diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
index 766cb2db7b2a9e..9b4512f40ee2ca 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
@@ -14,6 +14,7 @@
 
 package com.google.devtools.build.lib.analysis;
 
+
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Supplier;
@@ -197,6 +198,7 @@ public AnalysisResult update(
       Set<String> multiCpu,
       ImmutableSet<String> explicitTargetPatterns,
       List<String> aspects,
+      ImmutableMap<String, String> aspectsParameters,
       AnalysisOptions viewOptions,
       boolean keepGoing,
       boolean checkForActionConflicts,
@@ -348,7 +350,7 @@ public AnalysisResult update(
       if (!aspectClasses.isEmpty()) {
         aspectsKeys.add(
             AspectKeyCreator.createTopLevelAspectsKey(
-                aspectClasses, targetSpec.getLabel(), configuration));
+                aspectClasses, targetSpec.getLabel(), configuration, aspectsParameters));
       }
     }
 
diff --git a/src/main/java/com/google/devtools/build/lib/buildtool/AnalysisAndExecutionPhaseRunner.java b/src/main/java/com/google/devtools/build/lib/buildtool/AnalysisAndExecutionPhaseRunner.java
index 7cd92bf88468b9..c812f2380e32fc 100644
--- a/src/main/java/com/google/devtools/build/lib/buildtool/AnalysisAndExecutionPhaseRunner.java
+++ b/src/main/java/com/google/devtools/build/lib/buildtool/AnalysisAndExecutionPhaseRunner.java
@@ -186,6 +186,7 @@ private static AnalysisAndExecutionResult runAnalysisAndExecutionPhase(
                 multiCpu,
                 explicitTargetPatterns,
                 request.getAspects(),
+                request.getAspectsParameters(),
                 request.getViewOptions(),
                 request.getKeepGoing(),
                 request.getCheckForActionConflicts(),
diff --git a/src/main/java/com/google/devtools/build/lib/buildtool/AnalysisPhaseRunner.java b/src/main/java/com/google/devtools/build/lib/buildtool/AnalysisPhaseRunner.java
index 612494440fc96c..985e8d49b12ec0 100644
--- a/src/main/java/com/google/devtools/build/lib/buildtool/AnalysisPhaseRunner.java
+++ b/src/main/java/com/google/devtools/build/lib/buildtool/AnalysisPhaseRunner.java
@@ -220,6 +220,7 @@ private static AnalysisResult runAnalysisPhase(
             multiCpu,
             explicitTargetPatterns,
             request.getAspects(),
+            request.getAspectsParameters(),
             request.getViewOptions(),
             request.getKeepGoing(),
             request.getCheckForActionConflicts(),
diff --git a/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequest.java b/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequest.java
index 6f99524d7881ea..497b68c3b9ee0a 100644
--- a/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequest.java
+++ b/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequest.java
@@ -13,15 +13,19 @@
 // limitations under the License.
 package com.google.devtools.build.lib.buildtool;
 
+import static com.google.common.collect.ImmutableMap.toImmutableMap;
+
 import com.github.benmanes.caffeine.cache.Caffeine;
 import com.github.benmanes.caffeine.cache.LoadingCache;
 import com.google.common.base.Optional;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSortedSet;
 import com.google.devtools.build.lib.analysis.AnalysisOptions;
 import com.google.devtools.build.lib.analysis.OutputGroupInfo;
 import com.google.devtools.build.lib.analysis.TopLevelArtifactContext;
+import com.google.devtools.build.lib.analysis.ViewCreationFailedException;
 import com.google.devtools.build.lib.analysis.config.BuildOptions;
 import com.google.devtools.build.lib.buildeventstream.BuildEventProtocolOptions;
 import com.google.devtools.build.lib.exec.ExecutionOptions;
@@ -31,6 +35,8 @@
 import com.google.devtools.build.lib.runtime.KeepGoingOption;
 import com.google.devtools.build.lib.runtime.LoadingPhaseThreadsOption;
 import com.google.devtools.build.lib.runtime.UiOptions;
+import com.google.devtools.build.lib.server.FailureDetails.Analysis;
+import com.google.devtools.build.lib.server.FailureDetails.FailureDetail;
 import com.google.devtools.build.lib.util.OptionsUtils;
 import com.google.devtools.build.lib.util.io.OutErr;
 import com.google.devtools.common.options.OptionsBase;
@@ -40,6 +46,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
+import javax.annotation.Nullable;
 
 /**
  * A BuildRequest represents a single invocation of the build tool by a user.
@@ -383,6 +390,24 @@ public ImmutableList<String> getAspects() {
     return result.build();
   }
 
+  @Nullable
+  public ImmutableMap<String, String> getAspectsParameters() throws ViewCreationFailedException {
+    List<Map.Entry<String, String>> aspectsParametersList = getBuildOptions().aspectsParameters;
+    try {
+      return aspectsParametersList.stream()
+          .collect(toImmutableMap(Map.Entry::getKey, Map.Entry::getValue));
+    } catch (IllegalArgumentException e) {
+      String errorMessage = "Error in top-level aspects parameters";
+      throw new ViewCreationFailedException(
+          errorMessage,
+          FailureDetail.newBuilder()
+              .setMessage(errorMessage)
+              .setAnalysis(Analysis.newBuilder().setCode(Analysis.Code.ASPECT_CREATION_FAILED))
+              .build(),
+          e);
+    }
+  }
+
   /** Whether {@value #VALIDATION_ASPECT_NAME} is in use. */
   public boolean useValidationAspect() {
     return validationMode() == OutputGroupInfo.ValidationMode.ASPECT;
diff --git a/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java b/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java
index 816c30a3114179..28f081352f3cbe 100644
--- a/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java
@@ -34,6 +34,7 @@
 import com.google.devtools.common.options.OptionsParsingException;
 import com.google.devtools.common.options.RegexPatternOption;
 import java.util.List;
+import java.util.Map;
 import javax.annotation.Nullable;
 
 /**
@@ -318,6 +319,23 @@ public class BuildRequestOptions extends OptionsBase {
               + " 'my_aspect' is a top-level value from a file tools/my_def.bzl")
   public List<String> aspects;
 
+  @Option(
+      name = "aspects_parameters",
+      converter = Converters.AssignmentConverter.class,
+      defaultValue = "null",
+      documentationCategory = OptionDocumentationCategory.GENERIC_INPUTS,
+      effectTags = {OptionEffectTag.LOADING_AND_ANALYSIS},
+      allowMultiple = true,
+      help =
+          "Specifies the values of the command-line aspects parameters. Each parameter value is"
+              + " specified via <param_name>=<param_value>, for example 'my_param=my_val' where"
+              + " 'my_param' is a parameter of some aspect in --aspects list or required by an"
+              + " aspect in the list. This option can be used multiple times. However, it is not"
+              + " allowed to assign values to the same parameter more than once. This option is"
+              + " only be effective under the experimental flag"
+              + " --experimental_allow_top_level_aspects_parameters.")
+  public List<Map.Entry<String, String>> aspectsParameters;
+
   public BuildRequestOptions() throws OptionsParsingException {}
 
   public String getSymlinkPrefix(String productName) {
diff --git a/src/main/java/com/google/devtools/build/lib/packages/AspectsListBuilder.java b/src/main/java/com/google/devtools/build/lib/packages/AspectsListBuilder.java
index 5f9d288749a02f..2863aab5ce749e 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/AspectsListBuilder.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/AspectsListBuilder.java
@@ -14,8 +14,12 @@
 
 package com.google.devtools.build.lib.packages;
 
+import static com.google.common.collect.ImmutableList.toImmutableList;
+
 import com.google.common.base.Function;
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;
@@ -48,20 +52,64 @@ public ImmutableList<AspectDetails<?>> getAspectsDetails() {
     return ImmutableList.copyOf(aspects.values());
   }
 
