feat(collection): added alias management

README.md

@@ -105,6 +105,9 @@ Using a different client, or want STDIO/HTTP/Docker options? See the per-client
 | `add-fields` | Add fields to a collection schema (additive only; existing fields cannot be modified) |
 | `add-field-types` | Add field types — custom analyzers, `DenseVectorField` for semantic search, etc. |
 | `get-schema` | Retrieve schema information for a collection |
+| `list-aliases` | List all Solr aliases and the collections they point to |
+| `create-alias` | Create or update a Solr alias pointing to one or more collections |
+| `delete-alias` | Delete a Solr alias (underlying collections are not affected) |
 
 Every tool advertises MCP behavior hints (`readOnlyHint`, `destructiveHint`, `idempotentHint`) so clients can build sensible approval UX — `search` and the metadata tools are read-only, indexing is destructive but idempotent, schema modification is additive.
 

src/main/java/org/apache/solr/mcp/server/collection/AliasResult.java

@@ -0,0 +1,43 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.solr.mcp.server.collection;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import java.util.Date;
+import org.jspecify.annotations.Nullable;
+
+/**
+ * Result record for alias management operations.
+ *
+ * <p>
+ * Returned by {@link AliasService} methods to communicate the outcome of
+ * create, update, and delete operations on Solr aliases.
+ *
+ * @param aliasName
+ *            the alias that was operated on
+ * @param collections
+ *            the target collection(s) (null for delete operations)
+ * @param success
+ *            whether the operation completed successfully
+ * @param message
+ *            human-readable description of the outcome
+ * @param timestamp
+ *            when the operation was performed
+ */
+public record AliasResult(String aliasName, @Nullable String collections, boolean success, String message,
+		@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'") Date timestamp) {
+}

