docs: Document Redis cluster-safe deletes

Author: danny-avila

content/docs/configuration/dotenv.mdx

@@ -2735,6 +2735,12 @@ For detailed configuration and examples, see: **[Redis Configuration Guide](/doc
       'Enable Redis cluster mode when using a single URI',
       '# USE_REDIS_CLUSTER="true"',
     ],
+    [
+      'REDIS_CLUSTER_SAFE_DELETE',
+      'boolean',
+      'Delete Redis cache keys individually to avoid CROSSSLOT errors on single-endpoint managed Redis services that shard keys internally.',
+      '# REDIS_CLUSTER_SAFE_DELETE=true',
+    ],
     [
       'REDIS_USERNAME',
       'string',
@@ -2796,6 +2802,7 @@ Notes:
 
 - When `USE_REDIS=true`, you must provide `REDIS_URI` or the application will throw an error.
 - For Redis Cluster mode, provide multiple URIs: `redis://node1:7001,redis://node2:7002,redis://node3:7003` (cluster mode is auto-detected).
+- For single-endpoint managed Redis services that shard keys internally, keep `USE_REDIS_CLUSTER=false` and set `REDIS_CLUSTER_SAFE_DELETE=true` if cache clears fail with `CROSSSLOT` errors.
 - Use `rediss://` protocol for TLS connections and set `REDIS_CA` if your CA is not publicly trusted.
 - `REDIS_KEY_PREFIX_VAR` and `REDIS_KEY_PREFIX` are mutually exclusive.
 - **AWS Elasticache with TLS**: Elasticache may need to use an alternate dnsLookup for TLS connections. Set `REDIS_USE_ALTERNATIVE_DNS_LOOKUP=true` if using Elasticache with TLS. See [ioredis documentation](https://www.npmjs.com/package/ioredis) for more details.

content/docs/configuration/redis.mdx

@@ -61,6 +61,21 @@ REDIS_URI=redis://127.0.0.1:7001
 USE_REDIS_CLUSTER=true
 ```
 
+### Single-Endpoint Managed Redis Services
+
+Some managed Redis services, including AWS ElastiCache Serverless and Redis Enterprise Cloud on AWS, expose a single connection endpoint while sharding keys internally. In that setup, keep LibreChat in single-node connection mode, but enable cluster-safe deletes if cache clears fail with `CROSSSLOT Keys in request don't hash to the same slot`.
+
+```bash
+USE_REDIS=true
+REDIS_URI=rediss://your-managed-redis-endpoint:6379
+USE_REDIS_CLUSTER=false
+REDIS_CLUSTER_SAFE_DELETE=true
+```
+
+`REDIS_CLUSTER_SAFE_DELETE=true` makes LibreChat delete matching cache keys one at a time instead of sending multi-key `DEL` commands. This avoids `CROSSSLOT` errors without changing how LibreChat connects to Redis.
+
+Use `USE_REDIS_CLUSTER=true` only when LibreChat should create a Redis Cluster client. For single-endpoint managed services, `REDIS_CLUSTER_SAFE_DELETE=true` is the safer option.
+
 ### Redis with TLS/SSL
 
 For secure Redis connections:
@@ -104,9 +119,10 @@ REDIS_URI=rediss://your-redis-host:6380
 # Provide CA certificate for verification
 REDIS_CA=/path/to/your/ca-certificate.pem
 ```
+
 ### TLS with Elasticache
 
-Elasticache may need to use an alternate dnsLookup for TLS connections.  see "Special Note: Aws Elasticache Clusters with TLS" on this webpage: https://www.npmjs.com/package/ioredis
+Elasticache may need to use an alternate dnsLookup for TLS connections. see "Special Note: Aws Elasticache Clusters with TLS" on this webpage: https://www.npmjs.com/package/ioredis
 
 ```bash
 # Enable redis alternate dnsLookup
@@ -153,11 +169,13 @@ REDIS_KEY_PREFIX=dev-john-local
 **Important**: You cannot set both `REDIS_KEY_PREFIX_VAR` and `REDIS_KEY_PREFIX` simultaneously.
 
 **Examples of contamination without prefixing**:
+
 - Production cache overwritten by staging deployment
 - Feature branch tests corrupting main branch cache
 - Old deployment versions serving stale cached data
 
 **Key prefixing format**:
+
 - IoRedis client: `{prefix}::{key}`
 - Keyv client: Handled by the store layer
 
@@ -183,6 +201,7 @@ REDIS_PING_INTERVAL=300
 ```
 
