diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/constraint/BooleanConstraint.java b/core/api/src/main/java/org/onlab/onos/net/intent/constraint/BooleanConstraint.java
new file mode 100644
index 0000000..9ad4ac7
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/constraint/BooleanConstraint.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2014 Open Networking Laboratory
+ *
+ * Licensed 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.onlab.onos.net.intent.constraint;
+
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.intent.Constraint;
+import org.onlab.onos.net.resource.LinkResourceService;
+
+/**
+ * Abstract base class for various constraints that evaluate link viability
+ * in a yes/no fashion.
+ */
+public abstract class BooleanConstraint implements Constraint {
+
+    /**
+     * Returns true if the specified link satisfies the constraint.
+     *
+     * @param link            link to be validated
+     * @param resourceService resource service for checking available link resources
+     * @return true if link is viable
+     */
+    public abstract boolean isValid(Link link, LinkResourceService resourceService);
+
+    @Override
+    public double cost(Link link, LinkResourceService resourceService) {
+        return isValid(link, resourceService) ? +1 : -1;
+    }
+
+    @Override
+    public boolean validate(Path path, LinkResourceService resourceService) {
+        for (Link link : path.links()) {
+            if (isValid(link, resourceService)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+}