-  /**
-   * Returns a list of Aspect objects for top level aspects.
-   *
-   * <p>Since top level aspects do not have parameters, a rule is not required to create their
-   * Aspect objects.
-   */
-  public ImmutableList<Aspect> buildAspects() {
+  /** Returns a list of Aspect objects for top level aspects. */
+  public ImmutableList<Aspect> buildAspects(ImmutableMap<String, String> aspectsParameters)
+      throws EvalException {
+    Preconditions.checkArgument(aspectsParameters != null, "aspectsParameters cannot be null");
+
     ImmutableList.Builder<Aspect> aspectsList = ImmutableList.builder();
     for (AspectDetails<?> aspect : aspects.values()) {
-      aspectsList.add(aspect.getAspect(null));
+      aspectsList.add(aspect.getTopLevelAspect(aspectsParameters));
     }
     return aspectsList.build();
   }
 
+  /**
+   * Validates top-level aspects parameters and reports error in the following cases:
+   *
+   * <p>If a parameter name is specified in command line but no aspect has a parameter with that
+   * name.
+   *
+   * <p>If a mandatory aspect attribute is not given a value in the top-level parameters list.
+   */
+  public boolean validateTopLevelAspectsParameters(ImmutableMap<String, String> aspectsParameters)
+      throws EvalException {
+    Preconditions.checkArgument(aspectsParameters != null, "aspectsParameters cannot be null");
+
+    ImmutableSet.Builder<String> usedParametersBuilder = ImmutableSet.builder();
+    for (AspectDetails<?> aspectDetails : aspects.values()) {
+      if (aspectDetails instanceof StarlarkAspectDetails) {
+        ImmutableList<Attribute> aspectAttributes =
+            ((StarlarkAspectDetails) aspectDetails).aspect.getAttributes();
+        for (Attribute attr : aspectAttributes) {
+          if (attr.isImplicit() || attr.isLateBound()) {
+            continue;
+          }
+          String attrName = attr.getName();
+          if (aspectsParameters.containsKey(attrName)) {
+            usedParametersBuilder.add(attrName);
+          } else if (attr.isMandatory()) {
+            throw Starlark.errorf(
+                "Missing mandatory attribute '%s' for aspect '%s'.",
+                attrName, aspectDetails.getName());
+          }
+        }
+      }
+    }
+    ImmutableSet<String> usedParameters = usedParametersBuilder.build();
+    ImmutableList<String> unusedParameters =
+        aspectsParameters.keySet().stream()
+            .filter(p -> !usedParameters.contains(p))
+            .collect(toImmutableList());
+    if (!unusedParameters.isEmpty()) {
+      throw Starlark.errorf(
+          "Parameters '%s' are not parameters of any of the top-level aspects but they are"
+              + " specified in --aspects_parameters.",
+          unusedParameters);
+    }
+    return true;
+  }
+
   /** Wraps the information necessary to construct an Aspect. */
   @VisibleForSerialization
   abstract static class AspectDetails<C extends AspectClass> {
@@ -92,7 +140,10 @@ ImmutableSet<String> getRequiredParameters() {
       return ImmutableSet.of();
     }
 
-    protected abstract Aspect getAspect(@Nullable Rule rule);
+    protected abstract Aspect getAspect(Rule rule);
+
+    protected abstract Aspect getTopLevelAspect(ImmutableMap<String, String> aspectParameters)
+        throws EvalException;
 
     C getAspectClass() {
       return aspectClass;
@@ -114,14 +165,16 @@ private static class NativeAspectDetails extends AspectDetails<NativeAspectClass
 
     @Override
     public Aspect getAspect(Rule rule) {
-      AspectParameters params;
-      if (rule == null) {
-        params = AspectParameters.EMPTY;
-      } else {
-        params = parametersExtractor.apply(rule);
-      }
+      AspectParameters params = parametersExtractor.apply(rule);
       return params == null ? null : Aspect.forNative(aspectClass, params);
     }
+
+    @Override
+    protected Aspect getTopLevelAspect(ImmutableMap<String, String> aspectParameters)
+        throws EvalException {
+      // Native aspects ignore their top-level parameters values for now.
+      return Aspect.forNative(aspectClass, AspectParameters.EMPTY);
+    }
   }
 
   @VisibleForSerialization
@@ -142,12 +195,14 @@ public ImmutableSet<String> getRequiredParameters() {
 
     @Override
     public Aspect getAspect(Rule rule) {
-      AspectParameters params;
-      if (rule == null) {
-        params = AspectParameters.EMPTY;
-      } else {
-        params = parametersExtractor.apply(rule);
-      }
+      AspectParameters params = parametersExtractor.apply(rule);
+      return Aspect.forStarlark(aspectClass, aspect.getDefinition(params), params);
+    }
+
+    @Override
+    public Aspect getTopLevelAspect(ImmutableMap<String, String> aspectParameters)
+        throws EvalException {
+      AspectParameters params = aspect.extractTopLevelParameters(aspectParameters);
       return Aspect.forStarlark(aspectClass, aspect.getDefinition(params), params);
     }
   }
@@ -165,6 +220,12 @@ private static class PredefinedAspectDetails extends AspectDetails<AspectClass>
     public Aspect getAspect(Rule rule) {
       return aspect;
     }
+
+    @Override
+    public Aspect getTopLevelAspect(ImmutableMap<String, String> aspectParameters)
+        throws EvalException {
+      return aspect;
+    }
   }
 
   @SerializationConstant @AutoCodec.VisibleForSerialization
diff --git a/src/main/java/com/google/devtools/build/lib/packages/StarlarkDefinedAspect.java b/src/main/java/com/google/devtools/build/lib/packages/StarlarkDefinedAspect.java
index da9d580c1c800b..279a1c6a17d60a 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/StarlarkDefinedAspect.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/StarlarkDefinedAspect.java
@@ -17,6 +17,7 @@
 import com.google.common.base.Function;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.analysis.config.transitions.ConfigurationTransition;
 import com.google.devtools.build.lib.cmdline.Label;
@@ -219,6 +220,38 @@ public Function<Rule, AspectParameters> getDefaultParametersExtractor() {
     };
   }
 
+  public AspectParameters extractTopLevelParameters(ImmutableMap<String, String> parametersValues)
+      throws EvalException {
+    AspectParameters.Builder builder = new AspectParameters.Builder();
+    for (Attribute aspectParameter : attributes) {
+      String parameterName = aspectParameter.getName();
+      if (Attribute.isImplicit(parameterName) || Attribute.isLateBound(parameterName)) {
+        // These attributes are the private matters of the aspect
+        continue;
+      }
+
+      Preconditions.checkArgument(
+          aspectParameter.getType() == Type.STRING,
+          "Cannot pass value of non-string attribute '%s' in aspect %s.",
+          getName(),
+          parameterName);
+
+      String parameterValue =
+          parametersValues.getOrDefault(
+              parameterName, (String) aspectParameter.getDefaultValue(null));
+
+      PredicateWithMessage<Object> allowedValues = aspectParameter.getAllowedValues();
+      if (allowedValues.apply(parameterValue)) {
+        builder.addAttribute(parameterName, parameterValue);
+      } else {
+        throw Starlark.errorf(
+            "%s: invalid value in '%s' attribute: %s",
+            getName(), parameterName, allowedValues.getErrorReason(parameterValue));
+      }
+    }
+    return builder.build();
+  }
+
   public ImmutableList<Label> getRequiredToolchains() {
     return requiredToolchains;
   }
diff --git a/src/main/java/com/google/devtools/build/lib/packages/semantics/BuildLanguageOptions.java b/src/main/java/com/google/devtools/build/lib/packages/semantics/BuildLanguageOptions.java
index bf1906fda08172..aefef22b7f6049 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/semantics/BuildLanguageOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/semantics/BuildLanguageOptions.java
@@ -538,6 +538,17 @@ public final class BuildLanguageOptions extends OptionsBase {
               + " providers of the aspect.")
   public boolean incompatibleTopLevelAspectsRequireProviders;
 
