Last updated 2024-04-26

Define a namespace

In the Kadena ecosystem, a namespace is conceptually similar to a domain name except that the name is a static prefix that establishes a private boundary for the contracts and keyset definitions you control.

When you are building, testing, and deploying smart contracts on your local development network, you don't need to define a namespace. Your work is isolated from others because your blockchain—and any smart contracts you deploy—run exclusively on your local computer.

However, if you want to deploy a smart contract on the Kadena test network or another public blockchain, the contract must have a unique name that distinguishes your Pact module from all the others. If you try to deploy a Pact module with a name that's already being used on the network where you are trying to deploy, the deployment will fail with an error and you'll pay a transaction fee for the failed attempt.

To prevent name collisions on the same network, Kadena allows you to define your own unique namespace on the blockchain. The namespace segregates your work—your smart contracts, keyset definitions, and Pact modules—from applications and modules created and deployed by others. Within your namespace, you can define whatever keysets and modules you need and control who can update the namespace with changes. As long as you choose a unique name for your namespace, everything you define inside of that namespace is automatically unique, too.

In this tutorial, you'll learn how to define a namespace for the election application and how to use that namespace in the remaining tutorials. If you want to learn more about namespaces and how they are used before continuing, see An Introductory Guide to Kadena Namespaces.

Before you begin

Before you start this tutorial, verify the following basic requirements:

You have an internet connection and a web browser installed on your local computer.
You have a code editor, such as Visual Studio Code, access to an interactive terminal shell, and are generally familiar with using command-line programs.
You have cloned the [election-dapp](https://github.com/kadena-community/voting-dapp.git election-dapp) repository as described in Prepare your workspace and have checked out the 01-getting-started branch.
You have the development network running in a Docker container as described in Start a local blockchain.
You are connected to the development network using your local host IP address and port number 8080.
You have created and funded an administrative account as described in Add an administrator account.

Write a transaction in Pact

In this tutorial, you'll write and execute some code using the Pact smart contract programming language and the Pact REPL.

To write a simple transaction in Pact:

Open the election-dapp/pact folder in a terminal shell on your computer.
Create a new file named namespace.repl in the pact folder.

Write an empty transaction by typing the following lines of code in the namespace.repl file:

(begin-tx  "Define a namespace called 'election")(commit-tx)

(begin-tx  "Define a namespace called 'election")(commit-tx)

Execute the transaction using the pact command-line program running locally or in a browser.

If pact-cli is installed locally, run the following command in the current terminal shell:
```
pact namespace.repl --trace
```
```
pact namespace.repl --trace
```
After you execute the file, you should see the following output:
```
namespace.repl:1:0:Trace: Begin Tx 0: Define a namespace called 'electionnamespace.repl:4:0:Trace: Commit Tx 0: Define a namespace called 'electionLoad successful
```
```
namespace.repl:1:0:Trace: Begin Tx 0: Define a namespace called 'electionnamespace.repl:4:0:Trace: Commit Tx 0: Define a namespace called 'electionLoad successful
```
If you don't have pact installed locally, you can open the pact-cli from the Docker container. However, to use the pact-cli in the development network, you must mount the pact folder in the container. To mount the pact folder, start the development network with the following command:
```
docker run --interactive --tty --publish 8080:8080 \ --volume ./pact:/pact-cli:ro kadena/devnet:latest
```
```
docker run --interactive --tty --publish 8080:8080 \ --volume ./pact:/pact-cli:ro kadena/devnet:latest
```
After you start the development network with the pact folder mounted, you can load the namespace.repl file in the pact-cli with the following command:
```
(load "namespace.repl")
```
```
(load "namespace.repl")
```
If you are using the pact-cli in a browser, you can replace the pact namespace.repl -t command with (load "namespace.repl") throughout this tutorial.

Use Pact built-in functions

Pact has two built-in functions to define and work inside of a namespace: define-namespace and namespace. To define a namespace, you must specify a user keyset and an admin keyset. These two keysets control who can access the namespace and what they can do.

The user keyset controls who can use the modules and contracts deployed to the namespace.
The admin keyset controls who owns the namespace and can upload or modify what the namespace contains.

