diff --git a/CHANGELOG.md b/CHANGELOG.md
index b27c70c5201..5f12e189a89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,7 +11,7 @@ changes in the following format: PR #1234***
 ## LORIS 25.0 (Release Date: ????-??-??)
 ### Core
 #### Features
-- placeholder 
+- Added new interface intended to be used for querying module data from PHP (PR #8215) 
 
 #### Updates and Improvements
 - Rename subproject to Cohort (PR #7817)
@@ -77,7 +77,6 @@ changes in the following format: PR #1234***
 #### API
 - Ability to use PSCID instead of the CandID in the candidates API (PR #8138)
 
-
 ## LORIS 24.0 (Release Date: 2022-03-24)
 ### Core
 #### Features
diff --git a/src/Data/Query/Criteria.php b/src/Data/Query/Criteria.php
new file mode 100644
index 00000000000..b48080b6bd3
--- /dev/null
+++ b/src/Data/Query/Criteria.php
@@ -0,0 +1,17 @@
+<?php
+namespace LORIS\Data\Query;
+
+/**
+ * A Criteria represents a comparison to compare a data dictionary
+ * against for the purposes of querying.
+ *
+ * Generally, the operator is defined by the class type and the
+ * the value by getValue().
+ */
+interface Criteria
+{
+    /**
+     * Get the value of the comparison.
+     */
+    public function getValue();
+}
diff --git a/src/Data/Query/Criteria/EndsWith.php b/src/Data/Query/Criteria/EndsWith.php
new file mode 100644
index 00000000000..86380453ae3
--- /dev/null
+++ b/src/Data/Query/Criteria/EndsWith.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+/**
+ * An EndsWith criteria represents a search for values that
+ * the string representation of ends with a certain value.
+ */
+class EndsWith implements \LORIS\Data\Query\Criteria
+{
+    /**
+     * Construct an EndsWith criteria
+     *
+     * @param mixed $suffix The suffix that values must end with
+     */
+    public function __construct(private $suffix)
+    {
+    }
+
+    public function getValue()
+    {
+        return $this->suffix;
+    }
+}
diff --git a/src/Data/Query/Criteria/Equal.php b/src/Data/Query/Criteria/Equal.php
new file mode 100644
index 00000000000..e041db4e32f
--- /dev/null
+++ b/src/Data/Query/Criteria/Equal.php
@@ -0,0 +1,28 @@
+<?php
+namespace LORIS\Data\Query\Criteria;
+
+use LORIS\Data\Query\Criteria;
+
+/**
+ * An Equal criteria matches data which equals a given
+ * value.
+ */
+class Equal implements Criteria
+{
+    /**
+     * Construct an Equal criteria.
+     *
+     * @param mixed $value The value that must be equal
+     */
+    public function __construct(private $value)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Data/Query/Criteria/GreaterThan.php b/src/Data/Query/Criteria/GreaterThan.php
new file mode 100644
index 00000000000..d9c02b6fd65
--- /dev/null
+++ b/src/Data/Query/Criteria/GreaterThan.php
@@ -0,0 +1,26 @@
+<?php
+namespace LORIS\Data\Query\Criteria;
+
+use LORIS\Data\Query\Criteria;
+
+/**
+ * A GreaterThan Criteria specifies that an item must be strictly
+ * > a given value.
+ */
+class GreaterThan implements Criteria
+{
+    /**
+     * Construct a GreaterThan comparison
+     */
+    public function __construct(protected $value)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Data/Query/Criteria/GreaterThanOrEqual.php b/src/Data/Query/Criteria/GreaterThanOrEqual.php
new file mode 100644
index 00000000000..a53ee2df13e
--- /dev/null
+++ b/src/Data/Query/Criteria/GreaterThanOrEqual.php
@@ -0,0 +1,26 @@
+<?php
+namespace LORIS\Data\Query\Criteria;
+
+use LORIS\Data\Query\Criteria;
+
+/**
+ * A GreaterThanOrEqual criteria denotes a criteria that must
+ * be >= a given value.
