method

S3Client.list

list(

input?: null | S3ListObjectsOptions,

): Promise<S3ListObjectsResponse>;

Returns some or all (up to 1,000) of the objects in a bucket with each request.

Use the request parameters as selection criteria to return a subset of the objects in a bucket.

@param input

Options for listing objects in the bucket

@param options

Additional S3 options to override defaults

@returns

A promise that resolves to the list response

// List (up to) 1000 objects in the bucket
const allObjects = await bucket.list();

// List (up to) 500 objects under `uploads/` prefix, with owner field for each object
const uploads = await bucket.list({
  prefix: 'uploads/',
  maxKeys: 500,
  fetchOwner: true,
});

// Check if more results are available
if (uploads.isTruncated) {
  // List next batch of objects under `uploads/` prefix
  const moreUploads = await bucket.list({
    prefix: 'uploads/',
    maxKeys: 500,
    startAfter: uploads.contents!.at(-1).key,
    fetchOwner: true,
  });
}

Referenced types

interface S3ListObjectsOptions

continuationToken?: string
Indicates that the listing is being continued on this bucket with a token from a previous response. The token is obfuscated and is not a real key. Use it to paginate the list results.
delimiter?: string
A delimiter is a character that you use to group keys.
encodingType?: 'url'
Encoding type used by S3 to encode the object keys in the response. Responses are encoded only in UTF-8. An object key can contain any Unicode character, but the XML 1.0 parser can't parse some characters, such as those with an ASCII value from 0 to 10. For those keys, set this parameter to ask S3 to encode the keys in the response.
fetchOwner?: boolean
Set to true to include the owner field with each key in the result.
maxKeys?: number
The maximum number of keys returned in the response. By default, the action returns up to 1,000 key names. The response might contain fewer keys but never contains more.
prefix?: string
Limits the response to keys that begin with the specified prefix.
startAfter?: string
S3 starts listing after this key. It can be any key in the bucket.

interface S3Options

Configuration options for S3 operations

accessKeyId?: string
The access key ID for authentication. Defaults to S3_ACCESS_KEY_ID or AWS_ACCESS_KEY_ID environment variables.
acl?: 'private' | 'public-read' | 'public-read-write' | 'aws-exec-read' | 'authenticated-read' | 'bucket-owner-read' | 'bucket-owner-full-control' | 'log-delivery-write'
The Access Control List (ACL) policy for the file. Controls who can access the file and what permissions they have.
// Setting public read access const file = s3.file("public-file.txt", { acl: "public-read", bucket: "my-bucket" });

bucket?: string

The S3 bucket name. Defaults to S3_BUCKET or AWS_BUCKET environment variables.

// Using explicit bucket
const file = s3.file("my-file.txt", { bucket: "my-bucket" });

contentDisposition?: string

The Content-Disposition header value. Controls how the file is presented when downloaded.

// Setting attachment disposition with filename
const file = s3.file("report.pdf", {
  contentDisposition: "attachment; filename=\"quarterly-report.pdf\""
});

contentEncoding?: string
The Content-Encoding header value. Specifies what content encodings have been applied to the object, for example to indicate that it has been compressed.
// Setting gzip encoding const file = s3.file("data.json.gz", { contentEncoding: "gzip" });
endings?: EndingType
endpoint?: string
The S3-compatible service endpoint URL. Defaults to S3_ENDPOINT or AWS_ENDPOINT environment variables.
// AWS S3 const file = s3.file("my-file.txt", { endpoint: "https://s3.us-east-1.amazonaws.com" });

partSize?: number

The size of each part in multipart uploads (in bytes).

Minimum: 5 MiB
Maximum: 5120 MiB
Default: 5 MiB

// Configuring multipart uploads
const file = s3.file("large-file.dat", {
  partSize: 10 * 1024 * 1024, // 10 MiB parts
  queueSize: 4  // Upload 4 parts in parallel
});

const writer = file.writer();
// ... write large file in chunks

queueSize?: number
Number of parts to upload in parallel for multipart uploads.
Default: 5
Maximum: 255
Increasing this value can improve upload speeds for large files but uses more memory.

region?: string

The AWS region. Defaults to S3_REGION or AWS_REGION environment variables.

const file = s3.file("my-file.txt", {
  bucket: "my-bucket",
  region: "us-west-2"
});

requestPayer?: boolean

When set to true, confirms that the requester knows they will be charged for the request and data transfer costs. Required for accessing objects in Requester Pays buckets.

// Accessing a file in a Requester Pays bucket
const file = s3.file("data.csv", {
  bucket: "requester-pays-bucket",
  requestPayer: true
});
const content = await file.text();

retry?: number

Number of retry attempts for failed uploads.