+  @Option(
+      name = "experimental_allow_top_level_aspects_parameters",
+      defaultValue = "false",
+      documentationCategory = OptionDocumentationCategory.STARLARK_SEMANTICS,
+      metadataTags = {OptionMetadataTag.EXPERIMENTAL},
+      effectTags = {OptionEffectTag.LOADING_AND_ANALYSIS},
+      help =
+          "If set to true, top level aspects will accept values for their parameters passed via"
+              + " --aspects_parameters option.")
+  public boolean experimentalAllowTopLevelAspectsParameters;
+
   /**
    * An interner to reduce the number of StarlarkSemantics instances. A single Blaze instance should
    * never accumulate a large number of these and being able to shortcut on object identity makes a
@@ -605,6 +616,9 @@ public StarlarkSemantics toStarlarkSemantics() {
             .setBool(
                 INCOMPATIBLE_TOP_LEVEL_ASPECTS_REQUIRE_PROVIDERS,
                 incompatibleTopLevelAspectsRequireProviders)
+            .setBool(
+                EXPERIMENTAL_ALLOW_TOP_LEVEL_ASPECTS_PARAMETERS,
+                experimentalAllowTopLevelAspectsParameters)
             .build();
     return INTERNER.intern(semantics);
   }
@@ -673,6 +687,8 @@ public StarlarkSemantics toStarlarkSemantics() {
       "-incompatible_visibility_private_attributes_at_definition";
   public static final String INCOMPATIBLE_TOP_LEVEL_ASPECTS_REQUIRE_PROVIDERS =
       "-incompatible_top_level_aspects_require_providers";
+  public static final String EXPERIMENTAL_ALLOW_TOP_LEVEL_ASPECTS_PARAMETERS =
+      "-experimental_allow_top_level_aspects_parameters";
 
   // non-booleans
   public static final StarlarkSemantics.Key<String> EXPERIMENTAL_BUILTINS_BZL_PATH =
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/AspectKeyCreator.java b/src/main/java/com/google/devtools/build/lib/skyframe/AspectKeyCreator.java
index 3b140dd3395800..c373247621f222 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/AspectKeyCreator.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/AspectKeyCreator.java
@@ -15,6 +15,7 @@
 
 import com.google.common.base.Objects;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Interner;
 import com.google.devtools.build.lib.actions.ActionLookupKey;
 import com.google.devtools.build.lib.analysis.config.BuildConfigurationValue;
@@ -48,14 +49,13 @@ public static AspectKey createAspectKey(
   public static TopLevelAspectsKey createTopLevelAspectsKey(
       ImmutableList<AspectClass> topLevelAspectsClasses,
       Label targetLabel,
-      @Nullable BuildConfigurationValue configuration) {
+      @Nullable BuildConfigurationValue configuration,
+      ImmutableMap<String, String> topLevelAspectsParameters) {
     return TopLevelAspectsKey.createInternal(
         topLevelAspectsClasses,
         targetLabel,
-        ConfiguredTargetKey.builder()
-            .setLabel(targetLabel)
-            .setConfiguration(configuration)
-            .build());
+        ConfiguredTargetKey.builder().setLabel(targetLabel).setConfiguration(configuration).build(),
+        topLevelAspectsParameters);
   }
 
   /** Common superclass for {@link AspectKey} and {@link TopLevelAspectsKey}. */
@@ -223,36 +223,48 @@ AspectKey withLabel(Label label) {
     }
   }
 
-  /** The key for top level aspects specified by --aspects option on a top level target. */
+  /**
+   * The key for top level aspects specified by --aspects option and their parameters specified by
+   * --aspects_parameters applied on a top level target.
+   */
   @AutoCodec
   public static final class TopLevelAspectsKey extends AspectBaseKey {
     private static final Interner<TopLevelAspectsKey> interner = BlazeInterners.newWeakInterner();
 
     private final ImmutableList<AspectClass> topLevelAspectsClasses;
     private final Label targetLabel;
+    private final ImmutableMap<String, String> topLevelAspectsParameters;
 
     @AutoCodec.Instantiator
     @AutoCodec.VisibleForSerialization
     static TopLevelAspectsKey createInternal(
         ImmutableList<AspectClass> topLevelAspectsClasses,
         Label targetLabel,
-        ConfiguredTargetKey baseConfiguredTargetKey) {
+        ConfiguredTargetKey baseConfiguredTargetKey,
+        ImmutableMap<String, String> topLevelAspectsParameters) {
       return interner.intern(
           new TopLevelAspectsKey(
               topLevelAspectsClasses,
               targetLabel,
               baseConfiguredTargetKey,
-              Objects.hashCode(topLevelAspectsClasses, targetLabel, baseConfiguredTargetKey)));
+              topLevelAspectsParameters,
+              Objects.hashCode(
+                  topLevelAspectsClasses,
+                  targetLabel,
+                  baseConfiguredTargetKey,
+                  topLevelAspectsParameters)));
     }
 
     private TopLevelAspectsKey(
         ImmutableList<AspectClass> topLevelAspectsClasses,
         Label targetLabel,
         ConfiguredTargetKey baseConfiguredTargetKey,
+        ImmutableMap<String, String> topLevelAspectsParameters,
         int hashCode) {
       super(baseConfiguredTargetKey, hashCode);
       this.topLevelAspectsClasses = topLevelAspectsClasses;
       this.targetLabel = targetLabel;
+      this.topLevelAspectsParameters = topLevelAspectsParameters;
     }
 
     @Override
@@ -269,13 +281,19 @@ ImmutableList<AspectClass> getTopLevelAspectsClasses() {
       return topLevelAspectsClasses;
     }
 
+    ImmutableMap<String, String> getTopLevelAspectsParameters() {
+      return topLevelAspectsParameters;
+    }
+
     @Override
     public Label getLabel() {
       return targetLabel;
     }
 
     String getDescription() {
-      return topLevelAspectsClasses + " on " + targetLabel;
+      return String.format(
+          "%s with parameters %s on %s",
+          topLevelAspectsClasses, topLevelAspectsParameters, targetLabel);
     }
 
     @Override
@@ -290,7 +308,8 @@ public boolean equals(Object o) {
       return hashCode() == that.hashCode()
           && Objects.equal(targetLabel, that.targetLabel)
           && Objects.equal(getBaseConfiguredTargetKey(), that.getBaseConfiguredTargetKey())
-          && Objects.equal(topLevelAspectsClasses, that.topLevelAspectsClasses);
+          && Objects.equal(topLevelAspectsClasses, that.topLevelAspectsClasses)
+          && Objects.equal(topLevelAspectsParameters, that.topLevelAspectsParameters);
     }
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/BuildTopLevelAspectsDetailsFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/BuildTopLevelAspectsDetailsFunction.java
index c0b56e1e5d0bbc..e25474dbb458e3 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/BuildTopLevelAspectsDetailsFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/BuildTopLevelAspectsDetailsFunction.java
@@ -15,8 +15,10 @@
 package com.google.devtools.build.lib.skyframe;
 
 import com.google.common.base.MoreObjects;
+import com.google.common.base.Objects;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Interner;
 import com.google.devtools.build.lib.analysis.AspectCollection;
 import com.google.devtools.build.lib.analysis.AspectCollection.AspectCycleOnPathException;
@@ -30,6 +32,7 @@
 import com.google.devtools.build.lib.packages.StarlarkAspect;
 import com.google.devtools.build.lib.packages.StarlarkAspectClass;
 import com.google.devtools.build.lib.packages.StarlarkDefinedAspect;
+import com.google.devtools.build.lib.packages.semantics.BuildLanguageOptions;
 import com.google.devtools.build.lib.server.FailureDetails.Analysis;
 import com.google.devtools.build.lib.server.FailureDetails.Analysis.Code;
 import com.google.devtools.build.lib.server.FailureDetails.FailureDetail;
@@ -47,6 +50,7 @@
 import java.util.Map;
 import javax.annotation.Nullable;
 import net.starlark.java.eval.EvalException;
+import net.starlark.java.eval.StarlarkSemantics;
 
 /**
  * {@link SkyFunction} to load top level aspects, build the dependency relation between them based
@@ -69,8 +73,20 @@ public SkyValue compute(SkyKey skyKey, Environment env)
     BuildTopLevelAspectsDetailsKey topLevelAspectsDetailsKey =
         (BuildTopLevelAspectsDetailsKey) skyKey.argument();
 
