diff --git a/nisaba/interim/grm2/rewrite/base_rule_cascade.h b/nisaba/interim/grm2/rewrite/base_rule_cascade.h
index 8ba9cc88..a0f16eaf 100644
--- a/nisaba/interim/grm2/rewrite/base_rule_cascade.h
+++ b/nisaba/interim/grm2/rewrite/base_rule_cascade.h
@@ -234,7 +234,7 @@ bool BaseRuleCascade<Arc>::TopRewrite(absl::string_view input,
   debug->clear();
   std::vector<Label> labels;
   if (!TopRewrite(input, &labels)) return false;
-  if (!::fst::LabelsToString(labels, output, token_type_)) return false;
+  if (!::fst::LabelsToString<Label>(labels, output, token_type_)) return false;
   LabelsToDebugString(*output, labels, debug);
   return true;
 }
@@ -281,7 +281,7 @@ bool BaseRuleCascade<Arc>::OneTopRewrite(absl::string_view input,
   debug->clear();
   std::vector<Label> labels;
   if (!OneTopRewrite(input, &labels)) return false;
-  if (!::fst::LabelsToString(labels, output, token_type_)) return false;
+  if (!::fst::LabelsToString<Label>(labels, output, token_type_)) return false;
   LabelsToDebugString(*output, labels, debug);
   return true;
 }
@@ -332,7 +332,7 @@ bool BaseRuleCascade<Arc>::TopRewrites(absl::string_view input,
   for (const auto &labels : labelss) {
     output->emplace_back();
     debug->emplace_back();
-    if (!::fst::LabelsToString(labels, &output->back(), token_type_)) {
+    if (!::fst::LabelsToString<Label>(labels, &output->back(), token_type_)) {
       return false;
     }
     LabelsToDebugString(output->back(), labels, &debug->back());
@@ -394,7 +394,7 @@ bool BaseRuleCascade<Arc>::TopRewrites(absl::string_view input,
   for (const auto &labels : labelss) {
     output->emplace_back();
     debug->emplace_back();
-    if (!::fst::LabelsToString(labels, &output->back(), token_type_)) {
+    if (!::fst::LabelsToString<Label>(labels, &output->back(), token_type_)) {
       return false;
     }
     LabelsToDebugString(output->back(), labels, &debug->back());
@@ -455,7 +455,7 @@ bool BaseRuleCascade<Arc>::Rewrites(absl::string_view input,
   for (const auto &labels : labelss) {
     output->emplace_back();
     debug->emplace_back();
-    if (!::fst::LabelsToString(labels, &output->back(), token_type_)) {
+    if (!::fst::LabelsToString<Label>(labels, &output->back(), token_type_)) {
       return false;
     }
     LabelsToDebugString(output->back(), labels, &debug->back());
diff --git a/nisaba/interim/grm2/thrax/rewrite-tester.cc b/nisaba/interim/grm2/thrax/rewrite-tester.cc
index d946d6f8..005ff2fb 100644
--- a/nisaba/interim/grm2/thrax/rewrite-tester.cc
+++ b/nisaba/interim/grm2/thrax/rewrite-tester.cc
@@ -261,7 +261,7 @@ bool RewriteTester::AppendLabel(Label label, std::string *path) const {
       std::string utf8_string;
       std::vector<Label> labels;
       labels.push_back(label);
-      if (!LabelsToUTF8String(labels, &utf8_string)) {
+      if (!LabelsToUTF8String<Label>(labels, &utf8_string)) {
         LOG(ERROR) << "LabelsToUTF8String: Bad code point: " << label;
         return false;
       }
diff --git a/nisaba/interim/grm2/thrax/walker/util/function/symbols.cc b/nisaba/interim/grm2/thrax/walker/util/function/symbols.cc
index d584d0bb..1ef533a0 100644
--- a/nisaba/interim/grm2/thrax/walker/util/function/symbols.cc
+++ b/nisaba/interim/grm2/thrax/walker/util/function/symbols.cc
@@ -21,6 +21,7 @@
 #include <vector>
 
 #include "absl/synchronization/mutex.h"
+#include "fst/icu.h"
 #include "fst/string.h"
 
 namespace thrax {
@@ -194,7 +195,7 @@ void SymbolTableBuilder::GenerateUtf8SymbolTable() {
     std::vector<int> labels;
     labels.push_back(c);
     std::string utf8_label;
-    if (::fst::LabelsToUTF8String(labels, &utf8_label)) {
+    if (::fst::LabelsToUTF8String<int>(labels, &utf8_label)) {
       if (IsUnicodeSpaceOrControl(c)) {
         char c_str[7];
         snprintf(c_str, sizeof(c_str), "0x%04x", c);
diff --git a/nisaba/scripts/abjad_alphabet/__init__.py b/nisaba/scripts/abjad_alphabet/__init__.py
index 29de9369..4baf6f62 100644
--- a/nisaba/scripts/abjad_alphabet/__init__.py
+++ b/nisaba/scripts/abjad_alphabet/__init__.py
@@ -23,6 +23,7 @@
 import string
 
 import pynini
+
 from nisaba.scripts.abjad_alphabet import util as u
 from nisaba.scripts.utils import far
 from nisaba.scripts.utils import rewrite
diff --git a/nisaba/scripts/abjad_alphabet/fst_properties_test.py b/nisaba/scripts/abjad_alphabet/fst_properties_test.py
index 37ceb6bf..e63bfb1a 100644
--- a/nisaba/scripts/abjad_alphabet/fst_properties_test.py
+++ b/nisaba/scripts/abjad_alphabet/fst_properties_test.py
@@ -17,6 +17,7 @@
 import itertools
 
 import pynini
+
 from absl.testing import absltest
 from absl.testing import parameterized
 from nisaba.scripts.abjad_alphabet import util as u
diff --git a/nisaba/scripts/abjad_alphabet/nfc.py b/nisaba/scripts/abjad_alphabet/nfc.py
index 6fd13b3c..167a7648 100644
--- a/nisaba/scripts/abjad_alphabet/nfc.py
+++ b/nisaba/scripts/abjad_alphabet/nfc.py
@@ -17,7 +17,7 @@
 To try for Urdu:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   nisaba/scripts/abjad_alphabet:nfc
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -28,7 +28,7 @@
 """
 
 import pynini
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.abjad_alphabet import util as u
 from nisaba.scripts.utils import rule
 
diff --git a/nisaba/scripts/abjad_alphabet/reading_norm.py b/nisaba/scripts/abjad_alphabet/reading_norm.py
index 00a7ce53..b616a83f 100644
--- a/nisaba/scripts/abjad_alphabet/reading_norm.py
+++ b/nisaba/scripts/abjad_alphabet/reading_norm.py
@@ -17,7 +17,7 @@
 To try for Urdu:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   nisaba/scripts/abjad_alphabet:reading_norm
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -29,9 +29,8 @@
 """
 
 from absl import flags
-
 import pynini
-from pynini.export import grm
+from opengrm.pynini.export import grm
 import nisaba.scripts.abjad_alphabet.util as u
 from nisaba.scripts.utils import rule
 
diff --git a/nisaba/scripts/abjad_alphabet/reading_norm_utf8.py b/nisaba/scripts/abjad_alphabet/reading_norm_utf8.py
index 786ab0c5..14923309 100644
--- a/nisaba/scripts/abjad_alphabet/reading_norm_utf8.py
+++ b/nisaba/scripts/abjad_alphabet/reading_norm_utf8.py
@@ -17,7 +17,7 @@
 To try for Urdu:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   nisaba/scripts/abjad_alphabet:reading_norm
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -28,7 +28,7 @@
 ```
 """
 
-from pynini.export import grm
+from opengrm.pynini.export import grm
 from nisaba.scripts.abjad_alphabet import reading_norm
 
 
diff --git a/nisaba/scripts/abjad_alphabet/reversible_roman.py b/nisaba/scripts/abjad_alphabet/reversible_roman.py
index 78291f73..2fe5a49d 100644
--- a/nisaba/scripts/abjad_alphabet/reversible_roman.py
+++ b/nisaba/scripts/abjad_alphabet/reversible_roman.py
@@ -18,7 +18,7 @@
 
 ```shell
 ABJAD_ALPHABET_DIR=nisaba/scripts/abjad_alphabet
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   ${ABJAD_ALPHABET_DIR}:reversible_roman
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -29,7 +29,7 @@
 """
 
 import pynini
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.abjad_alphabet import util
 from nisaba.scripts.utils import file
 from nisaba.scripts.utils import rewrite
diff --git a/nisaba/scripts/abjad_alphabet/testdata/reading_norm.textproto b/nisaba/scripts/abjad_alphabet/testdata/reading_norm.textproto
index b59b9c2f..c9c0574f 100644
--- a/nisaba/scripts/abjad_alphabet/testdata/reading_norm.textproto
+++ b/nisaba/scripts/abjad_alphabet/testdata/reading_norm.textproto
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# proto-file: testing/testdata.proto
+# proto-file: third_party/opengrm/testing/testdata.proto
 # proto-message: Rewrites
 
 # Reading normalization test data.
diff --git a/nisaba/scripts/abjad_alphabet/testdata/visual_norm.textproto b/nisaba/scripts/abjad_alphabet/testdata/visual_norm.textproto
index 784ce144..9c730975 100644
--- a/nisaba/scripts/abjad_alphabet/testdata/visual_norm.textproto
+++ b/nisaba/scripts/abjad_alphabet/testdata/visual_norm.textproto
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# proto-file: testing/testdata.proto
+# proto-file: third_party/opengrm/testing/testdata.proto
 # proto-message: Rewrites
 
 # Unit tests for visual norm of abjad / alphabet script languages.
diff --git a/nisaba/scripts/abjad_alphabet/visual_norm.py b/nisaba/scripts/abjad_alphabet/visual_norm.py
index 8ae8d6bb..64e4f581 100644
--- a/nisaba/scripts/abjad_alphabet/visual_norm.py
+++ b/nisaba/scripts/abjad_alphabet/visual_norm.py
@@ -18,7 +18,7 @@
 To try for Urdu:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   nisaba/scripts/abjad_alphabet:visual_norm_byte
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -31,7 +31,7 @@
 
 from absl import flags
 import pynini
-from pynini.export import grm
+from opengrm.pynini.export import grm
 from nisaba.scripts.abjad_alphabet import visual_norm_common
 import nisaba.scripts.abjad_alphabet.util as u
 from nisaba.scripts.utils import rewrite
diff --git a/nisaba/scripts/brahmic/BUILD.bazel b/nisaba/scripts/brahmic/BUILD.bazel
index e11dbd57..f5c2f5a6 100644
--- a/nisaba/scripts/brahmic/BUILD.bazel
+++ b/nisaba/scripts/brahmic/BUILD.bazel
@@ -19,6 +19,7 @@ load("@rules_proto//proto:defs.bzl", "proto_library")
 
 load("@pip_deps//:requirements.bzl", "requirement")
 
+load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 load(
     "//nisaba/scripts/brahmic:constant.bzl",
     "FIXED_RULE_SCRIPTS",
@@ -89,7 +90,45 @@ nisaba_compile_multi_grm_py(
         "//nisaba/scripts/utils:file",
         "//nisaba/scripts/utils:rewrite",
         "@org_opengrm_pynini//pynini",
-        "@org_opengrm_pynini//pynini/lib:pynutil",
+        "@org_opengrm_pynini//pynini/pynini/lib:pynutil",
+    ],
+)
+
+nisaba_compile_multi_grm_py(
+    name = "iso_sttable",
+    src = "iso.py",
+    outs = {
+        "byte": "iso_sttable.far",
+        "utf8": "iso_sttable_utf8.far",
+    },
+    data = [
+        ":nfc.far",
+        ":nfc_utf8.far",
+        ":sigma_utf8.far",
+    ] + [
+        "//nisaba/scripts/brahmic/data/{}:{}.tsv".format(script, file_name)
+        for script in SCRIPTS
+        for file_name in [
+            "coda",
+            "consonant",
+            "dead_consonant",
+            "inherent_vowel",
+            "standalone",
+            "subjoined_consonant",
+            "virama",
+            "vowel",
+            "vowel_length_sign",
+            "vowel_sign",
+        ]
+    ] + ["//nisaba/scripts/brahmic/data:symbol.tsv"],
+    far_type = "sttable",
+    visibility = ["//visibility:public"],
+    deps = [
+        ":util",
+        "//nisaba/scripts/utils:file",
+        "//nisaba/scripts/utils:rewrite",
+        "@org_opengrm_pynini//pynini",
+        "@org_opengrm_pynini//pynini/pynini/lib:pynutil",
     ],
 )
 
