feat: change plugin manager to use cpex and remove context forge imports and dependencies

Dockerfile

@@ -36,12 +36,13 @@ RUN if [ -n "$PLUGIN_DEPS" ]; then \
         echo "$PLUGIN_DEPS" | tr ',' '\n' | while read plugin; do \
             plugin=$(echo "$plugin" | xargs); \
             if [ -n "$plugin" ]; then \
-                req_file="plugins/examples/$plugin/requirements.txt"; \
+                plugin_dir="plugins/examples/$plugin"; \
+                req_file="$plugin_dir/pyproject.toml"; \
                 if [ -f "$req_file" ]; then \
-                    echo "Installing dependencies from $req_file"; \
-                    pip install --no-cache-dir -r "$req_file"; \
+                    echo "Installing dependencies from $plugin_dir"; \
+                    pip install --no-cache-dir $plugin_dir; \
                 else \
-                    echo "Warning: No requirements.txt found for plugin '$plugin' at $req_file"; \
+                    echo "Warning: No pyproject.toml found for plugin '$plugin' at $req_file"; \
                 fi; \
             fi; \
         done; \

Makefile

@@ -28,7 +28,7 @@ endif
 
 # Build the combined broker and router 
 build:
-	$(CONTAINER_RUNTIME) build -t $(IMAGE_LOCAL) .
+	$(CONTAINER_RUNTIME) build -t $(IMAGE_LOCAL) . --build-arg PLUGIN_DEPS=${PLUGIN_DEPS}
 
 load:
 	kind load docker-image $(IMAGE_LOCAL) --name mcp-gateway
@@ -72,3 +72,7 @@ deploy_quay:
 	kubectl apply -f ext-proc.yaml
 	kubectl apply -f filter.yaml
 
+dev-run-nemocheck:
+	export PYTHONPATH="${PYTHONPATH}:.";  \
+	pip install -e  plugins/examples/nemocheck; \
+	python src/server.py

README.md

@@ -20,7 +20,7 @@ An Envoy external processor (ext-proc) for configuring and invoking guardrails i
 
 3. **Deploy to kind cluster**
    ```bash
-   make all
+   make all PLUGIN_DEPS=nemocheck #replace nemocheck with comma seperated list of plugins to include other plugins
    ```
 
 See [detailed build instructions](./docs/build.md) for manual build steps.

plugins/examples/nemocheck/plugin.py

@@ -8,7 +8,7 @@
 """
 
 # First-Party
-from mcpgateway.plugins.framework import (
+from cpex.framework import (
     Plugin,
     PluginConfig,
     PluginContext,
@@ -122,6 +122,7 @@ async def tool_pre_invoke(
         )
 
         tool_name = payload.name
+        assert payload.args is not None
         check_nemo_payload = {
             "model": self.model_name,
             "messages": [

plugins/examples/nemocheck/pyproject.toml

@@ -44,8 +44,9 @@ authors = [
 ]
 
 dependencies = [
+    "cpex",
     "mcp>=1.16.0",
-    "mcp-contextforge-gateway",
+    "requests>=2.32.5",
 ]
 
 # URLs
@@ -56,9 +57,6 @@ Repository = "https://github.com/IBM/mcp-context-forge"
 "Bug Tracker" = "https://github.com/IBM/mcp-context-forge/issues"
 Changelog = "https://github.com/IBM/mcp-context-forge/blob/main/CHANGELOG.md"
 
-[tool.uv.sources]
-mcp-contextforge-gateway = { git = "https://github.com/IBM/mcp-context-forge.git", rev = "main" }
-
 # ----------------------------------------------------------------
 # Optional dependency groups (extras)
 # ----------------------------------------------------------------
@@ -97,6 +95,9 @@ nemocheck = [
   "resources/plugins/config.yaml",
 ]
 
