Service Nervous System (SNS)

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A Decentralized Autonomous Organization, or DAO for short, is a system that allows many parties to jointly control an entity. Similarly to how the Network Nervous System (NNS) is the open tokenized DAO that controls the Internet Computer blockchain (IC), service nervous systems (SNSs) are algorithmic DAOs that allow developers to create decentralized, token-based governance systems for their dapps. This means, each dapp that would like to be under decentralized control will have a separate SNS.

What is a DAO?

Let’s first clarify what we mean by decentralized in this context. First, an application can run on a decentralized platform. This means that the platform itself is controlled by many different parties and, in particular, that even if some of these parties fail or turn malicious, the application will still keep running successfully. The IC is such a platform as it is run by many nodes that are owned by independent node providers. Therefore, we call applications that run on the IC decentralized applications or dapps.

A second kind of decentralized denotes who is in control of changing a dapp, or a smart contract more generally. In general, dapps running on the IC or smart contracts on other decentralized platforms can still be controlled by a single, central entity and thus still be under centralized control. As we will motivate below, it is often beneficial if a dapp is also under decentralized control. This means that no single party can decide how the dapp is evolved. Instead, the dapp can only be changed according to decisions that many parties jointly make. This decentralized control of a dapp is what a DAO achieves.

Motivation: why a DAO?

We next discuss the main motivations for DAOs from the point of view of two main actors on the IC: the dapp developers, who build dapps on the IC, and the end-users, who interact with and invest in dapps.

Dapp users

Dapps on the IC are realized as a set of canister smart contracts. Canisters define a controller specifying which principals can modify them. Most dapp canisters are either controlled by some developers or have no controller at all. Both situations are undesirable for a dapp’s users. In the case where a dapp is controlled by a centralized group of developers, users of the dapp must trust these developers not to stop the application and not to modify the application in an undesirable way, e.g., that favors the developers. In the case where the canister has no controller, it cannot be upgraded at all. This not only prevents evolving the dapp regarding new requirements but might also be a problem when it is necessary to fix security bugs.

DAOs provide a third option, namely to hand over the control over a dapp to a community that can jointly decide how to evolve a dapp in an open governance system, i.e., to decentralize a dapp’s control. This protects users as the control is now in the hand of a community rather than in the hand of a few parties. Moreover, dapp users can join the open governance themselves and thereby directly impact how the dapp is evolved.

Dapp developers

Decentralizing a dapp’s control is not only an advantage for the dapp’s users but can also be an advantage for the dapp’s developers. After all, it is in the developer’s interest to build the features users want.

Apart from this, another motivation for dapp developers to adopt a DAO such as the SNS is that it allows to tokenize the dapp which can help to get initial funding and initial adoption.

For a dapp that has an assigned SNS, everyone can purchase SNS tokens and participate in SNS governance. Thereby, anyone in the world can contribute to the funding of the project. This is fundamental for developers as this allows the SNS to decide to spend some of these funds, for example to pay for the dapp’s cycles or to pay developers.

The SNS can also decide to use different tokenomics models to create new incentive systems. For example, the SNS can decide to introduce voting rewards to motivate active governance participation. Moreover, rewards can be given to early adopters of the dapp and active users, which will help attract users. Furthermore, those who then possess SNS tokens are motivated to help increase the value of the tokens by attracting even more users. Therefore, such incentive systems can have positive network effects that are critical for the success of some dapps.

Dapp investors

Apart from active dapp users and dapp developers a third user group are those who would like to invest in a dapp. As already mentioned above, investors too profit both from the tokenization and decentralization that a DAO such as the SNS can provide. First, tokenization allows investors to get SNS tokens and invest in a dapp. The fact that tokens can then be staked in neurons and thus allow for governance participation, ensures that investors can contribute to the decisions on how the dapp will be evolved. Voting rewards might further incentivize investors to participate in governance. Finally, the positive network effects that tokenomics can have are of course also in the interest of the investors whose tokens have an increased value if the project is successful.

How to deploy and maintain a DAO

There are at least the following options on how to get and maintain a DAO for your dapp.

