Object Storage

Use CoreWeave's S3-compatible Object Storage for flexible and efficient data storage
Coreweave Object Storage is an S3-compatible storage system that allows data to be stored and retrieved in a flexible and efficient way.
CoreWeave's Object Storage features include:
Multi-region support
CoreWeave Object Storage also supports multiple regions, allowing you to utilize regionally optimized clusters for your needs.
Easy SDK integrations
Because Object Storage works over HTTP, any compatible S3 CLI tool or SDK integration may be used in tandem with Object Storage.
Simple setup
To get started with Object Storage, simply generate a key pair, download your credentials, and start managing your data!
Accelerated Object Storage offers a series of anycasted NVMe-backed storage caches that provide blazing fast download speeds. Best suited for data such as model weights and training data.

Get started

Currently, Object Storage is configured and accessed either by:
User CRDs
Use CoreWeave's Kubernetes Custom Resource Definitions (CRD) for Users to create a Custom Resource with the appropriate permissions.
Cloud UI
Use the CoreWeave Cloud UI to generate a config file, which is then manually passed to s3cmd to authenticate to Object Storage.

Using the Cloud UI and s3cmd

Using the CoreWeave Cloud UI, an Object Storage configuration file can be generated to authenticate to Object Storage using s3cmd. To access Object Storage using the CoreWeave Cloud UI, log in to your CoreWeave Cloud account, then navigate to the Object Storage page.
Screenshot of the Object Storage link on the side nav of the Cloud UI
The Object Storage link is located on the left-hand menu on the Cloud UI
To create a new token, click the button labelled Create a New Token. This will bring up the New Storage Token modal, which prompts you to assign a name, a default S3 region (which can be changed later), and an access level to the token.
Screenshot of the new storage token modal
The New Storage Token modal
Finally, clicking the Generate button generates the token's configuration file:
access_key = <redacted>
secret_key = <redacted>
# The region for the host_bucket and host_base must be the same.
host_base =
host_bucket = %(bucket)
check_ssl_certificate = True
check_ssl_hostname = True
This generated config file is used to authenticate to Object Storage by using the free s3cmd CLI tool.


After the s3cmd tool is installed, place the configuration file generated previously in the home directory with the filename .s3cfg (for example: /home/myuser/.s3cfg). The s3cmd tool looks for the config file at this path by default, but other filepaths may alternatively be passed directly to s3cmd using the -config= option.
Example s3cmd usage
Make a bucket
s3cmd mb s3://BUCKET
Remove a bucket
s3cmd rb s3://BUCKET
List the object inside a bucket
s3cmd ls [s3://BUCKET[/PREFIX]]
A list of all s3cmd commands may be found in the s3cmd official documentation.
When using AWS SDKs, the variable AWS_REGION is defined within the V4 signature headers. The object storage region for CoreWeave is named default.

Using Custom Resource Definitions (CRDs)

CoreWeave provides Kubernetes Custom Resource Definitions (CRDs) for programmatic and automated methods of generating access to Object Storage clusters.
In most cases, a single user can be used, but if you wish to have separate access credentials per system or user in your account, it is possible to generate multiple users who have read and write permissions granted, then lock down storage buckets further by using a full access user.

The user CRD

The user CRD generates access to the Object Storage clusters. Each user is given both an access key and a secret key, which are stored inside of a Kubernetes secret in your namespace. Each secret is associated with the user, and is deleted when the user is deleted.
Here is an example CRD for creating a user with the permission level full:
kind: User
name: user-name
namespace: your-namespace
owner: your-namespace
access: full # Possible options are: full, readwrite, read, or write

Storage classes

There are three designated storage classes for Object Storage formats, which correspond to regional Object Storage endpoints:
Storage class
Object Storage endpoint
Each endpoint represents an independent, exclusive object store. This means that objects stored in ORD1buckets are not accessible from the LAS1 region, and so on.
Users may use any regional Object Storage endpoint and create and use buckets as they wish, but each region comes with its own quota limit. The default quota limit is 30TB of data per region.
Should you require an increase in your quota limit, please contact support.

Server Side Encryption

Server Side Encryption is implemented according to AWS SSE-C standards.
CoreWeave supports Server Side Encryption via customer-provided encryption keys. The client passes an encryption key along with each request to read or write encrypted data. No modifications to your bucket need to be made to enable Server Side Encryption (SSE-C); simply specify the required encryption headers in your requests.
It is the client’s responsibility to manage all keys, and to remember which key is used to encrypt each object.