+[tool.uv.sources]
+cpex = { git = "https://github.com/contextforge-org/contextforge-plugins-framework.git" }
+
 [dependency-groups]
 dev = [
     "pytest>=8.4.2",

plugins/examples/nemocheck/tests/test_all.py

@@ -6,10 +6,13 @@
 
 # Third-Party
 import pytest
+from enum import Enum
+from typing import Any, Dict, List, Literal, Optional, Union
+from pydantic import BaseModel, Field
 
 # First-Party
-from mcpgateway.common.models import Message, PromptResult, Role, TextContent
-from mcpgateway.plugins.framework import (
+# from mcpgateway.common.models import Message, PromptResult, Role, TextContent
+from cpex.framework import (
     GlobalContext,
     PluginManager,
     PromptHookType,
@@ -20,6 +23,85 @@
 )
 
 
+##----- Temporary classes from contextforge-plugins-framework/tests/unit/cpex/fixtures/common/models.py ##
+## Available at https://github.com/contextforge-org/contextforge-plugins-framework/blob/5769b1bbced23cdc7448bf001aecdbe6a44f22d5/tests/unit/cpex/fixtures/common/models.py
+class Role(str, Enum):
+    """Message role in conversations."""
+
+    ASSISTANT = "assistant"
+    USER = "user"
+
+
+# Base content types
+class TextContent(BaseModel):
+    """Text content for messages (MCP spec-compliant)."""
+
+    type: Literal["text"]
+    text: str
+    annotations: Optional[Any] = None
+    meta: Optional[Dict[str, Any]] = Field(None, alias="_meta")
+
+
+class ResourceContents(BaseModel):
+    """Base class for resource contents (MCP spec-compliant)."""
+
+    uri: str
+    mime_type: Optional[str] = Field(None, alias="mimeType")
+    meta: Optional[Dict[str, Any]] = Field(None, alias="_meta")
+
+
+# Legacy ResourceContent for backwards compatibility
+class ResourceContent(BaseModel):
+    """Resource content that can be embedded (LEGACY - use TextResourceContents or BlobResourceContents)."""
+
+    type: Literal["resource"]
+    id: str
+    uri: str
+    mime_type: Optional[str] = None
+    text: Optional[str] = None
+    blob: Optional[bytes] = None
+
+
+ContentType = Union[TextContent, ResourceContent]
+
+
+# Message types
+class Message(BaseModel):
+    """A message in a conversation.
+
+    Attributes:
+        role (Role): The role of the message sender.
+        content (ContentType): The content of the message.
+    """
+
+    role: Role
+    content: ContentType
+
+
+class PromptMessage(BaseModel):
+    """Message in a prompt (MCP spec-compliant)."""
+
+    role: Role
+    content: "ContentBlock"  # Uses ContentBlock union (includes ResourceLink and EmbeddedResource)
+
+
+class PromptResult(BaseModel):
+    """Result of rendering a prompt template.
+
+    Attributes:
+        messages (List[Message]): The list of messages produced by rendering the prompt.
+        description (Optional[str]): An optional description of the rendered result.
+    """
+
+    messages: List[Message]
+    description: Optional[str] = None
+
+
+# MCP spec-compliant ContentBlock union for prompts and tool results
+# Per spec: ContentBlock can include ResourceLink and EmbeddedResource
+ContentBlock = Union[TextContent]
+
+
 @pytest.fixture(scope="module", autouse=True)
 def plugin_manager():
     """Initialize plugin manager."""
@@ -49,7 +131,8 @@ async def test_prompt_post_hook(plugin_manager: PluginManager):
     """Test prompt post hook across all registered plugins."""
     # Customize payload for testing
     message = Message(
-        content=TextContent(type="text", text="prompt"), role=Role.USER
+        content=TextContent(type="text", text="prompt", _meta={}),
+        role=Role.USER,
     )
     prompt_result = PromptResult(messages=[message])
     payload = PromptPosthookPayload(

plugins/examples/nemocheck/tests/test_nemocheck.py

@@ -7,7 +7,7 @@
 import pytest
 
 # First-Party
-from mcpgateway.plugins.framework import (
+from cpex.framework import (
     PluginConfig,
     PluginContext,
     GlobalContext,