Default: 3
Maximum: 255

// Setting retry attempts
const file = s3.file("my-file.txt", {
  retry: 5 // Retry failed uploads up to 5 times
});

secretAccessKey?: string
The secret access key for authentication. Defaults to S3_SECRET_ACCESS_KEY or AWS_SECRET_ACCESS_KEY environment variables.

sessionToken?: string

Optional session token for temporary credentials. Defaults to S3_SESSION_TOKEN or AWS_SESSION_TOKEN environment variables.

// Using temporary credentials
const file = s3.file("my-file.txt", {
  accessKeyId: tempAccessKey,
  secretAccessKey: tempSecretKey,
  sessionToken: tempSessionToken
});

storageClass?: 'STANDARD' | 'DEEP_ARCHIVE' | 'EXPRESS_ONEZONE' | 'GLACIER' | 'GLACIER_IR' | 'INTELLIGENT_TIERING' | 'ONEZONE_IA' | 'OUTPOSTS' | 'REDUCED_REDUNDANCY' | 'SNOW' | 'STANDARD_IA'
The storage class for the object. By default, Amazon S3 stores newly created objects in the STANDARD storage class.
// Setting an explicit storage class const file = s3.file("my-file.json", { storageClass: "STANDARD_IA" });

type?: string

The Content-Type of the file. Automatically set based on file extension when possible.

// Setting explicit content type
const file = s3.file("data.bin", {
  type: "application/octet-stream"
});

virtualHostedStyle?: boolean
Use a virtual hosted-style endpoint, where the bucket name is part of the hostname. Defaults to false. When true, if endpoint is provided, the bucket option is ignored.
// Using virtual hosted style const file = s3.file("my-file.txt", { virtualHostedStyle: true, endpoint: "https://my-bucket.s3.us-east-1.amazonaws.com" });

interface S3ListObjectsResponse

commonPrefixes?: { prefix: string }[]
Keys that share the same prefix, grouped together (up to 1,000). When counting the total number of returns by this API operation, each group counts as one item.
A response can contain CommonPrefixes only if you specify a delimiter.
CommonPrefixes contains all (if there are any) keys between Prefix and the next occurrence of the string specified by a delimiter. These keys act like subdirectories in the directory specified by Prefix.
For example, if the prefix is notes/ and the delimiter is a slash (/) as in notes/summer/july, the common prefix is notes/summer/. All of the keys that roll up into a common prefix count as a single return when calculating the number of returns.
contents?: { checksumAlgorithm: 'CRC32' | 'CRC32C' | 'SHA1' | 'SHA256' | 'CRC64NVME'; checksumType: 'COMPOSITE' | 'FULL_OBJECT'; eTag: string; key: string; lastModified: string; owner: { displayName: string; id: string }; restoreStatus: { isRestoreInProgress: boolean; restoreExpiryDate: string }; size: number; storageClass: 'STANDARD' | 'DEEP_ARCHIVE' | 'EXPRESS_ONEZONE' | 'GLACIER' | 'GLACIER_IR' | 'INTELLIGENT_TIERING' | 'ONEZONE_IA' | 'OUTPOSTS' | 'REDUCED_REDUNDANCY' | 'SNOW' | 'STANDARD_IA' }[]
Metadata about each object returned.
continuationToken?: string
If ContinuationToken was sent with the request, it is included in the response. You can use the returned ContinuationToken for pagination of the list response.
delimiter?: string
Causes keys that contain the same string between the prefix and the first occurrence of the delimiter to be rolled up into a single result element in the CommonPrefixes collection. These rolled-up keys are not returned elsewhere in the response. Each rolled-up result counts as only one return against the MaxKeys value.
encodingType?: 'url'
Encoding type used by S3 to encode object key names in the XML response.
isTruncated?: boolean
Set to false if all of the results were returned. Set to true if more keys are available to return. If the number of results exceeds that specified by MaxKeys, all of the results might not be returned.
keyCount?: number
The number of keys returned with this request. KeyCount is always less than or equal to the MaxKeys field.
maxKeys?: number
The maximum number of keys returned in the response. By default, the action returns up to 1,000 key names. The response might contain fewer keys but never contains more.
name?: string
The bucket name.
nextContinuationToken?: string
NextContinuationToken is sent when isTruncated is true, which means there are more keys in the bucket that can be listed. Continue the next list request to S3 with this NextContinuationToken. NextContinuationToken is obfuscated and is not a real key.
prefix?: string
Keys that begin with the indicated prefix.
startAfter?: string
If StartAfter was sent with the request, it is included in the response.