diff --git a/.gitignore b/.gitignore
index 4d2fe1b..f6ad342 100644
--- a/.gitignore
+++ b/.gitignore
@@ -215,7 +215,8 @@ __marimo__/
 # Streamlit
 .streamlit/secrets.toml
 
-
+# MacOS
+.DS_Store
 
 
 
diff --git a/pyproject.toml b/pyproject.toml
index 00652a9..6776668 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,6 +14,7 @@ dependencies = [
     "pyzmq>=27.1.0",
     "silero-vad>=6.0.0",
     "spade>=4.1.0",
+    "spade-bdi>=0.3.2",
     "torch>=2.8.0",
     "uvicorn>=0.37.0",
 ]
diff --git a/src/control_backend/agents/bdi/__init__.py b/src/control_backend/agents/bdi/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/control_backend/agents/bdi/bdi_core.py b/src/control_backend/agents/bdi/bdi_core.py
new file mode 100644
index 0000000..7311061
--- /dev/null
+++ b/src/control_backend/agents/bdi/bdi_core.py
@@ -0,0 +1,35 @@
+import logging
+
+import agentspeak
+from spade_bdi.bdi import BDIAgent
+
+from control_backend.agents.bdi.behaviours.belief_setter import BeliefSetter
+
+class BDICoreAgent(BDIAgent):
+    """
+    This is the Brain agent that does the belief inference with AgentSpeak. 
+    This is a continous process that happens automatically in the background.
+    This class contains all the actions that can be called from AgentSpeak plans.
+    It has the BeliefSetter behaviour.
+    """
+    logger = logging.getLogger("BDI Core")
+
+    async def setup(self):
+        belief_setter = BeliefSetter()
+        self.add_behaviour(belief_setter)
+
+    def add_custom_actions(self, actions):
+        @actions.add(".reply", 1)
+        def _reply(agent, term, intention):
+            message = agentspeak.grounded(term.args[0], intention.scope)
+            self.logger.info(f"Replying to message: {message}")
+            reply = self._send_to_llm(message)
+            self.logger.info(f"Received reply: {reply}")
+
+            yield
+
+    def _send_to_llm(self, message) -> str:
+        """TODO: implement"""
+        return f"This is a reply to {message}"
+
+
diff --git a/src/control_backend/agents/bdi/behaviours/__init__.py b/src/control_backend/agents/bdi/behaviours/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/src/control_backend/agents/bdi/behaviours/belief_setter.py b/src/control_backend/agents/bdi/behaviours/belief_setter.py
new file mode 100644
index 0000000..777dda3
--- /dev/null
+++ b/src/control_backend/agents/bdi/behaviours/belief_setter.py
@@ -0,0 +1,60 @@
+import asyncio
+import json
+import logging
+
+from spade.agent import Message
+from spade.behaviour import CyclicBehaviour
+from spade_bdi.bdi import BDIAgent
+
+from control_backend.core.config import settings
+
+class BeliefSetter(CyclicBehaviour):
+    """
+    This is the behaviour that the BDI agent runs.
+    This behaviour waits for incoming message and processes it based on sender.
+    Currently, t only waits for messages containing beliefs from Belief Collector and adds these to its KB.
+    """
+    agent: BDIAgent
+    logger = logging.getLogger("BDI/Belief Setter")
+    
+    async def run(self):
+        msg = await self.receive(timeout=0.1)
+        if msg:
+            self.logger.info(f"Received message {msg.body}")
+            self._process_message(msg)
+        await asyncio.sleep(1)
+
+    def _process_message(self, message: Message):
+        sender = message.sender.node  # removes host from jid and converts to str
+        self.logger.debug("Sender: %s", sender)
+
+        match sender:
+            case settings.agent_settings.belief_collector_agent_name:
+                self.logger.debug("Processing message from belief collector.")
+                self._process_belief_message(message)
+            case _:
+                pass
+
+    def _process_belief_message(self, message: Message):
+        if not message.body: return
+
+        match message.thread:
+            case "beliefs":
+                try:
+                    beliefs: dict[str, list[list[str]]] = json.loads(message.body)
+                    self._set_beliefs(beliefs)
+                except json.JSONDecodeError as e:
+                    self.logger.error("Could not decode beliefs into JSON format: %s", e)
+            case _:
+                pass
+
+
+    def _set_beliefs(self, beliefs: dict[str, list[list[str]]]):
+        if self.agent.bdi is None:
+            self.logger.warning("Cannot set beliefs, since agent's BDI is not yet initialized.")
+            return
+
+        for belief, arguments_list in beliefs.items():
+            for arguments in arguments_list:
+                self.agent.bdi.set_belief(belief, *arguments)
+                self.logger.info("Set belief %s with arguments %s", belief, arguments)
diff --git a/src/control_backend/agents/bdi/rules.asl b/src/control_backend/agents/bdi/rules.asl
new file mode 100644
index 0000000..41660a4
--- /dev/null
+++ b/src/control_backend/agents/bdi/rules.asl
@@ -0,0 +1,3 @@
++user_said(Message) : not responded <-
+  +responded;
+  .reply(Message).
diff --git a/src/control_backend/api/v1/endpoints/message.py b/src/control_backend/api/v1/endpoints/message.py
index 1ad0b65..fef07b8 100644
--- a/src/control_backend/api/v1/endpoints/message.py
+++ b/src/control_backend/api/v1/endpoints/message.py
@@ -1,13 +1,23 @@
 from fastapi import APIRouter, Request
 import logging
 