 **Important**:
+
 - Setting `REDIS_PING_INTERVAL=0` or omitting it disables pinging entirely
 - Only set a positive value (in seconds) if you experience connection timeout issues
 - The interval is specified in seconds and applies to both IoRedis and Keyv Redis clients
@@ -199,40 +218,42 @@ FORCED_IN_MEMORY_CACHE_NAMESPACES=ROLES,MESSAGES
 
 Valid cache keys (from the `CacheKeys` enum in `librechat-data-provider`):
 
-| Key | Description |
-|---|---|
-| `CONFIG_STORE` | Configuration store |
-| `ROLES` | User roles |
-| `PLUGINS` | Plugins data |
-| `GEN_TITLE` | Generated titles |
-| `TOOLS` | Tools data |
-| `MODELS_CONFIG` | Models configuration |
-| `MODEL_QUERIES` | Model queries |
-| `STARTUP_CONFIG` | Startup configuration |
-| `ENDPOINT_CONFIG` | Endpoint configuration |
-| `TOKEN_CONFIG` | Token configuration |
-| `APP_CONFIG` | Application configuration |
-| `ABORT_KEYS` | Abort keys |
-| `BANS` | Ban data |
-| `ENCODED_DOMAINS` | Encoded domains |
-| `AUDIO_RUNS` | Audio processing runs |
-| `MESSAGES` | Messages |
-| `FLOWS` | Flows data |
-| `PENDING_REQ` | Pending requests |
-| `S3_EXPIRY_INTERVAL` | S3 expiry intervals |
-| `OPENID_EXCHANGED_TOKENS` | OpenID exchanged tokens |
-| `OPENID_SESSION` | OpenID sessions |
-| `SAML_SESSION` | SAML sessions |
+| Key                       | Description               |
+| ------------------------- | ------------------------- |
+| `CONFIG_STORE`            | Configuration store       |
+| `ROLES`                   | User roles                |
+| `PLUGINS`                 | Plugins data              |
+| `GEN_TITLE`               | Generated titles          |
+| `TOOLS`                   | Tools data                |
+| `MODELS_CONFIG`           | Models configuration      |
+| `MODEL_QUERIES`           | Model queries             |
+| `STARTUP_CONFIG`          | Startup configuration     |
+| `ENDPOINT_CONFIG`         | Endpoint configuration    |
+| `TOKEN_CONFIG`            | Token configuration       |
+| `APP_CONFIG`              | Application configuration |
+| `ABORT_KEYS`              | Abort keys                |
+| `BANS`                    | Ban data                  |
+| `ENCODED_DOMAINS`         | Encoded domains           |
+| `AUDIO_RUNS`              | Audio processing runs     |
+| `MESSAGES`                | Messages                  |
+| `FLOWS`                   | Flows data                |
+| `PENDING_REQ`             | Pending requests          |
+| `S3_EXPIRY_INTERVAL`      | S3 expiry intervals       |
+| `OPENID_EXCHANGED_TOKENS` | OpenID exchanged tokens   |
+| `OPENID_SESSION`          | OpenID sessions           |
+| `SAML_SESSION`            | SAML sessions             |
 
 <Callout type="warn" title="Invalid keys">
-Using an invalid key (e.g., the deprecated `STATIC_CONFIG`) will cause a startup error. Only use keys from the table above.
+  Using an invalid key (e.g., the deprecated `STATIC_CONFIG`) will cause a startup error. Only use
+  keys from the table above.
 </Callout>
 
 ## Performance Tuning
 
 ### Connection Keep-Alive
 
 The application implements configurable connection keep-alive:
+
 - Ping intervals are controlled by `REDIS_PING_INTERVAL` environment variable
 - Default behavior: No pinging (recommended for most deployments)
 - When enabled, pings both IoRedis and Keyv Redis clients at the specified interval
@@ -241,6 +262,7 @@ The application implements configurable connection keep-alive:
 ### Cache Strategy
 
 The application uses a dual-client approach:
+
 - **IoRedis client**: Primary Redis operations with automatic prefixing
 - **Keyv Redis client**: Store-layer operations with prefix handling in `cacheFactory.js`
 
@@ -319,4 +341,4 @@ USE_REDIS_CLUSTER=true
 REDIS_URI=redis://node1:7001,redis://node2:7002,redis://node3:7003
 ```
 
-See [Resumable Streams](/docs/features/resumable_streams) for more details on this feature.
+See [Resumable Streams](/docs/features/resumable_streams) for more details on this feature.