diff --git a/flagsmith/mappers.py b/flagsmith/mappers.py
index 8d8179a..7564a89 100644
--- a/flagsmith/mappers.py
+++ b/flagsmith/mappers.py
@@ -93,7 +93,6 @@ def map_context_and_identity_data_to_context(
         **context,
         "identity": {
             "identifier": identifier,
-            "key": f"{context['environment']['key']}_{identifier}",
             "traits": {
                 trait_key: (
                     trait_value_or_config["value"]
@@ -200,7 +199,6 @@ def _map_identity_overrides_to_segments(
             overrides=[
                 {
                     "key": "",  # Identity overrides never carry multivariate options
-                    "feature_key": str(flagsmith_id),
                     "name": feature_name,
                     "enabled": feature_enabled,
                     "value": feature_value,
@@ -245,7 +243,6 @@ def _map_environment_document_feature_states_to_feature_contexts(
             key=str(
                 feature_state.get("django_id") or feature_state["featurestate_uuid"]
             ),
-            feature_key=str(feature_state["feature"]["id"]),
             name=feature_state["feature"]["name"],
             enabled=feature_state["enabled"],
             value=feature_state["feature_state_value"],
diff --git a/poetry.lock b/poetry.lock
index 7b7aedf..4d9f539 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 2.2.0 and should not be changed by hand.
+# This file is automatically @generated by Poetry 2.1.3 and should not be changed by hand.
 
 [[package]]
 name = "certifi"
@@ -259,14 +259,14 @@ files = [
 
 [[package]]
 name = "flagsmith-flag-engine"
-version = "9.1.0"
+version = "10.0.0"
 description = "Flag engine for the Flagsmith API."
 optional = false
 python-versions = "*"
 groups = ["main"]
 files = [
-    {file = "flagsmith_flag_engine-9.1.0-py3-none-any.whl", hash = "sha256:1afe9aa37469ce4208f5e62c2a90669e2fdada401d4b795b339ea9bf019da733"},
-    {file = "flagsmith_flag_engine-9.1.0.tar.gz", hash = "sha256:d18f8daef0684f1b0224a9f98c279c966cafd29d52444682705c474247d3b4ce"},
+    {file = "flagsmith_flag_engine-10.0.0-py3-none-any.whl", hash = "sha256:da9dec37556416a6bec2004ec6dbe7e2581dfdd24167fe224a2280db7f01c011"},
+    {file = "flagsmith_flag_engine-10.0.0.tar.gz", hash = "sha256:c3318504d904532cb4673df849cfc222ccbd92915d1697d34c9e9e55f3f5eb53"},
 ]
 
 [package.dependencies]
@@ -947,4 +947,4 @@ test = ["covdefaults (>=2.3)", "coverage (>=7.2.7)", "coverage-enable-subprocess
 [metadata]
 lock-version = "2.1"
 python-versions = ">=3.9,<4"
-content-hash = "7feced3e0ab64b956db1c6eaf112aa2553494bf4a27127a5afd0a8062d952917"
+content-hash = "cfe10e9fdb3ea780c9d8fae0f9cf8b92b3a37356be13633f655d910f71e0035e"
diff --git a/pyproject.toml b/pyproject.toml
index c1df2ec..858d6b1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -10,7 +10,7 @@ documentation = "https://docs.flagsmith.com"
 packages = [{ include = "flagsmith" }]
 
 [tool.poetry.dependencies]
-flagsmith-flag-engine = "^9.1.0"
+flagsmith-flag-engine = "^10.0.0"
 python = ">=3.9,<4"
 requests = "^2.32.3"
 requests-futures = "^1.0.1"
diff --git a/tests/test_flagsmith.py b/tests/test_flagsmith.py
index 6d5258c..ce9219b 100644
--- a/tests/test_flagsmith.py
+++ b/tests/test_flagsmith.py
@@ -165,7 +165,6 @@ def test_get_identity_flags_uses_local_environment_when_available(
                 "name": "some_feature",
                 "enabled": True,
                 "value": "some-feature-state-value",
-                "feature_key": "1",
                 "metadata": {"flagsmith_id": 1},
             }
         },
diff --git a/tests/test_models.py b/tests/test_models.py
index 35d960d..7cc8283 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -10,7 +10,6 @@ def test_flag_from_evaluation_result() -> None:
     # Given
     flag_result: SDKFlagResult = {
         "enabled": True,
-        "feature_key": "123",
         "name": "test_feature",
         "reason": "DEFAULT",
         "value": "test-value",
@@ -36,7 +35,6 @@ def test_flag_from_evaluation_result() -> None:
             {
                 "feature1": {
                     "enabled": True,
-                    "feature_key": "1",
                     "name": "feature1",
                     "reason": "DEFAULT",
                     "value": "value1",
@@ -49,7 +47,6 @@ def test_flag_from_evaluation_result() -> None:
             {
                 "feature1": {
                     "enabled": True,
-                    "feature_key": "1",
                     "name": "feature1",
                     "reason": "DEFAULT",
                     "value": "value1",
@@ -62,7 +59,6 @@ def test_flag_from_evaluation_result() -> None:
             {
                 "feature1": {
                     "enabled": True,
-                    "feature_key": "1",
                     "name": "feature1",
                     "reason": "DEFAULT",
                     "value": "value1",
@@ -70,7 +66,6 @@ def test_flag_from_evaluation_result() -> None:
                 },
                 "feature2": {
                     "enabled": True,
-                    "feature_key": "2",
                     "name": "feature2",
                     "reason": "DEFAULT",
                     "value": "value2",
@@ -78,7 +73,6 @@ def test_flag_from_evaluation_result() -> None:
                 },
                 "feature3": {
                     "enabled": True,
-                    "feature_key": "3",
                     "name": "feature3",
                     "reason": "DEFAULT",
                     "value": 42,
@@ -130,7 +124,6 @@ def test_flag_from_evaluation_result_value_types(
     # Given
     flag_result: SDKFlagResult = {
         "enabled": True,
-        "feature_key": "123",
         "name": "test_feature",
         "reason": "DEFAULT",
         "value": value,
@@ -148,7 +141,6 @@ def test_flag_from_evaluation_result_missing_metadata__raises_expected() -> None
     # Given
     flag_result: SDKFlagResult = {
         "enabled": True,
-        "feature_key": "123",
         "name": "test_feature",
         "reason": "DEFAULT",
         "value": "test-value",