+ */
+class GreaterThanOrEqual implements Criteria
+{
+    /**
+     * Constructor
+     */
+    public function __construct(protected $value)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Data/Query/Criteria/In.php b/src/Data/Query/Criteria/In.php
new file mode 100644
index 00000000000..a1c8286e871
--- /dev/null
+++ b/src/Data/Query/Criteria/In.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+/**
+ * In represents a criteria specifying that the value must be
+ * in a given set of choices.
+ */
+class In implements \LORIS\Data\Query\Criteria
+{
+    protected array $val;
+
+    /**
+     * Construct an In criteria.
+     *
+     * @param $val The set that the value must be in.
+     */
+    public function __construct(...$val)
+    {
+        $this->val = $val;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->val;
+    }
+}
diff --git a/src/Data/Query/Criteria/IsNull.php b/src/Data/Query/Criteria/IsNull.php
new file mode 100644
index 00000000000..27cf14c521d
--- /dev/null
+++ b/src/Data/Query/Criteria/IsNull.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+/**
+ * Criteria to compare if a value is null
+ */
+class IsNull implements \LORIS\Data\Query\Criteria
+{
+    /**
+     * Constructor
+     */
+    public function __construct()
+    {
+    }
+
+    /**
+     * Stub to implement Criteria interface
+     */
+    public function getValue()
+    {
+        return null;
+    }
+}
diff --git a/src/Data/Query/Criteria/LessThan.php b/src/Data/Query/Criteria/LessThan.php
new file mode 100644
index 00000000000..b3ae39f57a3
--- /dev/null
+++ b/src/Data/Query/Criteria/LessThan.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+/**
+ * Criteria to specify that a given item must be strictly <
+ * a comparison value.
+ */
+class LessThan implements \LORIS\Data\Query\Criteria
+{
+    /**
+     * Constructor
+     */
+    public function __construct(protected $value)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Data/Query/Criteria/LessThanOrEqual.php b/src/Data/Query/Criteria/LessThanOrEqual.php
new file mode 100644
index 00000000000..7d5686773db
--- /dev/null
+++ b/src/Data/Query/Criteria/LessThanOrEqual.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+/**
+ * A Criteria to determine that a DictionaryItem must be <= a
+ * given value
+ */
+class LessThanOrEqual implements \LORIS\Data\Query\Criteria
+{
+    /**
+     * Constructor
+     *
+     * @param mixed $value The comparison value
+     */
+    public function __construct(protected $value)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Data/Query/Criteria/NotEqual.php b/src/Data/Query/Criteria/NotEqual.php
new file mode 100644
index 00000000000..3665b3e4571
--- /dev/null
+++ b/src/Data/Query/Criteria/NotEqual.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+use LORIS\Data\Query\Criteria;
+
+/**
+ * A NotEqual Criteria specifies that the value should be compared
+ * against not being a given value.
+ */
+class NotEqual implements Criteria
+{
+    /**
+     * Construct a NotEqual criteria
+     */
+    public function __construct(protected $value)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
+}
diff --git a/src/Data/Query/Criteria/NotNull.php b/src/Data/Query/Criteria/NotNull.php
new file mode 100644
index 00000000000..07582513ad7
--- /dev/null
+++ b/src/Data/Query/Criteria/NotNull.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+/**
+ * A Criteria to specify querying for items that must not be
+ * null
+ */
+class NotNull implements \LORIS\Data\Query\Criteria
+{
+    /**
+     * Constructor
+     */
+    public function __construct()
+    {
+    }
+
+    /**
+     * Stub to implement Criteria interface
+     */
+    public function getValue()
+    {
+        return null;
+    }
+}
diff --git a/src/Data/Query/Criteria/StartsWith.php b/src/Data/Query/Criteria/StartsWith.php
new file mode 100644
index 00000000000..48f103799b1
--- /dev/null
+++ b/src/Data/Query/Criteria/StartsWith.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+/**
+ * A Criteria to specify that the string serialization must
+ * start with a given prefix.
