From fe6b8a64d11d6e78fdce55236416c5398919b585 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 5 Nov 2025 15:25:37 +0000
Subject: [PATCH 01/12] Initial plan

Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>

From f3d1184632e9d4f061d8c419b8d13e67e73aa029 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 5 Nov 2025 15:45:50 +0000
Subject: [PATCH 02/12] Document selector migration guidance for in-process
 mode

- Add comprehensive migration guidance section for selector handling
- Clarify that selector changes only affect in-process and file modes
- Document backward compatibility and future breaking changes
- Update provider docstring with selector migration note
- Link to upstream flagd issue #1814

Co-authored-by: aepfli <9987394+aepfli@users.noreply.github.com>
Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 .../openfeature-provider-flagd/README.md      | 44 +++++++++++++++++++
 .../contrib/provider/flagd/provider.py        |  3 ++
 2 files changed, 47 insertions(+)

diff --git a/providers/openfeature-provider-flagd/README.md b/providers/openfeature-provider-flagd/README.md
index 60d27fcf..f2a7e5a1 100644
--- a/providers/openfeature-provider-flagd/README.md
+++ b/providers/openfeature-provider-flagd/README.md
@@ -93,6 +93,9 @@ The default options can be defined in the FlagdProvider constructor.
 | retry_backoff_ms         | FLAGD_RETRY_BACKOFF_MS         | int                        | 1000                          | rpc                 |
 | offline_flag_source_path | FLAGD_OFFLINE_FLAG_SOURCE_PATH | str                        | null                          | in-process          |
 
+> [!NOTE]
+> The `selector` configuration is only used in **in-process** mode for filtering flag configurations. See [Selector Handling](#selector-handling-in-process-mode-only) for migration guidance.
+
 <!-- not implemented
 | target_uri               | FLAGD_TARGET_URI               | alternative to host/port, supporting custom name resolution | string    | null                | rpc & in-process |
 | socket_path              | FLAGD_SOCKET_PATH              | alternative to host port, unix socket                       | String    | null                | rpc & in-process |
@@ -103,6 +106,47 @@ The default options can be defined in the FlagdProvider constructor.
 > [!NOTE]
 > Some configurations are only applicable for RPC resolver.
 
+### Selector Handling (In-Process Mode Only)
+
+> [!IMPORTANT]
+> This section only applies to **in-process** and **file** resolver modes. RPC mode is not affected by selector handling changes.
+
+#### Migration Guidance
+
+As of flagd v0.11.0 and related services, selector normalization has been updated to prefer gRPC metadata headers over request body fields for the `selector` parameter. This change affects how the in-process provider communicates with flagd's sync service.
+
+**Current Behavior (Preferred):**
+The Python SDK currently passes the `selector` via the gRPC request body when using in-process mode. While this approach continues to work for backward compatibility, the flagd ecosystem is transitioning to header-based selector passing.
+
+**Configuration Example:**
+```python
+from openfeature import api
+from openfeature.contrib.provider.flagd import FlagdProvider
+from openfeature.contrib.provider.flagd.config import ResolverType
+
+api.set_provider(FlagdProvider(
+    resolver_type=ResolverType.IN_PROCESS,
+    selector="my-flag-source",  # Currently passed in request body
+))
+```
+
+#### Backward Compatibility
+
+The current implementation maintains backward compatibility by continuing to pass selectors in the request body. flagd services support both approaches:
+- **Request body selector** (current implementation) - Supported for backward compatibility
+- **Header-based selector** (future preferred) - Will be supported in a future SDK update
+
+#### Future Breaking Change
+
+In a future major version of this SDK, the selector handling will be updated to use gRPC metadata headers (`flagd-selector`) instead of the request body field. This aligns with the flagd ecosystem's standardized approach to selector normalization.
+
+**Action Required:**
+No immediate action is required. The current implementation will continue to work with both current and future versions of flagd services. Monitor release notes for announcements about the transition to header-based selectors.
+
+**Related Resources:**
+- Upstream issue: [open-feature/flagd#1814](https://github.com/open-feature/flagd/issues/1814)
+- Selector normalization affects in-process evaluations that filter flag configurations by source
+
 <!--
 ### Unix socket support
 Unix socket communication with flagd is facilitated by usaging of the linux-native `epoll` library on `linux-x86_64`
diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
index 149220f1..1d415e7e 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
@@ -75,6 +75,9 @@ def __init__(  # noqa: PLR0913
         :param deadline_ms: the maximum to wait before a request times out
         :param timeout: the maximum time to wait before a request times out
         :param retry_backoff_ms: the number of milliseconds to backoff
+        :param selector: filter flag configurations by source (in-process mode only)
+                         Note: Currently passed via request body. Future versions will use
+                         gRPC metadata headers. See README for migration guidance.
         :param offline_flag_source_path: the path to the flag source file
         :param stream_deadline_ms: the maximum time to wait before a request times out
         :param keep_alive_time: the number of milliseconds to keep alive

