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# Linking Neo4j as a source

**Alpha release**

This source is currently in **alpha**. The interface and available tables may change.

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Let AI connect your sources for you

Skip the manual setup — run this in your project and the wizard auto-detects your databases and APIs and connects them to PostHog.

`npx @posthog/wizard warehouse`

![PostHog Wizard hedgehog](https://res.cloudinary.com/dmukukwp6/image/upload/wizard_3f8bb7a240.png)

![](https://res.cloudinary.com/dmukukwp6/image/upload/wizard_3f8bb7a240.png)Let AI connect your sources for you

The Neo4j connector syncs nodes and relationships from your Neo4j graph database into PostHog, so you can query graph data alongside your product data using SQL.

PostHog discovers every node label and relationship type in your database and creates a table for each one. Node tables are prefixed `node_` and relationship tables are prefixed `rel_`.

## Prerequisites

-   A Neo4j Aura instance, or a self-managed Neo4j 5.19+ deployment with a **public HTTPS endpoint**. Self-managed versions before 5.25 require the [Query API to be enabled](https://neo4j.com/docs/operations-manual/current/) explicitly.

-   A database user with **read access**. PostHog only reads data.

-   The database credentials (username and password) you received when you created the Aura instance, or equivalent credentials from your database administrator.

## Adding a data source

1.  In PostHog, go to the [Sources tab](https://app.posthog.com/data-management/sources) of the data pipeline section.
2.  Click **\+ New source** and click **Link** next to this source.
3.  Enter your credentials (see [Configuration](#configuration) below) and click **Next**.
4.  Select the tables you want to sync, choose a sync method and frequency, then click **Import**.

Once the syncs are complete, you can start querying this data in PostHog.

When linking Neo4j, you need:

-   **HTTPS host** – the public URL of your Neo4j instance, for example `https://your-instance.databases.neo4j.io`. Must be HTTPS with no path, query string, or embedded credentials.

-   **Database** – the name of the database to connect to, for example `neo4j`.

-   **Username** – your Neo4j username, typically `neo4j` on Aura instances.

-   **Password** – the password for the database user.

PostHog validates the host, authenticates with Basic auth, and discovers available tables automatically.

## Configuration

| Option | Type | Required |
| --- | --- | --- |
| `HTTPS host` | text | Yes |
| `Database` | text | Yes |
| `Username` | text | Yes |
| `Password` | password | Yes |

## Supported tables

The tables available from this source are discovered from your account when you connect it, so the exact list depends on your data. Once connected, you can pick which tables to sync from the [sources tab](https://app.posthog.com/data-management/sources).

### How tables are discovered

PostHog calls `db.labels()` and `db.relationshipTypes()` to discover every node label and relationship type in the connected database. Each label becomes a `node_<label>` table and each relationship type becomes a `rel_<type>` table.

### Node tables (`node_<label>`)

| Column | Description |
| --- | --- |
| `element_id` | The node identifier assigned by Neo4j. |
| `labels` | The labels attached to the node. |
| *property columns* | One column for each property found on the nodes. |

### Relationship tables (`rel_<type>`)

| Column | Description |
| --- | --- |
| `element_id` | The relationship identifier assigned by Neo4j. |
| `start_element_id` | The identifier of the start node. |
| `end_element_id` | The identifier of the end node. |
| *property columns* | One column for each property found on the relationships. |

### Sync behavior

-   **Full refresh only** – every sync re-downloads all rows. Incremental and append syncs aren't supported.

-   **Row limit** – each table is limited to 1,000,000 rows. If a table exceeds this limit, the import fails rather than silently truncating data.

-   **Unlabeled nodes** are excluded. Nodes with multiple labels appear in each corresponding `node_` table.

-   **Reserved column names** – if a node or relationship has a property named `element_id`, `labels`, `start_element_id`, or `end_element_id`, the import for that table fails. Rename the conflicting property in Neo4j before syncing.

-   **No durable resume** – if a sync is interrupted, it restarts from the beginning. Neo4j doesn't guarantee `elementId` identity across transactions, so there's no reliable checkpoint.

-   **Concurrent changes** – because paging uses `SKIP`/`LIMIT` ordering, concurrent writes to the graph can shift rows between pages during a sync.

## Troubleshooting

### Authentication failed

Check your database username and password. On Aura, use the credentials from when you created the instance. If the password has expired, reset it in the Neo4j console before reconnecting.

### Query API not found

Verify that:

1.  The **HTTPS host** is correct and publicly reachable.
2.  The **database name** matches an existing database.
3.  The Query API is enabled. Aura enables it by default. Self-managed deployments on versions before 5.25 may need to [enable it manually](https://neo4j.com/docs/operations-manual/current/).

### Row limit exceeded

The table contains more than 1,000,000 rows. Filter your graph data by using a more specific label or relationship type, or reduce the dataset before syncing.

### Property conflicts with a reserved column name

A property on your nodes or relationships uses one of the reserved column names (`element_id`, `labels`, `start_element_id`, or `end_element_id`). Rename the conflicting property in Neo4j and re-sync.

If your sync is failing or data looks wrong, see the [Data warehouse troubleshooting guide](/docs/data-warehouse/troubleshooting.md). If that doesn't help, [contact support](https://us.posthog.com/#panel=support%3Asupport%3Adata_warehouse%3A%3Atrue) – we're happy to help.

### Still have questions?

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