+ */
+class StartsWith implements \LORIS\Data\Query\Criteria
+{
+    /**
+     * Construct a StartsWith
+     */
+    public function __construct(protected $prefix)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->prefix;
+    }
+}
diff --git a/src/Data/Query/Criteria/Substring.php b/src/Data/Query/Criteria/Substring.php
new file mode 100644
index 00000000000..db63dc171da
--- /dev/null
+++ b/src/Data/Query/Criteria/Substring.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace LORIS\Data\Query\Criteria;
+
+/**
+ * Criteria to specify that the string serialization of a
+ * value must contain a substring.
+ */
+class Substring implements \LORIS\Data\Query\Criteria
+{
+    /**
+     * Construct a Substring criteria
+     *
+     * @param string $substr The substring that must be contained in
+     *                       the value
+     */
+    public function __construct(protected $substr)
+    {
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getValue()
+    {
+        return $this->substr;
+    }
+}
diff --git a/src/Data/Query/QueryEngine.php b/src/Data/Query/QueryEngine.php
new file mode 100644
index 00000000000..deb02282a59
--- /dev/null
+++ b/src/Data/Query/QueryEngine.php
@@ -0,0 +1,64 @@
+<?php declare(strict_types=1);
+namespace LORIS\Data\Query;
+
+use \LORIS\StudyEntities\Candidate\CandID;
+use \LORIS\Data\Dictionary\DictionaryItem;
+use \LORIS\Data\DataInstance;
+
+/**
+ * A QueryEngine is an entity which represents a set of data and
+ * the ability to query against them.
+ *
+ * Queries are divided into 2 phases, filtering the data down to
+ * a set of CandIDs, and retrieving the data for a known set of
+ * CandID/SessionIDs.
+ *
+ * There is usually one query engine per module that deals with
+ * candidate data.
+ */
+interface QueryEngine
+{
+    /**
+     * Return a data dictionary of data types managed by this QueryEngine.
+     * DictionaryItems are grouped into categories and an engine may know
+     * about 0 or more categories of DictionaryItems.
+     *
+     * @return \LORIS\Data\Dictionary\Category[]
+     */
+    public function getDataDictionary() : iterable;
+
+    /**
+     * Return an iterable of CandIDs matching the given criteria.
+     *
+     * If visitlist is provided, session scoped variables will match
+     * if the criteria is met for at least one of those visit labels.
+     */
+    public function getCandidateMatches(
+        QueryTerm $criteria,
+        ?array $visitlist = null
+    ) : iterable;
+
+    /**
+     * Retrieve the data for a given list of DictionaryItems from this
+     * engine's data dictionary and a given list of CandIDs.
+     *
+     * If visits is declared, only include data for those visits labels.
+     *
+     * @param DictionaryItem[] $items Data points to retrieve
+     * @param CandID[] $candidates    Candidates to retrieve data for
+     * @param ?string[] $visits       Visit labels to restrict data to
+     *
+     * @return DataInstance[]
+     */
+    public function getCandidateData(array $items, iterable $candidates, ?array $visitlist) : iterable;
+
+    /**
+     * Get the list of visits at which a DictionaryItem is valid
+     *
+     * @return string[]
+     */
+    public function getVisitList(
+        \LORIS\Data\Dictionary\Category $inst,
+        \LORIS\Data\Dictionary\DictionaryItem $item
+    ) : iterable;
+}
diff --git a/src/Data/Query/QueryTerm.php b/src/Data/Query/QueryTerm.php
new file mode 100644
index 00000000000..8ad711f47ce
--- /dev/null
+++ b/src/Data/Query/QueryTerm.php
@@ -0,0 +1,24 @@
+<?php
+namespace LORIS\Data\Query;
+
+use LORIS\Data\Dictionary\DictionaryItem;
+
+/**
+ * A QueryTerm represents a single criteria used as part of a query
+ * For instance "age < 5"
+ */
+class QueryTerm
+{
+    /**
+     * Construct a query term.
+     *
+     * @param DictionaryItem $dictionary The term being compared.
+     * @param Criteria       $criteria   The criteria to compare the
+     *                                   term against.
+     */
+    public function __construct(
+        public \LORIS\Data\Dictionary\DictionaryItem $dictionary,
+        public Criteria $criteria
+    ) {
+    }
+}