@@ -173,12 +212,13 @@ nisaba_grm_textproto_test(
 py_library(
     name = "util",
     srcs = ["util.py"],
+    visibility = ["//visibility:public"],
     deps = [
         ":script_config_py_pb2",
         "//nisaba/scripts/utils:file",
-        "@com_google_protobuf//:protobuf_python",
+        "//third_party/py/google/protobuf",
         "@org_opengrm_pynini//pynini",
-        "@org_opengrm_pynini//pynini/lib:byte",
+        "@org_opengrm_pynini//pynini/pynini/lib:byte",
         "@rules_python//python/runfiles",
         requirement("pandas"),
     ],
@@ -223,13 +263,14 @@ py_library(
         "//nisaba/scripts/utils:char",
         "//nisaba/scripts/utils:rewrite",
         "@org_opengrm_pynini//pynini",
-        "@org_opengrm_pynini//pynini/lib:pynutil",
+        "@org_opengrm_pynini//pynini/pynini/lib:pynutil",
     ],
 )
 
 nisaba_compile_grm_py(
     name = "sigma",
     out = "sigma_utf8.far",
+    visibility = ["//visibility:public"],
     deps = [
         ":char_util",
         ":util",
@@ -321,7 +362,7 @@ nisaba_compile_script_lang_multi_grm_py(
         "//nisaba/scripts/utils:rule",
         "@io_abseil_py//absl/flags",
         "@org_opengrm_pynini//pynini",
-        "@org_opengrm_pynini//pynini/lib:pynutil",
+        "@org_opengrm_pynini//pynini/pynini/lib:pynutil",
     ],
 )
 
@@ -422,6 +463,7 @@ py_library(
         ":iso.far",
         ":nfc.far",
         ":reading_norm.far",
+        ":sigma_utf8.far",
         ":visual_norm.far",
         ":wellformed.far",
     ] + [
@@ -492,6 +534,7 @@ cc_library(
         "//nisaba/interim/grm2/thrax:grm-manager-lib",
         "//nisaba/port:file_util",
         "//nisaba/port:status_macros",
+        "@com_google_absl//absl/base:no_destructor",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
@@ -528,3 +571,10 @@ filegroup(
        ":wellformed.far",
    ],
 )
+
+bzl_library(
+    name = "constant_bzl",
+    srcs = ["constant.bzl"],
+    parse_tests = False,
+    visibility = ["//visibility:private"],
+)
diff --git a/nisaba/scripts/brahmic/__init__.py b/nisaba/scripts/brahmic/__init__.py
index cf5a4d6b..a2c117e0 100644
--- a/nisaba/scripts/brahmic/__init__.py
+++ b/nisaba/scripts/brahmic/__init__.py
@@ -20,6 +20,7 @@
 import string
 
 import pynini
+
 from nisaba.scripts.brahmic import util as u
 from nisaba.scripts.utils import far
 
@@ -58,6 +59,10 @@ def visual_norm(self) -> far.Far:
   def wellformed(self) -> far.Far:
     return far.Far(u.FAR_DIR / 'wellformed.far')
 
+  @functools.cached_property
+  def sigma(self) -> far.Far:
+    return far.Far(u.FAR_DIR / 'sigma_utf8.far')
+
 
 _FARS = _FarStore()
 
@@ -82,6 +87,23 @@ def WellFormed(script: str) -> far.Far.FstWrapper:
   return _FARS.wellformed.Fst(script.upper())
 
 
+def Sigma(script: str = 'Brahmic') -> far.Far.FstWrapper:
+  """Returns a sigma-star acceptor for a script.
+
+  The returned FstWrapper accepts any word composed entirely of
+  characters from the given script's alphabet. If no script is
+  specified, accepts words from any supported Brahmic script.
+
+  Args:
+    script: ISO 15924 script code (e.g. 'Mlym', 'Deva') or 'Brahmic' for the
+      union of all scripts. Defaults to 'Brahmic'.
+
+  Returns:
+    An FstWrapper with AcceptText() support.
+  """
+  return _FARS.sigma.Fst(script.upper() + '_STAR', token_type='utf8')
+
+
 class ScriptError(ValueError):
   pass
 
diff --git a/nisaba/scripts/brahmic/brahmic_test.py b/nisaba/scripts/brahmic/brahmic_test.py
index e286e502..592cdc2c 100644
--- a/nisaba/scripts/brahmic/brahmic_test.py
+++ b/nisaba/scripts/brahmic/brahmic_test.py
@@ -32,6 +32,28 @@ def setUp(self):
     self._wellformed_mlym = brahmic.WellFormed('Mlym')
     self._norm_acceptor_deva = brahmic.NormalizingAcceptor('Deva')
     self._norm_acceptor_sinh = brahmic.NormalizingAcceptor('Sinh')
+    self._sigma_brahmic = brahmic.Sigma('Brahmic')
+    self._sigma_deva = brahmic.Sigma('Deva')
+    self._sigma_mlym = brahmic.Sigma('Mlym')
+    self._wellformed_brahmic = brahmic.WellFormed('Brahmic')
+
+  def testSigma(self):
+    # Brahmic sigma accepts any word of supported Brahmic scripts
+    self.assertTrue(self._sigma_brahmic.AcceptText('लब'))
+    self.assertTrue(self._sigma_brahmic.AcceptText('നെ'))
+    self.assertTrue(
+        self._sigma_brahmic.AcceptText('काु')
+    )  # Accepts ill-formed too
+    # Reject strings with spaces, english, punctuation etc
+    self.assertFalse(self._sigma_brahmic.AcceptText('लब നെ'))
+    self.assertFalse(self._sigma_brahmic.AcceptText('abc'))
+    self.assertFalse(self._sigma_brahmic.AcceptText('लब.'))
+
+    # Script specific sigmas
+    self.assertTrue(self._sigma_deva.AcceptText('लब'))
+    self.assertFalse(self._sigma_deva.AcceptText('നെ'))
+    self.assertTrue(self._sigma_mlym.AcceptText('നെ'))
+    self.assertFalse(self._sigma_mlym.AcceptText('लब'))
 
   def testApplyOnText(self):
     self.assertEqual('क़्लब', self._nfc.ApplyOnText('क़्लब'))
@@ -46,6 +68,16 @@ def testAcceptText(self):
     self.assertFalse(self._wellformed_mlym.AcceptText('ന്‍'))
     self.assertFalse(self._wellformed_deva.AcceptText('लब ന്'))
 
+    # BRAHMIC wellformed acceptor tests
+    self.assertTrue(self._wellformed_brahmic.AcceptText('लब'))
+    self.assertTrue(self._wellformed_brahmic.AcceptText('മലയാളം'))
+    self.assertFalse(
+        self._wellformed_brahmic.AcceptText('काु')
+    )  # Devanagari ill-formed
+    self.assertFalse(
+        self._wellformed_brahmic.AcceptText('്ന')
+    )  # Malayalam ill-formed
+
   def testAcceptTextWarning(self):
     # Raises a warning about underlying FST.
     with warnings.catch_warnings(record=True) as warns:
diff --git a/nisaba/scripts/brahmic/char_util.py b/nisaba/scripts/brahmic/char_util.py
index d2d4ec51..df9cf278 100644
--- a/nisaba/scripts/brahmic/char_util.py
+++ b/nisaba/scripts/brahmic/char_util.py
@@ -15,11 +15,11 @@
 """Acyclic acceptor accepting characters from Brahmic scripts."""
 
 from collections.abc import Iterable
-
 import unicodedata
 
 import pynini
-from pynini.lib import pynutil
+from opengrm.pynini.lib import pynutil
+
 import nisaba.scripts.brahmic.util as u
 import nisaba.scripts.utils.char as uc
 import nisaba.scripts.utils.rewrite as ur
diff --git a/nisaba/scripts/brahmic/fixed.py b/nisaba/scripts/brahmic/fixed.py
index ef0328e0..344e7d17 100644
--- a/nisaba/scripts/brahmic/fixed.py
+++ b/nisaba/scripts/brahmic/fixed.py
@@ -28,7 +28,7 @@
 To try:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   nisaba/scripts/brahmic:fixed
 
 cat /tmp/ml-latn-text.txt |
@@ -41,7 +41,8 @@
 import string
 
 import pynini
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
+
 import nisaba.scripts.brahmic.util as u
 from nisaba.scripts.utils import rule
 import nisaba.scripts.utils.char as uc
diff --git a/nisaba/scripts/brahmic/fst_properties_test.py b/nisaba/scripts/brahmic/fst_properties_test.py
index 69478a5f..1862ee19 100644
--- a/nisaba/scripts/brahmic/fst_properties_test.py
+++ b/nisaba/scripts/brahmic/fst_properties_test.py
@@ -17,6 +17,7 @@
 import itertools
 
 import pynini
+
 from absl.testing import absltest
 from absl.testing import parameterized
 from nisaba.scripts.brahmic import util as u
@@ -28,20 +29,37 @@ class FstPropertiesTest(parameterized.TestCase,
 
   @parameterized.parameters(
       itertools.product(
-          u.SCRIPTS,
-          (pynini.ACYCLIC, pynini.UNWEIGHTED, pynini.I_DETERMINISTIC,
-           pynini.NO_EPSILONS, pynini.ACCESSIBLE, pynini.COACCESSIBLE,
-           pynini.ACCEPTOR)))
+          u.SCRIPTS + ['Brahmic'],
+          (
+              pynini.ACYCLIC,
+              pynini.UNWEIGHTED,
+              pynini.I_DETERMINISTIC,
+              pynini.NO_EPSILONS,
+              pynini.ACCESSIBLE,
+              pynini.COACCESSIBLE,
+              pynini.ACCEPTOR,
+          ),
+      )
+  )
   def test_sigma_utf8(self, script: str, prop: pynini.FstProperties):
     fst = u.OpenFstFromBrahmicFar('sigma', script, token_type='utf8')
     self.AssertFstCompliesWithProperties(fst, prop)
 
   @parameterized.parameters(
       itertools.product(
-          u.SCRIPTS,
-          (pynini.CYCLIC, pynini.UNWEIGHTED, pynini.I_DETERMINISTIC,
-           pynini.NO_EPSILONS, pynini.ACCESSIBLE, pynini.COACCESSIBLE,
-           pynini.ACCEPTOR), ('byte', 'utf8')))
+          u.SCRIPTS + ['Brahmic'],
+          (
+              pynini.CYCLIC,
+              pynini.UNWEIGHTED,
+              pynini.I_DETERMINISTIC,
+              pynini.NO_EPSILONS,
+              pynini.ACCESSIBLE,
+              pynini.COACCESSIBLE,
+              pynini.ACCEPTOR,
+          ),
+          ('byte', 'utf8'),
+      )
+  )
   def test_wellformed(self, script: str, prop: pynini.FstProperties,
                       token_type: str):
     fst = u.OpenFstFromBrahmicFar('wellformed', script, token_type)
diff --git a/nisaba/scripts/brahmic/grammar.cc b/nisaba/scripts/brahmic/grammar.cc
index c22b946b..8f836724 100644
--- a/nisaba/scripts/brahmic/grammar.cc
+++ b/nisaba/scripts/brahmic/grammar.cc
@@ -14,14 +14,16 @@
 
 #include "nisaba/scripts/brahmic/grammar.h"
 
+#include <map>
 #include <memory>
 
-#include "nisaba/interim/grm2/thrax/grm-manager.h"
+#include "absl/base/no_destructor.h"
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
 #include "absl/strings/ascii.h"
 #include "absl/strings/str_cat.h"
 #include "nisaba/port/file_util.h"
+#include "third_party/opengrm/thrax/grm-manager.h"
 #include "nisaba/port/status_macros.h"
 
 namespace nisaba {
@@ -73,14 +75,22 @@ absl::Status Grammar::VerifyLoad() {
   const auto far_path = file::GetRunfilesResourcePath(far_file_path_);
   if (!far_path.ok()) return far_path.status();
 