From 020a3a315b0d4e7e3cc596fe69553cff011cb971 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 5 Nov 2025 15:59:31 +0000
Subject: [PATCH 03/12] Implement selector passing via gRPC metadata header for
 in-process mode

- Update GrpcWatcher to pass selector via flagd-selector metadata header
- Add GrpcMultiCallableArgs.metadata field to support gRPC metadata
- Update README to reflect current header-based implementation
- Add test to verify selector is passed via metadata, not request body
- Aligns with flagd v0.11.0+ selector normalization standard

Co-authored-by: aepfli <9987394+aepfli@users.noreply.github.com>
Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 .../openfeature-provider-flagd/README.md      | 24 ++++++----------
 .../contrib/provider/flagd/provider.py        |  3 +-
 .../process/connector/grpc_watcher.py         | 21 ++++++++++++--
 .../contrib/provider/flagd/resolvers/types.py |  1 +
 .../tests/test_grpc_watcher.py                | 28 +++++++++++++++++++
 5 files changed, 58 insertions(+), 19 deletions(-)

diff --git a/providers/openfeature-provider-flagd/README.md b/providers/openfeature-provider-flagd/README.md
index f2a7e5a1..f5a557b9 100644
--- a/providers/openfeature-provider-flagd/README.md
+++ b/providers/openfeature-provider-flagd/README.md
@@ -111,12 +111,9 @@ The default options can be defined in the FlagdProvider constructor.
 > [!IMPORTANT]
 > This section only applies to **in-process** and **file** resolver modes. RPC mode is not affected by selector handling changes.
 
-#### Migration Guidance
+#### Current Implementation
 
-As of flagd v0.11.0 and related services, selector normalization has been updated to prefer gRPC metadata headers over request body fields for the `selector` parameter. This change affects how the in-process provider communicates with flagd's sync service.
-
-**Current Behavior (Preferred):**
-The Python SDK currently passes the `selector` via the gRPC request body when using in-process mode. While this approach continues to work for backward compatibility, the flagd ecosystem is transitioning to header-based selector passing.
+As of this SDK version, the `selector` parameter is passed via gRPC metadata headers (`flagd-selector`) when using in-process mode. This aligns with flagd v0.11.0+ selector normalization standards.
 
 **Configuration Example:**
 ```python
@@ -126,22 +123,19 @@ from openfeature.contrib.provider.flagd.config import ResolverType
 
 api.set_provider(FlagdProvider(
     resolver_type=ResolverType.IN_PROCESS,
-    selector="my-flag-source",  # Currently passed in request body
+    selector="my-flag-source",  # Passed via flagd-selector header
 ))
 ```
 
-#### Backward Compatibility
-
-The current implementation maintains backward compatibility by continuing to pass selectors in the request body. flagd services support both approaches:
-- **Request body selector** (current implementation) - Supported for backward compatibility
-- **Header-based selector** (future preferred) - Will be supported in a future SDK update
+The selector is automatically passed via the `flagd-selector` gRPC metadata header, ensuring compatibility with flagd services that implement selector normalization.
 
