> ## 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.

# Delta Lake (S3)

> How to configure Delta Lake on AWS S3 as a destination in Mage to write data to a Delta table using S3 URIs.

## Configuration Parameters

To use **Delta Lake on AWS S3** as a destination in Mage, provide the following parameters:

| Key                     | Description                                                                                                                                            | Example Value                              | Required |
| ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------ | -------- |
| `aws_access_key_id`     | Your AWS access key ID. Required to authenticate with S3.                                                                                              | `AKIAIOSFODNN7EXAMPLE`                     | ✅        |
| `aws_secret_access_key` | Your AWS secret access key. Used for writing to the S3 bucket.                                                                                         | `wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY` | ✅        |
| `aws_region`            | AWS region where your S3 bucket is located.                                                                                                            | `us-west-2` *(default)*                    | ✅        |
| `bucket`                | Name of the S3 bucket where the Delta table is stored.                                                                                                 | `mage-spark-data`                          | ✅        |
| `table`                 | Logical name of the Delta table that Mage will write to.                                                                                               | `dim_profiles_v1`                          | ✅        |
| `mode`                  | Write mode: <br />- `append`: Adds rows to the table. Fails if schema changes.<br />- `overwrite`: Replaces all existing rows and recreates the table. | `append` (default) or `overwrite`          | ✅        |
| `object_key_path`       | Path inside the S3 bucket where the Delta table is written. Exclude `s3://`, bucket name, and table name from this path.                               | `users/ds/20250708`                        | ✅        |

***

## Notes

* The object key path is relative to the S3 bucket and should not include the scheme (`s3://`), bucket name, or table name.
* Mage uses the [delta-rs](https://delta-io.github.io/delta-rs/python/usage.html) engine for writing data to Delta Lake on S3.
* Use `overwrite` mode with caution: it deletes all existing rows and recreates the table.

***

## Related Resources

* [Delta Lake Python API (`delta-rs`)](https://delta-io.github.io/delta-rs/python/usage.html)
* [Delta Lake Overview](https://delta.io/)
* [Working with S3 Buckets](https://docs.aws.amazon.com/AmazonS3/latest/userguide/UsingBucket.html)