Linking MongoDB as a source

The MongoDB connector can link your MongoDB collections to PostHog.

To link MongoDB:

1. Go to the Data pipeline page and the sources tab in PostHog
2. Click New source and select MongoDB
3. Enter your MongoDB connection string. If your connection string doesn't include a database name, enter it in the optional Database name field.
4. Click Next, select the collections you want to sync, as well as the sync method, and then press Import

Tip: MongoDB Atlas SRV connection strings usually omit the database name (e.g., mongodb+srv://user:pass@cluster.mongodb.net/). If yours doesn't include one, fill in the Database name field. A database specified in the connection string (e.g., mongodb+srv://user:pass@cluster.mongodb.net/my_database) takes precedence over this field.

Once the syncs are complete, you can start using MongoDB data in PostHog.

Note: MongoDB data is unstructured so the returned columns are an _id field and a data column that contain the entire document contents. Data fields can be selected with dot notation (e.g. data.field1)

Configuration

Incremental and append-only syncing

MongoDB supports incremental and append-only sync methods. For a field to be available for these sync methods, it must:

1. Have an index — only indexed fields are eligible.
2. Be a supported type — the following BSON types work:
   • date or timestamp
   • int or long
   • double or decimal
   • objectId (only for the _id field)

PostHog infers field types from the first 10,000 documents in the collection, so fields with mixed types may resolve to an unsupported type.

Inbound IP addresses

We use a set of IP addresses to access your instance. To ensure this connector works, add these IPs to your inbound security rules: