diff --git a/faiss/cppcontrib/factory_tools.cpp b/faiss/cppcontrib/factory_tools.cpp
new file mode 100644
index 0000000000..76cbe73efe
--- /dev/null
+++ b/faiss/cppcontrib/factory_tools.cpp
@@ -0,0 +1,152 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// -*- c++ -*-
+
+#include <faiss/cppcontrib/factory_tools.h>
+#include <map>
+
+namespace faiss {
+
+namespace {
+
+const std::map<faiss::ScalarQuantizer::QuantizerType, std::string> sq_types = {
+        {faiss::ScalarQuantizer::QT_8bit, "SQ8"},
+        {faiss::ScalarQuantizer::QT_4bit, "SQ4"},
+        {faiss::ScalarQuantizer::QT_6bit, "SQ6"},
+        {faiss::ScalarQuantizer::QT_fp16, "SQfp16"},
+        {faiss::ScalarQuantizer::QT_bf16, "SQbf16"},
+        {faiss::ScalarQuantizer::QT_8bit_direct_signed, "SQ8_direct_signed"},
+        {faiss::ScalarQuantizer::QT_8bit_direct, "SQ8_direct"},
+};
+
+int get_hnsw_M(const faiss::IndexHNSW* index) {
+    if (index->hnsw.cum_nneighbor_per_level.size() >= 1) {
+        return index->hnsw.cum_nneighbor_per_level[1] / 2;
+    }
+    // Avoid runtime error, just return 0.
+    return 0;
+}
+
+} // namespace
+
+// Reference for reverse_index_factory:
+// https://github.com/facebookresearch/faiss/blob/838612c9d7f2f619811434ec9209c020f44107cb/contrib/factory_tools.py#L81
+std::string reverse_index_factory(const faiss::Index* index) {
+    std::string prefix;
+    if (dynamic_cast<const faiss::IndexFlat*>(index)) {
+        return "Flat";
+    } else if (
+            const faiss::IndexIVF* ivf_index =
+                    dynamic_cast<const faiss::IndexIVF*>(index)) {
+        const faiss::Index* quantizer = ivf_index->quantizer;
+
+        if (dynamic_cast<const faiss::IndexFlat*>(quantizer)) {
+            prefix = "IVF" + std::to_string(ivf_index->nlist);
+        } else if (
+                const faiss::MultiIndexQuantizer* miq =
+                        dynamic_cast<const faiss::MultiIndexQuantizer*>(
+                                quantizer)) {
+            prefix = "IMI" + std::to_string(miq->pq.M) + "x" +
+                    std::to_string(miq->pq.nbits);
+        } else if (
+                const faiss::IndexHNSW* hnsw_index =
+                        dynamic_cast<const faiss::IndexHNSW*>(quantizer)) {
+            prefix = "IVF" + std::to_string(ivf_index->nlist) + "_HNSW" +
+                    std::to_string(get_hnsw_M(hnsw_index));
+        } else {
+            prefix = "IVF" + std::to_string(ivf_index->nlist) + "(" +
+                    reverse_index_factory(quantizer) + ")";
+        }
+
+        if (dynamic_cast<const faiss::IndexIVFFlat*>(ivf_index)) {
+            return prefix + ",Flat";
+        } else if (
+                auto sq_index =
+                        dynamic_cast<const faiss::IndexIVFScalarQuantizer*>(
+                                ivf_index)) {
+            return prefix + "," + sq_types.at(sq_index->sq.qtype);
+        } else if (
+                const faiss::IndexIVFPQ* ivfpq_index =
+                        dynamic_cast<const faiss::IndexIVFPQ*>(ivf_index)) {
+            return prefix + ",PQ" + std::to_string(ivfpq_index->pq.M) + "x" +
+                    std::to_string(ivfpq_index->pq.nbits);
+        } else if (
+                const faiss::IndexIVFPQFastScan* ivfpqfs_index =
+                        dynamic_cast<const faiss::IndexIVFPQFastScan*>(
+                                ivf_index)) {
+            return prefix + ",PQ" + std::to_string(ivfpqfs_index->pq.M) + "x" +
+                    std::to_string(ivfpqfs_index->pq.nbits) + "fs";
+        }
+    } else if (
+            const faiss::IndexPreTransform* pretransform_index =
+                    dynamic_cast<const faiss::IndexPreTransform*>(index)) {
+        if (pretransform_index->chain.size() != 1) {
+            // Avoid runtime error, just return empty string for logging.