+    StarlarkSemantics starlarkSemantics = PrecomputedValue.STARLARK_SEMANTICS.get(env);
+    if (starlarkSemantics == null) {
+      return null;
+    }
+    boolean allowTopLevelAspectsParametersValues =
+        starlarkSemantics.getBool(
+            BuildLanguageOptions.EXPERIMENTAL_ALLOW_TOP_LEVEL_ASPECTS_PARAMETERS);
+
     ImmutableList<Aspect> topLevelAspects =
-        getTopLevelAspects(env, topLevelAspectsDetailsKey.getTopLevelAspectsClasses());
+        getTopLevelAspects(
+            env,
+            topLevelAspectsDetailsKey.getTopLevelAspectsClasses(),
+            topLevelAspectsDetailsKey.getTopLevelAspectsParameters(),
+            allowTopLevelAspectsParametersValues);
 
     if (topLevelAspects == null) {
       return null; // some aspects are not loaded
@@ -98,7 +114,7 @@ public String extractTag(SkyKey skyKey) {
 
   @Nullable
   private static StarlarkDefinedAspect loadStarlarkAspect(
-      Environment env, StarlarkAspectClass aspectClass)
+      Environment env, StarlarkAspectClass aspectClass, boolean allowTopLevelAspectsParameters)
       throws InterruptedException, BuildTopLevelAspectsDetailsFunctionException {
     StarlarkDefinedAspect starlarkAspect;
     try {
@@ -118,7 +134,7 @@ private static StarlarkDefinedAspect loadStarlarkAspect(
               e.getMessage(), Code.ASPECT_CREATION_FAILED));
     }
 
-    if (!starlarkAspect.getParamAttributes().isEmpty()) {
+    if (!allowTopLevelAspectsParameters && !starlarkAspect.getParamAttributes().isEmpty()) {
       String msg =
           String.format(
               "Cannot instantiate parameterized aspect %s at the top level.",
@@ -135,19 +151,24 @@ private static StarlarkDefinedAspect loadStarlarkAspect(
 
   @Nullable
   private static ImmutableList<Aspect> getTopLevelAspects(
-      Environment env, ImmutableList<AspectClass> topLevelAspectsClasses)
+      Environment env,
+      ImmutableList<AspectClass> topLevelAspectsClasses,
+      ImmutableMap<String, String> topLevelAspectsParameters,
+      boolean allowTopLevelAspectsParameters)
       throws InterruptedException, BuildTopLevelAspectsDetailsFunctionException {
     AspectsListBuilder aspectsList = new AspectsListBuilder();
 
     for (AspectClass aspectClass : topLevelAspectsClasses) {
       if (aspectClass instanceof StarlarkAspectClass) {
-        StarlarkAspect starlarkAspect = loadStarlarkAspect(env, (StarlarkAspectClass) aspectClass);
+        StarlarkAspect starlarkAspect =
+            loadStarlarkAspect(
+                env, (StarlarkAspectClass) aspectClass, allowTopLevelAspectsParameters);
         if (starlarkAspect == null) {
           return null;
         }
         try {
           starlarkAspect.attachToAspectsList(
-              /*baseAspectName=*/ null, aspectsList, /*allowAspectsParameters=*/ false);
+              /*baseAspectName=*/ null, aspectsList, allowTopLevelAspectsParameters);
         } catch (EvalException e) {
           env.getListener().handle(Event.error(e.getMessage()));
           throw new BuildTopLevelAspectsDetailsFunctionException(
@@ -165,7 +186,21 @@ private static ImmutableList<Aspect> getTopLevelAspects(
         }
       }
     }
-    return aspectsList.buildAspects();
+
+    try {
+      if (allowTopLevelAspectsParameters) {
+        // Only use the parameters list if the experimental flag is used.
+        aspectsList.validateTopLevelAspectsParameters(topLevelAspectsParameters);
+        return aspectsList.buildAspects(topLevelAspectsParameters);
+      } else {
+        return aspectsList.buildAspects(ImmutableMap.of());
+      }
+    } catch (EvalException e) {
+      env.getListener().handle(Event.error(e.getMessage()));
+      throw new BuildTopLevelAspectsDetailsFunctionException(
+          new TopLevelAspectsDetailsBuildFailedException(
+              e.getMessage(), Code.ASPECT_CREATION_FAILED));
+    }
   }
 
   private static Collection<AspectDetails> getTopLevelAspectsDetails(
@@ -252,20 +287,27 @@ static final class BuildTopLevelAspectsDetailsKey implements SkyKey {
         BlazeInterners.newWeakInterner();
 
     private final ImmutableList<AspectClass> topLevelAspectsClasses;
+    private final ImmutableMap<String, String> topLevelAspectsParameters;
     private final int hashCode;
 
     @AutoCodec.Instantiator
     static BuildTopLevelAspectsDetailsKey create(
-        ImmutableList<AspectClass> topLevelAspectsClasses) {
+        ImmutableList<AspectClass> topLevelAspectsClasses,
+        ImmutableMap<String, String> topLevelAspectsParameters) {
       return interner.intern(
           new BuildTopLevelAspectsDetailsKey(
-              topLevelAspectsClasses, topLevelAspectsClasses.hashCode()));
+              topLevelAspectsClasses,
+              topLevelAspectsParameters,
+              Objects.hashCode(topLevelAspectsClasses, topLevelAspectsParameters)));
     }
 
     private BuildTopLevelAspectsDetailsKey(
-        ImmutableList<AspectClass> topLevelAspectsClasses, int hashCode) {
+        ImmutableList<AspectClass> topLevelAspectsClasses,
+        @Nullable ImmutableMap<String, String> topLevelAspectsParameters,
+        int hashCode) {
       Preconditions.checkArgument(!topLevelAspectsClasses.isEmpty(), "No aspects");
       this.topLevelAspectsClasses = topLevelAspectsClasses;
+      this.topLevelAspectsParameters = topLevelAspectsParameters;
       this.hashCode = hashCode;
     }
 
@@ -278,6 +320,10 @@ ImmutableList<AspectClass> getTopLevelAspectsClasses() {
       return topLevelAspectsClasses;
     }
 
+    ImmutableMap<String, String> getTopLevelAspectsParameters() {
+      return topLevelAspectsParameters;
+    }
+
     @Override
     public int hashCode() {
       return hashCode;
@@ -293,13 +339,15 @@ public boolean equals(Object o) {
       }
       BuildTopLevelAspectsDetailsKey that = (BuildTopLevelAspectsDetailsKey) o;
       return hashCode == that.hashCode
-          && topLevelAspectsClasses.equals(that.topLevelAspectsClasses);
+          && topLevelAspectsClasses.equals(that.topLevelAspectsClasses)
+          && topLevelAspectsParameters.equals(that.topLevelAspectsParameters);
     }
 
     @Override
     public String toString() {
       return MoreObjects.toStringHelper(this)
           .add("topLevelAspectsClasses", topLevelAspectsClasses)
+          .add("topLevelAspectsParameters", topLevelAspectsParameters)
           .toString();
     }
   }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ToplevelStarlarkAspectFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ToplevelStarlarkAspectFunction.java
index 211cf68fecf168..97942724e28e0f 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ToplevelStarlarkAspectFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ToplevelStarlarkAspectFunction.java
@@ -54,7 +54,8 @@ public SkyValue compute(SkyKey skyKey, Environment env)
         (BuildTopLevelAspectsDetailsValue)
             env.getValue(
                 BuildTopLevelAspectsDetailsKey.create(
-                    topLevelAspectsKey.getTopLevelAspectsClasses()));
+                    topLevelAspectsKey.getTopLevelAspectsClasses(),
+                    topLevelAspectsKey.getTopLevelAspectsParameters()));
     if (topLevelAspectsDetails == null) {
       return null; // some aspects details are not ready
     }
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisTestCase.java b/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisTestCase.java
index 22800334cbf420..3bc2a8c37a0d27 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisTestCase.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisTestCase.java
@@ -340,6 +340,7 @@ protected AnalysisResult update(
       FlagBuilder config,
       ImmutableSet<String> explicitTargetPatterns,
       ImmutableList<String> aspects,
+      ImmutableMap<String, String> aspectsParameters,
       String... labels)
       throws Exception {
     Set<Flag> flags = config.flags;
@@ -397,6 +398,7 @@ protected AnalysisResult update(
             multiCpu,
             explicitTargetPatterns,
             aspects,
+            aspectsParameters,
             viewOptions,
             keepGoing,
             LOADING_PHASE_THREADS,
@@ -414,7 +416,13 @@ protected AnalysisResult update(
   protected AnalysisResult update(
       EventBus eventBus, FlagBuilder config, ImmutableList<String> aspects, String... labels)
       throws Exception {
-    return update(eventBus, config, /*explicitTargetPatterns=*/ ImmutableSet.of(), aspects, labels);
+    return update(
+        eventBus,
+        config,
+        /*explicitTargetPatterns=*/ ImmutableSet.of(),
+        aspects,
+        /*aspectsParameters=*/ ImmutableMap.of(),
+        labels);
   }
 
   protected AnalysisResult update(EventBus eventBus, FlagBuilder config, String... labels)
@@ -438,6 +446,20 @@ protected AnalysisResult update(ImmutableList<String> aspects, String... labels)
     return update(new EventBus(), defaultFlags(), aspects, labels);
   }
 