+from zmq import Socket
+
 from control_backend.schemas.message import Message
 
 logger = logging.getLogger(__name__)
 
 router = APIRouter()
 
-# TODO: implement
-@router.post("/message")
+@router.post("/message", status_code=202)
 async def receive_message(message: Message, request: Request):
     logger.info("Received message: %s", message.message)
+
+    topic = b"message"
+    body = message.model_dump_json().encode("utf-8")
+
+    pub_socket: Socket = request.app.state.internal_comm_socket
+
+    pub_socket.send_multipart([topic, body])
+
+    return {"status": "Message received"}
diff --git a/src/control_backend/core/config.py b/src/control_backend/core/config.py
index 8d91af5..07a828d 100644
--- a/src/control_backend/core/config.py
+++ b/src/control_backend/core/config.py
@@ -1,11 +1,25 @@
-from pydantic import HttpUrl
+from re import L
+from pydantic import BaseModel
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
+class ZMQSettings(BaseModel):
+    internal_comm_address: str = "tcp://localhost:5560"
+
+class AgentSettings(BaseModel):
+    host: str = "localhost"
+    bdi_core_agent_name: str = "bdi_core"
+    belief_collector_agent_name: str = "belief_collector"
+    test_agent_name: str = "test_agent"
+
 class Settings(BaseSettings):
     app_title: str = "PepperPlus"
-    
+
     ui_url: str = "http://localhost:5173"
+
+    zmq_settings: ZMQSettings = ZMQSettings()
+
+    agent_settings: AgentSettings = AgentSettings()
     
     model_config = SettingsConfigDict(env_file=".env")
     
-settings = Settings()
\ No newline at end of file
+settings = Settings()
diff --git a/src/control_backend/core/zmq_context.py b/src/control_backend/core/zmq_context.py
new file mode 100644
index 0000000..a74544f
--- /dev/null
+++ b/src/control_backend/core/zmq_context.py
@@ -0,0 +1,3 @@
+from zmq.asyncio import Context
+
+context = Context()
diff --git a/src/control_backend/main.py b/src/control_backend/main.py
index 8fa0428..1f377c4 100644
--- a/src/control_backend/main.py
+++ b/src/control_backend/main.py
@@ -1,24 +1,43 @@
+# Standard library imports
+import asyncio
+import json
+
 # External imports
 import contextlib
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 import logging
+from spade.agent import Agent, Message
+from spade.behaviour import OneShotBehaviour
+import zmq
 
 # Internal imports
+from control_backend.agents.bdi.bdi_core import BDICoreAgent
 from control_backend.api.v1.router import api_router
-from control_backend.core.config import settings
+from control_backend.core.config import AgentSettings, settings
+from control_backend.core.zmq_context import context
 
 logger = logging.getLogger(__name__)
-logging.basicConfig(level=logging.INFO)
+logging.basicConfig(level=logging.DEBUG)
 
 @contextlib.asynccontextmanager
 async def lifespan(app: FastAPI):
     logger.info("%s starting up.", app.title)
+
+    # Initiate sockets
+    internal_comm_socket = context.socket(zmq.PUB)
+    internal_comm_address = settings.zmq_settings.internal_comm_address
+    internal_comm_socket.bind(internal_comm_address)
+    app.state.internal_comm_socket = internal_comm_socket
+    logger.info("Internal publishing socket bound to %s", internal_comm_socket)
+
+    # Initiate agents
+    bdi_core = BDICoreAgent(settings.agent_settings.bdi_core_agent_name + '@' + settings.agent_settings.host, settings.agent_settings.bdi_core_agent_name, "src/control_backend/agents/bdi/rules.asl")
+    await bdi_core.start()
     
     yield
     
     logger.info("%s shutting down.", app.title)
-    
 
 # if __name__ == "__main__":
 app = FastAPI(title=settings.app_title, lifespan=lifespan)
@@ -34,4 +53,4 @@ app.include_router(api_router, prefix="") # TODO: make prefix /api/v1
 