-#### Future Breaking Change
+#### Backward Compatibility
 
-In a future major version of this SDK, the selector handling will be updated to use gRPC metadata headers (`flagd-selector`) instead of the request body field. This aligns with the flagd ecosystem's standardized approach to selector normalization.
+flagd services maintain backward compatibility with both selector passing approaches:
+- **gRPC metadata header** (`flagd-selector`) - Current implementation (recommended)
+- **Request body selector** - Legacy approach (still supported by flagd for backward compatibility)
 
-**Action Required:**
-No immediate action is required. The current implementation will continue to work with both current and future versions of flagd services. Monitor release notes for announcements about the transition to header-based selectors.
+This ensures the Python SDK works correctly with both older and newer versions of flagd services.
 
 **Related Resources:**
 - Upstream issue: [open-feature/flagd#1814](https://github.com/open-feature/flagd/issues/1814)
diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
index 1d415e7e..5e916a93 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
@@ -76,8 +76,7 @@ def __init__(  # noqa: PLR0913
         :param timeout: the maximum time to wait before a request times out
         :param retry_backoff_ms: the number of milliseconds to backoff
         :param selector: filter flag configurations by source (in-process mode only)
-                         Note: Currently passed via request body. Future versions will use
-                         gRPC metadata headers. See README for migration guidance.
+                         Passed via flagd-selector gRPC metadata header.
         :param offline_flag_source_path: the path to the flag source file
         :param stream_deadline_ms: the maximum time to wait before a request times out
         :param keep_alive_time: the number of milliseconds to keep alive
diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
index 60a1473a..34341a1d 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
@@ -205,13 +205,24 @@ def shutdown(self) -> None:
 
     def _create_request_args(self) -> dict:
         request_args = {}
-        if self.selector is not None:
-            request_args["selector"] = self.selector
+        # Note: selector is now passed via gRPC metadata header instead of request body
+        # This maintains compatibility with flagd v0.11.0+ selector normalization
         if self.provider_id is not None:
             request_args["provider_id"] = self.provider_id
 
         return request_args
 
+    def _create_metadata(self) -> typing.Optional[typing.List[typing.Tuple[str, str]]]:
+        """Create gRPC metadata headers for the request.
+        
+        Returns gRPC metadata as a list of tuples containing header key-value pairs.
+        The selector is passed via the 'flagd-selector' header per flagd v0.11.0+ specification.
+        """
+        if self.selector is None:
+            return None
+        
+        return [("flagd-selector", self.selector)]
+
     def _fetch_metadata(self) -> typing.Optional[sync_pb2.GetMetadataResponse]:
         if self.config.sync_metadata_disabled:
             return None
@@ -233,6 +244,12 @@ def listen(self) -> None:  # noqa: C901
         call_args: GrpcMultiCallableArgs = {"wait_for_ready": True}
         if self.streamline_deadline_seconds > 0:
             call_args["timeout"] = self.streamline_deadline_seconds
+        
+        # Add selector via gRPC metadata header (flagd v0.11.0+ preferred approach)
+        metadata = self._create_metadata()
+        if metadata is not None:
+            call_args["metadata"] = metadata
+        
         request_args = self._create_request_args()
 
