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diff --git a/src/mongo/db/query/query_stats/key.cpp b/src/mongo/db/query/query_stats/key.cpp
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+++ b/src/mongo/db/query/query_stats/key.cpp
@@ -0,0 +1,223 @@
+/**
+ *    Copyright (C) 2023-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/db/query/query_stats/key.h"
+
+#include "mongo/db/query/query_stats/query_stats_helpers.h"
+#include "mongo/rpc/metadata/client_metadata.h"
+
+namespace mongo::query_stats {
+
+namespace {
+
+BSONObj scrubHighCardinalityFields(const ClientMetadata* clientMetadata) {
+    if (!clientMetadata) {
+        return BSONObj();
+    }
+    return clientMetadata->documentWithoutMongosInfo();
+}
+
+BSONObj shapifyReadPreference(boost::optional<BSONObj> readPreference) {
+    if (!readPreference) {
+        return BSONObj();
+    }
+
+    BSONObjBuilder builder;
+    for (const auto& elem : *readPreference) {
+        if (elem.fieldNameStringData() != "tags"_sd) {
+            builder.append(elem);
+            continue;
+        }
+
+        // Sort the $readPreference tags so that different orderings still map to one query stats
+        // store key.
+        BSONObjSet sortedTags = SimpleBSONObjComparator::kInstance.makeBSONObjSet();
+        for (const auto& tag : elem.Array()) {
+            sortedTags.insert(tag.Obj());
+        }
+
+        BSONArrayBuilder arrBuilder(builder.subarrayStart("tags"_sd));
+        for (const auto& tag : sortedTags) {
+            arrBuilder.append(tag);
+        }
+    }
+    return builder.obj();
+}
+
+}  // namespace
+
+UniversalKeyComponents::UniversalKeyComponents(std::unique_ptr<query_shape::Shape> queryShape,
+                                               const ClientMetadata* clientMetadata,
+                                               boost::optional<BSONObj> commentObj,
+                                               boost::optional<BSONObj> hint,
+                                               boost::optional<BSONObj> readPreference,
+                                               boost::optional<BSONObj> writeConcern,
+                                               boost::optional<BSONObj> readConcern,
+                                               std::unique_ptr<APIParameters> apiParams,
+                                               query_shape::CollectionType collectionType,
+                                               bool maxTimeMS)
+    : _clientMetaData(scrubHighCardinalityFields(clientMetadata)),
+      _commentObj(commentObj.value_or(BSONObj()).getOwned()),
+      _hintObj(hint.value_or(BSONObj()).getOwned()),
+      _writeConcern(writeConcern.value_or(BSONObj()).getOwned()),
+      _shapifiedReadPreference(shapifyReadPreference(readPreference)),
+      _shapifiedReadConcern(shapifyReadConcern(readConcern.value_or(BSONObj()))),
+      _comment(commentObj ? _commentObj.firstElement() : BSONElement()),
+      _queryShape(std::move(queryShape)),
+      _apiParams(std::move(apiParams)),
+      _clientMetaDataHash(clientMetadata ? clientMetadata->hashWithoutMongosInfo()
+                                         : simpleHash(BSONObj())),
+      _collectionType(collectionType),
+      _hasField() {
+    _hasField.clientMetaData = bool(clientMetadata);
+    _hasField.comment = bool(commentObj);
+    _hasField.hint = bool(hint);
+    _hasField.readPreference = bool(readPreference);
+    _hasField.writeConcern = bool(writeConcern);
+    _hasField.readConcern = bool(readConcern);
+    _hasField.maxTimeMS = maxTimeMS;
+    tassert(7973600, "shape must not be null", _queryShape);
+}
+
+BSONObj UniversalKeyComponents::shapifyReadConcern(const BSONObj& readConcern,
+                                                   const SerializationOptions& opts) {
+    // Read concern should not be considered a literal.
+    // afterClusterTime is distinct for every operation with causal consistency enabled. We
+    // normalize it in order not to blow out the queryStats store cache.