+  protected AnalysisResult update(
+      ImmutableList<String> aspects,
+      ImmutableMap<String, String> aspectsParameters,
+      String... labels)
+      throws Exception {
+    return update(
+        new EventBus(),
+        defaultFlags(),
+        /*explicitTargetPatterns=*/ ImmutableSet.of(),
+        aspects,
+        aspectsParameters,
+        labels);
+  }
+
   protected ConfiguredTargetAndData getConfiguredTargetAndTarget(String label)
       throws InterruptedException {
     return getConfiguredTargetAndTarget(label, getTargetConfiguration());
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewForTesting.java b/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewForTesting.java
index 21196b0be467f8..12528e7e142d15 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewForTesting.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewForTesting.java
@@ -196,6 +196,7 @@ public AnalysisResult update(
       Set<String> multiCpu,
       ImmutableSet<String> explicitTargetPatterns,
       List<String> aspects,
+      ImmutableMap<String, String> aspectsParameters,
       AnalysisOptions viewOptions,
       boolean keepGoing,
       int loadingPhaseThreads,
@@ -210,6 +211,7 @@ public AnalysisResult update(
         multiCpu,
         explicitTargetPatterns,
         aspects,
+        aspectsParameters,
         viewOptions,
         keepGoing,
         /*checkForActionConflicts=*/ true,
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewTestCase.java b/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewTestCase.java
index f7a4d6be558faa..c8d224d772d1ee 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewTestCase.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/util/BuildViewTestCase.java
@@ -2041,6 +2041,7 @@ protected AnalysisResult update(
         /* multiCpu= */ ImmutableSet.of(),
         /*explicitTargetPatterns=*/ ImmutableSet.of(),
         aspects,
+        /*aspectsParameters=*/ ImmutableMap.of(),
         viewOptions,
         keepGoing,
         loadingPhaseThreads,
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/TargetCycleReporterTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/TargetCycleReporterTest.java
index 535edc397df71a..0ae646d554afaf 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/TargetCycleReporterTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/TargetCycleReporterTest.java
@@ -16,6 +16,7 @@
 import static com.google.common.truth.Truth.assertThat;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.util.BuildViewTestCase;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.packages.StarlarkAspectClass;
@@ -74,7 +75,8 @@ public void loadingPhaseCycleWithDifferentTopLevelKeyTypes() throws Exception {
                 new StarlarkAspectClass(
                     Label.parseAbsoluteUnchecked("//foo:b"), "my Starlark key")),
             Label.parseAbsoluteUnchecked("//foo:a"),
-            targetConfig);
+            targetConfig,
+            /* topLevelAspectsParameters= */ ImmutableMap.of());
     assertThat(cycleReporter.getAdditionalMessageAboutCycle(reporter, starlarkAspectKey, cycle))
         .contains(
             "The cycle is caused by a visibility edge from //foo:b to the non-package_group "
diff --git a/src/test/java/com/google/devtools/build/lib/starlark/StarlarkDefinedAspectsTest.java b/src/test/java/com/google/devtools/build/lib/starlark/StarlarkDefinedAspectsTest.java
index 7bc0af9ac06084..ef91b34b1c25ec 100644
--- a/src/test/java/com/google/devtools/build/lib/starlark/StarlarkDefinedAspectsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/starlark/StarlarkDefinedAspectsTest.java
@@ -6660,6 +6660,562 @@ public void testDependentAspectWithNonExecutableTool_doesNotCrash() throws Excep
     update(ImmutableList.of("test/defs.bzl%aspect_a", "test/defs.bzl%aspect_b"), "//test:bin");
   }
 