Arguments for the define-namespace function

For this tutorial, you're going to call the define-namespace function inside the transaction you created in the namespace.repl file. For this function call, you must provide the following information as arguments:

The name of the namespace.
The keyset that defines who can use the namespace.
The keyset that defines who governs the namespace.

Arguments for the expect function

The define-namespace function is wrapped by the expect function to test that calling define-namespace will succeed. The expect function takes three arguments:

The title of the test.
The expected output of the define-namespace function.
The define-namespace function call.

Define the election namespace

To define the election application namespace with the define-namespace function:

Open the election-dapp/pact/namespace.repl file in a terminal shell on your computer.

Add the following lines of code between the begin-tx and commit-tx lines:

(expect  "Test whether a namespace can be defined"  "Namespace defined: election"  (define-namespace 'election (read-keyset 'user-keyset) (read-keyset 'admin-keyset)))

(expect  "Test whether a namespace can be defined"  "Namespace defined: election"  (define-namespace 'election (read-keyset 'user-keyset) (read-keyset 'admin-keyset)))

Execute the transaction using the pact command-line program by running the following command in the current terminal shell:

pact namespace.repl -t

pact namespace.repl -t

You'll see that this transaction fails with output similar to the following:

namespace.repl:1:0:Trace: Begin Tx 0: Define a namespace called 'electionnamespace.repl:4:0:Trace: FAILURE: Test whether a namespace can be defined: evaluation of actual failed:namespace.repl:7:32: No such key in message: user-keysetnamespace.repl:9:0:Trace: Commit Tx 0: Define a namespace called 'electionnamespace.repl:4:0:ExecError: FAILURE: Test whether a namespace can be defined: evaluation of actual failed:namespace.repl:7:32: No such key in message: user-keysetLoad failed

namespace.repl:1:0:Trace: Begin Tx 0: Define a namespace called 'electionnamespace.repl:4:0:Trace: FAILURE: Test whether a namespace can be defined: evaluation of actual failed:namespace.repl:7:32: No such key in message: user-keysetnamespace.repl:9:0:Trace: Commit Tx 0: Define a namespace called 'electionnamespace.repl:4:0:ExecError: FAILURE: Test whether a namespace can be defined: evaluation of actual failed:namespace.repl:7:32: No such key in message: user-keysetLoad failed

For the transaction to succeed, you must first load the user-keyset and admin-keyset into the context of the Pact REPL so they can be read using the read-keyset function.

Add the following lines at the top of the namespace.repl file:

(env-data { 'user-keyset :   { 'keys : [ 'user-public-key ]   , 'pred : 'keys-all   } , 'admin-keyset :   { 'keys : [ 'admin-public-key ]   , 'pred : 'keys-all   } })

(env-data { 'user-keyset :   { 'keys : [ 'user-public-key ]   , 'pred : 'keys-all   } , 'admin-keyset :   { 'keys : [ 'admin-public-key ]   , 'pred : 'keys-all   } })

Execute the transaction using the pact command-line program:

pact namespace.repl -t

pact namespace.repl -t

You'll see that this transaction succeeds with output similar to the following:

namespace.repl:1:0:Trace: Setting transaction datanamespace.repl:12:0:Trace: Begin Tx 0: Define a namespace called 'electionnamespace.repl:15:0:Trace: Expect: success: Test whether a namespace can be definednamespace.repl:20:0:Trace: Commit Tx 0: Define a namespace called 'electionLoad successful

namespace.repl:1:0:Trace: Setting transaction datanamespace.repl:12:0:Trace: Begin Tx 0: Define a namespace called 'electionnamespace.repl:15:0:Trace: Expect: success: Test whether a namespace can be definednamespace.repl:20:0:Trace: Commit Tx 0: Define a namespace called 'electionLoad successful

You now have a namespace called election defined in the Pact REPL.

Modify the namespace

After you define a namespace, only the admin-keyset—the namespace owner—you can update the namespace. You can test this behavior by creating a new transaction to modify the namespace with an instruction to allow the user-keyset to govern the namespace and limit the admin-keyset to only use the namespace.