+    if (readConcern["afterClusterTime"].eoo() && readConcern["atClusterTime"].eoo()) {
+        return readConcern.copy();
+    } else {
+        BSONObjBuilder bob;
+
+        if (auto levelElem = readConcern["level"]) {
+            bob.append(levelElem);
+        }
+        if (auto afterClusterTime = readConcern["afterClusterTime"]) {
+            opts.appendLiteral(&bob, "afterClusterTime", afterClusterTime);
+        }
+        if (auto atClusterTime = readConcern["atClusterTime"]) {
+            opts.appendLiteral(&bob, "atClusterTime", atClusterTime);
+        }
+        return bob.obj();
+    }
+}
+
+size_t UniversalKeyComponents::size() const {
+    return sizeof(*this) + _queryShape->size() +
+        (_apiParams ? sizeof(*_apiParams) + shape_helpers::optionalSize(_apiParams->getAPIVersion())
+                    : 0) +
+        _hintObj.objsize() + (_hasField.clientMetaData ? _clientMetaData.objsize() : 0) +
+        _commentObj.objsize() +
+        (_hasField.readPreference ? _shapifiedReadPreference.objsize() : 0) +
+        (_hasField.readConcern ? _shapifiedReadConcern.objsize() : 0) +
+        (_hasField.writeConcern ? _writeConcern.objsize() : 0);
+}
+
+void UniversalKeyComponents::appendTo(BSONObjBuilder& bob, const SerializationOptions& opts) const {
+    if (_hasField.comment) {
+        opts.appendLiteral(&bob, "comment", _comment);
+    }
+
+    if (_hasField.readConcern) {
+        auto readConcernToAppend = _shapifiedReadConcern;
+        if (opts != SerializationOptions::kRepresentativeQueryShapeSerializeOptions) {
+            // The options aren't the same as the first time we shapified, so re-computation is
+            // necessary (e.g. use "?timestamp" instead of the representative Timestamp(0, 0)).
+            readConcernToAppend = shapifyReadConcern(_shapifiedReadConcern, opts);
+        }
+        bob.append("readConcern", readConcernToAppend);
+    }
+
+    if (const auto& apiVersion = _apiParams->getAPIVersion()) {
+        bob.append("apiVersion", apiVersion.value());
+    }
+
+    if (const auto& apiStrict = _apiParams->getAPIStrict()) {
+        bob.append("apiStrict", apiStrict.value());
+    }
+
+    if (const auto& apiDeprecationErrors = _apiParams->getAPIDeprecationErrors()) {
+        bob.append("apiDeprecationErrors", apiDeprecationErrors.value());
+    }
+
+    if (_hasField.readPreference) {
+        bob.append("$readPreference", _shapifiedReadPreference);
+    }
+
+    if (_hasField.writeConcern) {
+        bob.append("writeConcern", _writeConcern);
+    }
+
+    if (_hasField.clientMetaData) {
+        bob.append("client", _clientMetaData);
+    }
+    if (_collectionType > query_shape::CollectionType::kUnknown) {
+        bob.append("collectionType", toStringData(_collectionType));
+    }
+    if (!_hintObj.isEmpty()) {
+        bob.append("hint", shape_helpers::extractHintShape(_hintObj, opts));
+    }
+    if (_hasField.maxTimeMS) {
+        opts.appendLiteral(&bob, "maxTimeMS", 0ll);
+    }
+}
+Key::Key(OperationContext* opCtx,
+         std::unique_ptr<query_shape::Shape> queryShape,
+         boost::optional<BSONObj> hint,
+         boost::optional<BSONObj> readConcern,
+         bool maxTimeMS,
+         query_shape::CollectionType collectionType)
+    : _universalComponents(
+          std::move(queryShape),
+          ClientMetadata::get(opCtx->getClient()),
+          opCtx->getCommentOwnedCopy(),
+          hint,
+          ReadPreferenceSetting::get(opCtx).usedDefaultReadPrefValue()
+              ? boost::none
+              : boost::make_optional(ReadPreferenceSetting::get(opCtx).toInnerBSON()),
+          opCtx->getWriteConcern().isImplicitDefaultWriteConcern()
+              ? boost::none
+              : boost::make_optional(opCtx->getWriteConcern().toBSON()),
+          readConcern,
+          std::make_unique<APIParameters>(APIParameters::get(opCtx)),
+          collectionType,
+          maxTimeMS) {}
+
+BSONObj Key::toBson(OperationContext* opCtx, const SerializationOptions& opts) const {
+    BSONObjBuilder bob;
+
+    // We'll take care of appending this one outside of the appendTo() call below since it needs
+    // an OperationContext in some re-parsing cases. The rest is simpler.
+    bob.append("queryShape", _universalComponents._queryShape->toBson(opCtx, opts));
+
+    _universalComponents.appendTo(bob, opts);
+    appendCommandSpecificComponents(bob, opts);
+    return bob.obj();
+}
+}  // namespace mongo::query_stats