-  static const std::map<std::string, std::string>& lang_script_map =
-      {{"bn", "Beng"}, {"gu", "Gujr"}, {"hi", "Deva"}, {"kn", "Knda"},
-       {"ml", "Mlym"}, {"mr", "Deva"}, {"or", "Orya"}, {"pa", "Guru"},
-       {"si", "Sinh"}, {"ta", "Taml"}, {"te", "Telu"}};
+  static const absl::NoDestructor<std::map<std::string, std::string>>
+      lang_script_map({{"bn", "Beng"},
+                       {"gu", "Gujr"},
+                       {"hi", "Deva"},
+                       {"kn", "Knda"},
+                       {"ml", "Mlym"},
+                       {"mr", "Deva"},
+                       {"or", "Orya"},
+                       {"pa", "Guru"},
+                       {"si", "Sinh"},
+                       {"ta", "Taml"},
+                       {"te", "Telu"}});
 
   if (grm_mgr_->GetFstMap()->count(fst_name_) == 0) {
-    const auto entry = lang_script_map.find(absl::AsciiStrToLower(fst_name_));
-    if (entry == lang_script_map.end()) {
+    const auto entry = lang_script_map->find(absl::AsciiStrToLower(fst_name_));
+    if (entry == lang_script_map->end()) {
       return absl::InternalError(absl::StrCat(
           "FST \"", fst_name_, "\" not found in lowercase inside FAR \"",
           far_path.value(), "\""));
diff --git a/nisaba/scripts/brahmic/grammar.h b/nisaba/scripts/brahmic/grammar.h
index 4d90e42f..2b811722 100644
--- a/nisaba/scripts/brahmic/grammar.h
+++ b/nisaba/scripts/brahmic/grammar.h
@@ -20,11 +20,11 @@
 #include <memory>
 #include <string>
 
-#include "nisaba/interim/grm2/thrax/grm-manager.h"
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
 #include "absl/strings/ascii.h"
 #include "absl/strings/string_view.h"
+#include "third_party/opengrm/thrax/grm-manager.h"
 
 namespace nisaba {
 namespace brahmic {
diff --git a/nisaba/scripts/brahmic/iso.py b/nisaba/scripts/brahmic/iso.py
index d3f2474d..2f65fda8 100644
--- a/nisaba/scripts/brahmic/iso.py
+++ b/nisaba/scripts/brahmic/iso.py
@@ -19,7 +19,7 @@
 To try:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   nisaba/scripts/brahmic:iso
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -31,7 +31,7 @@
 To create input - output tsv:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   nisaba/scripts/brahmic:iso
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -47,8 +47,9 @@
 import os
 
 import pynini as p
-from pynini.export import multi_grm
-from pynini.lib import pynutil as pu
+from opengrm.pynini.export import multi_grm
+from opengrm.pynini.lib import pynutil as pu
+
 from nisaba.scripts.brahmic import util as u
 from nisaba.scripts.utils import file as f
 from nisaba.scripts.utils import rewrite as rw
diff --git a/nisaba/scripts/brahmic/nfc.py b/nisaba/scripts/brahmic/nfc.py
index f2432a27..009e3e3c 100644
--- a/nisaba/scripts/brahmic/nfc.py
+++ b/nisaba/scripts/brahmic/nfc.py
@@ -18,7 +18,7 @@
 To try each rule:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
   nisaba/scripts/brahmic:nfc
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -28,7 +28,7 @@
 """
 
 import pynini
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 import nisaba.scripts.brahmic.util as u
 import nisaba.scripts.utils.rule as r
 
diff --git a/nisaba/scripts/brahmic/randgen_test.py b/nisaba/scripts/brahmic/randgen_test.py
index 574c1c5d..1fe0f0e7 100644
--- a/nisaba/scripts/brahmic/randgen_test.py
+++ b/nisaba/scripts/brahmic/randgen_test.py
@@ -17,6 +17,7 @@
 import itertools
 
 import pynini
+
 from absl.testing import absltest
 from absl.testing import parameterized
 from nisaba.scripts.brahmic import util as u
diff --git a/nisaba/scripts/brahmic/reading_norm.py b/nisaba/scripts/brahmic/reading_norm.py
index 6bc1c4da..917077ed 100644
--- a/nisaba/scripts/brahmic/reading_norm.py
+++ b/nisaba/scripts/brahmic/reading_norm.py
@@ -17,7 +17,7 @@
 To try each rule:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
                    nisaba/scripts/brahmic:reading_norm
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -29,9 +29,9 @@
 import pathlib
 
 from absl import flags
-
 import pynini
-from pynini.export import grm
+from opengrm.pynini.export import grm
+
 import nisaba.scripts.brahmic.util as u
 from nisaba.scripts.utils import file
 from nisaba.scripts.utils import rewrite
diff --git a/nisaba/scripts/brahmic/sigma.py b/nisaba/scripts/brahmic/sigma.py
index 6d0e14e6..ca2f3db6 100644
--- a/nisaba/scripts/brahmic/sigma.py
+++ b/nisaba/scripts/brahmic/sigma.py
@@ -15,7 +15,7 @@
 """Acyclic acceptor accepting characters from Brahmic scripts."""
 
 import pynini
-from pynini.export import grm
+from opengrm.pynini.export import grm
 import nisaba.scripts.brahmic.char_util as cu
 import nisaba.scripts.brahmic.util as u
 import nisaba.scripts.utils.char as uc
@@ -27,9 +27,19 @@ def generator_main(exporter: grm.Exporter):
   # NOTE: It isn't useful for us to create a byte-mode sigma, so only export
   # utf8-mode sigma.
   with pynini.default_token_type('utf8'):
+    all_sigmas = []
     for script in u.SCRIPTS:
       chars = cu.script_chars(script)
-      exporter[script.upper()] = uc.derive_sigma(chars)
+      sigma = uc.derive_sigma(chars)
+      exporter[script.upper()] = sigma
+      # Accepts words (multi-character strings), not just single characters.
+      exporter[script.upper() + '_STAR'] = pynini.closure(sigma).optimize()
+      all_sigmas.append(sigma)
+
+    # Union of all script sigmas.
+    brahmic_sigma = pynini.union(*all_sigmas).optimize()
+    exporter['BRAHMIC'] = brahmic_sigma
+    exporter['BRAHMIC_STAR'] = pynini.closure(brahmic_sigma).optimize()
 
 
 if __name__ == '__main__':
diff --git a/nisaba/scripts/brahmic/util.py b/nisaba/scripts/brahmic/util.py
index 14e483eb..0e17a8ed 100644
--- a/nisaba/scripts/brahmic/util.py
+++ b/nisaba/scripts/brahmic/util.py
@@ -19,7 +19,8 @@
 
 from google.protobuf import text_format
 import pynini
-from pynini.lib import byte
+from opengrm.pynini.lib import byte
+
 from nisaba.scripts.brahmic import script_config_pb2
 import nisaba.scripts.utils.file as uf
 
@@ -31,18 +32,22 @@ def BuildSigmaFstFromSymbolTable(syms: pynini.SymbolTableView) -> pynini.Fst:
   final_state = f.add_state()
   f.set_final(final_state)
   for lbl, _ in syms:
-    f.add_arc(start_state,
-              pynini.Arc(lbl, lbl, pynini.Weight.one("tropical"), final_state))
+    f.add_arc(
+        start_state,
+        pynini.Arc(lbl, lbl, pynini.Weight.one("tropical"), final_state),
+    )
   return f
 
 
-def OpenFstFromBrahmicFar(far_name: str, fst_name: str,
-                          token_type: str) -> pynini.Fst:
+def OpenFstFromBrahmicFar(
+    far_name: str, fst_name: str, token_type: str
+) -> pynini.Fst:
   return uf.OpenFstFromFar(FAR_DIR, far_name, token_type, fst_name)
 
 
-def OpenFstFromBrahmicFarSafe(far_name: str, fst_name: str, token_type: str,
-                              default: pynini.Fst) -> pynini.Fst:
+def OpenFstFromBrahmicFarSafe(
+    far_name: str, fst_name: str, token_type: str, default: pynini.Fst
+) -> pynini.Fst:
   """Returns FST from a given FAR; returns default if FST is not found."""
   return uf.OpenFstFromFarSafe(FAR_DIR, far_name, token_type, fst_name, default)
 
@@ -58,7 +63,8 @@ def OpenSigma(script: str, token_type: str) -> pynini.Fst:
 
 
 def MaybeLoadScriptConfig(
-    file_path: os.PathLike[str]) -> script_config_pb2.ScriptConfig:
+    file_path: os.PathLike[str],
+) -> script_config_pb2.ScriptConfig:
   """Loads script configuration, if present."""
   pb = script_config_pb2.ScriptConfig()
   if not uf.IsFileExist(file_path):
diff --git a/nisaba/scripts/brahmic/visual_norm.py b/nisaba/scripts/brahmic/visual_norm.py
index 0a41025a..3566d85a 100644
--- a/nisaba/scripts/brahmic/visual_norm.py
+++ b/nisaba/scripts/brahmic/visual_norm.py
@@ -17,7 +17,7 @@
 To try each rule:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
                    nisaba/scripts/brahmic:visual_norm
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -30,8 +30,9 @@
 
