> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mage.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Amazon S3

> How to configure Amazon S3 as a destination in Mage to write data to your S3 bucket in CSV or Parquet format.

Configure **Amazon S3** as a Mage destination to write data files in CSV or Parquet format directly into your AWS S3 bucket.

***

## Configuration Parameters

The following parameters are required to set up Amazon S3 as a destination:

| Key                     | Description                                                                                                                       | Example Value                           | Required |
| ----------------------- | --------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------- | -------- |
| `aws_access_key_id`     | Your AWS access key ID.                                                                                                           | `AKIA...`                               | ✅        |
| `aws_secret_access_key` | Your AWS secret access key.                                                                                                       | `xyz456...`                             | ✅        |
| `aws_region`            | AWS region where your S3 bucket is located.                                                                                       | `us-west-2`                             | ✅        |
| `role_arn`              | (Optional) ARN of an IAM role to assume for access. Useful for temporary or cross-account access.                                 | `arn:aws:iam::111111:role/example-role` | ❌        |
| `bucket`                | The name of the S3 bucket where data will be written.                                                                             | `user_generated_content`                | ✅        |
| `file_type`             | The file format to use when writing to S3. Supported values: `csv`, `parquet`.                                                    | `parquet`                               | ✅        |
| `object_key_path`       | The S3 object key prefix (path) to write files under. Do **not** include `s3://`, the bucket name, or table name in this path.    | `users/ds/20221225`                     | ✅        |
| `column_header_format`  | (Optional) Format for column headers. Will be applied before writing to S3. Options: `upper`, `lower`, or `null` (no formatting). | `lower`                                 | ❌        |
| `date_partition_format` | (Optional) Format for date-based partitioning in file paths. If null, partitioning is skipped. Examples: `%Y%m%d`, `%Y%m%dT%H`.   | `%Y%m%d`                                | ❌        |
| `aws_endpoint`          | (Optional) Custom endpoint URL for non-AWS S3-compatible services (e.g., MinIO).                                                  | `https://play.min.io`                   | ❌        |

***

## Credential Requirements

To use Amazon S3, you need an AWS IAM user or role with permissions to:

* Put objects (`s3:PutObject`)
* Create folders (`s3:PutObject`)
* Optionally assume roles (`sts:AssumeRole`) if `role_arn` is used

Ensure the credentials provided have appropriate access to the target bucket and path.

***

## FAQs

### Can I write to MinIO or other S3-compatible storage?

Yes. Set the `aws_endpoint` field to your custom endpoint URL (e.g., `https://play.min.io`). Ensure your credentials and permissions are configured accordingly.

### How are files named in S3?

Mage automatically handles file naming using table names and batch metadata. Your `object_key_path` acts as the prefix under which the files are written.

### What happens if I don’t set `date_partition_format`?

Files will be written directly into the specified path without date-based folder partitioning.

### What if both `role_arn` and access keys are set?

Mage will attempt to assume the IAM role using the provided access key credentials. This is helpful in cross-account setups or for short-lived access via STS.

***

## Related Resources

* [Amazon S3 Documentation](https://docs.aws.amazon.com/s3/)
* [IAM Policy Reference](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html)
* [MinIO Documentation](https://min.io/docs/minio/linux/index.html)