Bittensor (TAO): how it works, supply and reviews
In short
- Type
- Substrate-based blockchain (subtensor) coordinating off-chain work in subnets
- Maximum supply
- Hard cap of 21 million TAO
- Risks and caveats
- The chain is Proof of Authority: only approved authorities produce and finalise blocks, and the set is changed by privileged administration.
- Checked
- 31 October 2026
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Key facts
- Ticker
- TAO
- Official site
- bittensor.com
Key facts checked on 31 October 2026 against official sources.
What is Bittensor
Bittensor is an open network of independent subnets, incentive markets in which miners produce digital commodities such as AI inference and validators score their work. The subtensor blockchain records participation and pays contributors in its token, TAO.
Network and consensus
| Parameter | Details |
|---|---|
| Type | Substrate-based blockchain (subtensor) coordinating off-chain work in subnets |
| Consensus | Proof of Authority with Aura and GRANDPA; a move to Nominated Proof of Stake is planned |
| Incentive layer | Yuma Consensus aggregates validators' scores of miners to set rewards; it does not produce blocks |
| Block time | One block every 12 seconds |
| Subnets | Each subnet has an owner, miners, validators and a TAO/alpha liquidity pool; netuid 0 is the root network |
| Launched | First block of the current Finney mainnet on 20 March 2023 |
Supply and issuance
| Parameter | Details |
|---|---|
| Maximum supply | Hard cap of 21 million TAO |
| Issuance | Base emission 1 TAO per block, halving each time issuance crosses the midpoint of the remaining supply |
| Halving | First halving in December 2025; emission is now 0.5 TAO per block, about 3,600 TAO a day |
| Recycling | Registration burns and fees are subtracted from issuance and can be re-emitted, delaying halvings |
| Subnet tokens | Since the dTAO upgrade (February 2025) each subnet has its own alpha token, also capped at 21M |
What TAO is used for
- Rewarding miners, validators and subnet owners through emissions
- Staking to validators (stake is a swap into a subnet's pool, or held as root TAO)
- Paying fees and subnet registration costs, which are recycled into issuance
Who develops and governs Bittensor
- Block producers
- A permissioned set of validator authorities produces and finalises blocks
- Administration
- The authority set can be changed through privileged on-chain administration
- Developer
- Rao Foundation core developers; the subtensor monorepo is on GitHub under RaoFoundation
- Open source
- The monorepo holds the subtensor chain, the Python SDK and btcli, and the docs
History
| Date | Event |
|---|---|
| 20 March 2023 | First block of the current Finney mainnet. |
| February 2025 | Dynamic TAO (dTAO) upgrade gives each subnet its own alpha token and pool. |
| December 2025 | First TAO halving: block emission falls from 1 to 0.5 TAO. |
Security and audits
- Finality requires agreement of more than two thirds of authority voting weight.
- The docs warn users to use only links and commands from the official docs or release announcements, because of malicious lookalikes.
Risks and caveats
- The chain is Proof of Authority: only approved authorities produce and finalise blocks, and the set is changed by privileged administration.
- The move to Nominated Proof of Stake is a planning estimate without a fixed activation date.
- Staking into subnets is a swap against a pool, so the trade itself moves the price and alpha values differ by subnet.
Official links
- Website: bittensor.com
- Docs: bittensor.com/docs
- Whitepaper: bittensor.com/whitepaper
- Source code: github.com/RaoFoundation
Questions and answers
What is Bittensor?
Bittensor is a network of subnets where miners produce digital commodities such as AI outputs, validators score them, and the subtensor chain pays them in TAO.
What is the maximum supply of TAO?
TAO is capped at 21 million. On 31 October 2026 the chain reported a total issuance of about 11.68 million TAO.
When is the TAO halving?
Halvings are triggered by issuance thresholds, not block counts. The first took place in December 2025, cutting emission to 0.5 TAO per block.
How does Bittensor reach consensus?
Blocks are produced and finalised by a permissioned Proof of Authority set using Aura and GRANDPA; Yuma Consensus only sets subnet rewards.
What is dTAO?
The dynamic TAO upgrade of February 2025 gave every subnet its own alpha token, traded against TAO in a per-subnet pool.
Sources
- Bittensor — Home
- Bittensor — About
- Bittensor Docs — The network
- Bittensor Docs — Emissions
- Bittensor Docs — Chain consensus
- Bittensor Docs — Money
- Bittensor Docs — Introduction (Wayback copy)
- subtensor README (GitHub)
- Bittensor Finney RPC — TotalIssuance and block timestamps
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