To test modifying the election application namespace:

Open the election-dapp/pact/namespace.repl file in a terminal shell on your computer.

Add the following lines of code as a second transaction at the bottom of the namespace.repl file:

(begin-tx  "Update the 'election' namespace")(expect  "An admin can modify the namespace to change the keyset governing the namespace"  "Namespace defined: election"  (define-namespace 'election (read-keyset 'admin-keyset) (read-keyset 'user-keyset)))(commit-tx)

(begin-tx  "Update the 'election' namespace")(expect  "An admin can modify the namespace to change the keyset governing the namespace"  "Namespace defined: election"  (define-namespace 'election (read-keyset 'admin-keyset) (read-keyset 'user-keyset)))(commit-tx)

Execute the transaction using the pact command-line program:
```
pact namespace.repl -t
```
```
pact namespace.repl -t
```
You'll see that this transaction fails with a message containing Keyset failure because only the admin-keyset is allowed to update the namespace and the transaction isn't signed by the admin-keyset.
Sign the transaction with the admin-keyset by loading it into the context of the Pact REPL right before the last transaction with the following lines of code and run namespace.repl again.
```
(env-sigs  [{ 'key  : 'admin-public-key   , 'caps : []  }])
```
```
(env-sigs  [{ 'key  : 'admin-public-key   , 'caps : []  }])
```

Execute the transaction using the pact command-line program:

pact namespace.repl -t

pact namespace.repl -t

You'll see that the update transaction succeeds with output similar to the following:

namespace.repl:1:0:Trace: Setting transaction datanamespace.repl:12:0:Trace: Begin Tx 0: Define a namespace called 'electionnamespace.repl:15:0:Trace: Expect: success: Test whether a namespace can be definednamespace.repl:20:0:Trace: Commit Tx 0: Define a namespace called 'electionnamespace.repl:21:0:Trace: Setting transaction signatures/capsnamespace.repl:26:0:Trace: Begin Tx 1: Update the 'election' namespacenamespace.repl:29:0:Trace: Expect: success: An admin can modify the namespace to change the keyset governing the namespacenamespace.repl:34:0:Trace: Commit Tx 1: Update the 'election' namespaceLoad successful

namespace.repl:1:0:Trace: Setting transaction datanamespace.repl:12:0:Trace: Begin Tx 0: Define a namespace called 'electionnamespace.repl:15:0:Trace: Expect: success: Test whether a namespace can be definednamespace.repl:20:0:Trace: Commit Tx 0: Define a namespace called 'electionnamespace.repl:21:0:Trace: Setting transaction signatures/capsnamespace.repl:26:0:Trace: Begin Tx 1: Update the 'election' namespacenamespace.repl:29:0:Trace: Expect: success: An admin can modify the namespace to change the keyset governing the namespacenamespace.repl:34:0:Trace: Commit Tx 1: Update the 'election' namespaceLoad successful

After this second transaction is successful, the admin-keyset no longer governs the election namespace.

Verify the admin-keyset doesn't govern the namespace

Now that you have successfully modified the election namespace, you can no longer use the admin-keyset to sign transactions that modify the namespace. You can confirm this behavior by adding another transaction that attempts to redefine the namespace with the same permissions that you used when you initially created the namespace.

This transaction is expected to fail because it's signed using the admin-keyset and the admin-keyset no longer governs the namespace. after the previous transaction. Therefore, for this example, you can wrap the define-namespace function inside an expect-failure function to assert that redefining the namespace will fail.

To verify that redefining the election application namespace fails:

Open the election-dapp/pact/namespace.repl file in a terminal shell on your computer.

