S3 API Compatibility

This page documents S3 APIs supported by MinIO Object Storage. For reference documentation on any given API, see the corresponding documentation for Amazon S3.

Object APIs

• CopyObject
• DeleteObject
• DeleteObjects
  • Conditional DELETE: published Server 20260903 ignores If-Match. Server 20260916 supports nonempty If-Match on single DeleteObject (#145/#178), including addressed-version comparison. Batch DeleteObjects still ignores <Object><ETag> and provides no per-item conditional guard. See scope and limitations.
• DeleteObjectTagging
• GetObject
• GetObjectAttributes
• GetObjectTagging
• HeadObject
• ListObjects
• ListObjectsV2
• ListObjectVersions
• PutObject
• PutObjectTagging
• RestoreObject
• SelectObjectContent

Write commit errors

PR #232, targeting the next Server release after 20261015, returns HTTP 503 SlowDownWrite when staged xl.meta disappears at the final commit of PUT or multipart completion. Earlier code could report 400 IncompleteBody for PUT or 404 NoSuchKey for completion. Actual incomplete client uploads retain their existing error handling. This classification allows SDK retries; it does not restore lost staging data. See the source and release boundary.

Object Locking

• GetObjectRetention
• PutObjectRetention
• GetObjectLegalHold
• PutObjectLegalHold
• GetObjectLockConfiguration
• PutObjectLockConfiguration

Unsupported API Object Endpoints

GetObjectAcl
PutObjectAcl

Multipart Uploads

• AbortMultipartUpload
• CompleteMultipartUpload
• CreateMultipartUpload
• ListMultipartUploads
• ListParts
• UploadPart
• UploadPartCopy

Differences from S3 APIs for Multipart Uploads

• Published Server 20260903 treats a non-empty ListMultipartUploads prefix as an exact object name. An empty prefix uses node-local volatile state without complete pagination, marker or delimiter semantics.
• Server 20260916 adds persistent scanning as an opt-in strict mode while retaining legacy exact-key/cache behavior by default. Its historical upgrade contract still applies to those binaries.
• Unreleased #79 follow-up: persistent listing becomes the only path, with global prefix, delimiter and pagination semantics. The mode environment variable is ignored. Readable old uploads missing both identity fields are omitted without blocking new uploads; the old exact-key shortcut is removed. This historical-record omission is an explicit S3 compatibility exception. Metadata errors, insufficient coverage and resource limits still return errors. Preflight becomes diagnostic, and cancellation keeps its previous default read-quorum/best-effort behavior. Every page still scans storage; delayed creation writes can still restore an upload after cancellation. See the candidate contract, capacity and limits.
• The AbortIncompleteMultipartUpload lifecycle action is not supported with PutBucketLifecycle.

Bucket APIs

• CreateBucket
• DeleteBucket
• DeleteBucketEncryption
• DeleteBucketTagging
• GetBucketEncryption
• GetBucketLocation
• GetBucketTagging
• GetBucketVersioning
• HeadBucket
• ListBuckets
• ListDirectoryBuckets
• PutBucketEncryption
• PutBucketTagging
• PutBucketVersioning

Bucket Replication

• GetBucketReplication
• PutBucketReplication
• DeleteBucketReplication

Bucket Lifecycle

• GetBucketLifecycle
• GetBucketLifecycleConfiguration
• PutBucketLifecycle
• PutBucketLifecycleConfiguration
• DeleteBucketLifecycle

Bucket Notifications

• GetBucketNotification
• GetBucketNotificationConfiguration
• PutBucketNotification
• PutBucketNotificationConfiguration

Bucket Policies

• GetBucketPolicy
• GetBucketPolicyStatus
• PutBucketPolicy
• DeleteBucketPolicy
• GetBucketCors
• PutBucketCors
• DeleteBucketCors

Unsupported API Bucket Operations

GetBucketInventoryConfiguration
PutBucketInventoryConfiguration
DeleteBucketInventoryConfiguration
GetBucketMetricsConfiguration
PutBucketMetricsConfiguration
DeleteBucketMetricsConfiguration
PutBucketWebsite
GetBucketLogging
PutBucketLogging
PutBucketAccelerateConfiguration
DeleteBucketAccelerateConfiguration
PutBucketRequestPayment
DeleteBucketRequestPayment
PutBucketAcl
HeadBucketAcl
GetPublicAccessBlock
PutPublicAccessBlock
DeletePublicAccessBlock
GetBucketOwnershipControls
PutBucketOwnershipControls
DeleteBucketOwnershipControls
GetBucketIntelligentTieringConfiguration
PutBucketIntelligentTieringConfiguration
ListBucketIntelligentTieringConfigurations
DeleteBucketIntelligentTieringConfiguration
GetBucketAnalyticsConfiguration
PutBucketAnalyticsConfiguration
ListBucketAnalyticsConfigurations
DeleteBucketAnalyticsConfiguration
CreateSession

MinIO alternatives for unsupported Bucket resources

• For calls to BucketACL or ObjectACL operations, use Policies.
• BucketCORS operations are supported since RELEASE.2026-09-03T13-18-01Z. A bucket with its own CORS configuration is served only by that configuration; buckets without one use the server-wide MINIO_API_CORS_ALLOW_ORIGIN policy, which allows every origin by default.
• For calls to BucketWebsite operations, use caddy or nginx.
• For calls to BucketAnalytics, BucketMetrics, or BucketLogging operations, use Bucket Notifications.