--- title: Legacy Pre-3.0 Configuration description: Configuring Sync Gateway Pre-3.0 to provide secure cloud-to-edge synchronization of enterprise data using the standard, static, configuration file. pubDate: 2026-08-17T09:53:44.266Z antora: editUrl: https://github.com/couchbase/docs-sync-gateway/edit/release/3.3/modules/configuration/pages/configuration-properties-legacy.adoc xref: xref:3.3@sync-gateway:configuration:configuration-properties-legacy.adoc[] --- [Consult the llms.txt file for a full list of contents](/llms.txt) [View original HTML](/sync-gateway/3.3/configuration/configuration-properties-legacy.html) # Legacy Pre-3.0 Configuration > Configuring _Sync Gateway_ Pre-3.0 to provide secure cloud-to-edge synchronization of enterprise data using the standard, static, configuration file. Topic Group [Configuration Schema](configuration-properties-legacy.md)| [Javascript Functions](configuration-javascript-functions.md)| [Environment Variables](configuration-environment-variables.md)| [REST API](configuration-rest-api.md)| [Persistent Configuration](configuration-overview.md) > [!IMPORTANT] > Legacy Configuration > > You cannot use `collections` in Sync Gateway's legacy Pre-3.0 configuration method. For current configuration details, see: [Configuration Overview](configuration-overview.md) and-or [Bootstrap Configuration](configuration-schema-bootstrap.md). ## [](#introduction)Introduction This page describes Sync Gateway's legacy Pre-3.0 configuration method. It uses a centralized configuration file to hold all configuration settings in JSON form — see:[the schema](#lbl-schema) for the file contents. > [!IMPORTANT] > Persistent Configuration is enabled by default from 3.0. > > To continue using legacy Pre-3.0 configuration you should start sync gateway with [disable-persistent-config](#disable%5Fpersistent%5Fconfig) set `true` either in the configuration file or in [Command Line Options](../deploy/command-line-options.md). Many configuration settings can be changed using the [Admin REST API](../rest-api/rest-api-admin.md) **but these are not persisted beyond a Sync Gateway restart**. To make persistent changes you must edit the central Configuration Properties file — or switch to the 3.x persistent configuration — see: [Configuration Overview](configuration-overview.md) ## [](#lbl-format)File Format The Configuration Properties file defines sync gateway's runtime behavior. Its contents include, for example: * Details of the connected Couchbase databases * How replications are conducted * What security is to be used * What logging options are to be applied, and * Any customization of import filtering and synchronization. The majority of the configuration is achieved using standard JSON syntax — see [the schema](#lbl-schema) for more. > [!NOTE] > The `sync-gateway-config.json` file relies on the use of one _relaxed_ JSON feature; the use of back ticks (`` ` ``). Text between back ticks is treated as a string. It can span multiple lines and contain double-quotes. Those features make it ideal for the incorporation of inline JavaScript, which can be used to provision, for example, `sync` and `import_filter` functions. ## [](#lbl-running)Running Use the following command to run Sync Gateway with a configuration file: Run Sync Gateway ```bash sync_gateway -disable_persistent_config sync-gateway-config.json ``` See also — [Command Line Options](../deploy/command-line-options.md) ## [](#lbl-schema)Schema ## [](#lbl-example)Example ```json { "interface":":5984", "adminInterface":":5985", "logging": { "log_file_path": "/var/tmp/sglogs", "console": { "log_level": "debug", "log_keys": ["*"] }, "error": { "enabled": true, "rotation": { "max_size": 20, "max_age": 180 } }, "warn": { "enabled": true, "rotation": { "max_size": 20, "max_age": 90 } }, "info": { "enabled": false }, "debug": { "enabled": false } }, "databases": { "db1-local": { "import_docs": true, "bucket":"db1-local", "server": "couchbase://cb-server", "enable_shared_bucket_access":true, "delta_sync": { "enabled": true }, "import_filter": ` function(doc) { return true; } `, "username": "admin", "password": "password", "users":{ "admin": {"password": "password", "admin_channels": ["*"]}, "user1": {"password": "password", "admin_channels":["channel.user1"]} }, "num_index_replicas":0, "sgreplicate_enabled":false, "replications":{ "db1-rep-id1" : { "direction": "pushAndPull", "conflict_resolution_type":"custom", "custom_conflict_resolver":` function(conflict) { if ( (conflict.LocalDocument.type != null) && (conflict.RemoteDocument.type != null) && (conflict.LocalDocument.type == "usedefault")) { console.log("Will use default policy"); // Resolve using built-in policy return defaultPolicy(conflict); } else { // Merge local and remote docs var remoteDoc = conflict.RemoteDocument; console.log("full remoteDoc doc: "+JSON.stringify(remoteDoc)); var localDoc = conflict.LocalDocument; console.log("full localDoc doc: "+JSON.stringify(localDoc)); var mergedDoc = extend({}, localDoc, remoteDoc); delete mergedDoc._rev (1) console.log("full mergedDoc doc: "+JSON.stringify(mergedDoc)); // Resolve using this merged doc as the winner return mergedDoc; function extend(target) { var sources = [].slice.call(arguments, 1); sources.forEach(function (source) { for (var prop in source) { if (prop.indexOf('_') != 0) { (2) target[prop] = source[prop]; } } }); return target; } // end function extend() } // end if }` // end function() , // end custom_conflict_resolver "purge_on_removal":true, "remote": "http://user1:password@example.com:4984/db1-remote", "filter":"sync_gateway/bychannel", "query_params": { "channels":["channel.user1"] }, "enable_delta_sync": true, "batch_size" :1000, "continuous": true, "state": "running" } }, "sync": ` function sync(doc, oldDoc) { /* sanity check */ // check if document was removed from server or via SDK // In this case, just return if (isRemoved()) { return; } /* Routing */ // Add doc to the user's channel. channel("channel.user1"); // This is when document is removed via SDK or directly on server function isRemoved() { return( isDelete() && oldDoc == null); } function isDelete() { return (doc._deleted == true); } } ` }, "db2-local": { "import_docs": true, "bucket":"db2-local", "server": "couchbase://cb-server", "enable_shared_bucket_access":true, "delta_sync": { "enabled": true }, "import_filter": ` function(doc) { return true; } `, "username": "admin", "password": "password", "users":{ "admin": {"password": "password", "admin_channels": ["*"]}, "user1": {"password": "password", "admin_channels":["channel.user1"]} }, "num_index_replicas":0, "sgreplicate_enabled":true, "replications":{ "db2-rep-id1-pull" : { "direction": "pull", "purge_on_removal":true, "remote": "http://user1:password@example2.com:4984/db2-remote", "conflict_resolution_type":"remoteWins", "filter":"sync_gateway/bychannel", "query_params": { "channels":["channel.user1"] }, "enable_delta_sync": true, "batch_size" :1000, "continuous": true, "state": "stopped" } }, "sync": ` function sync(doc, oldDoc) { // . . . code as required ` } } } ``` --- ##### ## [](#related-content)Related Content ###### [](#-2) API Topics * [Public REST API](../rest-api/rest-api.md) * [Admin REST API](../rest-api/rest-api-admin.md) * [Metrics REST API](../rest-api/rest-api-metrics.md) ###### [](#-3) Reference * [Bootstrap](configuration-schema-bootstrap.md) * [Database](configuration-schema-database.md) * [Database Security](configuration-schema-db-security.md) * [Access Control](configuration-schema-access-control.md) * [Import Filter](configuration-schema-import-filter.md) * [Inter-Sync Gateway Replication](configuration-schema-isgr.md) * [Legacy Pre-3.0 Configuration](configuration-properties-legacy.md) ###### [](#-4) Community [Mobile Forum](https://forums.couchbase.com/c/mobile/14) | [Blog](https://blog.couchbase.com/) | [Blog (Mobile)](https://blog.couchbase.com/category/couchbase-mobile/?ref=blog-menu) | [Tutorials](https://docs.couchbase.com/tutorials/)