Developing applications with Momento SDKs

Welcome! This page provides information about common constructs you will need in order to assemble Momento clients in all of our SDKs. This page covers how to provide your Momento credentials (called API keys), how to configure your client, and some basic information about error handling and production readiness.

Constructing a Cache Client

The CacheClient is the main object you will use in your code to interact with Momento services. To instantiate one, you need to pass a CredentialProvider, a Configuration, and a default time to live (TTL) value. The default TTL determines how long items using that CacheClient will be stored in the cache before the cache deletes them. When performing Set operations, you can override this TTL value unique to that operation. See Expire data with Time-to-Live (TTL) in Momento Cache for more information.

Here is an example of how to construct a CacheClient:

JavaScript

return await CacheClient.create({
  configuration: Configurations.Laptop.v1(),
  credentialProvider: CredentialProvider.fromEnvVarV2(),
  defaultTtlSeconds: 60,
});

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Full example code and imports can be found here

Python

await CacheClientAsync.create(
    Configurations.Laptop.latest(),
    CredentialProvider.from_environment_variables_v2(),
    timedelta(seconds=60),
)

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Full example code and imports can be found here

Java

try (CacheClient cacheClient =
    CacheClient.create(
        CredentialProvider.fromEnvVarV2(),
        Configurations.Laptop.v1(),
        Duration.ofSeconds(60))) {
  // ...
}

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Full example code and imports can be found here

Kotlin

CacheClient(
    CredentialProvider.fromEnvVarV2(), Configurations.Laptop.latest, 60.seconds
).use { cacheClient ->
    //...
}

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Full example code and imports can be found here

Go

credentialProvider, err = auth.NewEnvMomentoV2TokenProvider()
if err != nil {
	panic(err)
}
defaultTtl := 60 * time.Second
eagerConnectTimeout := 30 * time.Second

client, err = momento.NewCacheClientWithEagerConnectTimeout(
	config.LaptopLatest(),
	credentialProvider,
	defaultTtl,
	eagerConnectTimeout,
)
if err != nil {
	panic(err)
}

client.Ping(ctx)

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Full example code and imports can be found here

PHP

new CacheClient(
    Laptop::latest(),
    CredentialProvider::fromEnvironmentVariablesV2(),
    60
);

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Full example code and imports can be found here

Rust

  let cache_client = CacheClient::builder()
      .default_ttl(Duration::from_secs(60))
      .configuration(momento::cache::configurations::Laptop::latest())
      .credential_provider(CredentialProvider::from_default_env_var_v2()?)
      .build()?;

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Full example code and imports can be found here

Elixir

config = Momento.Configurations.Laptop.latest()

credential_provider = Momento.Auth.CredentialProvider.from_env_var_v2!()
default_ttl_seconds = 60.0
Momento.CacheClient.create!(config, credential_provider, default_ttl_seconds)

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Full example code and imports can be found here

Swift

do {
    let credentialProvider = try CredentialProvider.fromEnvironmentVariablesV2()
    let cacheClient = CacheClient(
        configuration: CacheClientConfigurations.iOS.latest(),
        credentialProvider: credentialProvider,
        defaultTtlSeconds: 10
    )
} catch {
    print("Unable to create cache client: \(error)")
    exit(1)
}

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Full example code and imports can be found here

Dart

try {
  final cacheClient = CacheClient(
      CredentialProvider.fromEnvironmentVariablesV2(),
      CacheClientConfigurations.latest(),
      Duration(seconds: 30));
} catch (e) {
  print("Unable to create cache client: $e");
  exit(1);
}

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Full example code and imports can be found here

Instantiating credential providers using Momento API keys

You need to provide a Momento API key when instantiating a Momento client. If you don't have one yet, you can get one from the Momento Web Console.

You also need to provide a Momento service endpoint. You can find a list of them here.