 from absl import flags
 import pynini
-from pynini.export import grm
-from pynini.lib import pynutil
+from opengrm.pynini.export import grm
+from opengrm.pynini.lib import pynutil
+
 import nisaba.scripts.brahmic.char_util as cu
 import nisaba.scripts.brahmic.util as u
 from nisaba.scripts.utils import rule
diff --git a/nisaba/scripts/brahmic/wellformed.py b/nisaba/scripts/brahmic/wellformed.py
index ccb5eee6..26924005 100644
--- a/nisaba/scripts/brahmic/wellformed.py
+++ b/nisaba/scripts/brahmic/wellformed.py
@@ -17,7 +17,7 @@
 To try:
 
 ```sh
-bazel build -c opt nlp/grm2/thrax:rewrite-tester \
+bazel build -c opt third_party/opengrm/thrax:rewrite-tester \
                    nisaba/scripts/brahmic:wellformed
 
 bazel-bin/nisaba/interim/grm2/thrax/rewrite-tester \
@@ -30,7 +30,8 @@
 import os
 
 import pynini
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
+
 import nisaba.scripts.brahmic.util as u
 import nisaba.scripts.utils.file as uf
 
@@ -128,8 +129,9 @@ def generator_main(exporter_map: multi_grm.ExporterMapping):
   for token_type in ('byte', 'utf8'):
     with pynini.default_token_type(token_type):
       exporter = exporter_map[token_type]
+      all_wellformed = []
       for script in u.SCRIPTS:
-        exporter[script.upper()] = accept_well_formed(
+        wf = accept_well_formed(
             u.SCRIPT_DIR / script / 'script_config.textproto',
             u.SCRIPT_DIR / script / 'consonant.tsv',
             u.SCRIPT_DIR / script / 'dead_consonant.tsv',
@@ -141,7 +143,13 @@ def generator_main(exporter_map: multi_grm.ExporterMapping):
             u.SCRIPT_DIR / script / 'standalone.tsv',
             u.SCRIPT_DIR / script / 'virama.tsv',
             u.SCRIPT_DIR / script / 'accept.tsv',
-            u.SCRIPT_DIR / script / 'preserve.tsv')
+            u.SCRIPT_DIR / script / 'preserve.tsv',
+        )
+        exporter[script.upper()] = wf
+        all_wellformed.append(wf)
+
+      # Union of all script wellformed acceptors.
+      exporter['BRAHMIC'] = pynini.union(*all_wellformed).optimize()
 
 
 if __name__ == '__main__':
diff --git a/nisaba/scripts/natural_translit/brahmic/deromanizer.py b/nisaba/scripts/natural_translit/brahmic/deromanizer.py
index 23fa8646..52a6ce2e 100644
--- a/nisaba/scripts/natural_translit/brahmic/deromanizer.py
+++ b/nisaba/scripts/natural_translit/brahmic/deromanizer.py
@@ -20,6 +20,7 @@
 from typing import Any, Union
 
 import pynini as pyn
+
 from nisaba.scripts.natural_translit.brahmic import derom_inventory as derom
 from nisaba.scripts.natural_translit.brahmic import grapheme_inventory as gr
 from nisaba.scripts.natural_translit.latin import ltn_inventory
diff --git a/nisaba/scripts/natural_translit/brahmic/en_spellout.py b/nisaba/scripts/natural_translit/brahmic/en_spellout.py
index e558e65f..0a459684 100644
--- a/nisaba/scripts/natural_translit/brahmic/en_spellout.py
+++ b/nisaba/scripts/natural_translit/brahmic/en_spellout.py
@@ -17,6 +17,7 @@
 import itertools
 
 import pynini as pyn
+
 from nisaba.scripts.natural_translit.utils import fst_list as fl
 from nisaba.scripts.natural_translit.utils import inventory as i
 from nisaba.scripts.natural_translit.utils import type_op as ty
diff --git a/nisaba/scripts/natural_translit/deromanization/en_spellout.py b/nisaba/scripts/natural_translit/deromanization/en_spellout.py
index 228c8a9f..78a387b4 100644
--- a/nisaba/scripts/natural_translit/deromanization/en_spellout.py
+++ b/nisaba/scripts/natural_translit/deromanization/en_spellout.py
@@ -14,7 +14,7 @@
 
 """English letter spellout for various South Asian languages."""
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.brahmic import en_spellout
 
 _LANG_SCRIPTS = (
diff --git a/nisaba/scripts/natural_translit/deromanization/hi_deva.py b/nisaba/scripts/natural_translit/deromanization/hi_deva.py
index a59cdfd2..95c7638b 100644
--- a/nisaba/scripts/natural_translit/deromanization/hi_deva.py
+++ b/nisaba/scripts/natural_translit/deromanization/hi_deva.py
@@ -14,7 +14,7 @@
 
 """Rule based deromanizer for hi_deva."""
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import hi
 
 
diff --git a/nisaba/scripts/natural_translit/deromanization/hi_iso.py b/nisaba/scripts/natural_translit/deromanization/hi_iso.py
index 0bfb6d33..6a157bde 100644
--- a/nisaba/scripts/natural_translit/deromanization/hi_iso.py
+++ b/nisaba/scripts/natural_translit/deromanization/hi_iso.py
@@ -14,7 +14,7 @@
 
 """Rule based deromanizer for hi_iso."""
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import hi
 
 
diff --git a/nisaba/scripts/natural_translit/deromanization/ta_iso.py b/nisaba/scripts/natural_translit/deromanization/ta_iso.py
index 29f837a8..53eef29c 100644
--- a/nisaba/scripts/natural_translit/deromanization/ta_iso.py
+++ b/nisaba/scripts/natural_translit/deromanization/ta_iso.py
@@ -14,7 +14,7 @@
 
 """Rule based deromanizer for ta_iso."""
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ta
 
 
diff --git a/nisaba/scripts/natural_translit/deromanization/ta_taml.py b/nisaba/scripts/natural_translit/deromanization/ta_taml.py
index 899f464b..afd0d7b1 100644
--- a/nisaba/scripts/natural_translit/deromanization/ta_taml.py
+++ b/nisaba/scripts/natural_translit/deromanization/ta_taml.py
@@ -14,7 +14,7 @@
 
 """Rule based deromanizer for ta_taml."""
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ta
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/bn_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/bn_iso_ipa.py
index 4fef889d..97e5d1e8 100644
--- a/nisaba/scripts/natural_translit/g2p/bn_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/bn_iso_ipa.py
@@ -16,7 +16,7 @@
 """ISO to IPA grammar for Bengali."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import bn
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/gu_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/gu_iso_ipa.py
index 0e041707..e2ea4d3b 100644
--- a/nisaba/scripts/natural_translit/g2p/gu_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/gu_iso_ipa.py
@@ -16,7 +16,7 @@
 """ISO to IPA grammar for Gujarati."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import gu
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/hi_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/hi_iso_ipa.py
index 0bd27964..60bd62c4 100644
--- a/nisaba/scripts/natural_translit/g2p/hi_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/hi_iso_ipa.py
@@ -16,7 +16,7 @@
 """ISO to IPA grammar for Hindi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import hi
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/kn_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/kn_iso_ipa.py
index 0926c4a2..0f60700a 100644
--- a/nisaba/scripts/natural_translit/g2p/kn_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/kn_iso_ipa.py
@@ -16,7 +16,7 @@
 """ISO to IPA grammar for Kannada."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import kn
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/ml_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/ml_iso_ipa.py
index cc9a4873..4e217ded 100644
--- a/nisaba/scripts/natural_translit/g2p/ml_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/ml_iso_ipa.py
@@ -16,7 +16,7 @@
 """ISO to IPA grammar for Malayalam."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ml
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/mr_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/mr_iso_ipa.py
index 7fcc57f7..33d047df 100644
--- a/nisaba/scripts/natural_translit/g2p/mr_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/mr_iso_ipa.py
@@ -16,7 +16,7 @@
 """ISO to IPA grammar for Marathi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import mr
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/pa_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/pa_iso_ipa.py
index 7f36e05c..45d0c1c3 100644
--- a/nisaba/scripts/natural_translit/g2p/pa_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/pa_iso_ipa.py
@@ -16,7 +16,7 @@
 """Gurmukhi ISO to IPA grammar for Punjabi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import pa
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/ta_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/ta_iso_ipa.py
index 47daeba3..357831ab 100644
--- a/nisaba/scripts/natural_translit/g2p/ta_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/ta_iso_ipa.py
@@ -16,7 +16,7 @@
 """ISO to IPA grammar for Tamil."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ta
 
 
diff --git a/nisaba/scripts/natural_translit/g2p/te_iso_ipa.py b/nisaba/scripts/natural_translit/g2p/te_iso_ipa.py
index d3a4265b..47f750b9 100644
--- a/nisaba/scripts/natural_translit/g2p/te_iso_ipa.py
+++ b/nisaba/scripts/natural_translit/g2p/te_iso_ipa.py
@@ -16,7 +16,7 @@
 """ISO to IPA grammar for Telugu."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import te
 
 
diff --git a/nisaba/scripts/natural_translit/languages/hi_e2e.py b/nisaba/scripts/natural_translit/languages/hi_e2e.py
index 69c37ca0..b9cf59d9 100644
--- a/nisaba/scripts/natural_translit/languages/hi_e2e.py
+++ b/nisaba/scripts/natural_translit/languages/hi_e2e.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Hindi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import hi
 
 
diff --git a/nisaba/scripts/natural_translit/languages/kn_e2e.py b/nisaba/scripts/natural_translit/languages/kn_e2e.py
index 541008f2..12a97935 100644
--- a/nisaba/scripts/natural_translit/languages/kn_e2e.py
+++ b/nisaba/scripts/natural_translit/languages/kn_e2e.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Kannada."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import kn
 
 
diff --git a/nisaba/scripts/natural_translit/languages/ml_e2e.py b/nisaba/scripts/natural_translit/languages/ml_e2e.py
index 195088ad..836189e4 100644
--- a/nisaba/scripts/natural_translit/languages/ml_e2e.py
+++ b/nisaba/scripts/natural_translit/languages/ml_e2e.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Malayalam."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ml
 
 
diff --git a/nisaba/scripts/natural_translit/languages/ta_e2e.py b/nisaba/scripts/natural_translit/languages/ta_e2e.py
index 158f8207..ce8b5475 100644
--- a/nisaba/scripts/natural_translit/languages/ta_e2e.py
+++ b/nisaba/scripts/natural_translit/languages/ta_e2e.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Malayalam."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ta
 
 
diff --git a/nisaba/scripts/natural_translit/languages/te_e2e.py b/nisaba/scripts/natural_translit/languages/te_e2e.py
index d381687e..ce6758f3 100644
--- a/nisaba/scripts/natural_translit/languages/te_e2e.py
+++ b/nisaba/scripts/natural_translit/languages/te_e2e.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Telugu."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import te
 
 
diff --git a/nisaba/scripts/natural_translit/phonology/phon.py b/nisaba/scripts/natural_translit/phonology/phon.py
index e2a24826..eab798f7 100644
--- a/nisaba/scripts/natural_translit/phonology/phon.py
+++ b/nisaba/scripts/natural_translit/phonology/phon.py
@@ -19,6 +19,7 @@
 from typing import Union
 
 import pynini as pyn
+
 from nisaba.scripts.natural_translit.utils import alignment as al
 from nisaba.scripts.natural_translit.utils import fst_list as fl
 from nisaba.scripts.natural_translit.utils import inventory as i
diff --git a/nisaba/scripts/natural_translit/romanization/bn_iso_nat.py b/nisaba/scripts/natural_translit/romanization/bn_iso_nat.py
index 8ba62232..b431ab4d 100644
--- a/nisaba/scripts/natural_translit/romanization/bn_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/bn_iso_nat.py
@@ -16,7 +16,7 @@
 """ISO to natural transliteration for Bengali."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import bn
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/bn_iso_psac.py b/nisaba/scripts/natural_translit/romanization/bn_iso_psac.py
index a6d65d32..e0e25c53 100644
--- a/nisaba/scripts/natural_translit/romanization/bn_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/bn_iso_psac.py
@@ -16,7 +16,7 @@
 """ISO to coarse Pan South Asian transliteration for Bengali."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import bn
