diff --git a/.github/workflows/typecheck.yml b/.github/workflows/typecheck.yml
new file mode 100644
index 0000000..5d1b95f
--- /dev/null
+++ b/.github/workflows/typecheck.yml
@@ -0,0 +1,21 @@
+name: Type check
+
+on: [pull_request]
+
+jobs:
+  pyrefly:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - run: pipx install poetry
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.10"
+          cache: poetry
+      - name: Install Python dependencies
+        run: poetry install --no-root
+      - name: Type check with pyrefly
+        run: poetry run pyrefly check
diff --git a/poetry.lock b/poetry.lock
index f89dd17..51f5451 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 1.5.1 and should not be changed by hand.
+# This file is automatically @generated by Poetry 2.4.2 and should not be changed by hand.
 
 [[package]]
 name = "certifi"
@@ -6,6 +6,7 @@ version = "2024.12.14"
 description = "Python package for providing Mozilla's CA Bundle."
 optional = false
 python-versions = ">=3.6"
+groups = ["main"]
 files = [
     {file = "certifi-2024.12.14-py3-none-any.whl", hash = "sha256:1275f7a45be9464efc1173084eaa30f866fe2e47d389406136d332ed4967ec56"},
     {file = "certifi-2024.12.14.tar.gz", hash = "sha256:b650d30f370c2b724812bee08008be0c4163b163ddaec3f2546c1caf65f191db"},
@@ -17,6 +18,7 @@ version = "3.4.0"
 description = "The Real First Universal Charset Detector. Open, modern and actively maintained alternative to Chardet."
 optional = false
 python-versions = ">=3.7.0"
+groups = ["main"]
 files = [
     {file = "charset_normalizer-3.4.0-cp310-cp310-macosx_10_9_universal2.whl", hash = "sha256:4f9fc98dad6c2eaa32fc3af1417d95b5e3d08aff968df0cd320066def971f9a6"},
     {file = "charset_normalizer-3.4.0-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:0de7b687289d3c1b3e8660d0741874abe7888100efe14bd0f9fd7141bcbda92b"},
@@ -131,6 +133,7 @@ version = "8.1.7"
 description = "Composable command line interface toolkit"
 optional = false
 python-versions = ">=3.7"
+groups = ["main"]
 files = [
     {file = "click-8.1.7-py3-none-any.whl", hash = "sha256:ae74fb96c20a0277a1d615f1e4d73c8414f5a98db8b799a7931d1582f3390c28"},
     {file = "click-8.1.7.tar.gz", hash = "sha256:ca9853ad459e787e2192211578cc907e7594e294c7ccc834310722b41b9ca6de"},
@@ -145,6 +148,8 @@ version = "0.4.6"
 description = "Cross-platform colored terminal text."
 optional = false
 python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,!=3.5.*,!=3.6.*,>=2.7"
+groups = ["main"]
+markers = "platform_system == \"Windows\""
 files = [
     {file = "colorama-0.4.6-py2.py3-none-any.whl", hash = "sha256:4f1d9991f5acc0ca119f9d443620b77f9d6b33703e51011c16baf57afb285fc6"},
     {file = "colorama-0.4.6.tar.gz", hash = "sha256:08695f5cb7ed6e0531a20572697297273c47b8cae5a63ffc6d6ed5c201be6e44"},
@@ -156,6 +161,7 @@ version = "3.10"
 description = "Internationalized Domain Names in Applications (IDNA)"
 optional = false
 python-versions = ">=3.6"
+groups = ["main"]
 files = [
     {file = "idna-3.10-py3-none-any.whl", hash = "sha256:946d195a0d259cbba61165e88e65941f16e9b36ea6ddb97f00452bae8b1287d3"},
     {file = "idna-3.10.tar.gz", hash = "sha256:12f65c9b470abda6dc35cf8e63cc574b1c52b11df2c86030af0ac09b01b13ea9"},
@@ -164,12 +170,35 @@ files = [
 [package.extras]
 all = ["flake8 (>=7.1.1)", "mypy (>=1.11.2)", "pytest (>=8.3.2)", "ruff (>=0.6.2)"]
 