         while self.active:
diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
index a9ec7959..53fa90d5 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
@@ -4,3 +4,4 @@
 class GrpcMultiCallableArgs(typing.TypedDict, total=False):
     timeout: typing.Optional[float]
     wait_for_ready: typing.Optional[bool]
+    metadata: typing.Optional[typing.Sequence[typing.Tuple[str, str]]]
diff --git a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
index ad7a8015..87708421 100644
--- a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
@@ -133,3 +133,31 @@ def test_listen_with_sync_metadata_disabled_in_config(self):
             self.provider_details.message, "gRPC sync connection established"
         )
         self.assertEqual(self.context, {})
+
+    def test_selector_passed_via_metadata_header(self):
+        """Test that selector is passed via gRPC metadata header, not request body"""
+        self.grpc_watcher.selector = "test-selector"
+        mock_stream = iter(
+            [
+                SyncFlagsResponse(flag_configuration='{"flag_key": "flag_value"}'),
+            ]
+        )
+        self.mock_stub.SyncFlags = Mock(return_value=mock_stream)
+
+        self.run_listen_and_shutdown_after()
+
+        # Verify SyncFlags was called
+        self.mock_stub.SyncFlags.assert_called_once()
+        
+        # Get the call arguments
+        call_args = self.mock_stub.SyncFlags.call_args
+        
+        # Verify the request doesn't contain selector in body
+        request = call_args[0][0]  # First positional argument is the request
+        self.assertFalse(hasattr(request, 'selector') and request.selector)
+        
+        # Verify metadata contains flagd-selector header
+        kwargs = call_args[1]
+        self.assertIn('metadata', kwargs)
+        metadata = kwargs['metadata']
+        self.assertEqual(metadata, [('flagd-selector', 'test-selector')])

From d537a00d250d1bcd84d6ddeb410a0c9dcb890dfb Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 5 Nov 2025 16:28:07 +0000
Subject: [PATCH 04/12] Pass selector via both header and request body for
 backward compatibility

- Update _create_request_args to include selector in request body
- Maintain selector in flagd-selector gRPC metadata header
- Update test to verify both header and body contain selector
- Update documentation to reflect dual transmission approach
- Ensures compatibility with both older and newer flagd versions

Co-authored-by: aepfli <9987394+aepfli@users.noreply.github.com>
Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 providers/openfeature-provider-flagd/README.md  | 17 +++++++++--------
 .../contrib/provider/flagd/provider.py          |  3 ++-
 .../resolvers/process/connector/grpc_watcher.py |  9 ++++++---
 .../tests/test_grpc_watcher.py                  | 10 +++++-----
 4 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/providers/openfeature-provider-flagd/README.md b/providers/openfeature-provider-flagd/README.md
index f5a557b9..fc90d6b2 100644
--- a/providers/openfeature-provider-flagd/README.md
+++ b/providers/openfeature-provider-flagd/README.md
@@ -113,7 +113,7 @@ The default options can be defined in the FlagdProvider constructor.
 
 #### Current Implementation
 
-As of this SDK version, the `selector` parameter is passed via gRPC metadata headers (`flagd-selector`) when using in-process mode. This aligns with flagd v0.11.0+ selector normalization standards.
+As of this SDK version, the `selector` parameter is passed via **both** gRPC metadata headers (`flagd-selector`) and the request body when using in-process mode. This dual approach ensures maximum compatibility with all flagd versions.
 
 **Configuration Example:**
 ```python
@@ -123,19 +123,20 @@ from openfeature.contrib.provider.flagd.config import ResolverType
 
 api.set_provider(FlagdProvider(
     resolver_type=ResolverType.IN_PROCESS,
-    selector="my-flag-source",  # Passed via flagd-selector header
+    selector="my-flag-source",  # Passed via both header and request body
 ))
 ```
 
-The selector is automatically passed via the `flagd-selector` gRPC metadata header, ensuring compatibility with flagd services that implement selector normalization.
+The selector is automatically passed via:
+- **gRPC metadata header** (`flagd-selector`) - For flagd v0.11.0+ selector normalization
+- **Request body** - For backward compatibility with older flagd versions
 
 #### Backward Compatibility
 
-flagd services maintain backward compatibility with both selector passing approaches:
-- **gRPC metadata header** (`flagd-selector`) - Current implementation (recommended)
-- **Request body selector** - Legacy approach (still supported by flagd for backward compatibility)
-
-This ensures the Python SDK works correctly with both older and newer versions of flagd services.
+This dual transmission approach ensures the Python SDK works seamlessly with all flagd service versions:
+- **Older flagd versions** read the selector from the request body
+- **Newer flagd versions (v0.11.0+)** prefer the selector from the gRPC metadata header
+- Both approaches are supported simultaneously for maximum compatibility
 
