diff --git a/phosphor-regulators/src/actions/action_environment.hpp b/phosphor-regulators/src/actions/action_environment.hpp
new file mode 100644
index 0000000..fb34141
--- /dev/null
+++ b/phosphor-regulators/src/actions/action_environment.hpp
@@ -0,0 +1,230 @@
+/**
+ * Copyright © 2019 IBM Corporation
+ *
+ * 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.
+ */
+#pragma once
+
+#include "device.hpp"
+#include "id_map.hpp"
+#include "rule.hpp"
+
+#include <cstddef> // for size_t
+#include <stdexcept>
+#include <string>
+
+namespace phosphor
+{
+namespace power
+{
+namespace regulators
+{
+
+/**
+ * @class ActionEnvironment
+ *
+ * The current environment when executing actions.
+ *
+ * The ActionEnvironment contains the following information:
+ *   - current device ID
+ *   - current volts value (if any)
+ *   - mapping from device and rule IDs to the corresponding objects
+ *   - rule call stack depth (to detect infinite recursion)
+ */
+class ActionEnvironment
+{
+  public:
+    // Specify which compiler-generated methods we want
+    ActionEnvironment() = delete;
+    ActionEnvironment(const ActionEnvironment&) = delete;
+    ActionEnvironment(ActionEnvironment&&) = delete;
+    ActionEnvironment& operator=(const ActionEnvironment&) = delete;
+    ActionEnvironment& operator=(ActionEnvironment&&) = delete;
+    ~ActionEnvironment() = default;
+
+    /**
+     * Maximum rule call stack depth.  Used to detect infinite recursion.
+     */
+    static constexpr size_t maxRuleDepth{30};
+
+    /**
+     * Constructor.
+     *
+     * @param idMap mapping from IDs to the associated Device/Rule objects
+     * @param deviceID current device ID
+     */
+    explicit ActionEnvironment(const IDMap& idMap,
+                               const std::string& deviceID) :
+        idMap{idMap},
+        deviceID{deviceID}
+    {
+    }
+
+    /**
+     * Decrements the rule call stack depth by one.
+     *
+     * Should be used when a call to a rule returns.  Does nothing if depth is
+     * already 0.
+     */
+    void decrementRuleDepth()
+    {
+        if (ruleDepth > 0)
+        {
+            --ruleDepth;
+        }
+    }
+
+    /**
+     * Returns the device with the current device ID.
+     *
+     * Throws invalid_argument if no device is found with current ID.
+     *
+     * @return device with current device ID
+     */
+    Device& getDevice() const
+    {
+        return idMap.getDevice(deviceID);
+    }
+
+    /**
+     * Returns the current device ID.
+     *
+     * @return current device ID
+     */
+    const std::string& getDeviceID() const
+    {
+        return deviceID;
+    }
+
+    /**
+     * Returns the rule with the specified ID.
+     *
+     * Throws invalid_argument if no rule is found with specified ID.
+     *
+     * @param id rule ID
+     * @return rule with specified ID
+     */
+    Rule& getRule(const std::string& id) const
+    {
+        return idMap.getRule(id);
+    }
+
+    /**
+     * Returns the current rule call stack depth.
+     *
+     * The depth is 0 if no rules have been called.
+     *
+     * @return rule call stack depth
+     */
+    size_t getRuleDepth() const
+    {
+        return ruleDepth;
+    }
+
+    /**
+     * Returns the current volts value.
+     *
+     * Call hasVolts() first to check whether a volts value has been set.
+     *
+     * Throws logic_error if no volts value has been set.
+     *
+     * @return current volts value
+     */
+    double getVolts() const
+    {
+        if (!hasVoltsValue)
+        {
+            throw std::logic_error{"No volts value has been set."};
+        }
+        return volts;
+    }
+
+    /**
+     * Returns whether a volts value has been set.
+     *
+     * @return true if a volts value has been set, false otherwise
+     */
+    bool hasVolts() const
+    {
+        return hasVoltsValue;
+    }
+
+    /**
+     * Increments the rule call stack depth by one.
+     *
+     * Should be used when a rule is called.
+     *
+     * Throws runtime_error if the new depth exceeds maxRuleDepth.  This
+     * indicates that infinite recursion has probably occurred (rule A -> rule B
+     * -> rule A).
+     */
+    void incrementRuleDepth()
+    {
+        if (ruleDepth >= maxRuleDepth)
+        {
+            throw std::runtime_error("Maximum rule depth exceeded.");
+        }
+        ++ruleDepth;
+    }
+
+    /**
+     * Sets the current device ID.
+     *
+     * @param id device ID
+     */
+    void setDeviceID(const std::string& id)
+    {
+        deviceID = id;
+    }
+
+    /**
+     * Sets the current volts value.
+     *
+     * @param volts new volts value.
+     */
+    void setVolts(double volts)
+    {
+        this->volts = volts;
+        hasVoltsValue = true;
+    }
+
+  private:
+    /**
+     * Mapping from string IDs to the associated Device and Rule objects.
+     */
+    const IDMap& idMap{};
+
+    /**
+     * Current device ID.
+     */
+    std::string deviceID{};
+
+    /**
+     * Indicates whether a volts value has been set.
+     */
+    bool hasVoltsValue{false};
+
+    /**
+     * Current volts value (if set).
+     */
+    double volts{0};
+
+    /**
+     * Rule call stack depth.
+     */
+    size_t ruleDepth{0};
+};
+
+} // namespace regulators
+} // namespace power
+} // namespace phosphor