diff --git a/services/llm-client/adapters/db/__pycache__/interactions.cpython-39.pyc b/services/llm-client/adapters/db/__pycache__/interactions.cpython-39.pyc
index a4231f8..2eedd9f 100644
Binary files a/services/llm-client/adapters/db/__pycache__/interactions.cpython-39.pyc and b/services/llm-client/adapters/db/__pycache__/interactions.cpython-39.pyc differ
diff --git a/services/llm-client/adapters/db/interactions.py b/services/llm-client/adapters/db/interactions.py
index acebf3b..492faa1 100644
--- a/services/llm-client/adapters/db/interactions.py
+++ b/services/llm-client/adapters/db/interactions.py
@@ -2,4 +2,4 @@
 from utils import json
 
 def request_to_model(wire):
-    return InteractionRequest(wire.id, json.deserialize(wire.interaction, Interaction) , wire.response, wire.request_date, wire.status, wire.timeout)
\ No newline at end of file
+    return InteractionRequest(wire.id, json.deserialize(wire.interaction, Interaction), wire.response, wire.request_date, wire.status, wire.timeout, wire.details)
\ No newline at end of file
diff --git a/services/llm-client/diplomat/db/__pycache__/interactions.cpython-39.pyc b/services/llm-client/diplomat/db/__pycache__/interactions.cpython-39.pyc
index 8a7ca75..1548337 100644
Binary files a/services/llm-client/diplomat/db/__pycache__/interactions.cpython-39.pyc and b/services/llm-client/diplomat/db/__pycache__/interactions.cpython-39.pyc differ
diff --git a/services/llm-client/diplomat/db/interactions.py b/services/llm-client/diplomat/db/interactions.py
index 5cfc94c..6582c36 100644
--- a/services/llm-client/diplomat/db/interactions.py
+++ b/services/llm-client/diplomat/db/interactions.py
@@ -1,6 +1,7 @@
 from components.scylla_connection import ScyllaConnection
 from datetime import datetime, timezone
 from adapters.db import interactions as interactions_db_adapter
+from models.interactions import InteractionRequest
 from utils import json
 
 def get_interaction(interaction_id, scylla: ScyllaConnection):
@@ -10,24 +11,26 @@ def get_interaction(interaction_id, scylla: ScyllaConnection):
     return interactions_db_adapter.request_to_model(rows[0]) if rows else None
 
 def insert(interaction, scylla: ScyllaConnection):
-    print(json.serialize(interaction))
-    statement = """INSERT INTO execution.interaction_requests (id, interaction, response, request_date, status, timeout) 
-                   VALUES (?, ?, ?, ?, ?, ?)"""
+    statement = """INSERT INTO execution.interaction_requests (id, interaction, response, request_date, status, timeout, details) 
+                   VALUES (?, ?, ?, ?, ?, ?, ?)"""
     interaction_id = interaction.id
     interaction_value = json.serialize(interaction)
     response = None 
     request_date = int(datetime.now(timezone.utc).timestamp() * 1000)
     status = 'pending'  
     timeout = 30000 
+    details = None
     prepared_statement = scylla.session.prepare(statement)
-    scylla.session.execute(prepared_statement, (interaction_id, interaction_value, response, request_date, status, timeout))
+    scylla.session.execute(prepared_statement, (interaction_id, interaction_value, response, request_date, status, timeout, details))
+    return InteractionRequest(interaction_id,interaction, response, request_date, status, timeout, details)
 
 
-def update_interaction(interaction_result, scylla: ScyllaConnection):
+def update_interaction(interaction_request: InteractionRequest, scylla: ScyllaConnection):
     statement = """UPDATE execution.interaction_requests
-                   SET response = %s, status = %s
+                   SET response = %s, status = %s, details = %s
                    WHERE id = %s"""
-    interaction_id = interaction_result.id
-    response = interaction_result.response
-    status = interaction_result.status 
-    scylla.session.execute(statement, (response, status, interaction_id))
\ No newline at end of file
+    interaction_id = interaction_request.id
+    response = interaction_request.response
+    status = interaction_request.status 
+    details = interaction_request.details
+    scylla.session.execute(statement, (response, status, details, interaction_id))
\ No newline at end of file
diff --git a/services/llm-client/flows/__pycache__/interactions.cpython-39.pyc b/services/llm-client/flows/__pycache__/interactions.cpython-39.pyc
index 6ba6356..fb1583c 100644
Binary files a/services/llm-client/flows/__pycache__/interactions.cpython-39.pyc and b/services/llm-client/flows/__pycache__/interactions.cpython-39.pyc differ
diff --git a/services/llm-client/flows/interactions.py b/services/llm-client/flows/interactions.py
index c225b0c..0297259 100644
--- a/services/llm-client/flows/interactions.py
+++ b/services/llm-client/flows/interactions.py
@@ -1,10 +1,11 @@
 