 **Related Resources:**
 - Upstream issue: [open-feature/flagd#1814](https://github.com/open-feature/flagd/issues/1814)
diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
index 5e916a93..5efa995c 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py
@@ -76,7 +76,8 @@ def __init__(  # noqa: PLR0913
         :param timeout: the maximum time to wait before a request times out
         :param retry_backoff_ms: the number of milliseconds to backoff
         :param selector: filter flag configurations by source (in-process mode only)
-                         Passed via flagd-selector gRPC metadata header.
+                         Passed via both flagd-selector gRPC metadata header and request body
+                         for backward compatibility with all flagd versions.
         :param offline_flag_source_path: the path to the flag source file
         :param stream_deadline_ms: the maximum time to wait before a request times out
         :param keep_alive_time: the number of milliseconds to keep alive
diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
index 34341a1d..6051be70 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
@@ -205,8 +205,10 @@ def shutdown(self) -> None:
 
     def _create_request_args(self) -> dict:
         request_args = {}
-        # Note: selector is now passed via gRPC metadata header instead of request body
-        # This maintains compatibility with flagd v0.11.0+ selector normalization
+        # Pass selector in both request body (legacy) and metadata header (new) for backward compatibility
+        # This ensures compatibility with both older and newer flagd versions
+        if self.selector is not None:
+            request_args["selector"] = self.selector
         if self.provider_id is not None:
             request_args["provider_id"] = self.provider_id
 
@@ -216,7 +218,8 @@ def _create_metadata(self) -> typing.Optional[typing.List[typing.Tuple[str, str]
         """Create gRPC metadata headers for the request.
         
         Returns gRPC metadata as a list of tuples containing header key-value pairs.
-        The selector is passed via the 'flagd-selector' header per flagd v0.11.0+ specification.
+        The selector is passed via the 'flagd-selector' header per flagd v0.11.0+ specification,
+        while also being included in the request body for backward compatibility with older flagd versions.
         """
         if self.selector is None:
             return None
diff --git a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
index 87708421..6d441284 100644
--- a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
@@ -134,8 +134,8 @@ def test_listen_with_sync_metadata_disabled_in_config(self):
         )
         self.assertEqual(self.context, {})
 
-    def test_selector_passed_via_metadata_header(self):
-        """Test that selector is passed via gRPC metadata header, not request body"""
+    def test_selector_passed_via_both_metadata_and_body(self):
+        """Test that selector is passed via both gRPC metadata header and request body for backward compatibility"""
         self.grpc_watcher.selector = "test-selector"
         mock_stream = iter(
             [
@@ -152,11 +152,11 @@ def test_selector_passed_via_metadata_header(self):
         # Get the call arguments
         call_args = self.mock_stub.SyncFlags.call_args
         
-        # Verify the request doesn't contain selector in body
+        # Verify the request contains selector in body (backward compatibility)
         request = call_args[0][0]  # First positional argument is the request
-        self.assertFalse(hasattr(request, 'selector') and request.selector)
+        self.assertEqual(request.selector, 'test-selector')
         
-        # Verify metadata contains flagd-selector header
+        # Verify metadata also contains flagd-selector header (new approach)
         kwargs = call_args[1]
         self.assertIn('metadata', kwargs)
         metadata = kwargs['metadata']

From 9d7a22664a7495da9892e214ac1cfff5e392359a Mon Sep 17 00:00:00 2001
From: Simon Schrottner <simon.schrottner@dynatrace.com>
Date: Wed, 5 Nov 2025 18:17:15 +0100
Subject: [PATCH 05/12] Update
 providers/openfeature-provider-flagd/tests/test_grpc_watcher.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 .../openfeature-provider-flagd/tests/test_grpc_watcher.py     | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
index 6d441284..59b4a39c 100644
--- a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
@@ -153,11 +153,11 @@ def test_selector_passed_via_both_metadata_and_body(self):
         call_args = self.mock_stub.SyncFlags.call_args
         
