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

# AWS RDS

> Connect your RDS Postgres database to Ardent

Ardent is compatible with AWS RDS for PostgreSQL.

RDS needs a parameter-group change, a replication grant, and network access before Ardent can connect. Start with preflight so Ardent can tell you exactly what's missing before it stores credentials or creates a connector.

**Want Claude or Cursor to help?** Paste this prompt into your agent:

```
Check if my AWS RDS Postgres database is ready to connect to Ardent.
My connection string: [paste here]

Use Ardent preflight first:
ardent connector preflight postgresql '<connection-string>' --schemas public

Verify:
1. The endpoint is reachable from Ardent and the security group allows inbound Postgres traffic.
2. The URL points to the writable primary: SELECT pg_is_in_recovery(); must return false.
3. The DB parameter group has rds.logical_replication = 1 and the instance has been rebooted after the change.
4. The connecting role has GRANT rds_replication.
5. The Ardent preflight Grant script has been run for the schemas I want to replicate.
6. Tables selected for replication have a primary key, valid unique NOT NULL index, or REPLICA IDENTITY FULL.

After preflight passes, run:
ardent connector create postgresql '<connection-string>'
```

***

<Steps>
  <Step title="Enable logical replication">
    Create or modify a parameter group for your RDS Postgres major version and set:

    ```text theme={null}
    rds.logical_replication = 1
    ```

    Apply the parameter group to your RDS instance.

    <Warning>
      This requires a reboot before logical replication is actually enabled. Plan a maintenance window.
    </Warning>

    <Tip>
      Keep enough replication slots and WAL sender capacity for Ardent plus any existing replicas or CDC tools. Do not lower existing values that other replication consumers rely on.
    </Tip>
  </Step>

  <Step title="Allow network access">
    In the RDS console, open **Databases > your instance > Connectivity & security** and confirm the endpoint and port.

    Allow Ardent's egress IP to reach the instance on the Postgres port, usually `5432`. Ask your Ardent contact for the current egress IP if you do not already have it.

    If your RDS instance is private-only, use a BYOC environment and PrivateLink rather than opening public ingress.
  </Step>

  <Step title="Grant replication permissions">
    Connect as a role with `rds_superuser` privileges and grant the RDS replication role to the user Ardent will connect as:

    ```sql theme={null}
    GRANT rds_replication TO your_user;
    ```

    Ardent may also need per-database and per-schema grants for the schemas you want to replicate. Preflight generates the exact SQL.
  </Step>

  <Step title="Run preflight">
    Your RDS connection string looks like:

    ```text theme={null}
    postgresql://user:[YOUR-PASSWORD]@your-instance.region.rds.amazonaws.com:5432/mydb
    ```

    Run:

    ```bash theme={null}
    ardent connector preflight postgresql 'postgresql://user:[YOUR-PASSWORD]@your-instance.region.rds.amazonaws.com:5432/mydb' --schemas public
    ```

    Preflight checks reachability, credentials, source writability, logical replication, RDS replication permissions, table grants, and duplicate-source status without creating a connector or storing credentials.

    If preflight says the source is a read replica, use the writer endpoint instead. Ardent refuses read replicas because full-fidelity branching needs a source that can support logical replication and schema tracking.
  </Step>

  <Step title="Run the generated grant script if needed">
    If preflight reports missing table or schema grants, copy the **Grant script** section and run it in `psql` as a role allowed to grant those privileges.

    Then re-run preflight until it passes.
  </Step>

  <Step title="Connect your database">
    ```bash theme={null}
    ardent connector create postgresql 'postgresql://user:[YOUR-PASSWORD]@your-instance.region.rds.amazonaws.com:5432/mydb'
    ```

    Ardent stores encrypted credentials, discovers your schema, snapshots selected tables, and starts continuous replication. Initial setup time depends on data size, write rate, and network throughput.

    <Warning>
      Logical replication slots retain WAL while a consumer is behind. A very low WAL retention limit can invalidate the slot under heavy writes or long transactions, forcing a connector rebuild / resnapshot. Set retention with enough headroom and monitor long-running transactions.
    </Warning>
  </Step>

  <Step title="Create your first branch">
    When the connector is ready:

    ```bash theme={null}
    ardent branch create my-feature
    ```

    Done. You now have an isolated copy of your RDS database: schema, data, and all. The CLI returns a connection URL you can use anywhere.
  </Step>
</Steps>