Add the following lines of code as a third transaction at the bottom of the namespace.repl file:

(begin-tx   "Try to update the 'election' namespace with the wrong permissions")(expect-failure  "The previous admin can no longer update the namespace"  "Keyset failure (keys-all)"  (define-namespace 'election (read-keyset 'user-keyset) (read-keyset 'admin-keyset)))(commit-tx)

(begin-tx   "Try to update the 'election' namespace with the wrong permissions")(expect-failure  "The previous admin can no longer update the namespace"  "Keyset failure (keys-all)"  (define-namespace 'election (read-keyset 'user-keyset) (read-keyset 'admin-keyset)))(commit-tx)

Execute the transaction using the pact command-line program:

pact namespace.repl -t

pact namespace.repl -t

You'll see that the transaction fails as expected with output similar to the following:

namespace.repl:36:0:Trace: Begin Tx 2: Try to update the 'election' namespace with the wrong permissionsnamespace.repl:39:0:Trace: Expect failure: success: The previous admin can no longer update the namespacenamespace.repl:44:0:Trace: Commit Tx 2: Try to update the 'election' namespace with the wrong permissionsLoad successful

namespace.repl:36:0:Trace: Begin Tx 2: Try to update the 'election' namespace with the wrong permissionsnamespace.repl:39:0:Trace: Expect failure: success: The previous admin can no longer update the namespacenamespace.repl:44:0:Trace: Commit Tx 2: Try to update the 'election' namespace with the wrong permissionsLoad successful

Verify the user-keyset governs the namespace

To verify that the user-keyset can now redefine the namespace, you can load the signature of the user-keyset into the context of the Pact REPL and write a transaction to redefine the namespace.

To verify that redefining the election application namespace succeeds:

Open the election-dapp/pact/namespace.repl file in a terminal shell on your computer.

Add the following lines of code as a fourth transaction at the bottom of the namespace.repl file:

(env-sigs  [{ 'key  : 'user-public-key   , 'caps : []  }])(begin-tx  "Redefine a namespace called 'election as the new admin")(expect  "The new admin can update the namespace"  "Namespace defined: election"  (define-namespace 'election (read-keyset 'user-keyset) (read-keyset 'admin-keyset)))(commit-tx)

(env-sigs  [{ 'key  : 'user-public-key   , 'caps : []  }])(begin-tx  "Redefine a namespace called 'election as the new admin")(expect  "The new admin can update the namespace"  "Namespace defined: election"  (define-namespace 'election (read-keyset 'user-keyset) (read-keyset 'admin-keyset)))(commit-tx)

Execute the transaction using the pact command-line program:

pact namespace.repl -t

pact namespace.repl -t

You'll see that the transaction fails as expected with output similar to the following:

namespace.repl:50:0:Trace: Begin Tx 3: Redefine a namespace called 'election as the new adminnamespace.repl:53:0:Trace: Expect: success: The new admin can update the namespacenamespace.repl:58:0:Trace: Commit Tx 3: Redefine a namespace called 'election as the new adminLoad successful

namespace.repl:50:0:Trace: Begin Tx 3: Redefine a namespace called 'election as the new adminnamespace.repl:53:0:Trace: Expect: success: The new admin can update the namespacenamespace.repl:58:0:Trace: Commit Tx 3: Redefine a namespace called 'election as the new adminLoad successful

Create a principal namespace in the Pact REPL

So far, you've seen how to define and manage a namespace, but the function you used in the previous examples doesn't guarantee that your namespace would have a unique name that isn't being used by anyone else. To ensure your namespace has a unique name, Kadena provides a built-in ns module on the main, test, and development networks.

When you use the ns module, you can create a uniquely-named principal namespace on any Kadena network. The ns module includes a create-principal-namespace function specifically for this purpose. The create-principal-namespace function enables you to create a namespace using the prefix n_ followed by the hash of a keyset. This naming convention ensures that your principal namespace won't conflict with any other namespaces defined in the same network.

This example demonstrates creating a principal namespace using an admin-keyset that contains the public key of the sender00 account because the ns.create-principal-namespace function only accepts valid public keys inside the keyset. The steps are similar to what you've done before.

To create a principal namespace:

Open the election-dapp/pact folder in a terminal shell on your computer.
Create a new file named principal-namespace.repl in the pact folder.