  1. Deploy an SNS that is provided as a system functionality by the IC. An SNS is realized by a set of canisters. Deploying and maintaining them is not a simple task. If one of the SNS canisters is upgraded, it has to be guaranteed that the new version of this canister is still compatible with the other SNS canisters. Moreover, not all canister versions can be upgraded to all other canister versions without breaking some functionality, e.g., due to incompatibility during state migration. To help them with these challenges, projects can choose an SNS that is automatically maintained by the IC. This means that upgrades from one deployment to another deployment are provided, thoroughly tested, and then approved by the IC community (through NNS proposals). We denote this by saying that the IC community blesses a new SNS deployment. All the SNS communities have to do is to vote to upgrade the SNS according to the blessed upgrade path. This will automatically fetch the right canister versions that have previously been “blessed” and upgrade the SNS canisters to them. SNS communities can nevertheless customize their SNS by choosing a variety of parameters. Such SNSs are hosted on an SNS subnet that exclusively hosts blessed SNSs. This simplifies the verification for end users who can simply verify that an SNS is running on the SNS subnet and infer that the canisters run blessed versions rather than possibly altered code.
  2. Self-deploy an SNS and manually upgrade it. Any SNS community can choose to deploy the SNS code, which is open source and available here, on an application subnet. They can then choose to follow the blessed upgrade path or deviate from this path, e.g., leaving out some versions, or even modify the canisters’ code in a completely different way. In this option, canister upgrades require more actions of the SNS community (i.e., compiling new wasms and make upgrade proposals) and the SNS community has to ensure that the upgrades are secure. This includes ensuring that alternative canister versions are compatible and that upgrades to newer versions do not break any functionality.
  3. Build your own DAO or use frameworks provided by others to build your DAO. While this is conceptually similar to the second option, we would like to emphasize that there are of course other design than the SNS that also build a DAO. For most of these, the implications for the communities will be similar to the second option: The DAO communities will have to maintain the DAO versions, or trust a third party to do so and such DAOs can be deployed on a higher-replication application subnet.

These possibilities allow communities to choose between using DAOs that are provided as a service by the IC, where maintenance is as automated as possible, and DAOs that have full flexibility of how they can evolve. Because the possibilities for Options 2 and 3 are unbounded, we focus here on explaining the SNS in Option 1 in more detail.

SNS canisters

The SNS consists of a governance canister, a ledger canister, a root canister, and a decentralization sale canister that is explained in the next section.

The ledger canister implements the ICRC-1 standard and contains SNS tokens, which are unique tokens for each SNS. It stores which accounts own how many SNS tokens and the history of transactions between the principals.

The governance canister enables decentralized decision making. It stores proposals that are suggestions on how to evolve the dapp that the SNS governs and neurons that define who the governance participants are. Neurons facilitate stake-based voting as they contain staked SNS tokens. Everyone can become a government participant by staking SNS tokens in a neuron. The root canister is responsible for upgrading the other SNS canisters and the dapp canisters that the SNS controls.

SNS lifecycle

SNS launch

As already described above, SNS canisters are maintained and blessed by the IC community. In more detail, the blessed SNS versions and upgrade paths are stored on an NNS canister called the SNS wasm modules canister. Anyone can deploy an SNS. To do so, they can make a call to the SNS wasm modules canister, who takes the latest versions of the SNS canisters, initializes them with the parameters given by the user, and deploys them on the SNS subnet. This call is not permissioned and anyone can deploy an SNS in this way if they provide sufficient cycles for the SNS canisters.

A crucial part of launching an SNS is how it can be decentralized. That is, the newly created tokens must be distributed to a large community to ensure proper decentralization of voting power. There are of course many ways to do so. The first SNS version provides one simple way to achieve this: a developer can hand over the control of the dapp to a newly deployed SNS, that has at that stage limited capabilities as it may not be fully decentralized yet, and ask the Internet Computer to start a decentralization sale for this SNS. In this the decentralization sale, initial tokens are sold for ICP tokens. In the end of a successful decentralization sale, SNS tokens are owned by a large community and therefore the SNS governance control is decentralized. Moreover, the ICP that were collected in the decentralization sale provide initial funding for the SNS project. It is conceivable that alternative ways to decentralize a dapp are added in later SNS versions.


SNS maintenance

As mentioned, this SNS option is provided as a system function and the SNS canister versions are maintained by the IC. This eliminates much of the maintenance burden from the SNS community. However, there are still some maintenance tasks that have to be performed by an SNS community, such as deciding and voting on when an SNS should be upgraded to a new blessed version, adjusting the SNS parameters when needed, and making sure that the SNS canisters do not run out of cycles. Regarding the last point, we emphasize that currently, the SNS communities are responsible for individually topping up the cycles of all SNS canisters as well as all dapp canisters that are controlled by the SNS. This includes archive canisters that are spawn by the ledger canister to archive all blocks. In the future, this will be simplified in a new feature that allows canister groups, where cycles can be managed across different canisters.

Explore more

To learn more about interacting with SNS tokens, governance, and rewards, and the Community Fund see: