diff --git a/.basedpyright/baseline.json b/.basedpyright/baseline.json
new file mode 100644
index 0000000..c7d37d6
--- /dev/null
+++ b/.basedpyright/baseline.json
@@ -0,0 +1,166 @@
+{
+    "files": {
+        "./pygrist_mini/__init__.py": [
+            {
+                "code": "reportUnknownParameterType",
+                "range": {
+                    "startColumn": 17,
+                    "endColumn": 23,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportMissingParameterType",
+                "range": {
+                    "startColumn": 17,
+                    "endColumn": 23,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownParameterType",
+                "range": {
+                    "startColumn": 25,
+                    "endColumn": 29,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportMissingParameterType",
+                "range": {
+                    "startColumn": 25,
+                    "endColumn": 29,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownArgumentType",
+                "range": {
+                    "startColumn": 16,
+                    "endColumn": 22,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownArgumentType",
+                "range": {
+                    "startColumn": 24,
+                    "endColumn": 53,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownMemberType",
+                "range": {
+                    "startColumn": 15,
+                    "endColumn": 28,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownParameterType",
+                "range": {
+                    "startColumn": 26,
+                    "endColumn": 30,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportMissingParameterType",
+                "range": {
+                    "startColumn": 26,
+                    "endColumn": 30,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownMemberType",
+                "range": {
+                    "startColumn": 15,
+                    "endColumn": 28,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownArgumentType",
+                "range": {
+                    "startColumn": 38,
+                    "endColumn": 42,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownParameterType",
+                "range": {
+                    "startColumn": 25,
+                    "endColumn": 29,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportMissingParameterType",
+                "range": {
+                    "startColumn": 25,
+                    "endColumn": 29,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownMemberType",
+                "range": {
+                    "startColumn": 15,
+                    "endColumn": 28,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownArgumentType",
+                "range": {
+                    "startColumn": 37,
+                    "endColumn": 41,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownArgumentType",
+                "range": {
+                    "startColumn": 29,
+                    "endColumn": 41,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownMemberType",
+                "range": {
+                    "startColumn": 15,
+                    "endColumn": 31,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownMemberType",
+                "range": {
+                    "startColumn": 19,
+                    "endColumn": 34,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownMemberType",
+                "range": {
+                    "startColumn": 8,
+                    "endColumn": 23,
+                    "lineCount": 1
+                }
+            },
+            {
+                "code": "reportUnknownMemberType",
+                "range": {
+                    "startColumn": 27,
+                    "endColumn": 42,
+                    "lineCount": 1
+                }
+            }
+        ]
+    }
+}
\ No newline at end of file
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e4f20fd..63da833 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,4 +22,19 @@ jobs:
                 pipx install ruff
                 ruff check
 
+    basedpyright:
+        runs-on: ubuntu-latest
+        steps:
+        -   uses: actions/checkout@v3
+        -   uses: actions/setup-python@v4
+            with:
+                python-version: '3.x'
+        -   name: "Main Script"
+            run: |
+                python -m venv .testenv
+                source .testenv/bin/activate
+                pip install .
+                pip install basedpyright
+                basedpyright --baselinemode=auto
+
 # vim: sw=4
diff --git a/pygrist_mini/__init__.py b/pygrist_mini/__init__.py
index 0f984c9..44a37b2 100644
--- a/pygrist_mini/__init__.py
+++ b/pygrist_mini/__init__.py
@@ -2,10 +2,15 @@
 
 import datetime
 import json
-from typing import Any, Mapping, Sequence, TypedDict
+from dataclasses import dataclass
+from typing import TYPE_CHECKING, Any, TypedDict
+from zoneinfo import ZoneInfo
 
 import requests
-from zoneinfo import ZoneInfo
+
+
+if TYPE_CHECKING:
+    from collections.abc import Mapping, Sequence
 
 
 UTC  = ZoneInfo("UTC")
@@ -14,8 +19,8 @@
 class HTTPError(RuntimeError):
     def __init__(self, status_code: int, message: str):
         super().__init__(f"Status {status_code}: {message}")
-        self.status_code = status_code
-        self.message = message
+        self.status_code: int = status_code
+        self.message: str = message
 
 
 class Record(TypedDict):
@@ -29,14 +34,13 @@ def timestamp_to_date(tstamp: float) -> datetime.date:
 
 # {{{ grist client
 
+@dataclass(frozen=True)
 class GristClient:
     """Grist API client"""
-
-    def __init__(self, root_url, api_key, doc_id, timeout=None):
-        self.root_url = root_url
-        self.api_key = api_key
-        self.doc_id = doc_id
-        self.timeout = timeout
+    root_url: str
+    api_key: str
+    doc_id: str
+    timeout: float | None = None
 
     # {{{ generic request methods
 
@@ -124,7 +128,7 @@ def delete_records(self, table_id: str | int, ids: Sequence[int]) -> None:
 
     def sql(
             self, query: str, args: Sequence[object] | None = None,
-            timeout: float | None = None) -> Sequence[dict[str, object]]:
+            timeout: float | None = None) -> Sequence[dict[str, Any]]:
 
         json_body: dict[str, object] = {"sql": query}
         if args is not None:
diff --git a/pyproject.toml b/pyproject.toml
index 0d4482c..3cfa565 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,13 +4,13 @@ build-backend = "hatchling.build"
 
 [project]
 name = "pygrist_mini"
-version = "2026.1"
+version = "2026.1.1"
 authors = [
     {name = "Andreas Kloeckner", email = "inform@tiker.net"},
 ]
 description = "Minimal Grist API (document) client"
 readme = "README.md"
-requires-python = ">=3.8"
+requires-python = ">=3.10"
 license = "MIT"
 classifiers = [
     "Development Status :: 3 - Alpha",
@@ -66,3 +66,11 @@ multiline-quotes = "double"
 combine-as-imports = true
 lines-after-imports = 2
 required-imports = ["from __future__ import annotations"]
+
+[tool.basedpyright]
+reportImplicitStringConcatenation = "none"
+reportUnnecessaryIsInstance = "none"
+reportUnusedCallResult = "none"
+reportExplicitAny = "none"
+reportUnreachable = "hint"
+reportAny = "none"