         # Verify the request contains selector in body (backward compatibility)
-        request = call_args[0][0]  # First positional argument is the request
+        request = call_args.args[0]  # First positional argument is the request
         self.assertEqual(request.selector, 'test-selector')
         
         # Verify metadata also contains flagd-selector header (new approach)
-        kwargs = call_args[1]
+        kwargs = call_args.kwargs
         self.assertIn('metadata', kwargs)
         metadata = kwargs['metadata']
         self.assertEqual(metadata, [('flagd-selector', 'test-selector')])

From 438cb079256e406576500cb56bbd6bda555aa4f8 Mon Sep 17 00:00:00 2001
From: Simon Schrottner <simon.schrottner@dynatrace.com>
Date: Thu, 6 Nov 2025 14:12:26 +0100
Subject: [PATCH 06/12] fixup: linting

Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 .../resolvers/process/connector/grpc_watcher.py    |  8 ++++----
 .../tests/test_grpc_watcher.py                     | 14 +++++++-------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
index 6051be70..380a5ede 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
@@ -216,14 +216,14 @@ def _create_request_args(self) -> dict:
 
     def _create_metadata(self) -> typing.Optional[typing.List[typing.Tuple[str, str]]]:
         """Create gRPC metadata headers for the request.
-        
+
         Returns gRPC metadata as a list of tuples containing header key-value pairs.
         The selector is passed via the 'flagd-selector' header per flagd v0.11.0+ specification,
         while also being included in the request body for backward compatibility with older flagd versions.
         """
         if self.selector is None:
             return None
-        
+
         return [("flagd-selector", self.selector)]
 
     def _fetch_metadata(self) -> typing.Optional[sync_pb2.GetMetadataResponse]:
@@ -247,12 +247,12 @@ def listen(self) -> None:  # noqa: C901
         call_args: GrpcMultiCallableArgs = {"wait_for_ready": True}
         if self.streamline_deadline_seconds > 0:
             call_args["timeout"] = self.streamline_deadline_seconds
-        
+
         # Add selector via gRPC metadata header (flagd v0.11.0+ preferred approach)
         metadata = self._create_metadata()
         if metadata is not None:
             call_args["metadata"] = metadata
-        
+
         request_args = self._create_request_args()
 
         while self.active:
diff --git a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
index 59b4a39c..213f6795 100644
--- a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
@@ -148,16 +148,16 @@ def test_selector_passed_via_both_metadata_and_body(self):
 
         # Verify SyncFlags was called
         self.mock_stub.SyncFlags.assert_called_once()
-        
+
         # Get the call arguments
         call_args = self.mock_stub.SyncFlags.call_args
-        
+
         # Verify the request contains selector in body (backward compatibility)
         request = call_args.args[0]  # First positional argument is the request
-        self.assertEqual(request.selector, 'test-selector')
-        
+        self.assertEqual(request.selector, "test-selector")
+
         # Verify metadata also contains flagd-selector header (new approach)
         kwargs = call_args.kwargs
-        self.assertIn('metadata', kwargs)
-        metadata = kwargs['metadata']
-        self.assertEqual(metadata, [('flagd-selector', 'test-selector')])
+        self.assertIn("metadata", kwargs)
+        metadata = kwargs["metadata"]
+        self.assertEqual(metadata, [("flagd-selector", "test-selector")])

From 56dfd39b5224e40a14e161dfa340a5be4572d072 Mon Sep 17 00:00:00 2001
From: Simon Schrottner <simon.schrottner@dynatrace.com>
Date: Thu, 6 Nov 2025 14:19:41 +0100
Subject: [PATCH 07/12] fixup: types

Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 .../flagd/resolvers/process/connector/grpc_watcher.py         | 4 ++--
 .../src/openfeature/contrib/provider/flagd/resolvers/types.py | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
index 380a5ede..e98f0bcb 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
@@ -214,7 +214,7 @@ def _create_request_args(self) -> dict:
 
         return request_args
 
-    def _create_metadata(self) -> typing.Optional[typing.List[typing.Tuple[str, str]]]:
+    def _create_metadata(self) -> typing.Optional[typing.Tuple[typing.Tuple[str, str]]]:
         """Create gRPC metadata headers for the request.
 