 @app.get("/")
 async def root():
-    return {"status": "ok"}
\ No newline at end of file
+    return {"status": "ok"}
diff --git a/test/conftest.py b/test/conftest.py
new file mode 100644
index 0000000..1e51aca
--- /dev/null
+++ b/test/conftest.py
@@ -0,0 +1,37 @@
+import sys
+from unittest.mock import MagicMock
+
+import sys
+from unittest.mock import MagicMock
+
+def pytest_configure(config):
+    """
+    This hook runs at the start of the pytest session, before any tests are
+    collected. It mocks heavy or unavailable modules to prevent ImportErrors.
+    """
+    # --- Mock spade and spade-bdi ---
+    mock_spade = MagicMock()
+    mock_spade.agent = MagicMock()
+    mock_spade.behaviour = MagicMock()
+    mock_spade_bdi = MagicMock()
+    mock_spade_bdi.bdi = MagicMock()
+
+    mock_spade.agent.Message = MagicMock()
+    mock_spade.behaviour.CyclicBehaviour = type('CyclicBehaviour', (object,), {})
+    mock_spade_bdi.bdi.BDIAgent = type('BDIAgent', (object,), {})
+
+    sys.modules['spade'] = mock_spade
+    sys.modules['spade.agent'] = mock_spade.agent
+    sys.modules['spade.behaviour'] = mock_spade.behaviour
+    sys.modules['spade_bdi'] = mock_spade_bdi
+    sys.modules['spade_bdi.bdi'] = mock_spade_bdi.bdi
+
+    # --- Mock the config module to prevent Pydantic ImportError ---
+    mock_config_module = MagicMock()
+    
+    # The code under test does `from ... import settings`, so our mock module
+    # must have a `settings` attribute. We'll make it a MagicMock so we can
+    # configure it later in our tests using mocker.patch.
+    mock_config_module.settings = MagicMock()
+    
+    sys.modules['control_backend.core.config'] = mock_config_module
diff --git a/test/unit/agents/bdi/behaviours/test_belief_setter.py b/test/unit/agents/bdi/behaviours/test_belief_setter.py
new file mode 100644
index 0000000..8932834
--- /dev/null
+++ b/test/unit/agents/bdi/behaviours/test_belief_setter.py
@@ -0,0 +1,236 @@
+import json
+import logging
+from unittest.mock import MagicMock, AsyncMock, call
+
+import pytest
+
+from control_backend.agents.bdi.behaviours.belief_setter import BeliefSetter
+
+# Define a constant for the collector agent name to use in tests
+COLLECTOR_AGENT_NAME = "belief_collector"
+COLLECTOR_AGENT_JID = f"{COLLECTOR_AGENT_NAME}@test"
+
+
+@pytest.fixture
+def mock_agent(mocker):
+    """Fixture to create a mock BDIAgent."""
+    agent = MagicMock()
+    agent.bdi = MagicMock()
+    agent.jid = "bdi_agent@test"
+    return agent
+
+
+@pytest.fixture
+def belief_setter(mock_agent, mocker):
+    """Fixture to create an instance of BeliefSetter with a mocked agent."""
+    # Patch the settings to use a predictable agent name
+    mocker.patch(
+        "control_backend.agents.bdi.behaviours.belief_setter.settings.agent_settings.belief_collector_agent_name",
+        COLLECTOR_AGENT_NAME
+    )
+    # Patch asyncio.sleep to prevent tests from actually waiting
+    mocker.patch("asyncio.sleep", return_value=None)
+    
+    setter = BeliefSetter()
+    setter.agent = mock_agent
+    # Mock the receive method, we will control its return value in each test
+    setter.receive = AsyncMock()
+    return setter
+
+
+def create_mock_message(sender_node: str, body: str, thread: str) -> MagicMock:
+    """Helper function to create a configured mock message."""
+    msg = MagicMock()
+    msg.sender.node = sender_node  # MagicMock automatically creates nested mocks
+    msg.body = body
+    msg.thread = thread
+    return msg
+
+
+@pytest.mark.asyncio
+async def test_run_no_message_received(belief_setter, mocker):
+    """
+    Test that when no message is received, _process_message is not called.
+    """
+    # Arrange
+    belief_setter.receive.return_value = None
+    mocker.patch.object(belief_setter, "_process_message")
+
+    # Act
+    await belief_setter.run()
+
+    # Assert
+    belief_setter._process_message.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_run_message_received(belief_setter, mocker):
+    """
+    Test that when a message is received, _process_message is called.
+    """
+    # Arrange
+    msg = MagicMock();
+    belief_setter.receive.return_value = msg
+    mocker.patch.object(belief_setter, "_process_message")
+
+    # Act
+    await belief_setter.run()
+
+    # Assert
+    belief_setter._process_message.assert_called_once_with(msg)
+
+
+def test_process_message_from_belief_collector(belief_setter, mocker):
+    """
+    Test processing a message from the correct belief collector agent.
+    """
+    # Arrange
+    msg = create_mock_message(sender_node=COLLECTOR_AGENT_NAME, body="", thread="")
+    mock_process_belief = mocker.patch.object(belief_setter, "_process_belief_message")
+
+    # Act
+    belief_setter._process_message(msg)