+[[package]]
+name = "pyrefly"
+version = "1.2.0"
+description = "A fast type checker and language server for Python with powerful IDE features"
+optional = false
+python-versions = ">=3.8"
+groups = ["dev"]
+files = [
+    {file = "pyrefly-1.2.0-py3-none-macosx_10_12_x86_64.whl", hash = "sha256:7f46d983ac49ddd2b043694960a01dc6a19a5cfd8eec609d6bd9c42866f91b4e"},
+    {file = "pyrefly-1.2.0-py3-none-macosx_11_0_arm64.whl", hash = "sha256:756f669b5555090f5c1a4fef30db1785fabe657764f7e4e6dc88994dfb8ca82d"},
+    {file = "pyrefly-1.2.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:e3465812ce5ef4781fb592edbf2724547296f0a3124be115d73c7e8b2401862d"},
+    {file = "pyrefly-1.2.0-py3-none-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:5de7b2ad2bba5c8055181681a84b74143eac2234a48ba5d1b7ed7e7a722b02bd"},
+    {file = "pyrefly-1.2.0-py3-none-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl", hash = "sha256:25822ea9505f589ea8a725e4268b475132fb89e038fbf092e446510443ac142a"},
+    {file = "pyrefly-1.2.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:90efe75e17491ef5d636e10469e9278d7d0256b3b4c5e1f4750069bf3ae0f5d1"},
+    {file = "pyrefly-1.2.0-py3-none-musllinux_1_2_aarch64.whl", hash = "sha256:368aaf7eee4f511ddc0f8e564cf14e01ab2f10b0db9105c6d5b153bf498d07bf"},
+    {file = "pyrefly-1.2.0-py3-none-musllinux_1_2_x86_64.whl", hash = "sha256:d52d5da7bc65fb7675fbaa80eda879d4f8787c494f04cac21603330d3abbdbbe"},
+    {file = "pyrefly-1.2.0-py3-none-win32.whl", hash = "sha256:8c90751de8506d938e8f802659c74cf35bd7a0036510ee6c634a38eebb280bfa"},
+    {file = "pyrefly-1.2.0-py3-none-win_amd64.whl", hash = "sha256:8a8964c224ccc4882730130955815de21ff443c1ac3f0b90685b19bf63848170"},
+    {file = "pyrefly-1.2.0-py3-none-win_arm64.whl", hash = "sha256:3a90bb8df39dfbac74b1f3b2e9d7c526b8f80568884c3944d955023a73ebf61e"},
+    {file = "pyrefly-1.2.0.tar.gz", hash = "sha256:5485f960fc2481617068c918335c39ab1507ef90b6b5bd35bf57726e60e73185"},
+]
+
 [[package]]
 name = "requests"
 version = "2.32.3"
 description = "Python HTTP for Humans."
 optional = false
 python-versions = ">=3.8"
+groups = ["main"]
 files = [
     {file = "requests-2.32.3-py3-none-any.whl", hash = "sha256:70761cfe03c773ceb22aa2f671b4757976145175cdfca038c02654d061d6dcc6"},
     {file = "requests-2.32.3.tar.gz", hash = "sha256:55365417734eb18255590a9ff9eb97e9e1da868d4ccd6402399eaf68af20a760"},
@@ -191,6 +220,7 @@ version = "1.0.0"
 description = "A utility belt for advanced users of python-requests"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+groups = ["main"]
 files = [
     {file = "requests-toolbelt-1.0.0.tar.gz", hash = "sha256:7681a0a3d047012b5bdc0ee37d7f8f07ebe76ab08caeccfc3921ce23c88d5bc6"},
     {file = "requests_toolbelt-1.0.0-py2.py3-none-any.whl", hash = "sha256:cccfdd665f0a24fcf4726e690f65639d272bb0637b9b92dfd91a5568ccf6bd06"},
@@ -205,6 +235,7 @@ version = "0.8.3"
 description = "An extremely fast Python linter and code formatter, written in Rust."
 optional = false
 python-versions = ">=3.7"
+groups = ["dev"]
 files = [
     {file = "ruff-0.8.3-py3-none-linux_armv6l.whl", hash = "sha256:8d5d273ffffff0acd3db5bf626d4b131aa5a5ada1276126231c4174543ce20d6"},
     {file = "ruff-0.8.3-py3-none-macosx_10_12_x86_64.whl", hash = "sha256:e4d66a21de39f15c9757d00c50c8cdd20ac84f55684ca56def7891a025d7e939"},
@@ -232,18 +263,19 @@ version = "2.2.3"
 description = "HTTP library with thread-safe connection pooling, file post, and more."
 optional = false
 python-versions = ">=3.8"
+groups = ["main"]
 files = [
     {file = "urllib3-2.2.3-py3-none-any.whl", hash = "sha256:ca899ca043dcb1bafa3e262d73aa25c465bfb49e0bd9dd5d59f1d0acba2f8fac"},
     {file = "urllib3-2.2.3.tar.gz", hash = "sha256:e7d814a81dad81e6caf2ec9fdedb284ecc9c73076b62654547cc64ccdcae26e9"},
 ]
 