         Returns gRPC metadata as a list of tuples containing header key-value pairs.
@@ -224,7 +224,7 @@ def _create_metadata(self) -> typing.Optional[typing.List[typing.Tuple[str, str]
         if self.selector is None:
             return None
 
-        return [("flagd-selector", self.selector)]
+        return (("flagd-selector", self.selector),)
 
     def _fetch_metadata(self) -> typing.Optional[sync_pb2.GetMetadataResponse]:
         if self.config.sync_metadata_disabled:
diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
index 53fa90d5..f665ab4d 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
@@ -4,4 +4,4 @@
 class GrpcMultiCallableArgs(typing.TypedDict, total=False):
     timeout: typing.Optional[float]
     wait_for_ready: typing.Optional[bool]
-    metadata: typing.Optional[typing.Sequence[typing.Tuple[str, str]]]
+    metadata: typing.Optional[typing.Tuple[typing.Tuple[str, str]]]

From 99b28256a50fe9133812eaafe49aa7e62833a575 Mon Sep 17 00:00:00 2001
From: Simon Schrottner <simon.schrottner@dynatrace.com>
Date: Thu, 6 Nov 2025 14:36:29 +0100
Subject: [PATCH 08/12] fixup: linting

Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 .../process/connector/grpc_watcher.py         | 21 +++++++++++--------
 .../contrib/provider/flagd/resolvers/types.py |  2 +-
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
index e98f0bcb..a60a2db8 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
@@ -214,7 +214,7 @@ def _create_request_args(self) -> dict:
 
         return request_args
 
-    def _create_metadata(self) -> typing.Optional[typing.Tuple[typing.Tuple[str, str]]]:
+    def _create_metadata(self) -> typing.Optional[tuple[tuple[str, str]]]:
         """Create gRPC metadata headers for the request.
 
         Returns gRPC metadata as a list of tuples containing header key-value pairs.
@@ -244,14 +244,7 @@ def _fetch_metadata(self) -> typing.Optional[sync_pb2.GetMetadataResponse]:
                 raise e
 
     def listen(self) -> None:  # noqa: C901
-        call_args: GrpcMultiCallableArgs = {"wait_for_ready": True}
-        if self.streamline_deadline_seconds > 0:
-            call_args["timeout"] = self.streamline_deadline_seconds
-
-        # Add selector via gRPC metadata header (flagd v0.11.0+ preferred approach)
-        metadata = self._create_metadata()
-        if metadata is not None:
-            call_args["metadata"] = metadata
+        call_args = self.generate_grpc_call_args()
 
         request_args = self._create_request_args()
 
@@ -299,3 +292,13 @@ def listen(self) -> None:  # noqa: C901
                 logger.exception(
                     f"Could not parse flag data using flagd syntax: {flag_str=}"
                 )
+
+    def generate_grpc_call_args(self):
+        call_args: GrpcMultiCallableArgs = {"wait_for_ready": True}
+        if self.streamline_deadline_seconds > 0:
+            call_args["timeout"] = self.streamline_deadline_seconds
+        # Add selector via gRPC metadata header (flagd v0.11.0+ preferred approach)
+        metadata = self._create_metadata()
+        if metadata is not None:
+            call_args["metadata"] = metadata
+        return call_args
diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
index f665ab4d..1446470f 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/types.py
@@ -4,4 +4,4 @@
 class GrpcMultiCallableArgs(typing.TypedDict, total=False):
     timeout: typing.Optional[float]
     wait_for_ready: typing.Optional[bool]
-    metadata: typing.Optional[typing.Tuple[typing.Tuple[str, str]]]
+    metadata: typing.Optional[tuple[tuple[str, str]]]

From 75dc969ef6e03db6c15fcbd0918cf3681d5e266d Mon Sep 17 00:00:00 2001
From: Simon Schrottner <simon.schrottner@dynatrace.com>
Date: Thu, 6 Nov 2025 15:01:56 +0100
Subject: [PATCH 09/12] fixup: more formating

Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 .../flagd/resolvers/process/connector/grpc_watcher.py         | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
index a60a2db8..f665d696 100644
--- a/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/process/connector/grpc_watcher.py
@@ -243,7 +243,7 @@ def _fetch_metadata(self) -> typing.Optional[sync_pb2.GetMetadataResponse]:
             else:
                 raise e
 
-    def listen(self) -> None:  # noqa: C901
+    def listen(self) -> None:
         call_args = self.generate_grpc_call_args()
 
         request_args = self._create_request_args()
@@ -293,7 +293,7 @@ def listen(self) -> None:  # noqa: C901
                     f"Could not parse flag data using flagd syntax: {flag_str=}"
                 )
 
-    def generate_grpc_call_args(self):
+    def generate_grpc_call_args(self) -> GrpcMultiCallableArgs:
         call_args: GrpcMultiCallableArgs = {"wait_for_ready": True}
         if self.streamline_deadline_seconds > 0:
             call_args["timeout"] = self.streamline_deadline_seconds

From 122e5e084843d351247e55161621f6d315c38ee9 Mon Sep 17 00:00:00 2001
From: Simon Schrottner <simon.schrottner@dynatrace.com>
Date: Thu, 6 Nov 2025 15:16:52 +0100
Subject: [PATCH 10/12] fixup: changing assertion

Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 providers/openfeature-provider-flagd/tests/test_grpc_watcher.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
index 213f6795..26257aff 100644
--- a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
@@ -147,7 +147,7 @@ def test_selector_passed_via_both_metadata_and_body(self):
         self.run_listen_and_shutdown_after()
 
         # Verify SyncFlags was called
-        self.mock_stub.SyncFlags.assert_called_once()
+        self.mock_stub.SyncFlags.assert_called()
 
         # Get the call arguments
         call_args = self.mock_stub.SyncFlags.call_args

From 2a4977cfc0c42fd9788c6cbaffa3461877d0a93e Mon Sep 17 00:00:00 2001
From: Simon Schrottner <simon.schrottner@dynatrace.com>
Date: Thu, 6 Nov 2025 15:22:50 +0100
Subject: [PATCH 11/12] fixup: changing assertion

Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 providers/openfeature-provider-flagd/tests/test_grpc_watcher.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
index 26257aff..07ee5d80 100644
--- a/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
+++ b/providers/openfeature-provider-flagd/tests/test_grpc_watcher.py
@@ -160,4 +160,4 @@ def test_selector_passed_via_both_metadata_and_body(self):
         kwargs = call_args.kwargs
         self.assertIn("metadata", kwargs)
         metadata = kwargs["metadata"]
-        self.assertEqual(metadata, [("flagd-selector", "test-selector")])
+        self.assertEqual(metadata, (("flagd-selector", "test-selector"),))

From 5ec3a67462455c7d47a6134b7a7840d3af6c5b4c Mon Sep 17 00:00:00 2001
From: Simon Schrottner <simon.schrottner@dynatrace.com>
Date: Thu, 6 Nov 2025 15:55:45 +0100
Subject: [PATCH 12/12] Update providers/openfeature-provider-flagd/README.md

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Signed-off-by: Simon Schrottner <simon.schrottner@dynatrace.com>
---
 providers/openfeature-provider-flagd/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/providers/openfeature-provider-flagd/README.md b/providers/openfeature-provider-flagd/README.md
index fc90d6b2..9cbb865e 100644
--- a/providers/openfeature-provider-flagd/README.md
+++ b/providers/openfeature-provider-flagd/README.md
@@ -109,7 +109,7 @@ The default options can be defined in the FlagdProvider constructor.
 ### Selector Handling (In-Process Mode Only)
 
 > [!IMPORTANT]
-> This section only applies to **in-process** and **file** resolver modes. RPC mode is not affected by selector handling changes.
+> This section only applies to **in-process** resolver mode. RPC mode is not affected by selector handling changes.
 
 #### Current Implementation