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+# Base Image
+
+The base image provides reusable runtime dependencies for the Romexis Server image.
+
+Directory:
+
+```text
+romexis-base/
+```
+
+---
+
+## Responsibilities
+
+The base image provides:
+
+- Java 11 runtime
+- JavaFX/OpenJFX support
+- Microsoft SQL Server command-line tools
+- Firebird client libraries and tools
+- common OS packages
+- security updates
+
+---
+
+## Architecture-Specific Tags
+
+```text
+romexis-base-jre:11-amd64
+romexis-base-jre:11-arm64
+```
+
+The base image is architecture-specific because it contains native runtime packages.
+
+---
+
+## Firebird Tools
+
+For Firebird initialization, the Romexis container needs the Firebird CLI tools.
+
+The important tool is usually:
+
+```text
+isql-fb
+```
+
+not:
+
+```text
+isql
+```
+
+On Debian/Ubuntu, `isql` may refer to unixODBC. The Firebird initialization script should therefore default to:
+
+```bash
+ISQL="${ISQL:-isql-fb}"
+```
+
+Required packages are typically:
+
+```text
+firebird3.0-utils
+libfbclient2
+```
+
+Package names can differ depending on the base distribution.
+
+---
+
+## SQL Server Tools
+
+The MSSQL initialization script uses:
+
+```text
+/opt/mssql-tools18/bin/sqlcmd
+```
+
+This is required for:
+
+- waiting for SQL Server
+- creating the database
+- creating the Romexis database user
+- importing SQL scripts
+- updating Romexis data paths