 [package.extras]
-brotli = ["brotli (>=1.0.9)", "brotlicffi (>=0.8.0)"]
+brotli = ["brotli (>=1.0.9) ; platform_python_implementation == \"CPython\"", "brotlicffi (>=0.8.0) ; platform_python_implementation != \"CPython\""]
 h2 = ["h2 (>=4,<5)"]
 socks = ["pysocks (>=1.5.6,!=1.5.7,<2.0)"]
 zstd = ["zstandard (>=0.18.0)"]
 
 [metadata]
-lock-version = "2.0"
+lock-version = "2.1"
 python-versions = "^3.10"
-content-hash = "75633bc94c02973c3a4fd3807ef2e7a2e8f9d3dd20e07b33d81e7ef2fde79c9f"
+content-hash = "c8f286cbc7338aef97f92f1f5d38f64d1d542edba2ae5bf631f268e7bf06bc24"
diff --git a/pyproject.toml b/pyproject.toml
index 1d41585..3f77f44 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,12 @@ requests-toolbelt = "^1.0.0"
 
 [tool.poetry.group.dev.dependencies]
 ruff = "^0.8.3"
+pyrefly = "^1.2.0"
 
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
+
+[tool.pyrefly]
+project-includes = ["yeti"]
+project-excludes = ["tests"]
diff --git a/yeti/api.py b/yeti/api.py
index 6b0a737..b64873b 100644
--- a/yeti/api.py
+++ b/yeti/api.py
@@ -120,7 +120,7 @@ def do_request(
         if json_data and body:
             raise ValueError("You must provide either json or body, not both.")
 
-        request_kwargs = {}
+        request_kwargs: dict[str, Any] = {}
 
         if headers:
             request_kwargs["headers"] = headers
@@ -241,7 +241,7 @@ def search_indicators(
                 "You must provide one of name, indicator_type, pattern, description, or tags."
             )
 
-        query = {}
+        query: dict[str, Any] = {}
         if name:
             query["name"] = name
         if pattern:
@@ -328,7 +328,7 @@ def search_entities(
         if not any([name, entity_type, description]):
             raise ValueError("You must provide one of name, type, or description.")
 
-        query = {}
+        query: dict[str, Any] = {}
         if name:
             query["name"] = name
         if entity_type:
@@ -448,7 +448,7 @@ def search_observables(
         Returns:
           The response from the API; a dict representing the observable.
         """
-        query = {"value": value}
+        query: dict[str, Any] = {"value": value}
         if tags:
             query["tags"] = tags
         params = {"query": query, "count": count, "page": page}
@@ -526,7 +526,7 @@ def new_entity(
         Returns:
           The response from the API; a dict representing the entity.
         """
-        params = {"entity": entity}
+        params: dict[str, Any] = {"entity": entity}
         if tags:
             params["tags"] = tags
         response = self.do_request(
@@ -660,7 +660,7 @@ def search_dfiq(
         Returns:
             The response from the API; a dict representing the DFIQ object.
         """
-        query = {
+        query: dict[str, Any] = {
             "name": name,
         }
 
@@ -669,7 +669,7 @@ def search_dfiq(
         if dfiq_tags:
             query["dfiq_tags"] = dfiq_tags
 
-        params = {
+        params: dict[str, Any] = {
             "query": query,
             "count": count,
             "page": page,
@@ -751,7 +751,7 @@ def download_dfiq_archive(self, dfiq_type: str | None = None) -> bytes:
         Returns:
           The archive contents as bytes.
         """
-        params = {"count": 0}
+        params: dict[str, Any] = {"count": 0}
         if dfiq_type:
             params["query"] = {"type": dfiq_type}
         response = self.do_request(