src/main/java/org/apache/solr/mcp/server/collection/AliasService.java

@@ -0,0 +1,215 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.solr.mcp.server.collection;
+
+import io.micrometer.observation.annotation.Observed;
+import java.io.IOException;
+import java.util.Date;
+import java.util.Map;
+import org.apache.solr.client.solrj.SolrClient;
+import org.apache.solr.client.solrj.SolrServerException;
+import org.apache.solr.client.solrj.request.CollectionAdminRequest;
+import org.apache.solr.client.solrj.response.CollectionAdminResponse;
+import org.springaicommunity.mcp.annotation.McpTool;
+import org.springaicommunity.mcp.annotation.McpToolParam;
+import org.springframework.security.access.prepost.PreAuthorize;
+import org.springframework.stereotype.Service;
+
+/**
+ * Spring Service providing Solr alias management capabilities for MCP clients.
+ *
+ * <p>
+ * Aliases are virtual collection names that point to one or more physical
+ * collections. They enable zero-downtime reindexing, blue-green deployments,
+ * and read/write separation by allowing applications to reference a stable name
+ * while the underlying collection is swapped transparently.
+ *
+ * <p>
+ * <strong>Core Capabilities:</strong>
+ *
+ * <ul>
+ * <li><strong>List Aliases</strong>: Discover all aliases and their target
+ * collections
+ * <li><strong>Create/Update Alias</strong>: Point an alias to one or more
+ * collections (creates if new, updates if existing)
+ * <li><strong>Delete Alias</strong>: Remove an alias without affecting the
+ * underlying collections
+ * </ul>
+ *
+ * @see CollectionAdminRequest
+ */
+@Service
+@Observed
+public class AliasService {
+
+	/**
+	 * Error message for blank alias name validation
+	 */
+	private static final String BLANK_ALIAS_NAME_ERROR = "Alias name must not be blank";
+
+	/**
+	 * Error message for blank collections validation
+	 */
+	private static final String BLANK_COLLECTIONS_ERROR = "Collections must not be blank";
+
+	/**
+	 * SolrJ client for communicating with Solr server
+	 */
+	private final SolrClient solrClient;
+
+	/**
+	 * Constructs a new AliasService with the required dependencies.
+	 *
+	 * @param solrClient
+	 *            the SolrJ client instance for communicating with Solr
+	 */
+	public AliasService(SolrClient solrClient) {
+		this.solrClient = solrClient;
+	}
+
+	/**
+	 * Lists all aliases defined in the Solr cluster.
+	 *
+	 * <p>
+	 * Returns a map where each key is an alias name and the corresponding value is
+	 * the comma-separated list of collection names that the alias points to.
+	 *
+	 * <p>
+	 * <strong>MCP Tool Usage:</strong>
+	 *
+	 * <p>
+	 * Invoked by AI clients with natural language requests like "list all aliases",
+	 * "what aliases exist?", or "show me alias mappings".
+	 *
+	 * @return a map of alias names to their target collection(s); never null
+	 *         (returns an empty map when no aliases are defined)
+	 * @throws SolrServerException
+	 *             if there are errors communicating with Solr
+	 * @throws IOException
+	 *             if there are I/O errors during communication
+	 */
+	@PreAuthorize("isAuthenticated()")
+	@McpTool(
+			name = "list-aliases",
+			annotations = @McpTool.McpAnnotations(readOnlyHint = true),
+			description = "List all Solr aliases and the collections they point to")
+	public Map<String, String> listAliases() throws SolrServerException, IOException {
+		CollectionAdminRequest.ListAliases request = new CollectionAdminRequest.ListAliases();
+		CollectionAdminResponse response = request.process(solrClient);
+		Map<String, String> aliases = response.getAliases();
+		return aliases != null ? aliases : Map.of();
+	}
+
+	/**
+	 * Creates or updates a Solr alias pointing to one or more collections.
+	 *
+	 * <p>
+	 * If the alias already exists, it is updated to point to the new collection(s).
+	 * This is the mechanism for zero-downtime collection swaps: reindex into a new
+	 * collection, then update the alias to point to it.
+	 *
+	 * <p>
+	 * <strong>MCP Tool Usage:</strong>
+	 *
+	 * <p>
+	 * Invoked with requests like "create an alias ORDERS pointing to ORDERS_V2" or
+	 * "swap the LIVE alias to PRODUCTS_V3".
+	 *
+	 * @param aliasName
+	 *            the name of the alias to create or update (must not be blank)
+	 * @param collections
+	 *            comma-separated list of target collection names (must not be
+	 *            blank)
+	 * @return result describing the outcome of the operation
+	 * @throws IllegalArgumentException
+	 *             if aliasName or collections is blank
+	 * @throws SolrServerException
+	 *             if Solr returns an error
+	 * @throws IOException
+	 *             if there are I/O errors during communication
+	 */
+	@PreAuthorize("isAuthenticated()")
+	@McpTool(
+			name = "create-alias",
+			annotations = @McpTool.McpAnnotations(idempotentHint = true),
+			description = "Create or update a Solr alias pointing to one or more collections. "
+					+ "If the alias already exists, it is updated to point to the new collection(s).")
+	public AliasResult createAlias(
+			@McpToolParam(description = "Name of the alias to create or update") String aliasName,
+			@McpToolParam(
+					description = "Comma-separated list of collection names the alias should point to") String collections)
+			throws SolrServerException, IOException {
+
+		if (aliasName == null || aliasName.isBlank()) {
+			throw new IllegalArgumentException(BLANK_ALIAS_NAME_ERROR);
+		}
+		if (collections == null || collections.isBlank()) {
+			throw new IllegalArgumentException(BLANK_COLLECTIONS_ERROR);
+		}
+
+		CollectionAdminRequest.CreateAlias request = CollectionAdminRequest.createAlias(aliasName, collections);
+		CollectionAdminResponse response = request.process(solrClient);
+		boolean success = response.getStatus() == 0;
+
+		return new AliasResult(aliasName, collections, success,
+				success ? "Alias created/updated successfully" : "Alias creation/update failed", new Date());
+	}
+
+	/**
+	 * Deletes an existing Solr alias.
+	 *
+	 * <p>
+	 * Removes the alias definition only — the underlying collection(s) are not
+	 * affected. After deletion, the alias name is no longer resolvable.
+	 *
+	 * <p>
+	 * <strong>MCP Tool Usage:</strong>
+	 *
+	 * <p>
+	 * Invoked with requests like "delete the stale alias ORDERS_TEST" or "remove
+	 * alias OLD_PRODUCTS".
+	 *
+	 * @param aliasName
+	 *            the name of the alias to delete (must not be blank)
+	 * @return result describing the outcome of the operation
+	 * @throws IllegalArgumentException
+	 *             if aliasName is blank
+	 * @throws SolrServerException
+	 *             if Solr returns an error
+	 * @throws IOException
+	 *             if there are I/O errors during communication
+	 */
+	@PreAuthorize("isAuthenticated()")
+	@McpTool(
+			name = "delete-alias",
+			annotations = @McpTool.McpAnnotations(destructiveHint = true),
+			description = "Delete a Solr alias. The underlying collection(s) are not affected.")
+	public AliasResult deleteAlias(@McpToolParam(description = "Name of the alias to delete") String aliasName)
+			throws SolrServerException, IOException {
+
+		if (aliasName == null || aliasName.isBlank()) {
+			throw new IllegalArgumentException(BLANK_ALIAS_NAME_ERROR);
+		}
+
+		CollectionAdminRequest.DeleteAlias request = CollectionAdminRequest.deleteAlias(aliasName);
+		CollectionAdminResponse response = request.process(solrClient);
+		boolean success = response.getStatus() == 0;
+
+		return new AliasResult(aliasName, null, success,
+				success ? "Alias deleted successfully" : "Alias deletion failed", new Date());
+	}
+}

src/main/java/org/apache/solr/mcp/server/config/SolrNativeHints.java

@@ -65,6 +65,7 @@ public SolrNativeHints() {
 	 * image.
 	 */
 	private static final List<String> MCP_RESPONSE_RECORDS = List.of(
+			"org.apache.solr.mcp.server.collection.AliasResult",
 			"org.apache.solr.mcp.server.collection.CollectionCreationResult",
 			"org.apache.solr.mcp.server.collection.SolrHealthStatus",
 			"org.apache.solr.mcp.server.collection.SolrMetrics", "org.apache.solr.mcp.server.collection.IndexStats",