Kusama is Polkadot's "canary network": a live blockchain built on the same technology as Polkadot, where upgrades run with real value at stake before they reach Polkadot. The Polkadot Wiki says block times and throughput are the same on both chains. What differs is the rules. On Kusama, governance runs on shorter timelines, staking eras and unbonding are shorter, and the bonding requirement is lower. That makes Kusama faster and cheaper to build on, while Polkadot prioritises "stability and dependability". The newest development, as of 25 October 2026: KSM holders are voting until 3 November 2026 on how Kusama will run on JAM, the next-generation design for the Polkadot technology stack.
The newest development: Kusama's JAM infrastructure vote
On 19 October 2026, a Polkadot Forum paper titled "Kusama on JAM Prime: The Infrastructure Decision" set out four Wish-for-Change proposals. Each one trades guaranteed processing cores for a longer protected term:
| Guaranteed cores | Protected term | Referendum |
|---|---|---|
| 8 | 5 years | WFC #671 |
| 6 | 6 years 8 months | WFC #672 |
| 4 | 10 years | WFC #673 |
| 2 | 20 years | WFC #674 |
According to the paper, each option provides 40 coretime-years and has a common negotiating reference of US$4,320,000. That amount would be settled in DOT, within a 5,000,000 DOT ceiling, from eligible Kusama Vision Fund resources. The authors say they are neutral among the four options. Voting closes on 3 November 2026.
The vote comes on top of an earlier decision. Kusama Referendum #573, "Kusama JAM Upgrade: Option A – Lightweight and independent", is shown as executed on Subsquare. It proposed an independent JAM configuration with 32 cores and a 1-second block time, with KSM as the native token. Forum participants are now debating how the four new options fit with that earlier choice. That discussion is an open governance debate, not a settled outcome.
What a canary network is
A testnet uses tokens with no value. A canary network is a production chain with real economic value. The Polkadot Wiki calls Kusama a pre-production environment for Polkadot. Changes that would be risky to try first on Polkadot can run there under real conditions, with real users and real money. Kusama's governance history shows the pattern:
- Kusama activated OpenGov (Governance v2) through a runtime upgrade reported in the Polkadot Digest of 22 November 2022.
- Polkadot followed after Referendum 121 upgraded its relay chain to runtime v9420, reported in the Polkadot Digest of 16 June 2023.
- Kusama moved balances, staking and governance from its relay chain to Kusama Asset Hub on 7 October 2025. The Polkadot Digest of 8 October 2025 reported the move. Kusama referenda 590 and 600 were cancelled during the move and had to be resubmitted.
Kusama vs Polkadot: the rules side by side
Where do Kusama's governance, staking and supply rules differ from Polkadot's, and where are they the same?
| Parameter | Kusama | Polkadot | Source |
|---|---|---|---|
| Block times and throughput | Same as Polkadot | Same as Kusama | |
| Decision period (Root, Treasurer, Big Spender, Whitelisted Caller tracks) | 14 days | 28 days | |
| Confirmation period, Treasurer track | 2 days | 7 days | |
| Minimum enactment period (Whitelisted Caller: 10 minutes on both) | 1 day | 1 day | |
| Decision deposit, Root track | 3,333.33 KSM | 100,000 DOT | |
| Decision deposit, Treasurer track | 33.33 KSM | 1,000 DOT | |
| Decision deposit, Big Spender track | 13.33 KSM | 400 DOT | |
| Decision deposit, Whitelisted Caller track | 333.33 KSM | 10,000 DOT | |
| Staking era length | 6 hours | 24 hours | |
| Unbonding period (no rewards while unbonding) | 7 days | 28 days | |
| Minimum active nomination bond | 0.132977 KSM | 238.66 DOT | |
| Hard supply cap | None; a 21 million KSM cap was rejected (Referendum #596) | 2.1 billion DOT (Referendum 1710) |
This table shows current published parameters only. Minimum bonds change with network conditions and every value can be changed by referendum, so check on-chain before staking or opening a proposal; it does not cover the open JAM infrastructure vote closing 3 November 2026.
How Kusama differs from Polkadot
Governance timing
Both networks use OpenGov, in which each type of proposal runs on its own track. Current decision periods from the Polkadot Wiki:
| Track | Kusama decision period | Polkadot decision period |
|---|---|---|
| Root | 14 days | 28 days |
| Treasurer | 14 days | 28 days |
| Big Spender | 14 days | 28 days |
| Whitelisted Caller | 14 days | 28 days |
Opening a referendum for a decision also requires a deposit, and the amounts differ widely:
| Track | Kusama decision deposit | Polkadot decision deposit |
|---|---|---|
| Root | 3,333.33 KSM | 100,000 DOT |
| Treasurer | 33.33 KSM | 1,000 DOT |
| Big Spender | 13.33 KSM | 400 DOT |
| Whitelisted Caller | 333.33 KSM | 10,000 DOT |
Some tracks also have different confirmation periods. On the Treasurer track it is 2 days on Kusama and 7 days on Polkadot. The minimum enactment period on the tracks above is 1 day on both networks, except Whitelisted Caller, where it is 10 minutes. Older articles give a 7-day vote and 8-day enactment for Kusama. Those figures describe the governance system that OpenGov replaced and are no longer current.
Staking
| Parameter | Kusama | Polkadot |
|---|---|---|
| Era length | 6 hours | 24 hours |
| Unbonding period | 7 days | 28 days |
| Minimum active nomination bond | 0.132977 KSM | 238.66 DOT |
Kusama's unbonding period is 28 eras of 6 hours each. Minimum bonds change with network conditions, so check them on-chain before staking. No rewards are paid during unbonding.
Building on it
The Polkadot Wiki says the bonding requirement for projects is lower on Kusama, making it "the more affordable development environment". Kusama's governance is described there as "up to four times faster than Polkadot", but the chain itself is not faster: blocks are produced at the same rate on both.
KSM token and supply
KSM is used for staking, governance and fees. Unlike DOT, it has no hard supply cap. Polkadot holders passed Referendum 1710 with 81% support, and the result was announced in September 2025. It capped DOT supply at 2.1 billion and replaced issuance of 120 million DOT a year. KSM holders have rejected similar changes:
- Referendum #596, "Hard Pressure Capped & Stepped Supply Schedule", proposed a 21 million KSM cap. It was rejected with 35.3% Aye against 64.7% Nay.
- Referendum #627, "Sustainable KSM Economics via Burn Mechanisms (v1.2)", proposed cutting base inflation from 7.82% to 5% and adding fee and treasury burns. It failed.
Who Kusama is for
- Teams that want to run code against real users and value before deploying to Polkadot, with lower bonding costs and faster governance.
- KSM holders who want to take part in governance: decisions on Kusama close in two weeks, half the time Polkadot's tracks take.
- Stakers who prefer a shorter lock: 7 days to unbond on Kusama, against 28 days on Polkadot.
The trade-off is that Kusama is built to change quickly: its track parameters, staking rules and economics can be changed by referendum, and they shift faster than Polkadot's.