+
+    # Assert
+    mock_process_belief.assert_called_once_with(msg)
+
+
+def test_process_message_from_other_agent(belief_setter, mocker):
+    """
+    Test that messages from other agents are ignored.
+    """
+    # Arrange
+    msg = create_mock_message(sender_node="other_agent", body="", thread="")
+    mock_process_belief = mocker.patch.object(belief_setter, "_process_belief_message")
+
+    # Act
+    belief_setter._process_message(msg)
+
+    # Assert
+    mock_process_belief.assert_not_called()
+
+
+def test_process_belief_message_valid_json(belief_setter, mocker):
+    """
+    Test processing a valid belief message with correct thread and JSON body.
+    """
+    # Arrange
+    beliefs_payload = {
+        "is_hot": [["kitchen"]],
+        "is_clean": [["kitchen"], ["bathroom"]]
+    }
+    msg = create_mock_message(
+        sender_node=COLLECTOR_AGENT_JID,
+        body=json.dumps(beliefs_payload),
+        thread="beliefs"
+    )
+    mock_set_beliefs = mocker.patch.object(belief_setter, "_set_beliefs")
+
+    # Act
+    belief_setter._process_belief_message(msg)
+
+    # Assert
+    mock_set_beliefs.assert_called_once_with(beliefs_payload)
+
+
+def test_process_belief_message_invalid_json(belief_setter, mocker, caplog):
+    """
+    Test that a message with invalid JSON is handled gracefully and an error is logged.
+    """
+    # Arrange
+    msg = create_mock_message(
+        sender_node=COLLECTOR_AGENT_JID,
+        body="this is not a json string",
+        thread="beliefs"
+    )
+    mock_set_beliefs = mocker.patch.object(belief_setter, "_set_beliefs")
+
+    # Act
+    with caplog.at_level(logging.ERROR):
+        belief_setter._process_belief_message(msg)
+
+    # Assert
+    mock_set_beliefs.assert_not_called()
+    assert "Could not decode beliefs into JSON format" in caplog.text
+
+
+def test_process_belief_message_wrong_thread(belief_setter, mocker):
+    """
+    Test that a message with an incorrect thread is ignored.
+    """
+    # Arrange
+    msg = create_mock_message(
+        sender_node=COLLECTOR_AGENT_JID,
+        body='{"some": "data"}',
+        thread="not_beliefs"
+    )
+    mock_set_beliefs = mocker.patch.object(belief_setter, "_set_beliefs")
+
+    # Act
+    belief_setter._process_belief_message(msg)
+
+    # Assert
+    mock_set_beliefs.assert_not_called()
+
+def test_process_belief_message_empty_body(belief_setter, mocker):
+    """
+    Test that a message with an empty body is ignored.
+    """
+    # Arrange
+    msg = create_mock_message(
+        sender_node=COLLECTOR_AGENT_JID,
+        body="",
+        thread="beliefs"
+    )
+    mock_set_beliefs = mocker.patch.object(belief_setter, "_set_beliefs")
+
+    # Act
+    belief_setter._process_belief_message(msg)
+
+    # Assert
+    mock_set_beliefs.assert_not_called()
+
+
+def test_set_beliefs_success(belief_setter, mock_agent, caplog):
+    """
+    Test that beliefs are correctly set on the agent's BDI.
+    """
+    # Arrange
+    beliefs_to_set = {
+        "is_hot": [["kitchen"], ["living_room"]],
+        "door_is": [["front_door", "closed"]]
+    }
+    
+    # Act
+    with caplog.at_level(logging.INFO):
+        belief_setter._set_beliefs(beliefs_to_set)
+
+    # Assert
+    expected_calls = [
+        call("is_hot", "kitchen"),
+        call("is_hot", "living_room"),
+        call("door_is", "front_door", "closed")
+    ]
+    mock_agent.bdi.set_belief.assert_has_calls(expected_calls, any_order=True)
+    assert mock_agent.bdi.set_belief.call_count == 3
+    
+    # Check logs
+    assert "Set belief is_hot with arguments ['kitchen']" in caplog.text
+    assert "Set belief is_hot with arguments ['living_room']" in caplog.text
+    assert "Set belief door_is with arguments ['front_door', 'closed']" in caplog.text
+
+
+def test_set_beliefs_bdi_not_initialized(belief_setter, mock_agent, caplog):
+    """
+    Test that a warning is logged if the agent's BDI is not initialized.
+    """
+    # Arrange
+    mock_agent.bdi = None  # Simulate BDI not being ready
+    beliefs_to_set = {"is_hot": [["kitchen"]]}
+
+    # Act
+    with caplog.at_level(logging.WARNING):
+        belief_setter._set_beliefs(beliefs_to_set)
+
+    # Assert
+    assert "Cannot set beliefs, since agent's BDI is not yet initialized." in caplog.text
diff --git a/test/unit/test_temp.py b/test/unit/test_temp.py
deleted file mode 100644
index ac449ca..0000000
--- a/test/unit/test_temp.py
+++ /dev/null
@@ -1,6 +0,0 @@
-"""
-Temporary file to demonstrate unit testing.
-"""
-
-def test_temp():
-    assert True
diff --git a/uv.lock b/uv.lock
index 4b39c29..050aa28 100644
--- a/uv.lock
+++ b/uv.lock
@@ -6,6 +6,18 @@ resolution-markers = [
     "python_full_version < '3.14'",
 ]
 
