ClickHouse

How to start

1. Run the command in your terminal, in the project where you want it.
2. Set CLICKHOUSE_HOST, CLICKHOUSE_USER with --env or in your shell.
3. Check it: run /mcp in Claude Code and look for it in the list.

What it needs

• CLICKHOUSE_HOSTRequired. Hostname of the ClickHouse server
• CLICKHOUSE_USERRequired. Username for ClickHouse authentication
• CLICKHOUSE_PASSWORDOptional. Secret: keep it out of your repo. Password for ClickHouse authentication. Required unless a client certificate uses the default or mutual TLS mode
• CLICKHOUSE_PORTOptional. ClickHouse HTTP(S) port. Defaults to 8443 when CLICKHOUSE_SECURE=true, 8123 otherwise
• CLICKHOUSE_SECUREOptional. Use HTTPS to connect to ClickHouse
• CLICKHOUSE_VERIFYOptional. Verify SSL certificates
• CLICKHOUSE_CA_CERTOptional. Path to a PEM CA bundle for ClickHouse server certificate verification
• CLICKHOUSE_CLIENT_CERTOptional. Path to a PEM client certificate for the ClickHouse HTTPS connection
• CLICKHOUSE_CLIENT_CERT_KEYOptional. Path to the PEM private key for CLICKHOUSE_CLIENT_CERT
• CLICKHOUSE_TLS_MODEOptional. Client certificate mode: mutual, proxy, or strict
• CLICKHOUSE_DATABASEOptional. Default database to use
• CLICKHOUSE_ROLEOptional. ClickHouse role to activate for the session
• CLICKHOUSE_ALLOW_WRITE_ACCESSOptional. Allow write operations (DDL and DML). Queries run read-only by default
• CLICKHOUSE_ALLOW_DROPOptional. Allow destructive operations (DROP, TRUNCATE, DELETE, UPDATE, REPLACE, CLEAR, and DETACH PERMANENTLY) when write access is also enabled
• CLICKHOUSE_MCP_QUERY_TIMEOUTOptional. Query tool timeout in seconds
• CLICKHOUSE_MCP_MAX_WORKERSOptional. Maximum query worker thread pool size

Environment variables as listed in the server's MCP Registry entry.