diff --git a/.github/workflows/typecheck.yml b/.github/workflows/typecheck.yml
new file mode 100644
index 00000000..7454ca30
--- /dev/null
+++ b/.github/workflows/typecheck.yml
@@ -0,0 +1,35 @@
+name: Pyrefly Type Check
+
+on:
+  pull_request:
+    branches: [main]
+  workflow_dispatch:  # Allows manual triggering from the GitHub UI
+
+jobs:
+  typecheck:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@38f3f104447c67c051c4a08e39b64a148898af3a # v4
+        with:
+          enable-cache: true
+          cache-dependency-glob: |
+            **/pyproject.toml
+            **/uv.lock
+
+      - name: Set up Python
+        uses: actions/setup-python@7f4fc3e22c37d6ff65e88745f38bd3157c663f7c # v4
+        with:
+          python-version: '3.11'
+
+      - name: Install package and dependencies
+        run: |
+          uv sync --group dev
+
+      - name: Run Pyrefly Type Checker
+        run: |
+          make typecheck
diff --git a/Makefile b/Makefile
index ce40aef6..172595e0 100644
--- a/Makefile
+++ b/Makefile
@@ -23,9 +23,10 @@ help:
 	@echo "  test-e2e                 Run E2E tests"
 	@echo "  test-all                 Run both unit and E2E tests"
 	@echo ""
-	@echo "Linting:"
+	@echo "Linting & Type Checking:"
 	@echo "  lint                     Run ruff linter to check code"
 	@echo "  lint-fix                 Auto-fix linting issues"
+	@echo "  typecheck                Run pyrefly type checker"
 	@echo ""
 	@echo "Package Management:"
 	@echo "  package-test             Build and test package installation"
@@ -97,12 +98,18 @@ install-buildx:
 	fi
 	@docker buildx version
 
+.PHONY: check-pyrefly
+check-pyrefly:
+	@echo "Initializing pyrefly..."
+	uv run pyrefly init
+
 .PHONY: setup
 setup: check-uv
 	uv venv
 	uv sync --group dev
 	uv run pre-commit install
 	make install-buildx
+	make check-pyrefly
 
 .PHONY: reset
 reset:
@@ -133,6 +140,10 @@ lint:
 lint-fix:
 	uv run ruff check --fix .
 
+.PHONY: typecheck
+typecheck:
+	uv run pyrefly check --summarize-errors
+
 .PHONY: test-e2e
 test-e2e:
 	E2E_ENV_FILE=.env ./scripts/run-e2e-tests.sh
diff --git a/pyproject.toml b/pyproject.toml
index 368275d6..5dc58fb8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -79,7 +79,8 @@ test = [
 dev = [
     {include-group = "test"},
     "ruff==0.12.0",
-    "pre-commit>=4.2.0"
+    "pre-commit>=4.2.0",
+    "pyrefly>=0.1.0"
 ]
 
 [tool.uv]
@@ -88,3 +89,12 @@ package = true
 [tool.ruff]
 target-version = "py311"
 line-length = 120
+
+[tool.pyrefly]
+project-includes = ["**/*"]
+project-excludes = [
+    "**/node_modules",
+    "**/__pycache__",
+    "**/*venv/**/*",
+    "tests/**/*",
+]
diff --git a/uv.lock b/uv.lock
index 5bbf1c7c..c99fa87f 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1,5 +1,5 @@
 version = 1
-revision = 2
+revision = 3
 requires-python = ">=3.11"
 resolution-markers = [
     "python_full_version >= '3.13'",
@@ -273,6 +273,7 @@ dev = [
     { name = "coverage", extra = ["toml"] },
     { name = "hypothesis" },
     { name = "pre-commit" },
+    { name = "pyrefly" },
     { name = "pytest" },
     { name = "pytest-cov" },
     { name = "pytest-mock" },
@@ -328,6 +329,7 @@ dev = [
     { name = "coverage", extras = ["toml"], specifier = ">=7.0.0" },
     { name = "hypothesis", specifier = ">=6.0.0" },
     { name = "pre-commit", specifier = ">=4.2.0" },
+    { name = "pyrefly", specifier = ">=0.1.0" },
     { name = "pytest", specifier = ">=7.0.0" },
     { name = "pytest-cov", specifier = ">=4.0.0" },
     { name = "pytest-mock", specifier = ">=3.10.0" },
@@ -1114,6 +1116,22 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/61/ad/689f02752eeec26aed679477e80e632ef1b682313be70793d798c1d5fc8f/PyJWT-2.10.1-py3-none-any.whl", hash = "sha256:dcdd193e30abefd5debf142f9adfcdd2b58004e644f25406ffaebd50bd98dacb", size = 22997, upload-time = "2024-11-28T03:43:27.893Z" },
 ]
 