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/bn_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/bn_iso_psaf.py
index 64bbfca6..d8e5e684 100644
--- a/nisaba/scripts/natural_translit/romanization/bn_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/bn_iso_psaf.py
@@ -16,7 +16,7 @@
 """ISO to fine Pan South Asian transliteration for Bengali."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import bn
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/gu_iso_nat.py b/nisaba/scripts/natural_translit/romanization/gu_iso_nat.py
index 51763c2c..1924b134 100644
--- a/nisaba/scripts/natural_translit/romanization/gu_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/gu_iso_nat.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Gujarati."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import gu
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/gu_iso_psac.py b/nisaba/scripts/natural_translit/romanization/gu_iso_psac.py
index 448ff957..31754e32 100644
--- a/nisaba/scripts/natural_translit/romanization/gu_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/gu_iso_psac.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Gujarati."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import gu
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/gu_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/gu_iso_psaf.py
index 2443efc7..9a90bff7 100644
--- a/nisaba/scripts/natural_translit/romanization/gu_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/gu_iso_psaf.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Gujarati."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import gu
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/hi_iso_nat.py b/nisaba/scripts/natural_translit/romanization/hi_iso_nat.py
index 2e3b4865..08eb9bf2 100644
--- a/nisaba/scripts/natural_translit/romanization/hi_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/hi_iso_nat.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Hindi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import hi
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/hi_iso_psac.py b/nisaba/scripts/natural_translit/romanization/hi_iso_psac.py
index 53a064c2..178538c0 100644
--- a/nisaba/scripts/natural_translit/romanization/hi_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/hi_iso_psac.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Hindi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import hi
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/hi_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/hi_iso_psaf.py
index 7952811e..62e2bf79 100644
--- a/nisaba/scripts/natural_translit/romanization/hi_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/hi_iso_psaf.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Hindi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import hi
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/kn_iso_nat.py b/nisaba/scripts/natural_translit/romanization/kn_iso_nat.py
index 2583bcd7..03603337 100644
--- a/nisaba/scripts/natural_translit/romanization/kn_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/kn_iso_nat.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Kannada."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import kn
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/kn_iso_psac.py b/nisaba/scripts/natural_translit/romanization/kn_iso_psac.py
index 840add81..811da914 100644
--- a/nisaba/scripts/natural_translit/romanization/kn_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/kn_iso_psac.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Kannada."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import kn
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/kn_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/kn_iso_psaf.py
index 64279024..0c86834e 100644
--- a/nisaba/scripts/natural_translit/romanization/kn_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/kn_iso_psaf.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Kannada."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import kn
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/ml_iso_nat.py b/nisaba/scripts/natural_translit/romanization/ml_iso_nat.py
index 5305f630..10883e88 100644
--- a/nisaba/scripts/natural_translit/romanization/ml_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/ml_iso_nat.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Malayalam."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ml
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/ml_iso_psac.py b/nisaba/scripts/natural_translit/romanization/ml_iso_psac.py
index f3a834bb..cf14b281 100644
--- a/nisaba/scripts/natural_translit/romanization/ml_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/ml_iso_psac.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Malayalam."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ml
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/ml_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/ml_iso_psaf.py
index eb42b8a1..6f8fef18 100644
--- a/nisaba/scripts/natural_translit/romanization/ml_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/ml_iso_psaf.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Malayalam."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ml
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/mr_iso_nat.py b/nisaba/scripts/natural_translit/romanization/mr_iso_nat.py
index f83e0ce3..78df9912 100644
--- a/nisaba/scripts/natural_translit/romanization/mr_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/mr_iso_nat.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Marathi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import mr
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/mr_iso_psac.py b/nisaba/scripts/natural_translit/romanization/mr_iso_psac.py
index 697d4c41..958983d7 100644
--- a/nisaba/scripts/natural_translit/romanization/mr_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/mr_iso_psac.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Marathi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import mr
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/mr_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/mr_iso_psaf.py
index b8f18abe..e175e2f6 100644
--- a/nisaba/scripts/natural_translit/romanization/mr_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/mr_iso_psaf.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Marathi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import mr
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/pa_iso_nat.py b/nisaba/scripts/natural_translit/romanization/pa_iso_nat.py
index 95b90986..0d3a7c67 100644
--- a/nisaba/scripts/natural_translit/romanization/pa_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/pa_iso_nat.py
@@ -16,7 +16,7 @@
 """Gurmukhi ISO to natural transliteration for Punjabi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import pa
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/pa_iso_psac.py b/nisaba/scripts/natural_translit/romanization/pa_iso_psac.py
index e30c2a64..d8fbca49 100644
--- a/nisaba/scripts/natural_translit/romanization/pa_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/pa_iso_psac.py
@@ -16,7 +16,7 @@
 """Gurmukhi ISO to coarse Pan South Asian transliteration for Punjabi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import pa
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/pa_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/pa_iso_psaf.py
index 1c69d650..4b34330d 100644
--- a/nisaba/scripts/natural_translit/romanization/pa_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/pa_iso_psaf.py
@@ -16,7 +16,7 @@
 """Gurmukhi ISO to fine Pan South Asian transliteration for Punjabi."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import pa
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/ta_iso_nat.py b/nisaba/scripts/natural_translit/romanization/ta_iso_nat.py
index 52b5fb0d..8db2d4a0 100644
--- a/nisaba/scripts/natural_translit/romanization/ta_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/ta_iso_nat.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Tamil."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ta
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/ta_iso_psac.py b/nisaba/scripts/natural_translit/romanization/ta_iso_psac.py
index 2853de4f..d95142f8 100644
--- a/nisaba/scripts/natural_translit/romanization/ta_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/ta_iso_psac.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Tamil."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ta
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/ta_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/ta_iso_psaf.py
index f9e1a7d8..46e2953d 100644
--- a/nisaba/scripts/natural_translit/romanization/ta_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/ta_iso_psaf.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Tamil."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import ta
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/te_iso_nat.py b/nisaba/scripts/natural_translit/romanization/te_iso_nat.py
index 0115b363..c6137a8f 100644
--- a/nisaba/scripts/natural_translit/romanization/te_iso_nat.py
+++ b/nisaba/scripts/natural_translit/romanization/te_iso_nat.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Telugu."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import te
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/te_iso_psac.py b/nisaba/scripts/natural_translit/romanization/te_iso_psac.py
index e8eea3e5..96d44f1a 100644
--- a/nisaba/scripts/natural_translit/romanization/te_iso_psac.py
+++ b/nisaba/scripts/natural_translit/romanization/te_iso_psac.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Telugu."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import te
 
 
diff --git a/nisaba/scripts/natural_translit/romanization/te_iso_psaf.py b/nisaba/scripts/natural_translit/romanization/te_iso_psaf.py
index f766d933..9cb2d66a 100644
--- a/nisaba/scripts/natural_translit/romanization/te_iso_psaf.py
+++ b/nisaba/scripts/natural_translit/romanization/te_iso_psaf.py
@@ -16,7 +16,7 @@
 """End-to-end natural transliteration for Telugu."""
 
 import pynini as pyn
-from pynini.export import multi_grm
+from opengrm.pynini.export import multi_grm
 from nisaba.scripts.natural_translit.language_params import te
 
 
diff --git a/nisaba/scripts/natural_translit/utils/BUILD.bazel b/nisaba/scripts/natural_translit/utils/BUILD.bazel
index 56d4112f..7f200e7e 100644
--- a/nisaba/scripts/natural_translit/utils/BUILD.bazel
+++ b/nisaba/scripts/natural_translit/utils/BUILD.bazel
@@ -75,7 +75,7 @@ py_library(
     deps = [
         ":fst_list",
         "@org_opengrm_pynini//pynini",
-        "@org_opengrm_pynini//pynini/lib:byte",
+        "@org_opengrm_pynini//pynini/pynini/lib:byte",
     ],
 )
 
diff --git a/nisaba/scripts/natural_translit/utils/alignment.py b/nisaba/scripts/natural_translit/utils/alignment.py
index 9fc775bc..1505b2cf 100644
--- a/nisaba/scripts/natural_translit/utils/alignment.py
+++ b/nisaba/scripts/natural_translit/utils/alignment.py
@@ -16,7 +16,7 @@
 """Alignment forming functions and constants."""
 
 import pynini as pyn
-from pynini.lib import byte
+from opengrm.pynini.lib import byte
 from nisaba.scripts.natural_translit.utils import fst_list as fl
 
 # Constants
diff --git a/nisaba/scripts/natural_translit/utils/fst_list.py b/nisaba/scripts/natural_translit/utils/fst_list.py
index f3743321..4892a2f9 100644
--- a/nisaba/scripts/natural_translit/utils/fst_list.py
+++ b/nisaba/scripts/natural_translit/utils/fst_list.py
@@ -20,6 +20,7 @@
 from typing import Any
 
 import pynini as pyn
+
 from nisaba.scripts.natural_translit.utils import type_op as ty
 from nisaba.scripts.utils import rewrite
 
diff --git a/nisaba/scripts/natural_translit/utils/log_op.py b/nisaba/scripts/natural_translit/utils/log_op.py
index bd40c084..89551dfa 100644
--- a/nisaba/scripts/natural_translit/utils/log_op.py
+++ b/nisaba/scripts/natural_translit/utils/log_op.py
@@ -30,7 +30,6 @@
 from typing import TypeVar
 
 from absl import logging
-
 import pynini as pyn
 
 T = TypeVar('T')