+  @Test
+  public void testTopLevelAspectsWithParameters() throws Exception {
+    scratch.file(
+        "test/defs.bzl",
+        "def _aspect_a_impl(target, ctx):",
+        "  result = ['aspect_a on target {}, p1 = {} and a_p = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.a_p)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_a_result",
+        "  return struct(aspect_a_result = result)",
+        "",
+        "aspect_a = aspect(",
+        "  implementation = _aspect_a_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']),",
+        "            'a_p' : attr.string(values = ['a_p_v1', 'a_p_v2'])},",
+        ")",
+        "",
+        "def _aspect_b_impl(target, ctx):",
+        "  result = ['aspect_b on target {}, p1 = {} and b_p = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.b_p)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_b_result",
+        "  return struct(aspect_b_result = result)",
+        "",
+        "aspect_b = aspect(",
+        "  implementation = _aspect_b_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']),",
+        "            'b_p' : attr.string(values = ['b_p_v1', 'b_p_v2'])},",
+        ")",
+        "",
+        "def _my_rule_impl(ctx):",
+        "  pass",
+        "my_rule = rule(",
+        "  implementation = _my_rule_impl,",
+        "   attrs = { 'dep' : attr.label() },",
+        ")");
+    scratch.file(
+        "test/BUILD",
+        "load('//test:defs.bzl', 'my_rule')",
+        "my_rule(",
+        "  name = 'main_target',",
+        "  dep = ':dep_target_1',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_1',",
+        "  dep = ':dep_target_2',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_2',",
+        ")");
+    useConfiguration("--experimental_allow_top_level_aspects_parameters");
+
+    AnalysisResult analysisResult =
+        update(
+            ImmutableList.of("//test:defs.bzl%aspect_a", "//test:defs.bzl%aspect_b"),
+            ImmutableMap.of("p1", "p1_v1", "a_p", "a_p_v1", "b_p", "b_p_v1"),
+            "//test:main_target");
+
+    Map<AspectKey, ConfiguredAspect> configuredAspects = analysisResult.getAspectsMap();
+    ConfiguredAspect aspectA = getConfiguredAspect(configuredAspects, "aspect_a");
+    assertThat(aspectA).isNotNull();
+    StarlarkList<?> aspectAResult = (StarlarkList) aspectA.get("aspect_a_result");
+    assertThat(Starlark.toIterable(aspectAResult))
+        .containsExactly(
+            "aspect_a on target //test:main_target, p1 = p1_v1 and a_p = a_p_v1",
+            "aspect_a on target //test:dep_target_1, p1 = p1_v1 and a_p = a_p_v1",
+            "aspect_a on target //test:dep_target_2, p1 = p1_v1 and a_p = a_p_v1");
+
+    ConfiguredAspect aspectB = getConfiguredAspect(configuredAspects, "aspect_b");
+    assertThat(aspectB).isNotNull();
+    StarlarkList<?> aspectBResult = (StarlarkList) aspectB.get("aspect_b_result");
+    assertThat(Starlark.toIterable(aspectBResult))
+        .containsExactly(
+            "aspect_b on target //test:main_target, p1 = p1_v1 and b_p = b_p_v1",
+            "aspect_b on target //test:dep_target_1, p1 = p1_v1 and b_p = b_p_v1",
+            "aspect_b on target //test:dep_target_2, p1 = p1_v1 and b_p = b_p_v1");
+  }
+
+  @Test
+  public void testTopLevelAspectsWithParameters_differentAllowedValues() throws Exception {
+    scratch.file(
+        "test/defs.bzl",
+        "def _aspect_a_impl(target, ctx):",
+        "  result = ['aspect_a on target {}, p1 = {} and p2 = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.p2)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_a_result",
+        "  return struct(aspect_a_result = result)",
+        "",
+        "aspect_a = aspect(",
+        "  implementation = _aspect_a_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']) },",
+        ")",
+        "",
+        "def _aspect_b_impl(target, ctx):",
+        "  result = ['aspect_b on target {}, p1 = {} and p2 = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.p2)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_b_result",
+        "  return struct(aspect_b_result = result)",
+        "",
+        "aspect_b = aspect(",
+        "  implementation = _aspect_b_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v2', 'p1_v3']) },",
+        ")",
+        "",
+        "def _my_rule_impl(ctx):",
+        "  pass",
+        "my_rule = rule(",
+        "  implementation = _my_rule_impl,",
+        "   attrs = { 'dep' : attr.label() },",
+        ")");
+    scratch.file(
+        "test/BUILD",
+        "load('//test:defs.bzl', 'my_rule')",
+        "my_rule(",
+        "  name = 'main_target',",
+        "  dep = ':dep_target_1',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_1',",
+        "  dep = ':dep_target_2',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_2',",
+        ")");
+    useConfiguration("--experimental_allow_top_level_aspects_parameters");
+    reporter.removeHandler(failFastHandler);
+
+    // This call succeeds if "--keep_going" was passed, which it does in the WithKeepGoing test
+    // suite. Otherwise, it fails and throws a ViewCreationFailedException.
+    if (keepGoing()) {
+      AnalysisResult analysisResult =
+          update(
+              ImmutableList.of("//test:defs.bzl%aspect_a", "//test:defs.bzl%aspect_b"),
+              ImmutableMap.of("p1", "p1_v1"),
+              "//test:main_target");
+      assertThat(analysisResult.hasError()).isTrue();
+    } else {
+      assertThrows(
+          ViewCreationFailedException.class,
+          () ->
+              update(
+                  ImmutableList.of("//test:defs.bzl%aspect_a", "//test:defs.bzl%aspect_b"),
+                  ImmutableMap.of("p1", "p1_v1"),
+                  "//test:main_target"));
+    }
+    assertContainsEvent(
+        "//test:defs.bzl%aspect_b: invalid value in 'p1' attribute: has to be one of 'p1_v2' or"
+            + " 'p1_v3' instead of 'p1_v1'");
+  }
+
+  @Test
+  public void testTopLevelAspectsWithParameters_useDefaultValue() throws Exception {
+    scratch.file(
+        "test/defs.bzl",
+        "def _aspect_a_impl(target, ctx):",
+        "  result = ['aspect_a on target {}, p1 = {} and p2 = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.p2)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_a_result",
+        "  return struct(aspect_a_result = result)",
+        "",
+        "aspect_a = aspect(",
+        "  implementation = _aspect_a_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2'], default = 'p1_v1'),",
+        "            'p2' : attr.string(values = ['p2_v1', 'p2_v2'], default = 'p2_v1')},",
+        ")",
+        "",
+        "def _my_rule_impl(ctx):",
+        "  pass",
+        "my_rule = rule(",
+        "  implementation = _my_rule_impl,",
+        "   attrs = { 'dep' : attr.label() },",
+        ")");
+    scratch.file(
+        "test/BUILD",
+        "load('//test:defs.bzl', 'my_rule')",
+        "my_rule(",
+        "  name = 'main_target',",
+        "  dep = ':dep_target_1',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_1',",
+        "  dep = ':dep_target_2',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_2',",
+        ")");
+    useConfiguration("--experimental_allow_top_level_aspects_parameters");
+
+    AnalysisResult analysisResult =
+        update(
+            ImmutableList.of("//test:defs.bzl%aspect_a"),
+            ImmutableMap.of("p1", "p1_v2"),
+            "//test:main_target");
+
+    Map<AspectKey, ConfiguredAspect> configuredAspects = analysisResult.getAspectsMap();
+    ConfiguredAspect aspectA = getConfiguredAspect(configuredAspects, "aspect_a");
+    assertThat(aspectA).isNotNull();
+    StarlarkList<?> aspectAResult = (StarlarkList) aspectA.get("aspect_a_result");
+    assertThat(Starlark.toIterable(aspectAResult))
+        .containsExactly(
+            "aspect_a on target //test:main_target, p1 = p1_v2 and p2 = p2_v1",
+            "aspect_a on target //test:dep_target_1, p1 = p1_v2 and p2 = p2_v1",
+            "aspect_a on target //test:dep_target_2, p1 = p1_v2 and p2 = p2_v1");
+  }
+
+  @Test
+  public void testTopLevelAspectsWithParameters_passParametersToRequiredAspect() throws Exception {
+    scratch.file(
+        "test/defs.bzl",
+        "def _aspect_b_impl(target, ctx):",
+        "  result = ['aspect_b on target {}, p1 = {} and p3 = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.p3)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_b_result",
+        "  return struct(aspect_b_result = result)",
+        "",
+        "aspect_b = aspect(",
+        "  implementation = _aspect_b_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']),",
+        "            'p3' : attr.string(values = ['p3_v1', 'p3_v2', 'p3_v3'])},",
+        ")",
+        "",
+        "def _aspect_a_impl(target, ctx):",
+        "  result = ['aspect_a on target {}, p1 = {} and p2 = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.p2)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_a_result",
+        "  return struct(aspect_a_result = result)",
+        "",
+        "aspect_a = aspect(",
+        "  implementation = _aspect_a_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']),",
+        "            'p2' : attr.string(values = ['p2_v1', 'p2_v2'])},",
+        "  requires = [aspect_b],",
+        ")",
+        "",
+        "def _my_rule_impl(ctx):",
+        "  pass",
+        "my_rule = rule(",
+        "  implementation = _my_rule_impl,",
+        "   attrs = { 'dep' : attr.label() },",
+        ")");
+    scratch.file(
+        "test/BUILD",
+        "load('//test:defs.bzl', 'my_rule')",
+        "my_rule(",
+        "  name = 'main_target',",
+        "  dep = ':dep_target_1',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_1',",
+        "  dep = ':dep_target_2',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_2',",
+        ")");
+    useConfiguration("--experimental_allow_top_level_aspects_parameters");
+
+    AnalysisResult analysisResult =
+        update(
+            ImmutableList.of("//test:defs.bzl%aspect_a"),
+            ImmutableMap.of("p1", "p1_v1", "p2", "p2_v2", "p3", "p3_v3"),
+            "//test:main_target");
+
+    Map<AspectKey, ConfiguredAspect> configuredAspects = analysisResult.getAspectsMap();
+    ConfiguredAspect aspectA = getConfiguredAspect(configuredAspects, "aspect_a");
+    assertThat(aspectA).isNotNull();
+    StarlarkList<?> aspectAResult = (StarlarkList) aspectA.get("aspect_a_result");
+    assertThat(Starlark.toIterable(aspectAResult))
+        .containsExactly(
+            "aspect_a on target //test:main_target, p1 = p1_v1 and p2 = p2_v2",
+            "aspect_a on target //test:dep_target_1, p1 = p1_v1 and p2 = p2_v2",