+[[package]]
+name = "agentspeak"
+version = "0.2.2"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "colorama" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/d0/a3/f8e9292cfd47aa5558f4578c498ca12c068a3a1d60ddfd0af13a87c1e47a/agentspeak-0.2.2.tar.gz", hash = "sha256:7c7fcf689fd54460597be1798ce11535f42a60c3d79af59381af3e13ef7a41bb", size = 59628, upload-time = "2024-03-21T11:55:39.026Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/03/b5/e95cbd9d9e999ac8dc4e0bb7a940112a2751cf98880b4ff0626e53d14249/agentspeak-0.2.2-py3-none-any.whl", hash = "sha256:9b454bc0adf63cb0d73fb4a3a9a489e7d892d5fbf17f750de532670736c0c4dd", size = 61628, upload-time = "2024-03-21T11:55:36.741Z" },
+]
+
 [[package]]
 name = "aiodns"
 version = "3.5.0"
@@ -1291,6 +1303,7 @@ dependencies = [
     { name = "pyzmq" },
     { name = "silero-vad" },
     { name = "spade" },
+    { name = "spade-bdi" },
     { name = "torch" },
     { name = "uvicorn" },
 ]
@@ -1314,6 +1327,7 @@ requires-dist = [
     { name = "pyzmq", specifier = ">=27.1.0" },
     { name = "silero-vad", specifier = ">=6.0.0" },
     { name = "spade", specifier = ">=4.1.0" },
+    { name = "spade-bdi", specifier = ">=0.3.2" },
     { name = "torch", specifier = ">=2.8.0" },
     { name = "uvicorn", specifier = ">=0.37.0" },
 ]
@@ -2090,6 +2104,20 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/e9/06/21d0e937f4daa905a9a007700f59b06de644a44e5f594c3428c3ff93ca39/spade-4.1.0-py2.py3-none-any.whl", hash = "sha256:8b20e7fcb12f836cb0504e9da31f7bd867c7276440e19ebca864aecabc71b114", size = 37033, upload-time = "2025-05-22T17:19:06.524Z" },
 ]
 
+[[package]]
+name = "spade-bdi"
+version = "0.3.2"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "agentspeak" },
+    { name = "loguru" },
+    { name = "spade" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/16/b4/d52d9d06ad17d4b3a90ca11b64a14194f3f944f561f4da1395ce3fe3994d/spade_bdi-0.3.2.tar.gz", hash = "sha256:5d03661425f78771e39f3592f8a602ff8240465682b79d333926d3e562657d81", size = 21208, upload-time = "2025-01-03T14:16:43.755Z" }
+wheels = [
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