Load the admin-keyset with the public key of the sender00 account into the context of the Pact REPL by adding the following lines at the top of the principal-namespace.repl file:

(env-data  { 'admin-keyset :    { 'keys : [ "368820f80c324bbc7c2b0610688a7da43e39f91d118732671cd9c7500ff43cca" ]    , 'pred : 'keys-all    }  })

(env-data  { 'admin-keyset :    { 'keys : [ "368820f80c324bbc7c2b0610688a7da43e39f91d118732671cd9c7500ff43cca" ]    , 'pred : 'keys-all    }  })

Load the ns module from the local filesystem to make it available in the Pact REPL by adding the following lines of code to the principal-namespace.repl:
```
(begin-tx)(load "root/ns.pact")(commit-tx)
```
```
(begin-tx)(load "root/ns.pact")(commit-tx)
```
Loading the ns module from the local ./pact/root folder of the project is only required for testing in the Pact REPL.

Add a transaction to create the principal namespace by typing the following lines of code in the principal-namespace.repl file:

(begin-tx  "Define a principal namespace")(expect  "A principal namespace can be created"  "Namespace defined: n_560eefcee4a090a24f12d7cf68cd48f11d8d2bd9"  (let ((ns-name (ns.create-principal-namespace (read-keyset 'admin-keyset))))    (define-namespace ns-name (read-keyset 'admin-keyset ) (read-keyset 'admin-keyset ))  ))(commit-tx)

(begin-tx  "Define a principal namespace")(expect  "A principal namespace can be created"  "Namespace defined: n_560eefcee4a090a24f12d7cf68cd48f11d8d2bd9"  (let ((ns-name (ns.create-principal-namespace (read-keyset 'admin-keyset))))    (define-namespace ns-name (read-keyset 'admin-keyset ) (read-keyset 'admin-keyset ))  ))(commit-tx)

In this code:

The admin-keyset calls the ns.create-principal-namespace function.
The output of the ns.create-principal-namespace function is stored in the ns-name variable.
The define-namespace function takes the output stored in ns-name variable as its first argument to create the unique name for the namespace.

The code is similar to the code you wrote in the namespace.repl file except that you're using the ns module and passing the ns-name variable ns-name instead of using a hardcoded string election.

Execute the transaction using the pact command-line program:

pact namespace.repl -t

pact namespace.repl -t

You'll see that the transaction succeeds with output similar to the following:

principal-namespace.repl:1:0:Trace: Setting transaction dataprincipal-namespace.repl:9:0:Trace: Begin Tx 0principal-namespace.repl:10:3:Trace: Loading root/ns.pact...root/ns.pact:1:0:Trace: Loaded module ns, hash jXT9VNDw_Wn0wsWQcLCejEQfAdpyA_GUjeINHG9Z3aUprincipal-namespace.repl:11:0:Trace: Commit Tx 0principal-namespace.repl:13:0:Trace: Begin Tx 1: Define a principal namespaceprincipal-namespace.repl:16:0:Trace: Expect: success: A principal namespace can be createdprincipal-namespace.repl:23:0:Trace: Commit Tx 1: Define a principal namespaceLoad successful

principal-namespace.repl:1:0:Trace: Setting transaction dataprincipal-namespace.repl:9:0:Trace: Begin Tx 0principal-namespace.repl:10:3:Trace: Loading root/ns.pact...root/ns.pact:1:0:Trace: Loaded module ns, hash jXT9VNDw_Wn0wsWQcLCejEQfAdpyA_GUjeINHG9Z3aUprincipal-namespace.repl:11:0:Trace: Commit Tx 0principal-namespace.repl:13:0:Trace: Begin Tx 1: Define a principal namespaceprincipal-namespace.repl:16:0:Trace: Expect: success: A principal namespace can be createdprincipal-namespace.repl:23:0:Trace: Commit Tx 1: Define a principal namespaceLoad successful

In this example, you defined a principal namespace in the Pact REPL using the public key for sender00 account. Next, you can define a principal namespace on the development network using the administrative account you created in Add an administrator account.

Create your own principal namespace

Now that you've seen how to use the define-namespace and create-principal-namespace functions, you're ready to create your own principal namespace on your local development network with the administrative account you created using Chainweaver.