+            "aspect_a on target //test:dep_target_2, p1 = p1_v1 and p2 = p2_v2");
+
+    ConfiguredAspect aspectB = getConfiguredAspect(configuredAspects, "aspect_b");
+    assertThat(aspectB).isNotNull();
+    StarlarkList<?> aspectBResult = (StarlarkList) aspectB.get("aspect_b_result");
+    assertThat(Starlark.toIterable(aspectBResult))
+        .containsExactly(
+            "aspect_b on target //test:main_target, p1 = p1_v1 and p3 = p3_v3",
+            "aspect_b on target //test:dep_target_1, p1 = p1_v1 and p3 = p3_v3",
+            "aspect_b on target //test:dep_target_2, p1 = p1_v1 and p3 = p3_v3");
+  }
+
+  @Test
+  public void testTopLevelAspectsWithParameters_invalidParameterValue() throws Exception {
+    scratch.file(
+        "test/defs.bzl",
+        "def _aspect_a_impl(target, ctx):",
+        "  result = ['aspect_a on target {}, p = {}'.",
+        "                                    format(target.label, ctx.attr.p)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_a_result",
+        "  return struct(aspect_a_result = result)",
+        "",
+        "aspect_a = aspect(",
+        "  implementation = _aspect_a_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p' : attr.string(values = ['p_v1', 'p_v2']) },",
+        ")",
+        "",
+        "def _my_rule_impl(ctx):",
+        "  pass",
+        "my_rule = rule(",
+        "  implementation = _my_rule_impl,",
+        "   attrs = { 'dep' : attr.label() },",
+        ")");
+    scratch.file(
+        "test/BUILD",
+        "load('//test:defs.bzl', 'my_rule')",
+        "my_rule(",
+        "  name = 'main_target',",
+        "  dep = ':dep_target_1',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_1',",
+        "  dep = ':dep_target_2',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_2',",
+        ")");
+    useConfiguration("--experimental_allow_top_level_aspects_parameters");
+    reporter.removeHandler(failFastHandler);
+
+    // This call succeeds if "--keep_going" was passed, which it does in the WithKeepGoing test
+    // suite. Otherwise, it fails and throws a ViewCreationFailedException.
+    if (keepGoing()) {
+      AnalysisResult analysisResult =
+          update(
+              ImmutableList.of("//test:defs.bzl%aspect_a"),
+              ImmutableMap.of("p", "p_v"),
+              "//test:main_target");
+      assertThat(analysisResult.hasError()).isTrue();
+    } else {
+      assertThrows(
+          ViewCreationFailedException.class,
+          () ->
+              update(
+                  ImmutableList.of("//test:defs.bzl%aspect_a"),
+                  ImmutableMap.of("p", "p_v"),
+                  "//test:main_target"));
+    }
+    assertContainsEvent(
+        "//test:defs.bzl%aspect_a: invalid value in 'p' attribute: has to be one of 'p_v1' or"
+            + " 'p_v2' instead of 'p_v'");
+  }
+
+  @Test
+  public void testTopLevelAspectsWithParameters_missingMandatoryParameter() throws Exception {
+    scratch.file(
+        "test/defs.bzl",
+        "def _aspect_a_impl(target, ctx):",
+        "  result = ['aspect_a on target {}, p1 = {}'.",
+        "                                    format(target.label, ctx.attr.p1)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_a_result",
+        "  return struct(aspect_a_result = result)",
+        "",
+        "aspect_a = aspect(",
+        "  implementation = _aspect_a_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(mandatory = True, default = 'p1_v1',",
+        "                               values = ['p1_v1', 'p1_v2']),",
+        "            'p2' : attr.string(values = ['p2_v1', 'p2_v2'])},",
+        ")",
+        "",
+        "def _my_rule_impl(ctx):",
+        "  pass",
+        "my_rule = rule(",
+        "  implementation = _my_rule_impl,",
+        "   attrs = { 'dep' : attr.label() },",
+        ")");
+    scratch.file(
+        "test/BUILD",
+        "load('//test:defs.bzl', 'my_rule')",
+        "my_rule(",
+        "  name = 'main_target',",
+        "  dep = ':dep_target_1',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_1',",
+        "  dep = ':dep_target_2',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_2',",
+        ")");
+    useConfiguration("--experimental_allow_top_level_aspects_parameters");
+    reporter.removeHandler(failFastHandler);
+
+    // This call succeeds if "--keep_going" was passed, which it does in the WithKeepGoing test
+    // suite. Otherwise, it fails and throws a ViewCreationFailedException.
+    if (keepGoing()) {
+      AnalysisResult analysisResult =
+          update(
+              ImmutableList.of("//test:defs.bzl%aspect_a"),
+              ImmutableMap.of("p2", "p2_v1"),
+              "//test:main_target");
+
+      assertThat(analysisResult.hasError()).isTrue();
+    } else {
+      assertThrows(
+          ViewCreationFailedException.class,
+          () ->
+              update(
+                  ImmutableList.of("//test:defs.bzl%aspect_a"),
+                  ImmutableMap.of("p2", "p2_v1"),
+                  "//test:main_target"));
+    }
+    assertContainsEvent("Missing mandatory attribute 'p1' for aspect '//test:defs.bzl%aspect_a'");
+  }
+
+  @Test
+  public void testTopLevelAspectsWithParameters_unusedParameter() throws Exception {
+    scratch.file(
+        "test/defs.bzl",
+        "def _aspect_a_impl(target, ctx):",
+        "  result = ['aspect_a on target {}, p1 = {} and a_p = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.a_p)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_a_result",
+        "  return struct(aspect_a_result = result)",
+        "",
+        "aspect_a = aspect(",
+        "  implementation = _aspect_a_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']),",
+        "            'a_p' : attr.string(values = ['a_p_v1', 'a_p_v2'])},",
+        ")",
+        "",
+        "def _aspect_b_impl(target, ctx):",
+        "  result = ['aspect_b on target {}, p1 = {} and b_p = {}'.",
+        "                                    format(target.label, ctx.attr.p1, ctx.attr.b_p)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_b_result",
+        "  return struct(aspect_b_result = result)",
+        "",
+        "aspect_b = aspect(",
+        "  implementation = _aspect_b_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']),",
+        "            'b_p' : attr.string(values = ['b_p_v1', 'b_p_v2'])},",
+        ")",
+        "",
+        "def _my_rule_impl(ctx):",
+        "  pass",
+        "my_rule = rule(",
+        "  implementation = _my_rule_impl,",
+        "   attrs = { 'dep' : attr.label() },",
+        ")");
+    scratch.file(
+        "test/BUILD",
+        "load('//test:defs.bzl', 'my_rule')",
+        "my_rule(",
+        "  name = 'main_target',",
+        "  dep = ':dep_target_1',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_1',",
+        "  dep = ':dep_target_2',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_2',",
+        ")");
+    useConfiguration("--experimental_allow_top_level_aspects_parameters");
+    reporter.removeHandler(failFastHandler);
+
+    // This call succeeds if "--keep_going" was passed, which it does in the WithKeepGoing test
+    // suite. Otherwise, it fails and throws a ViewCreationFailedException.
+    if (keepGoing()) {
+      AnalysisResult analysisResult =
+          update(
+              ImmutableList.of("//test:defs.bzl%aspect_a", "//test:defs.bzl%aspect_b"),
+              ImmutableMap.of("p2", "p2_v1", "b_p", "b_p_v1"),
+              "//test:main_target");
+
+      assertThat(analysisResult.hasError()).isTrue();
+    } else {
+      assertThrows(
+          ViewCreationFailedException.class,
+          () ->
+              update(
+                  ImmutableList.of("//test:defs.bzl%aspect_a", "//test:defs.bzl%aspect_b"),
+                  ImmutableMap.of("p2", "p2_v1", "b_p", "b_p_v1"),
+                  "//test:main_target"));
+    }
+    assertContainsEvent(
+        "Parameters '[p2]' are not parameters of any of the top-level aspects but they are"
+            + " specified in --aspects_parameters.");
+  }
+
+  @Test
+  public void testTopLevelAspectsWithParameters_invalidDefaultParameterValue() throws Exception {
+    scratch.file(
+        "test/defs.bzl",
+        "def _aspect_a_impl(target, ctx):",
+        "  result = ['aspect_a on target {}, p = {}'.",
+        "                                    format(target.label, ctx.attr.p)]",
+        "  if ctx.rule.attr.dep:",
+        "    result += ctx.rule.attr.dep.aspect_a_result",
+        "  return struct(aspect_a_result = result)",
+        "",
+        "aspect_a = aspect(",
+        "  implementation = _aspect_a_impl,",
+        "  attr_aspects = ['dep'],",
+        "  attrs = { 'p' : attr.string(values = ['p_v1', 'p_v2']) },",
+        ")",
+        "",
+        "def _my_rule_impl(ctx):",
+        "  pass",
+        "my_rule = rule(",
+        "  implementation = _my_rule_impl,",
+        "   attrs = { 'dep' : attr.label() },",
+        ")");
+    scratch.file(
+        "test/BUILD",
+        "load('//test:defs.bzl', 'my_rule')",
+        "my_rule(",
+        "  name = 'main_target',",
+        "  dep = ':dep_target_1',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_1',",
+        "  dep = ':dep_target_2',",
+        ")",
+        "my_rule(",
+        "  name = 'dep_target_2',",
+        ")");
+    useConfiguration("--experimental_allow_top_level_aspects_parameters");
+    reporter.removeHandler(failFastHandler);
+
+    // This call succeeds if "--keep_going" was passed, which it does in the WithKeepGoing test
+    // suite. Otherwise, it fails and throws a ViewCreationFailedException.
+    if (keepGoing()) {
+      AnalysisResult analysisResult =
+          update(ImmutableList.of("//test:defs.bzl%aspect_a"), "//test:main_target");
+      assertThat(analysisResult.hasError()).isTrue();
+    } else {
+      assertThrows(
+          ViewCreationFailedException.class,
+          () -> update(ImmutableList.of("//test:defs.bzl%aspect_a"), "//test:main_target"));
+    }
+    assertContainsEvent(
+        "//test:defs.bzl%aspect_a: invalid value in 'p' attribute: has to be one of 'p_v1' or"
+            + " 'p_v2' instead of ''");
+  }
+
   private ConfiguredAspect getConfiguredAspect(
       Map<AspectKey, ConfiguredAspect> aspectsMap, String aspectName) {
     for (Map.Entry<AspectKey, ConfiguredAspect> entry : aspectsMap.entrySet()) {
diff --git a/src/test/shell/integration/aspect_test.sh b/src/test/shell/integration/aspect_test.sh
index dcfeb209f59fc0..206f2023020eda 100755
--- a/src/test/shell/integration/aspect_test.sh
+++ b/src/test/shell/integration/aspect_test.sh
@@ -1011,4 +1011,175 @@ EOF
   expect_log "aspect_b run on target t2"
 }
 