Once you have an API key and an endpoint, provide it to Momento SDKs when you create an instance of CredentialProvider. There are convenient factory methods provided to construct a CredentialProvider object, either from an environment variable or from a String. Below is an example of how to instantiate CredentialProvider from the default environment variables MOMENTO_API_KEY and MOMENTO_ENDPOINT:

JavaScript

CredentialProvider.fromEnvVarV2();

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Full example code and imports can be found here

Python

CredentialProvider.from_environment_variables_v2()

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Full example code and imports can be found here

Java

CredentialProvider.fromEnvVarV2();

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Full example code and imports can be found here

Kotlin

CredentialProvider.fromEnvVarV2()

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Full example code and imports can be found here

Go

credentialProvider, err = auth.FromEnvironmentVariablesV2()
if err != nil {
	panic(err)
}

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Full example code and imports can be found here

C#

new EnvMomentoV2TokenProvider();

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Full example code and imports can be found here

PHP

CredentialProvider::fromEnvironmentVariablesV2();

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Full example code and imports can be found here

Rust

  let credential_provider = CredentialProvider::from_default_env_var_v2()?;

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Full example code and imports can be found here

Elixir

Momento.Auth.CredentialProvider.from_env_var_v2!()

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Full example code and imports can be found here

Swift

do {
    let credentialProvider = try CredentialProvider.fromEnvironmentVariablesV2()
} catch {
    print("Unable to create credential provider: \(error)")
    exit(1)
}

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Full example code and imports can be found here

Alternately provide custom environment variable names:

JavaScript

CredentialProvider.fromEnvVarV2({
  apiKeyEnvVar: 'MOMENTO_API_KEY',
  endpointEnvVar: 'MOMENTO_ENDPOINT',
});

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Full example code and imports can be found here

Python

CredentialProvider.from_environment_variables_v2(
    api_key_env_var="MOMENTO_API_KEY", endpoint_env_var="MOMENTO_ENDPOINT"
)

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Full example code and imports can be found here

Java

CredentialProvider.fromEnvVarV2("MOMENTO_API_KEY", "MOMENTO_ENDPOINT");

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Full example code and imports can be found here

Kotlin

CredentialProvider.fromEnvVarV2("MOMENTO_API_KEY", "MOMENTO_ENDPOINT")

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Full example code and imports can be found here

Go

credentialProvider, err = auth.FromEnvironmentVariablesV2(auth.EnvVarV2Props{
	ApiKeyEnvVar:   "MOMENTO_API_KEY",
	EndpointEnvVar: "MOMENTO_ENDPOINT",
})
if err != nil {
	panic(err)
}

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Full example code and imports can be found here

C#

new EnvMomentoV2TokenProvider("MOMENTO_API_KEY", "MOMENTO_ENDPOINT");

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Full example code and imports can be found here

PHP

CredentialProvider::fromEnvironmentVariablesV2("MOMENTO_API_KEY", "MOMENTO_ENDPOINT");

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Full example code and imports can be found here

Rust

  let credential_provider = CredentialProvider::from_env_var_v2("MOMENTO_API_KEY", "MOMENTO_ENDPOINT")?;

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Full example code and imports can be found here

Elixir

Momento.Auth.CredentialProvider.from_env_var_v2!("MOMENTO_API_KEY", "MOMENTO_ENDPOINT")

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Full example code and imports can be found here

Swift

do {
    let credentialProvider = try CredentialProvider.fromEnvironmentVariablesV2(
        apiKeyEnvVar: "MOMENTO_API_KEY",
        endpointEnvVar: "MOMENTO_ENDPOINT"
    )
} catch {
    print("Unable to create credential provider: \(error)")
    exit(1)
}

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Full example code and imports can be found here

If you're storing your Momento auth token in a secret manager such as AWS Secret Manager, GCP Secret Manager, or a local config file, you must first retrieve the credentials from there and then instantiate a CredentialProvider from a string, like this:

JavaScript

const apiKey = retrieveApiKeyV2FromYourSecretsManager();
// using the us-west-2 region's endpoint for this example
const endpoint = 'cell-4-us-west-2-1.prod.a.momentohq.com';
CredentialProvider.fromApiKeyV2({apiKey: apiKey, endpoint: endpoint});

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Full example code and imports can be found here

Python

api_key = retrieve_api_key_v2_from_your_secrets_manager()
endpoint = "cell-4-us-west-2-1.prod.a.momentohq.com"
CredentialProvider.from_api_key_v2(api_key, endpoint)

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Full example code and imports can be found here

Java

final String apiKey = retrieveApiKeyV2FromYourSecretsManager();
final String endpoint = "cell-4-us-west-2-1.prod.a.momentohq.com";
CredentialProvider.fromApiKeyV2(apiKey, endpoint);

