# Custom Storage Integration

### 1. Supported storage type (requirements)

TransferChain S4 integrates only with S3 Object Storage (S3 API compatible) systems.

#### Supported examples

* AWS S3
* MinIO (on-prem or cloud)
* Ceph Object Gateway
* Wasabi, Backblaze B2 (S3 mode)
* Dell ECS, NetApp StorageGRID, Pure FlashBlade S3
* Any storage platform exposing a standard S3-compatible API

#### Not supported (by design)

* Block storage (EBS, iSCSI, SAN, LUN, etc.)
* File storage (NFS, SMB, CIFS, EFS, Windows shares, etc.)
* Local disk paths or mounted filesystem

Note:\
TransferChain S4 relies on object storage semantics such as PUT, GET, HEAD, multipart uploads, object keys and bucket level namespace.

### 2. Required client inputs

#### 2.1. Storage endpoint

The client must provide:

* S3 API endpoint\
  Generic format:\
  https\://\<your-s3-endpoint>\
  \
  Examples:
* MinIO → <https://minio.company.com>
* Ceph → <https://s3.company.local>
* AWS → <https://s3.\\><region>.amazonaws.com (example only)
* Region or region-equivalent identifier\
  Some providers require a region value for request signing. If not applicable, it can be left empty.

#### 2.2. Bucket detail

Provide:

* Bucket name
* Bucket region / zone (if applicable)
* Optional prefix / base path\
  Example: transferchain/production/

#### 2.3. Access credentials (required)

The client must provide static credentials for the target bucket.

* Access Key ID
* Secret Access Key

Credentials must be scoped using least-privilege permissions to the designated bucket and prefix.

#### 2.4. Authentication and connectivity constraints

Provide:

* Outbound allowlist / egress requirements (if firewall restricted)
* Proxy configuration (if applicable):
  * Proxy URL
  * Authentication method
  * TLS interception details and CA chain
  * DNS requirements&#x20;

#### 2.5. Required permissions

Credentials must be scoped to the target bucket and prefix.

**Object-level (prefix-scoped)**

* PutObject
* GetObject
* DeleteObject
* HeadObject
* AbortMultipartUpload

### 3. Storage-side configuration prerequisites (recommended)

#### 3.1. TLS / HTTPS

* Endpoint must support HTTPS with valid certificates
* If TLS interception is used, CA chain must be shared and must not break S3 request signing

#### 3.2. Multipart upload support

* Storage must support multipart uploads for large objects
* Client should confirm provider limits:<br>
* Minimum part size
* Maximum part count
* Maximum object size<br>

If you need any more assistance please contact <support@transferchain.io>

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