This quickstart guides you through creating, validating, and deploying your first userscript based on a cookbook example.
Before you begin
- Install MOLT Replicator v1.1.4 or later for full compatibility with the userscript API.
- Install a TypeScript-compatible IDE (for example, VS Code).
Step 1: Set up your environment
Create a new TypeScript file for your userscript in your IDE (for example, userscript.ts).
For IDE autocomplete and type-checking support, optionally add the Replicator TypeScript definitions. For details, refer to Access this API.
Step 2: Write a userscript
Use the userscript cookbook as a starting point. The cookbook provides ready-to-use examples that you can copy and adapt.
Copy and adapt a cookbook example that matches your use case. For example, adapt the template to filter a single table to exclude the audit_logs table from the public schema during replication:
import * as api from "replicator@v2";
const SCHEMA_NAME = "public";
const TABLE_TO_SKIP = "audit_logs";
api.configureTargetSchema(SCHEMA_NAME, {
onRowUpsert: (row, meta) => {
if (meta.table === TABLE_TO_SKIP) {
return null; // Skip this table
}
return row;
},
onRowDelete: (row, meta) => {
if (meta.table === TABLE_TO_SKIP) {
return null;
}
return row;
}
});
For details on the userscript API and handler functions, refer to the Userscript API.
When writing userscripts, follow the best practices.
Step 3: Use with Replicator
Include the --userscript flag to have MOLT Replicator apply the userscript. For example, to apply your userscript during PostgreSQL replication:
replicator pglogical \
--sourceConn $SOURCE \
--targetConn $TARGET \
--targetSchema defaultdb.public \
--slotName molt_slot \
--publicationName molt_fetch \
--stagingSchema defaultdb._replicator \
--stagingCreateSchema \
--userscript userscript.ts