To create your principal namespace on the development network:

Verify the development network is currently running on your local computer.
Open and unlock the Chainweaver desktop or web application and verify that:
- You're connected to development network (devnet) from the network list.
- Your administrative account name with the k: prefix exists on chain 1.
- Your administrative account name is funded with KDA on chain 1.
Verify your administrative account in Chainweaver

You're going to use Chainweaver to sign the transaction that creates the principal namespace.

Open the election-dapp/snippets/principal-namespace.ts file in your code editor.

The pactCommand variable in this file contains the Pact code for defining a principal namespace that you tested in the Pact REPL.

async function main(account: string) {  const pactCommand = `    (let ((ns-name (ns.create-principal-namespace (read-keyset 'admin-keyset))))      (define-namespace ns-name (read-keyset 'admin-keyset ) (read-keyset 'admin-keyset ))    )  `;

async function main(account: string) {  const pactCommand = `    (let ((ns-name (ns.create-principal-namespace (read-keyset 'admin-keyset))))      (define-namespace ns-name (read-keyset 'admin-keyset ) (read-keyset 'admin-keyset ))    )  `;

The next lines in the file add the keyset data with slightly different syntax and a transaction signer:

const transaction = Pact.builder  .execution(pactCommand)  .addData('admin-keyset', {    keys: [accountKey(account)],    pred: 'keys-all',  })  .addSigner(accountKey(account))  .setMeta({ chainId: getChainId(), senderAccount: account })  .setNetworkId(getNetworkId())  .createTransaction();

const transaction = Pact.builder  .execution(pactCommand)  .addData('admin-keyset', {    keys: [accountKey(account)],    pred: 'keys-all',  })  .addSigner(accountKey(account))  .setMeta({ chainId: getChainId(), senderAccount: account })  .setNetworkId(getNetworkId())  .createTransaction();

The signing code wasn't required to execute the transaction in the Pact REPL, but you need this code to execute the transaction on the development network. After the transaction is defined, Chainweaver signs the transaction so it can be executed:

const signedTx = await signWithChainweaver(transaction);

const signedTx = await signWithChainweaver(transaction);

In the remaining lines of code, the Kadena client processes the response it receives from your local development network.

Open the election-dapp/snippets folder in a terminal shell on your computer.
Create your principal namespace using the create-namespace script by running a command similar to the following with your administrative account name:
```
npm run create-namespace:devnet -- k:<your-public-key>
```
```
npm run create-namespace:devnet -- k:<your-public-key>
```
Remember that k:<your-public-key> is the default account name for your administrative account that you funded in Add an administrator account. You can copy this account name from Chainweaver when viewing the account watch list.

When you run the script, you should see Chainweaver display a QuickSign Request. For example:

Sample QuickSign request

If you don't see the request automatically, select Chainweaver to bring it to the foreground.
Click Sign All to sign the request.

After you click Sign All, the transaction is executed and the results are displayed in your terminal shell. For example, you should see output similar to the following:
```
{  status: 'success',  data: 'Namespace defined: n_14912521e87a6d387157d526b281bde8422371d1'}
```
```
{  status: 'success',  data: 'Namespace defined: n_14912521e87a6d387157d526b281bde8422371d1'}
```

You now have a unique principal namespace that you can use in your local development network and that can be governed and used by your administrative account.

Next steps

In this tutorial, you learned how to:

Define and update a namespace for the election application in the Pact REPL.
Specify the keysets that are allowed to use and govern the namespace.
Write simple transactions to test the keyset used to govern and modify the namespace.
Modify the keyset with permission to govern the namespace.
Create and test a principal namespace locally before defining a namespace on the network.
Create a principal namespace on the local development network that is governed by your administrative account.

The work you completed in this tutorial sets the groundwork for the next tutorial. In the next tutorial, you'll learn how to define a keyset inside your principal namespace and how the keyset you define is used to guard who can modify your election application smart contract.

To see the code for the activity you completed in this tutorial and get the starter code for the next tutorial, check out the 05-keysets branch from the election-dapp repository by running the following command in your terminal shell:

bash

git checkout 05-keysets

bash

git checkout 05-keysets