+            return "";
+        }
+        const faiss::VectorTransform* vt = pretransform_index->chain.at(0);
+        if (const faiss::OPQMatrix* opq_matrix =
+                    dynamic_cast<const faiss::OPQMatrix*>(vt)) {
+            prefix = "OPQ" + std::to_string(opq_matrix->M) + "_" +
+                    std::to_string(opq_matrix->d_out);
+        } else if (
+                const faiss::ITQTransform* itq_transform =
+                        dynamic_cast<const faiss::ITQTransform*>(vt)) {
+            prefix = "ITQ" + std::to_string(itq_transform->itq.d_out);
+        } else if (
+                const faiss::PCAMatrix* pca_matrix =
+                        dynamic_cast<const faiss::PCAMatrix*>(vt)) {
+            assert(pca_matrix->eigen_power == 0);
+            prefix = "PCA" +
+                    std::string(pca_matrix->random_rotation ? "R" : "") +
+                    std::to_string(pca_matrix->d_out);
+        } else {
+            // Avoid runtime error, just return empty string for logging.
+            return "";
+        }
+        return prefix + "," + reverse_index_factory(pretransform_index->index);
+    } else if (
+            const faiss::IndexHNSW* hnsw_index =
+                    dynamic_cast<const faiss::IndexHNSW*>(index)) {
+        return "HNSW" + std::to_string(get_hnsw_M(hnsw_index));
+    } else if (
+            const faiss::IndexRefine* refine_index =
+                    dynamic_cast<const faiss::IndexRefine*>(index)) {
+        return reverse_index_factory(refine_index->base_index) + ",Refine(" +
+                reverse_index_factory(refine_index->refine_index) + ")";
+    } else if (
+            const faiss::IndexPQFastScan* pqfs_index =
+                    dynamic_cast<const faiss::IndexPQFastScan*>(index)) {
+        return std::string("PQ") + std::to_string(pqfs_index->pq.M) + "x" +
+                std::to_string(pqfs_index->pq.nbits) + "fs";
+    } else if (
+            const faiss::IndexPQ* pq_index =
+                    dynamic_cast<const faiss::IndexPQ*>(index)) {
+        return std::string("PQ") + std::to_string(pq_index->pq.M) + "x" +
+                std::to_string(pq_index->pq.nbits);
+    } else if (
+            const faiss::IndexLSH* lsh_index =
+                    dynamic_cast<const faiss::IndexLSH*>(index)) {
+        std::string result = "LSH";
+        if (lsh_index->rotate_data) {
+            result += "r";
+        }
+        if (lsh_index->train_thresholds) {
+            result += "t";
+        }
+        return result;
+    } else if (
+            const faiss::IndexScalarQuantizer* sq_index =
+                    dynamic_cast<const faiss::IndexScalarQuantizer*>(index)) {
+        return std::string("SQ") + sq_types.at(sq_index->sq.qtype);
+    }
+    // Avoid runtime error, just return empty string for logging.
+    return "";
+}
+
+} // namespace faiss
diff --git a/faiss/cppcontrib/factory_tools.h b/faiss/cppcontrib/factory_tools.h
new file mode 100644
index 0000000000..bde4971854
--- /dev/null
+++ b/faiss/cppcontrib/factory_tools.h
@@ -0,0 +1,24 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// -*- c++ -*-
+
+#pragma once
+
+#include <faiss/IndexHNSW.h>
+#include <faiss/IndexIVFFlat.h>
+#include <faiss/IndexIVFPQFastScan.h>
+#include <faiss/IndexLSH.h>
+#include <faiss/IndexPQFastScan.h>
+#include <faiss/IndexPreTransform.h>
+#include <faiss/IndexRefine.h>
+
+namespace faiss {
+
+std::string reverse_index_factory(const faiss::Index* index);
+
+} // namespace faiss
diff --git a/tests/test_factory_tools.cpp b/tests/test_factory_tools.cpp
new file mode 100644
index 0000000000..c8d7f21c3f
--- /dev/null
+++ b/tests/test_factory_tools.cpp
@@ -0,0 +1,54 @@
+// (c) Meta Platforms, Inc. and affiliates. Confidential and proprietary.
+
+#include <faiss/cppcontrib/factory_tools.h>
+#include <faiss/index_factory.h>
+#include <gtest/gtest.h>
+
+using namespace faiss;
+
+TEST(TestFactoryTools, TestReverseIndexFactory) {
+    auto factory_string = "Flat";
+    auto index = faiss::index_factory(64, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+
+    factory_string = "IMI2x5,PQ8x8";
+    index = faiss::index_factory(32, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+
+    factory_string = "IVF32_HNSW32,SQ8";
+    index = faiss::index_factory(64, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+
+    factory_string = "IVF8,Flat";
+    index = faiss::index_factory(64, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+
+    factory_string = "IVF8,SQ4";
+    index = faiss::index_factory(64, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+
+    factory_string = "IVF8,PQ4x8";
+    index = faiss::index_factory(64, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+
+    factory_string = "LSHrt";
+    index = faiss::index_factory(64, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+
+    factory_string = "PQ4x8";
+    index = faiss::index_factory(64, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+
+    factory_string = "HNSW32";
+    index = faiss::index_factory(64, factory_string);
+    EXPECT_EQ(factory_string, reverse_index_factory(index));
+    delete index;
+}