aws-sdk-swift-usage

AWS SDK for Swift

Async Code Structure

All SDK operations are async. Use @main entry point:

@main
struct Main {
    static func main() async throws {
        let client = try await S3Client()
        // ... async operations
    }
}

CRITICAL: Use Struct Config Types

NEVER use S3ClientConfiguration or DynamoDBClientConfiguration - these are DEPRECATED classes.

ALWAYS use the struct-based config types:

• S3Client.S3ClientConfig (not S3ClientConfiguration)
• DynamoDBClient.DynamoDBClientConfig (not DynamoDBClientConfiguration)
• STSClient.STSClientConfig (not STSClientConfiguration)

Config parameters MUST be in declaration order. Region is ALWAYS required when creating a config. Check the service client source for exact order.

Client Creation

All service clients follow the same pattern: <Service>Client with <Service>Client.<Service>ClientConfig.

Model types (structs/enums used in requests/responses) are namespaced under <Service>ClientTypes:

• S3ClientTypes.Bucket, S3ClientTypes.Object
• DynamoDBClientTypes.AttributeValue
• CloudWatchClientTypes.MetricDatum, CloudWatchClientTypes.Dimension

Common config parameters (MUST follow declaration order):

• awsCredentialIdentityResolver - Custom credentials

• useFIPS - Enable FIPS endpoints

• useDualStack - Enable dual-stack endpoints

• awsRetryMode - Retry strategy (.adaptive, .standard, .legacy)

• maxAttempts - Max retry attempts

• region - AWS region

• httpClientEngine - Custom HTTP client (requires HttpClientConfiguration parameter):

  import ClientRuntime
  let httpConfig = HttpClientConfiguration()
  let httpClient = URLSessionHTTPClient(httpClientConfiguration: httpConfig)
  let config = try await S3Client.S3ClientConfig(
      region: "us-east-1",
      httpClientEngine: httpClient
  )

• endpoint - Custom endpoint URL

For service-specific config options or exact parameter order, check Sources/Services/AWS<Service>/Sources/AWS<Service>/<Service>Client.swift in the SDK.

Credential Resolvers

import AWSSDKIdentity
import SmithyIdentity
 
// Static credentials - pass credential object directly
let creds = AWSCredentialIdentity(accessKey: "AKIA...", secret: "...")
let resolver = StaticAWSCredentialIdentityResolver(creds)
 
// Assume role - REQUIRES underlying resolver
let underlying = try DefaultAWSCredentialIdentityResolverChain()
let resolver = try STSAssumeRoleAWSCredentialIdentityResolver(
    awsCredentialIdentityResolver: underlying,
    roleArn: "arn:aws:iam::123456789012:role/MyRole",
    sessionName: "session-name"
)
 
// Use in config
let config = try await S3Client.S3ClientConfig(
    awsCredentialIdentityResolver: resolver,
    region: "us-west-2"
)

Waiters

Import SmithyWaitersAPI. WaiterOptions requires maxWaitTime parameter:

import AWSS3
import SmithyWaitersAPI
 
let client = try await S3Client()
_ = try await client.waitUntilBucketExists(
    options: WaiterOptions(maxWaitTime: 120.0),
    input: HeadBucketInput(bucket: "my-bucket")
)

Pagination

let input = ListObjectsV2Input(bucket: "my-bucket")
for try await page in client.listObjectsV2Paginated(input: input) {
    for object in page.contents ?? [] {
        print(object.key ?? "")
    }
}

Presigned URLs

let url = try await client.presignedURLForGetObject(
    input: GetObjectInput(bucket: "my-bucket", key: "file.pdf"),
    expiration: 3600
)

Common Operations

// Put object
_ = try await client.putObject(input: PutObjectInput(
    body: .data(data),
    bucket: "bucket",
    key: "key"
))
 
// Get object
let output = try await client.getObject(input: GetObjectInput(bucket: "bucket", key: "key"))
let data = try await output.body?.readData()
 
// List buckets
let response = try await client.listBuckets(input: ListBucketsInput())
for bucket in response.buckets ?? [] {
    print(bucket.name ?? "")
}