+[[package]]
+name = "pyrefly"
+version = "0.37.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/4a/da/dcb6f917cc63c79d60f851aef334923ba2f9970ae543f4e8435b63b5a5ef/pyrefly-0.37.0.tar.gz", hash = "sha256:6f0d582e1be9e17bc9c49691d88fda17268426946157170e36790976144a3d5f", size = 1699530, upload-time = "2025-10-13T16:46:26.692Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/4e/a5/7e7d8fa4d79efc90c9222dfe90b935327458e8d9ab81d020d4a65fffdf0c/pyrefly-0.37.0-py3-none-macosx_10_12_x86_64.whl", hash = "sha256:297e92fe0f215ef25afc615de302ecc419e21e517f87153ec0e5be4023318427", size = 6932440, upload-time = "2025-10-13T16:46:11.962Z" },
+    { url = "https://files.pythonhosted.org/packages/0f/13/9c5425371b9b67695e2685e604421cf9b797ab7f3e97a11e9152fe9dd7aa/pyrefly-0.37.0-py3-none-macosx_11_0_arm64.whl", hash = "sha256:abf48a76b7484c9623354ba54e4aa77400223b706571bc339e67271ceb738830", size = 6459673, upload-time = "2025-10-13T16:46:14.422Z" },
+    { url = "https://files.pythonhosted.org/packages/d6/78/87da3f0adb7552e7db4a1053065bb8f8c03ce3b3bbe1367e1f67e97ec882/pyrefly-0.37.0-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:60d2cef64049356cac77363ab95b393974086f01c04a880b28ae4b08614f5e0a", size = 6699446, upload-time = "2025-10-13T16:46:16.174Z" },
+    { url = "https://files.pythonhosted.org/packages/c6/48/70fa5a6d019299bc5a5dc4216013114b21f5ef42aedf06b4780a67ccd3df/pyrefly-0.37.0-py3-none-manylinux_2_17_i686.manylinux2014_i686.whl", hash = "sha256:0da8bf10a4ce60c3282d6e210da26a88cb2f36d4983666663de15a8870bb283b", size = 7562849, upload-time = "2025-10-13T16:46:17.865Z" },
+    { url = "https://files.pythonhosted.org/packages/3a/7f/92d426a44ce6f2776a727992dc0ef4dd0f07b3ac47aaf73dfec679f52c68/pyrefly-0.37.0-py3-none-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:82be6258d0c3f5fc6103d07a10ccec9ba5428b3282e67b6f7199eb87b93566c1", size = 7210722, upload-time = "2025-10-13T16:46:19.756Z" },
+    { url = "https://files.pythonhosted.org/packages/02/5f/a8afc0b8277b7851079a1394e99cac21c5845e94312db26c1190f07f10f5/pyrefly-0.37.0-py3-none-win32.whl", hash = "sha256:79820b05b90fe11442d1d6d9ba3122e0322831ca2bd0001d21c0aea62db13522", size = 6736390, upload-time = "2025-10-13T16:46:21.386Z" },
+    { url = "https://files.pythonhosted.org/packages/85/2d/6fae569e4ea88610080fca98748f9a0b8affd80e8a21326c0b62b10e9fc6/pyrefly-0.37.0-py3-none-win_amd64.whl", hash = "sha256:054bf0a55959821cbc07305c9958da491493bd1f699c6db7d8dd33a8040be504", size = 7174438, upload-time = "2025-10-13T16:46:23.064Z" },
+    { url = "https://files.pythonhosted.org/packages/f6/2d/e82ec9dc7bb7f78b8400d5c3a3408c619099b6e2b3166660d66174862c1c/pyrefly-0.37.0-py3-none-win_arm64.whl", hash = "sha256:3725a195c159994e0f01d81778b0d47c735f54b55505c73a81bd0d8b69f25441", size = 6756218, upload-time = "2025-10-13T16:46:25.13Z" },
+]
+
 [[package]]
 name = "pysocks"
 version = "1.7.1"