ClickHouse
Connect Datost to ClickHouse for event analytics and OLAP queries in Slack.
Datost connects to ClickHouse so your team can ask event, product, and OLAP questions in Slack and get answers backed by real columnar data. It's a good fit for high-volume event streams, product analytics tables, and ClickHouse Cloud clusters.
Prerequisites
Before connecting, gather the following from your ClickHouse cluster:
- Host — e.g.
your-cluster.clickhouse.cloudor an IP address - HTTP port —
8123for HTTP,8443for HTTPS (ClickHouse Cloud defaults to HTTPS on8443) - Protocol — HTTP or HTTPS
- Username — defaults to
default - Password
- Database (optional) — leave empty to expose all non-system databases
Connect in the admin panel
Open Data Sources
In the Datost web app, go to Settings → Data Sources and click Add data source.
Choose ClickHouse
Select ClickHouse from the provider grid.
Paste a connection URL or fill fields manually
Paste a ClickHouse Cloud curl command or connection URL to auto-fill host, port, protocol, username, and password — or enter them manually. Supported shapes include clickhouse://user:pass@host:port/db, bare https://host.clickhouse.cloud:8443, and the curl --user 'user:pass' https://host:port snippet from the ClickHouse Cloud connect dialog.
Whitelist the Datost egress IP
If your cluster restricts traffic, add the egress IP shown in the modal to your ClickHouse IP allowlist.
Test and save
Click Test connection. Datost runs SELECT version() to confirm reachability and returns the server version. Save to finish.
Permissions required
The connecting user needs:
SELECTon the databases and tables you want Datost to query.SELECTonsystem.tablesandsystem.columnsfor schema introspection (used for table listing and column metadata).
Read-only users work well. Datost does not issue writes during normal operation.
Limitations
- HTTP only. The native TCP protocol isn't supported — use the HTTP/HTTPS interface (ports
8123/8443). - Client caching. Datost caches up to 50 ClickHouse clients per process with a 30-minute idle TTL; connections refresh automatically when credentials change.
- Statement termination. Trailing semicolons are stripped before the query is sent.
- Views vs. tables. Engines containing
Vieware surfaced as views; everything else is treated as a table.
Troubleshooting
- Connection test fails with a network error — verify the port matches your protocol (
8123for HTTP,8443for HTTPS) and that the Datost egress IP is whitelisted. - Authentication error — confirm the username (ClickHouse Cloud defaults to
default) and that the password has no leading/trailing whitespace from the paste. - Missing tables — check that the user has
SELECTonsystem.tablesandsystem.columns, and that you didn't scope the connection to a database that doesn't contain them.