SSE with customer-provided keys (SSE-C)

The following headers are utilized to specify SSE-C customizations.
Use this header to specify the encryption algorithm. The header value must be AES256.
Use this header to provide the 256-bit, base64-encoded encryption key to encrypt or decrypt your data.
Use this header to provide the base64-encoded, 128-bit MD5 digest of the encryption key according to RFC 1321. This header is used for a message integrity check to ensure that the encryption key was transmitted without error or interference.

Server Side Encryption example

The following example demonstrates using an S3 tool to configure Server Side Encryption for Object Storage.
Because SSE with static keys is not supported by s3cmdat this time, the AWS CLI tool is used for this example. For a full explanation of the parameters used with the s3 tool in this example, review the AWS CLI s3 documentation.
First, run aws configure to set up access and to configure your Secret Keys.
$ aws configure
Separately, generate a key using your preferred method. In this case, we use OpenSSL to print a new key to the file sse.key.
$ openssl rand 32 > sse.key
The generated key must be 32 bytes in length.
Once the process of aws configure is complete and your new key has been configured for use, run the following s3 commands to upload a file with Server Side Encryption.
$ aws s3 --endpoint-url= \
cp your-file.txt s3://your-bucket/your-file.txt \
--sse-c-key=fileb://sse.key \
--sse-c AES256
Finally, to retrieve the file, pass the path of the encryption key used (sse-customer-key) to aws s3 to decrypt the file:
$ aws s3 --endpoint-url= \
cp s3://your-bucket/your-file.txt your-file.txt \
--sse-c-key=fileb://sse.key \
--sse-c AES256

Identity and Access Management (IAM) and access levels

When an initial key pair is created for Object Storage access, that key pair is given the permissions specified on creation in order to read, write, and modify policies of the buckets which it owns. Each key pair is considered an individual user for access, and can be used to provide granular access to applications or users.
Permission levels that may be granted are:
Permission level
CRD key
Gives access to only read from buckets you own and have created
Gives access to only write to buckets you own and have created
Grants access to both read and write to buckets you own and have created
Grant Write/Read access, as well as admin access to create buckets and apply policies to buckets

Access levels via Cloud UI

Alternatively, key pair permissions may be specified via the Cloud UI on the Object Storage page.
From the Object Storage page, the Access Level field displays the key's current access level. The access of a new Object Storage token is set during creation by selecting an access level from the Select an access level drop-down menu located at the bottom of the New Storage Token module.
Access levels are displayed on the Object Storage page
Screenshot: Access levels drop-down
Any access level may be chosen from this drop-down

IAM actions

Currently, CoreWeave Cloud supports the following IAM bucket policy actions:
Click to expand - Supported IAM Actions
  • s3:AbortMultipartUpload
  • s3:CreateBucket
  • s3:DeleteBucketPolicy
  • s3:DeleteBucket
  • s3:DeleteBucketWebsite
  • s3:DeleteObject
  • s3:DeleteObjectVersion
  • s3:DeleteReplicationConfiguration
  • s3:GetAccelerateConfiguration
  • s3:GetBucketACL
  • s3:GetBucketCORS
  • s3:GetBucketLocation
  • s3:GetBucketLogging
  • s3:GetBucketNotification
  • s3:GetBucketPolicy
  • s3:GetBucketRequestPayment
  • s3:GetBucketTagging
  • s3:GetBucketVersioning
  • s3:GetBucketWebsite
  • s3:GetLifecycleConfiguration
  • s3:GetObjectAcl
  • s3:GetObject
  • s3:GetObjectTorrent
  • s3:GetObjectVersionAcl
  • s3:GetObjectVersion
  • s3:GetObjectVersionTorrent
  • s3:GetReplicationConfiguration
  • s3:ListAllMyBuckets
  • s3:ListBucketMultipartUploads
  • s3:ListBucket
  • s3:ListBucketVersions
  • s3:ListMultipartUploadParts
  • s3:PutAccelerateConfiguration
  • s3:PutBucketAcl
  • s3:PutBucketCORS
  • s3:PutBucketLogging
  • s3:PutBucketNotification
  • s3:PutBucketPolicy
  • s3:PutBucketRequestPayment
  • s3:PutBucketTagging
  • s3:PutBucketVersioning
  • s3:PutBucketWebsite
  • s3:PutLifecycleConfiguration
  • s3:PutObjectAcl
  • s3:PutObject
  • s3:PutObjectVersionAcl
  • s3:PutReplicationConfiguration
  • s3:RestoreObject
CoreWeave Cloud does not yet support setting policies on users, groups, or roles. Currently, account owners need to grant access directly to individual users. Granting an account access to a bucket grants access to all users in that account.
For all requests, the condition keys CoreWeave currently supports are:
  • aws:CurrentTime
  • aws:EpochTime
  • aws:PrincipalType
  • aws:Referer
  • aws:SecureTransport
  • aws:SourceIpaws:UserAgent
  • aws:username
Certain S3 condition keys for bucket and object requests are also supported. In the following tables, <perm> may be replaced with
  • read
  • write/read-acp
  • or write-acp/full-control
for read, write/read, or full control access, respectively.

