> For the complete documentation index, see [llms.txt](https://docs.adiom.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.adiom.io/reference/connectors.md).

# Connectors

Reference documentation for dsync connectors.

Each page has an **Emitted Format** section that shows what the connector hands to Dsync as a source: the data type, the ID, a sample document, and the CDC events. Read it before writing a [data transformation](/enterprise/running-dsynct/data-transformations.md).

| Connector                                                   | Source | Destination       | Data type    | ID                                    | Fetch by ID |
| ----------------------------------------------------------- | ------ | ----------------- | ------------ | ------------------------------------- | ----------- |
| [Cosmos DB NoSQL](/reference/connectors/cosmos-db-nosql.md) | Yes    | Yes               | JSON         | Shard key parts, then `id`            | Yes         |
| [DynamoDB](/reference/connectors/dynamodb.md)               | Yes    | Initial sync only | BSON or JSON | Built from the partition and sort key | No          |
| [MongoDB](/reference/connectors/mongodb.md)                 | Yes    | Yes               | BSON         | `_id`                                 | Yes         |
| [PostgreSQL](/reference/connectors/postgresql.md)           | Yes    | Yes               | BSON         | `_id`, built from the primary key     | No          |
| [SQL Batch](/reference/connectors/sql-batch.md)             | Yes    | No                | JSON         | The key columns you configure         | No          |

"Fetch by ID" is required on the source for `testsync`, Verify IDs and the Sync Tester. For sources without it (DynamoDB, PostgreSQL, SQL Batch), test transforms in Transform Studio with sample documents, then with a sync into a test destination.