diff --git a/nisaba/scripts/natural_translit/utils/type_op.py b/nisaba/scripts/natural_translit/utils/type_op.py
index bfcd477f..89df834f 100644
--- a/nisaba/scripts/natural_translit/utils/type_op.py
+++ b/nisaba/scripts/natural_translit/utils/type_op.py
@@ -27,6 +27,7 @@
 from typing import Any, TypeVar, Union
 
 import pynini as pyn
+
 from nisaba.scripts.natural_translit.utils import log_op as log
 
 # Custom types
diff --git a/nisaba/scripts/utils/BUILD.bazel b/nisaba/scripts/utils/BUILD.bazel
index 309948ef..8fd9d5dd 100644
--- a/nisaba/scripts/utils/BUILD.bazel
+++ b/nisaba/scripts/utils/BUILD.bazel
@@ -78,7 +78,7 @@ py_library(
         ":rewrite",
         "@io_abseil_py//absl/testing:absltest",
         "@org_opengrm_pynini//pynini",
-        "@org_opengrm_pynini//pynini/lib:utf8",
+        "@org_opengrm_pynini//pynini/pynini/lib:utf8",
     ],
 )
 
@@ -97,8 +97,8 @@ py_library(
     deps = [
         ":file",
         ":rewrite",
-        "@org_opengrm_pynini//pynini",
         requirement("networkx"),
+        "@org_opengrm_pynini//pynini",
         requirement("pandas"),
     ],
 )
@@ -109,7 +109,7 @@ py_library(
     deps = [
         ":file",
         "@org_opengrm_pynini//pynini",
-        "@org_opengrm_pynini//pynini/lib:byte",
+        "@org_opengrm_pynini//pynini/pynini/lib:byte",
     ],
 )
 
@@ -128,7 +128,7 @@ py_library(
     srcs = ["proto.py"],
     deps = [
         ":file",
-        "@com_google_protobuf//:protobuf_python",
+        "//third_party/py/google/protobuf",
     ],
 )
 
@@ -191,7 +191,7 @@ py_binary(
     deps = [
         ":unicode_strings_py_pb2",
         ":unicode_strings_util",
-        "@com_google_protobuf//:protobuf_python",
+        "//third_party/py/google/protobuf",
         "@io_abseil_py//absl:app",
         "@io_abseil_py//absl/flags",
         "@io_abseil_py//absl/logging",
diff --git a/nisaba/scripts/utils/char.py b/nisaba/scripts/utils/char.py
index 91af0286..0b2df01d 100644
--- a/nisaba/scripts/utils/char.py
+++ b/nisaba/scripts/utils/char.py
@@ -19,6 +19,7 @@
 import pathlib
 
 import pynini
+
 import pathlib
 import nisaba.scripts.utils.file as uf
 
diff --git a/nisaba/scripts/utils/far.py b/nisaba/scripts/utils/far.py
index c1140401..3db8ed88 100644
--- a/nisaba/scripts/utils/far.py
+++ b/nisaba/scripts/utils/far.py
@@ -15,9 +15,11 @@
 """Library to load a .far file and transduce a string with an FST from that."""
 
 import os
+from typing import Literal
 import warnings
 
 import pynini
+
 import functools
 import nisaba.scripts.utils.file as uf
 
@@ -36,8 +38,13 @@ class Far:
   class FstWrapper:
     """An FST object wrapper retrieved from a Far object."""
 
-    def __init__(self, fst: pynini.Fst) -> None:
+    _TOKEN_TYPE = Literal['byte', 'utf8']
+
+    def __init__(
+        self, fst: pynini.Fst, token_type: _TOKEN_TYPE = 'byte'
+    ) -> None:
       self._fst = fst
+      self._token_type = token_type
 
     def ApplyOnText(self, text: str) -> str:
       """Transduce the given string using the FST.
@@ -57,7 +64,10 @@ def ApplyOnText(self, text: str) -> str:
       try:
         # Square brackets and backslash carry special meaning in Pynini.
         # So they need to be escaped for unmanaged strings.
-        return pynini.shortestpath(pynini.escape(text) @ self._fst).string()
+        return pynini.shortestpath(
+            pynini.accep(pynini.escape(text), token_type=self._token_type)
+            @ self._fst
+        ).string(token_type=self._token_type)
       except pynini.FstOpError as error:
         raise FstInputError(
             f'{error} on the string (between quotes): `{text}`') from error
@@ -79,7 +89,12 @@ def AcceptText(self, text: str) -> bool:
       """
       if not self._fst.properties(pynini.ACCEPTOR, True):
         warnings.warn('Underlying WFST is not an acceptor.', RuntimeWarning)
-      lattice = text @ self._fst
+      # Square brackets and backslash carry special meaning in Pynini.
+      # So they need to be escaped for unmanaged strings.
+      lattice = (
+          pynini.accep(pynini.escape(text), token_type=self._token_type)
+          @ self._fst
+      )
       return lattice.start() != pynini.NO_STATE_ID
 
   def __init__(self, path_to_far: os.PathLike[str]) -> None:
@@ -91,9 +106,11 @@ def __init__(self, path_to_far: os.PathLike[str]) -> None:
   # ().
   @functools.lru_cache(maxsize=None)
   def _LoadFar(self) -> pynini.Far:
-    return pynini.Far(uf.AsResourcePath(self.path_to_far))
+    return pynini.Far(uf.AsResourcePath(self.path_to_far), 'r')
 
   @functools.lru_cache(maxsize=None)
-  def Fst(self, rule_name: str) -> 'FstWrapper':
+  def Fst(
+      self, rule_name: str, token_type: FstWrapper._TOKEN_TYPE = 'byte'
+  ) -> 'FstWrapper':
     far = self._LoadFar()
-    return self.FstWrapper(far[rule_name])
+    return self.FstWrapper(far[rule_name], token_type)
diff --git a/nisaba/scripts/utils/far_base.h b/nisaba/scripts/utils/far_base.h
index 15c0f490..9123980a 100644
--- a/nisaba/scripts/utils/far_base.h
+++ b/nisaba/scripts/utils/far_base.h
@@ -18,10 +18,10 @@
 #include <memory>
 #include <string>
 
-#include "nisaba/interim/grm2/thrax/grm-manager.h"
 #include "absl/status/status.h"
 #include "absl/strings/string_view.h"
 #include "fst/fstlib.h"
+#include "third_party/opengrm/thrax/grm-manager.h"
 
 namespace nisaba {
 
diff --git a/nisaba/scripts/utils/file.py b/nisaba/scripts/utils/file.py
index b0ee1084..b9a4383c 100644
--- a/nisaba/scripts/utils/file.py
+++ b/nisaba/scripts/utils/file.py
@@ -19,6 +19,7 @@
 import pathlib
 
 import pynini
+
 from rules_python.python.runfiles import runfiles
 
 EMPTY: pynini.Fst = pynini.intersect(
diff --git a/nisaba/scripts/utils/grammars.bzl b/nisaba/scripts/utils/grammars.bzl
index 61a8eb2e..02365b10 100644
--- a/nisaba/scripts/utils/grammars.bzl
+++ b/nisaba/scripts/utils/grammars.bzl
@@ -15,7 +15,7 @@
 """Starlark utilities for dealing with Pynini targets."""
 
 load(
-    "@org_opengrm_pynini//pynini/export:grm_py_build_defs.bzl",
+    "@org_opengrm_pynini//pynini/pynini/export:grm_py_build_defs.bzl",
     "compile_grm_py",
     "compile_multi_grm_py",
 )
diff --git a/nisaba/scripts/utils/proto.py b/nisaba/scripts/utils/proto.py
index a7455764..cd2d0ce1 100644
--- a/nisaba/scripts/utils/proto.py
+++ b/nisaba/scripts/utils/proto.py
@@ -20,6 +20,7 @@
 
 from google.protobuf import message
 from google.protobuf import text_format
+
 import nisaba.scripts.utils.file as uf
 
 _ParsableT = TypeVar(
diff --git a/nisaba/scripts/utils/rewrite.py b/nisaba/scripts/utils/rewrite.py
index a6dea558..bbc06f20 100644
--- a/nisaba/scripts/utils/rewrite.py
+++ b/nisaba/scripts/utils/rewrite.py
@@ -17,7 +17,8 @@
 from collections.abc import Iterable
 
 import pynini
-from pynini.lib import byte
+from opengrm.pynini.lib import byte
+
 from nisaba.scripts.utils import file
 
 
diff --git a/nisaba/scripts/utils/rule.py b/nisaba/scripts/utils/rule.py
index d98b12c7..18cc87bb 100644
--- a/nisaba/scripts/utils/rule.py
+++ b/nisaba/scripts/utils/rule.py
@@ -65,9 +65,9 @@
 from typing import NamedTuple
 
 import networkx as nx
+import pynini
 import pandas as pd
 
-import pynini
 import pathlib
 import nisaba.scripts.utils.file as uf
 import nisaba.scripts.utils.rewrite as ur
@@ -85,8 +85,14 @@ def rules_from_string_file(file: os.PathLike[str]) -> Iterator[Rule]:
 def rules_from_string_path(file: os.PathLike[str]) -> Iterator[Rule]:
   """Yields string rules from a text file with unweighted string maps."""
   with pathlib.Path(file).open('rt') as f:
-    df = pd.read_csv(f, sep='\t', comment='#', escapechar='\\',
-                     names=['lhs', 'rhs'], na_filter=False)
+    df = pd.read_csv(
+        f,
+        sep='\t',
+        comment='#',
+        escapechar='\\',
+        names=['lhs', 'rhs'],
+        na_filter=False,
+    )
     for row in df.itertuples(index=False, name='Rule'):
       if not row.lhs:
         raise ValueError('Rule expects an LHS: {}'.format(row))
@@ -116,8 +122,11 @@ def partition_unordered(rules: RuleSet) -> list[RuleSet]:
 
   g = nx.DiGraph()
   g.add_nodes_from(rules)
-  g.add_edges_from((p1, p2) for p1, p2 in it.product(rules, rules)
-                   if p1 != p2 and _match_lhs_in_lhs(p1, p2))
+  g.add_edges_from(
+      (p1, p2)
+      for p1, p2 in it.product(rules, rules)
+      if p1 != p2 and _match_lhs_in_lhs(p1, p2)
+  )
   partition = []
   while g.number_of_nodes() > 0:
     leaves = [node for node in g.nodes if g.out_degree(node) == 0]
@@ -139,8 +148,10 @@ def fst_from_rules(rules: RuleSet, sigma: pynini.Fst) -> pynini.Fst:
     The Rewrite FST for the specified rule file.
   """
 
-  fsts = [pynini.optimize(pynini.string_map(rule_set))
-          for rule_set in partition_unordered(rules)]
+  fsts = [
+      pynini.optimize(pynini.string_map(rule_set))
+      for rule_set in partition_unordered(rules)
+  ]
   return ur.RewriteAndComposeFsts(fsts, sigma)
 
 
@@ -175,8 +186,9 @@ def _fst_from_cascading_rules(rules: RuleSet, sigma: pynini.Fst) -> pynini.Fst:
   return ur.RewriteAndComposeFsts(fsts, sigma)
 
 
-def fst_from_cascading_rule_file(rule_file: os.PathLike[str],
-                                 sigma: pynini.Fst) -> pynini.Fst:
+def fst_from_cascading_rule_file(
+    rule_file: os.PathLike[str], sigma: pynini.Fst
+) -> pynini.Fst:
   """Gets rewrite FST from a given rewrite rule file.
 
   Args:
diff --git a/nisaba/scripts/utils/test_util.py b/nisaba/scripts/utils/test_util.py
index 3ea7ed7b..923afce8 100644
--- a/nisaba/scripts/utils/test_util.py
+++ b/nisaba/scripts/utils/test_util.py
@@ -19,7 +19,8 @@
 from typing import Optional
 
 import pynini
-from pynini.lib import utf8
+from opengrm.pynini.lib import utf8
+
 from absl.testing import absltest
 from nisaba.scripts.utils import rewrite
 
diff --git a/nisaba/translit/fst/BUILD.bazel b/nisaba/translit/fst/BUILD.bazel
index 236138fd..fc77744e 100644
--- a/nisaba/translit/fst/BUILD.bazel
+++ b/nisaba/translit/fst/BUILD.bazel
@@ -91,9 +91,11 @@ cc_library(
     deps = [
         ":pairlm_decoder_options_cc_proto",
         ":wordpiece-segmenter-lib",
+        "//base:char32",
         "//nisaba/port:file_util",
         "//nisaba/port:thread_pool",
         "//nisaba/port:utf8_util",
+        "//third_party/opengrm/sfst:ngram-count",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/container:flat_hash_set",
         "@com_google_absl//absl/log",
@@ -104,7 +106,6 @@ cc_library(
         "@org_openfst//:fst",
         "@org_openfst//:symbol-table",
         "@org_openfst//:weight",
-        "@org_opengrm_ngram//:opengrm-ngram-lib",
     ],
 )
 
diff --git a/nisaba/translit/fst/pairlm_decoder.cc b/nisaba/translit/fst/pairlm_decoder.cc
index bb6af6cd..25e20d3b 100644
--- a/nisaba/translit/fst/pairlm_decoder.cc
+++ b/nisaba/translit/fst/pairlm_decoder.cc
@@ -18,13 +18,14 @@
 #include <cmath>
 #include <cstddef>
 #include <cstdint>
+#include <limits>
 #include <memory>
 #include <string>
 #include <tuple>
 #include <utility>
 #include <vector>
 
-#include "ngram/ngram-count.h"
+#include "base/char32.h"
 #include "absl/log/check.h"
 #include "absl/log/log.h"
 #include "absl/random/random.h"
@@ -63,6 +64,7 @@
 #include "fst/union.h"
 #include "fst/vector-fst.h"
 #include "fst/weight.h"
+#include "third_party/opengrm/sfst/ngram-count.h"
 #include "nisaba/port/thread_pool.h"
 
 using fst::ArcIterator;
@@ -116,12 +118,12 @@ namespace translit {
 namespace fst {
 namespace {
 
-constexpr int kPhiSymbol = -2;   // Symbol used for phi-arcs.
-constexpr int kMaxWordCands = 100;     // Default for max_word_cands_.
-constexpr float kWordCandThresh = 12;  // Default for word_cand_thresh_.
+constexpr int kPhiSymbol = -2;            // Symbol used for phi-arcs.
+constexpr int kMaxWordCands = 100;        // Default for max_word_cands_.
+constexpr float kWordCandThresh = 12;     // Default for word_cand_thresh_.
 constexpr float kMinCandPosterior = 0.0;  // Default for min_cand_posterior_.
 constexpr float kDefaultMixWeight = 0.0;  // Default pairlm_translit_weight_.
-constexpr float kOOVCost = 10;         // Default for oov_cost_.
+constexpr float kOOVCost = 10;            // Default for oov_cost_.
 constexpr int kDefaultMaxParallelTokens = 4;  // Maximum number of cores to use.
 
