diff --git a/.grit/.gitignore b/.grit/.gitignore
new file mode 100644
index 00000000000..e4fdfb17c16
--- /dev/null
+++ b/.grit/.gitignore
@@ -0,0 +1,2 @@
+.gritmodules*
+*.log
diff --git a/.grit/grit.yaml b/.grit/grit.yaml
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index 00000000000..c93f16d6ecd
--- /dev/null
+++ b/.grit/grit.yaml
@@ -0,0 +1,3 @@
+version: 0.0.1
+patterns:
+  - name: github.com/getgrit/stdlib#*
diff --git a/.grit/patterns/runtime_data_migration.md b/.grit/patterns/runtime_data_migration.md
new file mode 100644
index 00000000000..8824d37127c
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+++ b/.grit/patterns/runtime_data_migration.md
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+---
+tags: [migration, code_quality]
+---
+# Migrate integration from hass.data to entry.runtime_data
+
+Migrate an integration from hass.data to entry.runtime_data
+
+```grit
+language python
+
+pattern import_from_custom($source) {
+    $name where {
+        $program <: module($statements),
+        $statements <: contains or {
+                import_from_statement(),
+                import_statement(),
+            } as $import,
+        // Ruff will handle double imports and sorting for us
+        // So we add always the import
+        $import => `from $source import $name\n$import`,
+    }
+}
+
+pattern refactor_functions($config_entry_type, $file_name, $config_entry_type_defined) {
+    function_definition($parameters, $body) as $func where {
+        // change config entry type
+        $parameters <: contains typed_parameter(name=$entry_name, $type) where {
+            $type <: type(type="ConfigEntry"),
+            $type => $config_entry_type,
+            if ($file_name <: not `__init__`) {
+                $config_entry_type <: import_from_custom(source = `.`),
+            },
+        },
+
+        if (and {$file_name <: `__init__`, $config_entry_type_defined <: undefined}) {
+            if ($func <: within decorated_definition() as $decorated) {
+                // we need to insert the new type before all function decorators
+                $func = $decorated,
+            },
+            $config_entry_type_definition = `# TODO: Please add the correct type\n`,
+            $config_entry_type_definition += `type $config_entry_type = ConfigEntry`,
+            $func => `$config_entry_type_definition\n\n$func`,
+            $config_entry_type_defined = true,
+        },
+
+        // migrate hass.data to entry.runtime_data
+        $body <: maybe contains assignment($left, $right) as $assignment where {
+            or {
+                and {
+                    $right <: `hass.data[$_][entry.entry_id]`,
+                    $assignment => `$left = $entry_name.runtime_data`
+                },
+                and {
+                    $left <: or {
+                            `hass.data.setdefault($...)[entry.entry_id]`,
+                            `hass.data[$_][entry.entry_id]`,
+                        } as $runtime_data where {
+                            $runtime_data => `$entry_name.runtime_data`
+                        },
+                }
+            }
+        },
+    }
+}
+
+multifile {
+    bubble($domain_list) file($name, $body) where {
+        // find all integrations, which can be migrated
+        $filename <: r".*components/([^/]+)/__init__\.py$"($domain),
+        $body <: contains or {
+        `hass.data.setdefault($...)[entry.entry_id]`,
+        `hass.data[$_][entry.entry_id]`,
+        },
+        if ($domain_list <: undefined) {
+            $domain_list = []
+        },
+        $domain_list += $domain,
+    },
+    bubble($domain_list) file($name, $body) where {
+        // migrate files
+        $filename <: r".*components/([^/]+)/([^/]+)\.py$"($domain, $file_name),
+        $domain_list <: includes $domain,
+        $config_entry_type = capitalize($domain),
+        $config_entry_type += "ConfigEntry",
+        $body <: contains refactor_functions($config_entry_type, $file_name, $config_entry_type_defined),
+    },
+}
+```
\ No newline at end of file