds a Docker image from its Dockerfile.
  2. Runs a prep phase (internet-accessible) so the solver can download model weights or other assets.
  3. Runs an inference phase with network access fully disabled, passing a set of held-out ARC-AGI-2 problems.
  4. Computes exact_match_rate — the fraction of problems the solver answers correctly — and returns that score to the validator.

Validators aggregate scores and assign on-chain weights. The reward distribution uses exponential decay (factor 0.8 per rank): only the top 5 miners that exceed a 20% accuracy floor receive any emission. If no miner clears the floor in a given round, the entire emission for that round is burned rather than distributed. Miners with identical repo + branch + commit combinations receive a cached score rather than a redundant evaluation, and a daily submission limit (default: one per miner per day) prevents gaming through rapid re-submissions. Weights feed into Yuma Consensus to determine per-epoch emissions.

References: manifold-inc/hone (GitHub)

Participating as a Miner

Miners must run an HTTP server (default port 8091) that returns their solution repository pointer at GET /info. The repository must contain a Dockerfile that the Sandbox Runner can build; all model downloads and setup should happen in the prep phase (before network isolation begins).

General setup flow:

  1. Register a hotkey on SN5: 
    btcli subnet register --subtensor.network finney --netuid 5 \
  --wallet.name <coldkey> --wallet.hotkey <hotkey>
  2. Clone the repository and set up the miner service: 
    git clone https://github.com/manifold-inc/hone.git
cd hone/miner
  3. Configure miner/.env with wallet credentials, chain endpoint, and your solution repository details, then start the miner: 
    docker compose up -d
  4. Announce your IP and port on-chain so validators can discover you: 
    python tools/post_ip_chain.py --wallet-name default --hotkey miner \
  --ip YOUR_IP --port 8091

Solution repositories can use any language or framework that builds inside Docker. The Sandbox Runner optionally starts a vLLM sidecar alongside the inference container for transformer-based solvers that need GPU-accelerated model inference.

References: manifold-inc/hone — Miner Setup, miner-solution-example (GitHub)

Participating as a Validator

Validators do not need a GPU. Their role is to query each registered miner’s /info endpoint, forward the solution pointers to the Sandbox Runner API, collect the returned exact_match_rate scores, and set on-chain weights accordingly.

Validator requirements (from the official README):

  • 4+ CPU cores
  • 8 GB+ RAM
  • 20 GB disk
  • A PostgreSQL database (provided via Docker Compose)
  • Reliable network connection

Setup:

  1. Clone the repository: 
    git clone https://github.com/manifold-inc/hone.git
cd hone/validator
  2. Create validator/.env with chain, wallet, and database credentials.
  3. Start all services: 
    docker compose up -d

The validator service polls registered miners, submits jobs to the Sandbox Runner, stores results in PostgreSQL, and pushes weights to the chain. Because the Sandbox Runner handles all GPU work, validators have a low hardware bar.

References: manifold-inc/hone — Validator Setup

On-Chain Identity

Subnet 5’s registered on-chain identity, verifiable via taostats.io/subnets/5:

Further Reading

Topics Subnets