 }  // namespace
@@ -148,7 +150,7 @@ bool Utf8Check(absl::string_view word_str) {
 }
 
 // Returns the backoff state for a given state, also backoff cost if needed.
-int GetBackoff(const StdVectorFst &lm_fst, int st, double *bo_cost) {
+int GetBackoff(const StdVectorFst& lm_fst, int st, double* bo_cost) {
   ArcIterator<StdVectorFst> aiter(lm_fst, st);
   const StdArc arc = aiter.Value();
   if (arc.ilabel != 0) {
@@ -161,7 +163,7 @@ int GetBackoff(const StdVectorFst &lm_fst, int st, double *bo_cost) {
 
 // Returns the final cost of the state, following backoff if required. Sets the
 // state's final cost to the calculated backoff value if state is non-final.
-double GetStateFinalCost(StdVectorFst *lm_fst, int st) {
+double GetStateFinalCost(StdVectorFst* lm_fst, int st) {
   if (st < 0) return StdArc::Weight::Zero().Value();
   if (lm_fst->Final(st) != StdArc::Weight::Zero())
     return lm_fst->Final(st).Value();
@@ -173,7 +175,7 @@ double GetStateFinalCost(StdVectorFst *lm_fst, int st) {
 }
 
 // Converts given language model into one that works with PhiMatcher.
-void MakePhiMatcherLM(StdVectorFst *lm_fst) {
+void MakePhiMatcherLM(StdVectorFst* lm_fst) {
   for (int st = 0; st < lm_fst->NumStates(); ++st) {
     if (lm_fst->Final(st) == StdArc::Weight::Zero() && st != lm_fst->Start()) {
       // Updates final cost for non-final states using backoff.
@@ -198,7 +200,7 @@ void MakePhiMatcherLM(StdVectorFst *lm_fst) {
 // is treated as the input symbol and N the output symbol; otherwise N is input
 // and M output. If the flip_transducer bool is true, then the resulting
 // transducer is inverted.
-StdVectorFst BuildUnicodeToPairTransducer(const SymbolTable *syms,
+StdVectorFst BuildUnicodeToPairTransducer(const SymbolTable* syms,
                                           bool invert_pairlm,
                                           bool flip_transducer) {
   QCHECK(syms != nullptr) << "Symbol table is empty";
@@ -207,7 +209,7 @@ StdVectorFst BuildUnicodeToPairTransducer(const SymbolTable *syms,
   const int single_state = unicode_to_pair_fst.AddState();
   unicode_to_pair_fst.SetStart(single_state);
   unicode_to_pair_fst.SetFinal(single_state, StdArc::Weight::One());
-  for (const auto &sym : *syms) {
+  for (const auto& sym : *syms) {
     if (sym.Label() > 0) {
       // Iterates through all symbols other than <epsilon>.
       const std::string symbol = sym.Symbol();
@@ -235,7 +237,7 @@ StdVectorFst BuildUnicodeToPairTransducer(const SymbolTable *syms,
 // Creates a linear FST with unicode codepoints as arc labels for word.
 // Takes FST to modify as argument, to allow also building word trie, i.e., add
 // a linear path from start state of existing FST.
-void WordToFst(absl::string_view input_word, StdVectorFst *string_fst) {
+void WordToFst(absl::string_view input_word, StdVectorFst* string_fst) {
   QCHECK_NE(string_fst, nullptr);
   int curr_state = string_fst->Start();
   QCHECK_GE(curr_state, 0);  // Provided string_fst must have start state.
@@ -251,8 +253,8 @@ void WordToFst(absl::string_view input_word, StdVectorFst *string_fst) {
 }
 
 // Reads the string from ilabels of linear (string automaton) and returns cost.
-double GetTextString(const StdVectorFst &best_pair_strings, int curr_state,
-                     std::string *new_symbol) {
+double GetTextString(const StdVectorFst& best_pair_strings, int curr_state,
+                     std::string* new_symbol) {
   double cost = 0.0;
   std::vector<int> text_labels;
   while (best_pair_strings.NumArcs(curr_state) > 0) {
@@ -267,13 +269,13 @@ double GetTextString(const StdVectorFst &best_pair_strings, int curr_state,
     curr_state = arc.nextstate;
   }
   cost += best_pair_strings.Final(curr_state).Value();
-  QCHECK(LabelsToUTF8String(text_labels, new_symbol));
+  QCHECK(LabelsToUTF8String<int>(text_labels, new_symbol));  // Crash OK
   return cost;
 }
 
 // Applies weight pushing in log semiring, then returns fst to std semiring.
 // Optionally determinizes the input FST as well.
-void PushInLogSemiring(StdVectorFst *fst, bool determinize = false) {
+void PushInLogSemiring(StdVectorFst* fst, bool determinize = false) {
   VectorFst<LogArc> log_fst;
   ArcMap(*fst, &log_fst, StdToLogMapper());
   if (determinize) {
@@ -286,9 +288,9 @@ void PushInLogSemiring(StdVectorFst *fst, bool determinize = false) {
 }
 
 // Derives the cutoff score for k_best extraction from the state.
-std::vector<bool> ApplyArcScoreThresh(const StdVectorFst &fst, int state,
+std::vector<bool> ApplyArcScoreThresh(const StdVectorFst& fst, int state,
                                       int k_best, double min_cand_posterior,
-                                      const std::vector<double> *costs) {
+                                      const std::vector<double>* costs) {
   QCHECK_LT(k_best, fst.NumArcs(state));
   std::vector<bool> keep_arc(fst.NumArcs(state), false);
   std::vector<std::pair<double, size_t>> scores;
@@ -321,7 +323,7 @@ std::vector<bool> ApplyArcScoreThresh(const StdVectorFst &fst, int state,
 }
 
 // Returns the next state in the trie if label matches, otherwise kNoStateId.
-int GetNextTrieState(const StdVectorFst &word_piece_trie_fst, int curr_state,
+int GetNextTrieState(const StdVectorFst& word_piece_trie_fst, int curr_state,
                      int label) {
   Matcher<StdFst> matcher(word_piece_trie_fst, MATCH_INPUT);
   matcher.SetState(curr_state);
@@ -334,9 +336,8 @@ int GetNextTrieState(const StdVectorFst &word_piece_trie_fst, int curr_state,
 
 // Returns vector of characters that as a string match an item in the lexicon.
 std::vector<int> GetMatchedTokens(
-    const std::vector<std::string> &new_sym_letters,
-    int string_start_position, const StdVectorFst &word_piece_trie_fst,
-    int curr_state) {
+    const std::vector<std::string>& new_sym_letters, int string_start_position,
+    const StdVectorFst& word_piece_trie_fst, int curr_state) {
   int match_length = 0;
   std::vector<int> matched_items;
   for (int i = string_start_position; i < new_sym_letters.size(); ++i) {
@@ -362,7 +363,7 @@ std::vector<int> GetMatchedTokens(
 
 // Produces a two-state transducer with the same arcs as the incoming
 // lattice_fst, which effectively removes the context.
-StdVectorFst RemoveContext(const StdVectorFst &lattice_fst) {
+StdVectorFst RemoveContext(const StdVectorFst& lattice_fst) {
   StdVectorFst contextless_fst;
   const int start_st = contextless_fst.AddState();
   contextless_fst.SetStart(start_st);
@@ -380,12 +381,12 @@ StdVectorFst RemoveContext(const StdVectorFst &lattice_fst) {
 }
 
 // Samples a single path through the input lattice FST.
-StdVectorFst SampleFromLattice(const StdVectorFst &transliteration_fst,
+StdVectorFst SampleFromLattice(const StdVectorFst& transliteration_fst,
                                uint64_t seed) {
-  LogProbArcSelector<StdArc> selector(seed);
+  LogProbArcSelector<StdArc> selector;
   RandGenOptions<LogProbArcSelector<StdArc>> opts(selector);
   StdVectorFst sampled_fst;
-  RandGen(transliteration_fst, &sampled_fst, opts);
+  RandGen(transliteration_fst, &sampled_fst, opts, seed);
   return sampled_fst;
 }
 
@@ -398,7 +399,7 @@ bool PairLMDecoder::CheckCache(absl::string_view input_word) const {
 }
 
 void PairLMDecoder::InitializePairLMDecoder(
-    const PairLMDecoderOptions &pairlm_config) {
+    const PairLMDecoderOptions& pairlm_config) {
   InitializeTranslitModel(pairlm_config);
   InitializeLanguageModel(pairlm_config);
   epsilon_symbol_ = pairlm_config.epsilon_symbol().empty()
@@ -425,7 +426,7 @@ void PairLMDecoder::InitializePairLMDecoder(
   sample_from_k_best_ = pairlm_config.sample_from_k_best();
   if (pairlm_config.has_random_seed()) {
     random_seed_ = pairlm_config.random_seed();
-  } else{
+  } else {
     absl::BitGen bitgen;
     random_seed_ = absl::Uniform<uint64_t>(
         bitgen, 1, std::numeric_limits<uint64_t>::max());
@@ -433,7 +434,7 @@ void PairLMDecoder::InitializePairLMDecoder(
 }
 
 void PairLMDecoder::InitializeTranslitModel(
-    const PairLMDecoderOptions &pairlm_config) {
+    const PairLMDecoderOptions& pairlm_config) {
   if (!pairlm_config.pairlm_file().empty()) {
     // Reads in pair LM transliteration model and builds related transducers.
     translit_fst_.reset(StdVectorFst::Read(pairlm_config.pairlm_file()));
@@ -463,12 +464,12 @@ void PairLMDecoder::InitializeTranslitModel(
 }
 
 void PairLMDecoder::InitializeLanguageModel(
-    const PairLMDecoderOptions &pairlm_config) {
+    const PairLMDecoderOptions& pairlm_config) {
   if (!pairlm_config.lm_file().empty()) {
     // Reads in language model FST and initializes related auxiliary resources.
     lm_fst_.reset(StdVectorFst::Read(pairlm_config.lm_file()));
-    QCHECK(lm_fst_ != nullptr) << "Failed to read LM FST from "
-                               << pairlm_config.lm_file();
+    QCHECK(lm_fst_ != nullptr)
+        << "Failed to read LM FST from " << pairlm_config.lm_file();
     impl::MakePhiMatcherLM(lm_fst_.get());
     if (pairlm_config.apply_closure_to_lm()) {
       Closure(lm_fst_.get(), CLOSURE_PLUS);
@@ -476,8 +477,8 @@ void PairLMDecoder::InitializeLanguageModel(
     }
     apply_lm_at_word_level_ = pairlm_config.apply_lm_at_word_level();
     const absl::string_view oov_symbol = pairlm_config.oov_symbol().empty()
-                                         ? symbols::kUnknownSymbol
-                                         : pairlm_config.oov_symbol();
+                                             ? symbols::kUnknownSymbol
+                                             : pairlm_config.oov_symbol();
     lm_oov_index_ = lm_fst_->InputSymbols()->Find(oov_symbol);
     if (pairlm_config.has_word_piece_model()) {
       auto wpm = std::make_unique<WordpieceSegmenter>(
@@ -497,12 +498,12 @@ void PairLMDecoder::InitializeLanguageModel(
 }
 
 void PairLMDecoder::InitializeWordPieceTrie(
-    const PairLMDecoderOptions &pairlm_config) {
+    const PairLMDecoderOptions& pairlm_config) {
   word_piece_internal_prefix_ = pairlm_config.word_piece_internal_prefix();
   QCHECK(!word_piece_internal_prefix_.empty());
   word_piece_trie_fst_ = std::make_unique<StdVectorFst>();
   word_piece_trie_fst_->SetStart(word_piece_trie_fst_->AddState());
-  for (const auto &sym : *lm_fst_->InputSymbols()) {
+  for (const auto& sym : *lm_fst_->InputSymbols()) {
     if (sym.Label() > 0 && sym.Label() != lm_oov_index_) {
       impl::WordToFst(sym.Symbol(), word_piece_trie_fst_.get());
     }
@@ -512,8 +513,8 @@ void PairLMDecoder::InitializeWordPieceTrie(
 
   // Finds the internal state in the trie corresponding to internal prefix.
   word_internal_cands_to_lm_start_state_ = word_piece_trie_fst_->Start();
-  for (absl::string_view prefix_letter : utf8::StrSplitByChar(
-           word_piece_internal_prefix_)) {
+  for (absl::string_view prefix_letter :
+       utf8::StrSplitByChar(word_piece_internal_prefix_)) {
     // Finds destination state for each letter in the prefix, checks non-zero.
     word_internal_cands_to_lm_start_state_ = impl::GetNextTrieState(
         *word_piece_trie_fst_, word_internal_cands_to_lm_start_state_,
@@ -526,7 +527,7 @@ void PairLMDecoder::InitializeInputCharacterSet() {
   // Looks at input side of model transducer, which is the translit_fst_ itself
   // if the bool translit_fst_is_transducer_ is set to true; otherwise the input
   // side of unicode_to_pair_fst_.
-  const StdVectorFst *input_transducer = translit_fst_is_transducer_
+  const StdVectorFst* input_transducer = translit_fst_is_transducer_
                                              ? translit_fst_.get()
                                              : unicode_to_pair_fst_.get();
   if (input_transducer != nullptr) {
@@ -544,16 +545,16 @@ void PairLMDecoder::InitializeInputCharacterSet() {
 }
 
 void PairLMDecoder::InitializeExternalTransliterations(
-    const PairLMDecoderOptions &pairlm_config) {
+    const PairLMDecoderOptions& pairlm_config) {
   if (!pairlm_config.translit_cands_file().empty()) {
     // Reads in externally provided word transliterations. Assumes three column
