diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
new file mode 100644
index 00000000000..e2ad79c0281
--- /dev/null
+++ b/.github/workflows/lint.yml
@@ -0,0 +1,44 @@
+---
+name: Linting
+
+on:
+  push:
+    paths-ignore:
+      - 'aider/website/**'
+      - README.md
+      - HISTORY.md
+    branches:
+      - main
+  pull_request:
+    paths-ignore:
+      - 'aider/website/**'
+      - README.md
+    branches:
+      - main
+
+jobs:
+  mypy:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Check out repository
+      uses: actions/checkout@v4
+
+    - name: Set up Python 3.12
+      uses: actions/setup-python@v5
+      with:
+        python-version: "3.12"
+
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install mypy
+        pip install '.[dev]'
+
+    - name: Run Mypy
+      uses: wearerequired/lint-action@v2.3.0
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        mypy: true
+        mypy_args: "."
+        continue_on_error: false
diff --git a/aider/coders/__init__.py b/aider/coders/__init__.py
index e9d334bc99f..b87c395ccaa 100644
--- a/aider/coders/__init__.py
+++ b/aider/coders/__init__.py
@@ -12,15 +12,15 @@
 # from .single_wholefile_func_coder import SingleWholeFileFunctionCoder
 
 __all__ = [
-    HelpCoder,
-    AskCoder,
-    Coder,
-    EditBlockCoder,
-    EditBlockFencedCoder,
-    WholeFileCoder,
-    UnifiedDiffCoder,
-    #    SingleWholeFileFunctionCoder,
-    ArchitectCoder,
-    EditorEditBlockCoder,
-    EditorWholeFileCoder,
+    "HelpCoder",
+    "AskCoder",
+    "Coder",
+    "EditBlockCoder",
+    "EditBlockFencedCoder",
+    "WholeFileCoder",
+    "UnifiedDiffCoder",
+    #    "SingleWholeFileFunctionCoder",
+    "ArchitectCoder",
+    "EditorEditBlockCoder",
+    "EditorWholeFileCoder",
 ]
diff --git a/aider/coders/base_prompts.py b/aider/coders/base_prompts.py
index c431c752018..447613e4156 100644
--- a/aider/coders/base_prompts.py
+++ b/aider/coders/base_prompts.py
@@ -1,3 +1,6 @@
+from __future__ import annotations
+
+
 class CoderPrompts:
     system_reminder = ""
 
@@ -37,7 +40,7 @@ class CoderPrompts:
         " stop and wait for your approval."
     )
 
-    repo_content_prefix = """Here are summaries of some files present in my git repository.
+    repo_content_prefix: str | None = """Here are summaries of some files present in my git repository.
 Do not propose changes to these files, treat them as *read-only*.
 If you need to edit any of these files, ask me to *add them to the chat* first.
 """
diff --git a/aider/io.py b/aider/io.py
index 81829a83bdf..c933622a65e 100644
--- a/aider/io.py
+++ b/aider/io.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import base64
 import os
 from collections import defaultdict
@@ -28,7 +30,7 @@
 
 @dataclass
 class ConfirmGroup:
-    preference: str = None
+    preference: str | None = None
     show_group: bool = True
 
     def __init__(self, items=None):
diff --git a/aider/llm.py b/aider/llm.py
index f750f41af4c..ead446225ab 100644
--- a/aider/llm.py
+++ b/aider/llm.py
@@ -37,4 +37,4 @@ def _load_litellm(self):
 
 litellm = LazyLiteLLM()
 
-__all__ = [litellm]
+__all__ = ["litellm"]
diff --git a/aider/models.py b/aider/models.py
index 4e7e529d3f0..b340f99f850 100644
--- a/aider/models.py
+++ b/aider/models.py
@@ -20,7 +20,7 @@
 DEFAULT_MODEL_NAME = "gpt-4o"
 ANTHROPIC_BETA_HEADER = "prompt-caching-2024-07-31"
 
-OPENAI_MODELS = """
+_OPENAI_MODELS = """
 gpt-4
 gpt-4o
 gpt-4o-2024-05-13
@@ -47,9 +47,9 @@
 gpt-3.5-turbo-16k-0613
 """
 
-OPENAI_MODELS = [ln.strip() for ln in OPENAI_MODELS.splitlines() if ln.strip()]
+OPENAI_MODELS = [ln.strip() for ln in _OPENAI_MODELS.splitlines() if ln.strip()]
 
-ANTHROPIC_MODELS = """
+_ANTHROPIC_MODELS = """
 claude-2
 claude-2.1
 claude-3-haiku-20240307
@@ -58,7 +58,7 @@
 claude-3-5-sonnet-20240620
 """
 
-ANTHROPIC_MODELS = [ln.strip() for ln in ANTHROPIC_MODELS.splitlines() if ln.strip()]
+ANTHROPIC_MODELS = [ln.strip() for ln in _ANTHROPIC_MODELS.splitlines() if ln.strip()]
 
 
 @dataclass
diff --git a/aider/repomap.py b/aider/repomap.py
index f0d42e19624..ca08dd500fe 100644
--- a/aider/repomap.py
+++ b/aider/repomap.py
@@ -24,7 +24,7 @@
 warnings.simplefilter("ignore", category=FutureWarning)
 from tree_sitter_languages import get_language, get_parser  # noqa: E402
 
-Tag = namedtuple("Tag", "rel_fname fname line name kind".split())
+Tag = namedtuple("Tag", ("rel_fname", "fname", "line", "name", "kind"))
 
 
 SQLITE_ERRORS = (sqlite3.OperationalError, sqlite3.DatabaseError)
diff --git a/mypy.ini b/mypy.ini
new file mode 100644
index 00000000000..cae65825f5d
--- /dev/null
+++ b/mypy.ini
@@ -0,0 +1,40 @@
+[mypy]
+exclude = (?x)(
+      ^\.git/
+    | ^benchmark/$
+    | ^build/$
+    | ^dist/$
+    | ^scripts/$
+  )
+allow_untyped_globals = True
+check_untyped_defs = False
+
+[mypy-configargparse]
+ignore_missing_imports = True
+
+[mypy-diff_match_patch]
+ignore_missing_imports = True
+
+[mypy-diskcache]
+ignore_missing_imports = True
+
+[mypy-grep_ast.*]
+ignore_missing_imports = True
+
+[mypy-imgcat]
+ignore_missing_imports = True
+
+[mypy-llama_index.*]
+ignore_missing_imports = True
+
+[mypy-pypandoc]
+ignore_missing_imports = True
+
+[mypy-pyperclip]
+ignore_missing_imports = True
+
+[mypy-soundfile]
+ignore_missing_imports = True
+
+[mypy-sounddevice]
+ignore_missing_imports = True