 from components.scylla_connection import ScyllaConnection
 from datetime import datetime, timezone
-from models.interactions import Interaction, InteractionResult
+from models.interactions import Interaction
 from diplomat.db import interactions as interactions_db
 from diplomat.db import prompts as prompts_db
 from logic import interactions as interactions_logic
+from logic import prompts as prompts_logic
 
 def new_interaction(interaction: Interaction, scylla: ScyllaConnection):
     existent_interaction = interactions_db.get_interaction(interaction.id, scylla)
@@ -13,22 +14,36 @@ def new_interaction(interaction: Interaction, scylla: ScyllaConnection):
             return existent_interaction
         else:
             if(interactions_logic.is_timed_out(existent_interaction, int(datetime.now(timezone.utc).timestamp() * 1000))):
-                existent_interaction.failed()
-                interactions_db.update_interaction(InteractionResult(existent_interaction.id, 'failed', None), scylla)
+                existent_interaction.failed("Timed out")
+                interactions_db.update_interaction(existent_interaction, scylla)
                 return existent_interaction
             else:
                 return existent_interaction
 
+    interaction_request = interactions_db.insert(interaction, scylla)
+
     prompt = prompts_db.get_prompt(interaction.prompt_name, scylla)
     if(prompt is None): 
-        return None
+        interaction_request.failed("Prompt not found")
+        interactions_db.update_interaction(interaction_request, scylla)
+        return interaction_request
     
-    # fill prompt with variables
-    interactions_db.insert(interaction, scylla)
+    prompt_variables = prompts_logic.find_variables(prompt)
+    missing_variables = prompts_logic.find_missing_variables(prompt_variables, interaction.variables)
+
+    if(missing_variables):
+        missing_variables = ", ".join(missing_variables)
+        interaction_request.failed(f"Variables missing: {missing_variables}")
+        interactions_db.update_interaction(interaction_request, scylla)
+        return interaction_request
+
+    rendered_prompt = prompts_logic.replace_variables(prompt, interaction.variables)
+    
+
     # request Open IA
     # update the database
     # return
-    return interaction
+    return rendered_prompt
 
 
     
diff --git a/services/llm-client/logic/__pycache__/prompts.cpython-39.pyc b/services/llm-client/logic/__pycache__/prompts.cpython-39.pyc
index c2e2390..8db0b9a 100644
Binary files a/services/llm-client/logic/__pycache__/prompts.cpython-39.pyc and b/services/llm-client/logic/__pycache__/prompts.cpython-39.pyc differ
diff --git a/services/llm-client/logic/prompts.py b/services/llm-client/logic/prompts.py
index 13a0725..c66c176 100644
--- a/services/llm-client/logic/prompts.py
+++ b/services/llm-client/logic/prompts.py
@@ -1,6 +1,18 @@
 from models.prompts import Prompt
+from typing import List, Dict, Any
 import re
 
 def find_variables(prompt : Prompt):
     pattern = r'\{\{(\w+)\}\}'
-    return re.findall(pattern, prompt.prompt)
\ No newline at end of file
+    return re.findall(pattern, prompt.prompt)
+
+def find_missing_variables(prompt_variables: List[str], received_variables: Dict[str, Any]) -> List[str]:
+    missing_vars = []
+    for var in prompt_variables:
+        if var not in received_variables or received_variables[var] is None:
+            missing_vars.append(var)
+    return missing_vars
+
+def replace_variables(prompt: Prompt, variables: dict[str, Any]) -> str:
+    pattern = re.compile(r"\{\{(.*?)\}\}")
+    return pattern.sub(lambda match: str(variables.get(match.group(1), match.group(0))), prompt.prompt)
diff --git a/services/llm-client/migrations/scripts/001_create_executions_table.py b/services/llm-client/migrations/scripts/001_create_executions_table.py
index 38f1b39..65ec8f8 100644
--- a/services/llm-client/migrations/scripts/001_create_executions_table.py
+++ b/services/llm-client/migrations/scripts/001_create_executions_table.py
@@ -12,6 +12,7 @@ def run_migration(session):
         response text,
         request_date bigint,
         status text,
-        timeout int 
+        timeout int,
+        details text             
     );
     """)
\ No newline at end of file
diff --git a/services/llm-client/migrations/scripts/003_insert_tick_shopping_items_prompt.py b/services/llm-client/migrations/scripts/003_insert_tick_shopping_items_prompt.py
index 44b3986..c1b0f08 100644
--- a/services/llm-client/migrations/scripts/003_insert_tick_shopping_items_prompt.py
+++ b/services/llm-client/migrations/scripts/003_insert_tick_shopping_items_prompt.py
@@ -3,6 +3,6 @@
 def run_migration(session):
     session.execute("""
     INSERT INTO configuration.prompts (prompt_name, prompt)
-    VALUES('tick_shopping_items', 'Are you able to tick items on a cart if I send you a picture?')
+    VALUES('tick_shopping_items', 'Are you able to tick items on a cart if I send you a {{item_name}}?')
     """)
     