Supported S3 Bucket Operations

Condition Keys
s3:x-amz-acl, s3:x-amz-grant-<perm>
s3:x-amz-acl s3:x-amz-grant-<perm>

Supported S3 Object Operations

Condition Keys
s3:x-amz-acl and s3:x-amz-grant-<perm>
Use PUT and COPY to overwrite or preserve metadata in COPY requests, respectively
s3:x-amz-acl and s3-amz-grant-<perm>
s3:x-amz-acl and s3-amz-grant-<perm>

Bucket policies

Another access control mechanism is bucket policies, which are managed through standard S3 operations. A bucket policy may be set or deleted by using s3cmd, as shown below. In this example, a bucket policy is created to make the bucket downloads public:
$ cat > examplepol
"Version": "2012-10-17",
"Statement": [
"Effect": "Allow",
"Principal": "*",
"Action": "s3:GetObject",
"Resource": [
The policy is then applied using s3cmd setpolicy:
$ s3cmd setpolicy examplepol s3://happybucket
Once the policy is applied, the data in your bucket may be accessed without credentials, for example, by using curl:
$ curl -v
Finally, the policy is deleted using s3cmd delpolicy:
$ s3cmd delpolicy s3://happybucket
Bucket policies do not yet support string interpolation.

Accelerated Object Storage

CoreWeave also offers Accelerated Object Storage, a series of Anycasted NVMe-backed storage caches that provide blazing fast download speeds. Accelerated Object Storage is best suited for frequently accessed data that doesn't change often, such as model weights and training data.
One of the biggest advantages of Anycasted Object Storage Caches is that data can be pulled from across data center regions, then be cached in the data center in which your workloads are located.
For example, if your models are hosted in ORD1 (Chicago), but have a deployment scale to all regions (ORD1, LAS1, LGA1), your call to will be routed to a cache located closest to the workload - that is to say, if you are calling from LGA1, it will hit the cache in LGA1; if you are calling from LAS1, it will hit the cache in LAS1. This drastically reduces spin up times for workloads where scaling is a concern.
You do not need to change the endpoint for every region your application is deployed in - this is the beauty of it!
Use of CoreWeave's Accelerated Object Storage is available at no additional cost. To use Accelerated Object Storage, simply modify your Object Storage endpoint to one of the addresses that corresponds to your Data Center region.

s3cmd alternatives

There are a few alternative clients to s3cmd, one of which is s5cmd. s5cmd is an interface ideal for running highly parallelized operations. As benchmarks have shown, s5cmd performs very well for tasks that involve moving large numbers of files to and from buckets.
To use s5cmd with CoreWeave Object Storage, first create a file at ~/.aws/credentials that contains the following parameters:
aws_access_key_id=<Your object storage access key>
aws_secret_access_key=<Your object storage secret key>
To use s5cmd with CoreWeave Object Storage, the --endpoint-url option must be included during use to specify the CoreWeave Object Storage endpoint URL:
It may be helpful to define an alias so as to avoid providing the endpoint URL every time.
$ alias s5="s5cmd --endpoint-url"
Once the ~/.aws/credentials file above is in place, run s5cmd. The full command, without an alias, looks like:
$ s5cmd --endpoint-url= cp ./my-local-directory/* s3://my-bucket/my-prefix/
With extremely large filesystems ( >1 million files) s5cmd may exhibit unwanted behavior. In these cases, reducing concurrency using the --concurrency option, or selecting standard endpoints instead of accelerated endpoints, may help.


The current price for Object Storage is $0.03 per GB per month.