     // format: input word; transliteration; negative log cost.
-    const auto read_lines_status = file::ReadLines(
-        pairlm_config.translit_cands_file(), kMaxLineLength);
-    QCHECK_OK(read_lines_status) << "Failed to read lines from "
-                                 << pairlm_config.translit_cands_file();
-    const std::vector<std::string> &input_lines = read_lines_status.value();
-    for (const auto &input_line : input_lines) {
+    const auto read_lines_status =
+        file::ReadLines(pairlm_config.translit_cands_file(), kMaxLineLength);
+    QCHECK_OK(read_lines_status)
+        << "Failed to read lines from " << pairlm_config.translit_cands_file();
+    const std::vector<std::string>& input_lines = read_lines_status.value();
+    for (const auto& input_line : input_lines) {
       const std::vector<absl::string_view> input_cols =
           absl::StrSplit(input_line, '\t', absl::SkipEmpty());
       QCHECK_EQ(input_cols.size(), 3);
@@ -632,10 +633,10 @@ StdVectorFst PairLMDecoder::GetWordTransliterations(
 }
 
 double PairLMDecoder::ParseCandWordPiece(absl::string_view new_symbol,
-                                         std::vector<int> *lm_syms) const {
+                                         std::vector<int>* lm_syms) const {
   double cost = 0.0;
-  const std::vector<std::string> new_sym_letters = utf8::StrSplitByChar(
-      new_symbol);
+  const std::vector<std::string> new_sym_letters =
+      utf8::StrSplitByChar(new_symbol);
   int string_position = 0;
   int curr_state = word_piece_trie_fst_->Start();
   std::string prefix = "";  // Gets set to word internal prefix later.
@@ -651,7 +652,8 @@ double PairLMDecoder::ParseCandWordPiece(absl::string_view new_symbol,
       cost += oov_cost_;
     } else {
       std::string word_piece_str;
-      QCHECK(LabelsToUTF8String(text_labels, &word_piece_str));
+      QCHECK(
+          LabelsToUTF8String<int>(text_labels, &word_piece_str));  // Crash OK
       lm_sym =
           lm_fst_->InputSymbols()->Find(absl::StrCat(prefix, word_piece_str));
       string_position += text_labels.size();
@@ -668,11 +670,11 @@ double PairLMDecoder::ParseCandWordPiece(absl::string_view new_symbol,
 }
 
 double PairLMDecoder::SegmentCandWordPiece(absl::string_view new_symbol,
-                                           std::vector<int> *lm_syms) const {
+                                           std::vector<int>* lm_syms) const {
   double cost = 0;
   const auto wp_status = wpm_->GetWordpieces(new_symbol);
   QCHECK_OK(wp_status);
-  for (const auto &wordpiece : wp_status.value()) {
+  for (const auto& wordpiece : wp_status.value()) {
     int lm_sym = lm_fst_->InputSymbols()->Find(wordpiece);
     if (lm_sym < 0) {
       lm_sym = lm_oov_index_;
@@ -687,7 +689,7 @@ double PairLMDecoder::SegmentCandWordPiece(absl::string_view new_symbol,
 
 void PairLMDecoder::AddToCandsToLMFst(absl::string_view new_symbol,
                                       int cand_sym,
-                                      TranslitContext &fst_params) {
+                                      TranslitContext& fst_params) {
   if (lm_fst_ == nullptr) return;
   double cost = 0.0;
   std::vector<int> lm_syms;
@@ -725,8 +727,8 @@ void PairLMDecoder::AddToCandsToLMFst(absl::string_view new_symbol,
 
 void PairLMDecoder::AddCandSymArc(absl::string_view new_symbol, double cost,
                                   int destination_state,
-                                  TranslitContext &fst_params,
-                                  StdVectorFst *word_transliterations) {
+                                  TranslitContext& fst_params,
+                                  StdVectorFst* word_transliterations) {
   // Look for candidate symbol in the symbol list, add if not there.
   int cand_sym = fst_params.cand_syms.Find(new_symbol);
   if (cand_sym == kNoSymbol) {
@@ -743,8 +745,8 @@ std::vector<std::string> PairLMDecoder::SegmentCoveredChars(
   std::vector<std::string> input_word_tokens;
   if (!input_word.empty()) {
     // Splits word into individual unicode codepoints.
-    const std::vector<std::string> input_codepoints = utf8::StrSplitByChar(
-        input_word);
+    const std::vector<std::string> input_codepoints =
+        utf8::StrSplitByChar(input_word);
     std::vector<bool> covered_codepoints(input_codepoints.size());
     int non_covered_count = 0;
     for (int i = 0; i < input_codepoints.size(); ++i) {
@@ -775,8 +777,8 @@ std::vector<std::string> PairLMDecoder::SegmentCoveredChars(
 }
 
 StdVectorFst PairLMDecoder::TransliterateSegmentedWord(
-    const std::vector<std::string> &segmented_word, int k_best,
-    TranslitContext &fst_params) {
+    const std::vector<std::string>& segmented_word, int k_best,
+    TranslitContext& fst_params) {
   StdVectorFst translit_result;
   if (!segmented_word.empty()) {
     // Transliterates each segment as an independent word.
@@ -831,12 +833,12 @@ StdVectorFst PairLMDecoder::TransliterateSegmentedWord(
 }
 
 void PairLMDecoder::ExtractCachedWordTransliterations(
-    absl::string_view input_word, TranslitContext &fst_params,
-    StdVectorFst &cached) {
+    absl::string_view input_word, TranslitContext& fst_params,
+    StdVectorFst& cached) {
   mutex_.lock_shared();
   const auto cached_pairs = global_word_transliteration_cache_.at(input_word);
   mutex_.unlock_shared();
-  for (const auto &pair : cached_pairs) {
+  for (const auto& pair : cached_pairs) {
     AddCandSymArc(pair.first, pair.second,
                   /*destination_state=*/1, fst_params, &(cached));
   }
@@ -845,7 +847,7 @@ void PairLMDecoder::ExtractCachedWordTransliterations(
 }
 
 StdVectorFst PairLMDecoder::TransliterateUnsegmentedWord(
-    absl::string_view input_word, int k_best, TranslitContext &fst_params) {
+    absl::string_view input_word, int k_best, TranslitContext& fst_params) {
   // Extracts k-best transliterations and adds them to the fst.
   StdVectorFst transliterated_lattice =
       GetWordTransliterations(input_word, /*prune_lattice=*/k_best > 1);
@@ -904,7 +906,7 @@ StdVectorFst PairLMDecoder::TransliterateUnsegmentedWord(
 
 StdVectorFst PairLMDecoder::TransliterateWord(absl::string_view input_word,
                                               int k_best,
-                                              TranslitContext &fst_params) {
+                                              TranslitContext& fst_params) {
   fst_params.mutex.lock();
   // We haven't seen this word, so initialize it in indexes.
   if (!fst_params.word_transliteration_cache.contains(input_word)) {
@@ -1005,8 +1007,8 @@ StdVectorFst PairLMDecoder::TransliterateWord(absl::string_view input_word,
 }
 
 StdVectorFst PairLMDecoder::BuildTransliterationFst(
-    absl::string_view input_line, int k_best, TranslitContext &fst_params,
-    std::vector<int> *unique_arc_id) {
+    absl::string_view input_line, int k_best, TranslitContext& fst_params,
+    std::vector<int>* unique_arc_id) {
   // Initialize the transducer.
   StdVectorFst transliteration_fst;
   int curr_state = transliteration_fst.AddState();
@@ -1034,7 +1036,7 @@ StdVectorFst PairLMDecoder::BuildTransliterationFst(
 
   // Loop through the fsts produced, joining them into a sentence lattice.
   for (int i = 0; i < input_words.size(); ++i) {
-    const auto &word_transliterations = translit_fsts[i];
+    const auto& word_transliterations = translit_fsts[i];
     const int next_state = transliteration_fst.AddState();
     QCHECK_GE(word_transliterations.NumArcs(word_transliterations.Start()), 1);
     for (ArcIterator<StdVectorFst> aiter(word_transliterations,
@@ -1063,7 +1065,7 @@ StdVectorFst PairLMDecoder::BuildTransliterationFst(
 }
 
 StdVectorFst PairLMDecoder::ComposeLatticeWithLM(
-    const StdVectorFst &transliteration_fst) const {
+    const StdVectorFst& transliteration_fst) const {
   StdVectorFst string_lm_composed_fst(StdComposeFst(
       transliteration_fst, *lm_fst_,
       ComposeFstOptions<StdArc, PhiMatcher<Matcher<StdFst>>>(
@@ -1079,8 +1081,8 @@ StdVectorFst PairLMDecoder::ComposeLatticeWithLM(
 }
 
 std::vector<double> PairLMDecoder::CollectUniqueArcCosts(
-    const StdVectorFst &string_lm_composed_fst,
-    const std::vector<int> &unique_arc_id) const {
+    const StdVectorFst& string_lm_composed_fst,
+    const std::vector<int>& unique_arc_id) const {
   QCHECK_GT(string_lm_composed_fst.NumStates(), 0)
       << "input string fst is empty.";
   // Initializes costs to 9999 (i.e., probability ~ 0) for all indices.
@@ -1089,7 +1091,7 @@ std::vector<double> PairLMDecoder::CollectUniqueArcCosts(
   // For each index, counts the probability mass of paths with that index.
   // Counting must happen in the log semiring to sum probabilities.
   auto ngram_counter =
-      std::make_unique<ngram::NGramCounter<Log64Weight>>(/*order=*/1, false);
+      std::make_unique<sfst::NGramCounter<Log64Weight>>(/*order=*/1, false);
   StdToLogMapper std2log_mapper;
   VectorFst<LogArc> log_string_fst;
   ArcMap(string_lm_composed_fst, &log_string_fst, std2log_mapper);
@@ -1108,8 +1110,7 @@ std::vector<double> PairLMDecoder::CollectUniqueArcCosts(
 }
 
 void PairLMDecoder::ApplyFinalKBestFilter(
-    int k_best,
-    StdVectorFst *transliteration_fst) const {
+    int k_best, StdVectorFst* transliteration_fst) const {
   int dead_state = kNoStateId;
   for (int s = 0; s < transliteration_fst->NumStates(); ++s) {
     if (transliteration_fst->NumArcs(s) > k_best) {
@@ -1138,14 +1139,13 @@ void PairLMDecoder::ApplyFinalKBestFilter(
 }
 
 void PairLMDecoder::AssignLabelsAndCostsToTranslitLattice(
-    const std::vector<int> &unique_arc_id,
-    const std::vector<double> &unique_arc_cost, int k_best,
-    absl::string_view input_line, TranslitContext &fst_params,
-    StdVectorFst *transliteration_fst) const {
+    const std::vector<int>& unique_arc_id,
+    const std::vector<double>& unique_arc_cost, int k_best,
+    absl::string_view input_line, TranslitContext& fst_params,
+    StdVectorFst* transliteration_fst) const {
   int dead_state = kNoStateId;
-  const std::vector<absl::string_view> input_string =
-      absl::StrSplit(input_line, utf8::Utf8WhitespaceDelimiter(),
-                     absl::SkipEmpty());
+  const std::vector<absl::string_view> input_string = absl::StrSplit(
+      input_line, utf8::Utf8WhitespaceDelimiter(), absl::SkipEmpty());
   QCHECK_EQ(input_string.size(), transliteration_fst->NumStates() - 1);
   for (int s = 0; s < input_string.size(); ++s) {
     int input_sym = fst_params.input_syms.Find(input_string[s]);
@@ -1222,7 +1222,7 @@ StdVectorFst PairLMDecoder::TransliterateString(absl::string_view input_line,
 }
 
 std::string PairLMDecoder::PrintTransliterations(
-    absl::string_view line_prefix, const StdVectorFst &transliteration_fst,
+    absl::string_view line_prefix, const StdVectorFst& transliteration_fst,
     bool include_final_endline) const {
   int curr_state = transliteration_fst.Start();
   std::vector<std::string> state_cands;
diff --git a/nisaba/translit/tools/BUILD.bazel b/nisaba/translit/tools/BUILD.bazel
index adad2e81..2d93e544 100644
--- a/nisaba/translit/tools/BUILD.bazel
+++ b/nisaba/translit/tools/BUILD.bazel
@@ -14,6 +14,7 @@
 
 # Error rate calculation utilities for specific transliteration use cases.
 
+load("@rules_python//python:py_test.bzl", "py_test")
 load("//third_party/bazel_rules/rules_cc/cc:cc_binary.bzl", "cc_binary")
 load("//third_party/bazel_rules/rules_cc/cc:cc_library.bzl", "cc_library")
 load("//third_party/bazel_rules/rules_cc/cc:cc_test.bzl", "cc_test")
diff --git a/nisaba/translit/tools/kbest-full-string-util.cc b/nisaba/translit/tools/kbest-full-string-util.cc
index 9c9d4c85..0b8a936a 100644
--- a/nisaba/translit/tools/kbest-full-string-util.cc
+++ b/nisaba/translit/tools/kbest-full-string-util.cc
@@ -22,7 +22,6 @@
 #include <utility>
 #include <vector>
 
-#include "ngram/ngram-count.h"
 #include "absl/container/flat_hash_set.h"
 #include "absl/log/check.h"
 #include "absl/strings/str_cat.h"
@@ -41,6 +40,7 @@
 #include "fst/shortest-path.h"
 #include "fst/symbol-table.h"
 #include "fst/vector-fst.h"
+#include "ngram/ngram-count.h"
 
 namespace nisaba {
 namespace translit {