+function test_top_level_aspects_parameters() {
+  local package="test"
+  mkdir -p "${package}"
+
+  cat > "${package}/defs.bzl" <<EOF
+def _aspect_a_impl(target, ctx):
+  print('aspect_a on target {}, p1 = {} and p3 = {}'.
+                    format(target.label, ctx.attr.p1, ctx.attr.p3))
+  return []
+
+aspect_a = aspect(
+              implementation = _aspect_a_impl,
+              attr_aspects = ['dep'],
+              attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']),
+                        'p3' : attr.string(values = ['p3_v1', 'p3_v2', 'p3_v3'])},
+)
+
+def _aspect_b_impl(target, ctx):
+  print('aspect_b on target {}, p1 = {} and p2 = {}'.
+                      format(target.label, ctx.attr.p1, ctx.attr.p2))
+  return []
+
+aspect_b = aspect(
+            implementation = _aspect_b_impl,
+            attr_aspects = ['dep'],
+            attrs = { 'p1' : attr.string(values = ['p1_v1', 'p1_v2']),
+                      'p2' : attr.string(values = ['p2_v1', 'p2_v2'])},
+)
+
+def _my_rule_impl(ctx):
+  pass
+
+my_rule = rule(
+           implementation = _my_rule_impl,
+           attrs = { 'dep' : attr.label() },
+)
+EOF
+
+  cat > "${package}/BUILD" <<EOF
+load('//test:defs.bzl', 'my_rule')
+my_rule(name = 'main_target',
+        dep = ':dep_target_1',
+)
+my_rule(name = 'dep_target_1',
+        dep = ':dep_target_2',
+)
+my_rule(name = 'dep_target_2')
+EOF
+
+  bazel build "//${package}:main_target" \
+      --aspects="//${package}:defs.bzl%aspect_a","//${package}:defs.bzl%aspect_b" \
+      --aspects_parameters="p1=p1_v1" \
+      --aspects_parameters="p2=p2_v2" \
+      --aspects_parameters="p3=p3_v3" \
+      --experimental_allow_top_level_aspects_parameters \
+      &> $TEST_log || fail "Build failed"
+
+  expect_log "aspect_a on target //test:main_target, p1 = p1_v1 and p3 = p3_v3"
+  expect_log "aspect_a on target //test:dep_target_1, p1 = p1_v1 and p3 = p3_v3"
+  expect_log "aspect_a on target //test:dep_target_2, p1 = p1_v1 and p3 = p3_v3"
+  expect_log "aspect_b on target //test:main_target, p1 = p1_v1 and p2 = p2_v2"
+  expect_log "aspect_b on target //test:dep_target_1, p1 = p1_v1 and p2 = p2_v2"
+  expect_log "aspect_b on target //test:dep_target_2, p1 = p1_v1 and p2 = p2_v2"
+}
+
+# aspect_a is propagated from command line on top level target main_target with
+# value p_v1 for its parameter p. It is also propagated from main_target rule
+# with value p_v2 to its parameter p. So aspect_a should run twice on dependency
+# dep_target, once with each parameter value.
+function test_top_level_aspects_parameters_with_same_aspect_propagated_from_rule() {
+  local package="test"
+  mkdir -p "${package}"
+
+  cat > "${package}/defs.bzl" <<EOF
+def _aspect_a_impl(target, ctx):
+  print('aspect_a on target {}, p = {}'.format(target.label, ctx.attr.p))
+  return []
+
+aspect_a = aspect(
+              implementation = _aspect_a_impl,
+              attr_aspects = ['dep'],
+              attrs = { 'p' : attr.string(values = ['p_v1', 'p_v2']) },
+)
+
+def _my_rule_impl(ctx):
+  pass
+
+my_rule = rule(
+           implementation = _my_rule_impl,
+           attrs = { 'dep' : attr.label(aspects = [aspect_a]),
+                     'p': attr.string()},
+)
+EOF
+
+  cat > "${package}/BUILD" <<EOF
+load('//test:defs.bzl', 'my_rule')
+my_rule(name = 'main_target',
+        dep = ':dep_target',
+        p = 'p_v2',
+)
+my_rule(name = 'dep_target',
+        p = 'p_v1',
+)
+EOF
+
+  bazel build "//${package}:main_target" \
+      --aspects="//${package}:defs.bzl%aspect_a" \
+      --aspects_parameters="p=p_v1" \
+      --experimental_allow_top_level_aspects_parameters \
+      &> $TEST_log || fail "Build failed"
+
+  expect_log "aspect_a on target //test:main_target, p = p_v1"
+  expect_log "aspect_a on target //test:dep_target, p = p_v1"
+  expect_log "aspect_a on target //test:dep_target, p = p_v2"
+}
+
+function test_top_level_aspects_parameters_invalid_multiple_param_values() {
+  local package="test"
+  mkdir -p "${package}"
+
+  cat > "${package}/defs.bzl" <<EOF
+def _aspect_a_impl(target, ctx):
+  print('aspect_a on target {}, p = {}'.format(target.label, ctx.attr.p))
+  return []
+
+aspect_a = aspect(
+              implementation = _aspect_a_impl,
+              attr_aspects = ['dep'],
+              attrs = { 'p' : attr.string(values = ['p_v1', 'p_v2']) },
+)
+
+def _my_rule_impl(ctx):
+  pass
+
+my_rule = rule(
+           implementation = _my_rule_impl,
+           attrs = { 'dep' : attr.label(aspects = [aspect_a]),
+                     'p': attr.string()},
+)
+EOF
+
+  cat > "${package}/BUILD" <<EOF
+load('//test:defs.bzl', 'my_rule')
+my_rule(name = 'main_target',
+        dep = ':dep_target',
+        p = 'p_v2',
+)
+my_rule(name = 'dep_target',
+        p = 'p_v1',
+)
+EOF
+
+  bazel build "//${package}:main_target" \
+      --aspects="//${package}:defs.bzl%aspect_a" \
+      --aspects_parameters="p=p_v1" \
+      --aspects_parameters="p=p_v2" \
+      --experimental_allow_top_level_aspects_parameters \
+      &> $TEST_log && fail "Build succeeded, expected to fail"
+
+  expect_log "Error in top-level aspects parameters: Multiple entries with same key: p=p_v2 and p=p_v1"
+
+  bazel build "//${package}:main_target" \
+      --aspects="//${package}:defs.bzl%aspect_a" \
+      --aspects_parameters="p=p_v1" \
+      --aspects_parameters="p=p_v1" \
+      --experimental_allow_top_level_aspects_parameters \
+      &> $TEST_log && fail "Build succeeded, expected to fail"
+
+  expect_log "Error in top-level aspects parameters: Multiple entries with same key: p=p_v1 and p=p_v1"
+}
+
 run_suite "Tests for aspects"