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Full example code and imports can be found here

Kotlin

val apiKey = retrieveApiKeyV2FromYourSecretsManager()
val endpoint = "cell-4-us-west-2-1.prod.a.momentohq.com"
CredentialProvider.fromApiKeyV2(apiKey, endpoint)

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Full example code and imports can be found here

Go

apiKey := retrieveApiKeyV2FromYourSecretsManager()
endpoint := "cell-4-us-west-2-1.prod.a.momentohq.com"
props := auth.ApiKeyV2Props{ApiKey: apiKey, Endpoint: endpoint}
credentialProvider, err = auth.FromApiKeyV2(props)
if err != nil {
	panic(err)
}

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Full example code and imports can be found here

C#

var endpoint = "cell-4-us-west-2-1.prod.a.momentohq.com";
var apiKey = RetrieveApiKeyV2FromYourSecretsManager();
new ApiKeyV2TokenProvider(apiKey, endpoint);

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Full example code and imports can be found here

PHP

$api_key = retrieveApiKeyV2FromYourSecretsManager();
$endpoint = "cell-4-us-west-2-1.prod.a.momentohq.com";
CredentialProvider::fromApiKeyV2($api_key, $endpoint);

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Full example code and imports can be found here

Rust

  let api_key = retrieve_api_key_v2_from_your_secrets_manager();
  let endpoint = "cell-4-us-west-2-1.prod.a.momentohq.com".to_string();
  let credential_provider = CredentialProvider::from_api_key_v2(api_key, endpoint)?;

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Full example code and imports can be found here

Elixir

api_key = retrieve_api_key_v2_from_your_secrets_manager()
endpoint = "cell-4-us-west-2-1.prod.a.momentohq.com"
Momento.Auth.CredentialProvider.from_api_key_v2!(api_key, endpoint)

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Full example code and imports can be found here

Swift

let apiKey = retrieveApiKeyV2FromYourSecretsManager()
let endpoint = "cell-4-us-west-2-1.prod.a.momentohq.com"
do {
    let credentialProvider = try CredentialProvider.fromApiKeyV2(
        apiKey: apiKey, endpoint: endpoint)
} catch {
    print("Unable to create credential provider: \(error)")
    exit(1)
}

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Full example code and imports can be found here

For an example of how to retrieve credentials from AWS Secrets Manager, see Retrieving a Momento auth token from AWS Secrets Manager.

If you have a disposable auth token or a v1 API key, you can instantiate a CredentialProvider like this:

JavaScript

const apiKey = retrieveApiKeyFromYourSecretsManager();
CredentialProvider.fromDisposableToken({apiKey: apiKey});

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Full example code and imports can be found here

Python

auth_token = retrieve_api_key_from_your_secrets_manager()
CredentialProvider.from_disposable_token(auth_token)

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Full example code and imports can be found here

Kotlin

val authToken = retrieveAuthTokenFromYourSecretsManager()
CredentialProvider.fromDisposableToken(authToken)

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Full example code and imports can be found here

Go

authToken := RetrieveApiKeyFromYourSecretsManager()
credentialProvider, err = auth.FromDisposableToken(authToken)
if err != nil {
	panic(err)
}

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Full example code and imports can be found here

C#

var authToken = RetrieveApiKeyFromYourSecretsManager();
new DisposableTokenProvider(authToken);

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Full example code and imports can be found here

PHP

$auth_token = retrieveApiKeyFromYourSecretsManager();
CredentialProvider::fromDisposableToken($auth_token);

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Full example code and imports can be found here

Rust

  let auth_token = generate_disposable_token();
  let credential_provider = CredentialProvider::from_disposable_token(auth_token)?;

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Full example code and imports can be found here

Elixir

api_key = retrieve_api_key_from_your_secrets_manager()
Momento.Auth.CredentialProvider.from_disposable_token!(api_key)

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Full example code and imports can be found here

Swift

let authToken = retrieveApiKeyFromYourSecretsManager()
do {
    let credentialProvider = try CredentialProvider.fromDisposableToken(token: authToken)
} catch {
    print("Unable to create credential provider: \(error)")
    exit(1)
}

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Full example code and imports can be found here

For general information on Momento authentication, see our auth page.

For more information, see our Response Objects page, and the docs for the specific SDK that you are using (under Develop->SDKs in the left nav).