\ No newline at end of file
diff --git a/services/llm-client/migrations/scripts/__pycache__/001_create_executions_table.cpython-39.pyc b/services/llm-client/migrations/scripts/__pycache__/001_create_executions_table.cpython-39.pyc
index fa213de..3df9a7f 100644
Binary files a/services/llm-client/migrations/scripts/__pycache__/001_create_executions_table.cpython-39.pyc and b/services/llm-client/migrations/scripts/__pycache__/001_create_executions_table.cpython-39.pyc differ
diff --git a/services/llm-client/migrations/scripts/__pycache__/003_insert_tick_shopping_items_prompt.cpython-39.pyc b/services/llm-client/migrations/scripts/__pycache__/003_insert_tick_shopping_items_prompt.cpython-39.pyc
index 992d2e2..0acbe26 100644
Binary files a/services/llm-client/migrations/scripts/__pycache__/003_insert_tick_shopping_items_prompt.cpython-39.pyc and b/services/llm-client/migrations/scripts/__pycache__/003_insert_tick_shopping_items_prompt.cpython-39.pyc differ
diff --git a/services/llm-client/models/__pycache__/interactions.cpython-39.pyc b/services/llm-client/models/__pycache__/interactions.cpython-39.pyc
index 4c1022f..7e0caac 100644
Binary files a/services/llm-client/models/__pycache__/interactions.cpython-39.pyc and b/services/llm-client/models/__pycache__/interactions.cpython-39.pyc differ
diff --git a/services/llm-client/models/interactions.py b/services/llm-client/models/interactions.py
index 14273cd..6f2f1e7 100644
--- a/services/llm-client/models/interactions.py
+++ b/services/llm-client/models/interactions.py
@@ -9,21 +9,17 @@ def __init__(self, id: UUID, prompt_name:str, variables:dict, images:dict, messa
         self.message = message
 
 class InteractionRequest:
-    def __init__(self, id, interaction, response, request_date, status, timeout):
+    def __init__(self, id, interaction, response, request_date, status, timeout, details):
         self.id = id
         self.interaction = interaction
         self.response = response
         self.request_date = request_date
         self.status = status
         self.timeout = timeout
+        self.details = details
 
-    def failed(self):
+    def failed(self, details: str):
         self.status = 'failed'
+        self.details = details
         return self
-        
-
-class InteractionResult:
-    def __init__(self, id, status, response):
-        self.id = id
-        self.status = status
-        self.response = response
\ No newline at end of file
+        
\ No newline at end of file
diff --git a/services/llm-client/pytest.ini b/services/llm-client/pytest.ini
deleted file mode 100644
index 180c0c0..0000000
--- a/services/llm-client/pytest.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[pytest]
-python_paths = llm-client
\ No newline at end of file
diff --git a/services/llm-client/tests/logic/__pycache__/prompts_test.cpython-39-pytest-8.3.2.pyc b/services/llm-client/tests/logic/__pycache__/prompts_test.cpython-39-pytest-8.3.2.pyc
index 8aadadb..29f8558 100644
Binary files a/services/llm-client/tests/logic/__pycache__/prompts_test.cpython-39-pytest-8.3.2.pyc and b/services/llm-client/tests/logic/__pycache__/prompts_test.cpython-39-pytest-8.3.2.pyc differ
diff --git a/services/llm-client/tests/logic/prompts_test.py b/services/llm-client/tests/logic/prompts_test.py
index 66c5cf9..1fe4766 100644
--- a/services/llm-client/tests/logic/prompts_test.py
+++ b/services/llm-client/tests/logic/prompts_test.py
@@ -1,5 +1,6 @@
 import pytest
 from logic import prompts 
+from typing import List, Dict, Any
 from models.prompts import Prompt
 
 def test_find_variables_basic():
@@ -20,4 +21,64 @@ def test_edge_case_empty_string():
 
 def test_edge_case_empty_braces():
     prompt = Prompt("", "{{}} should not be considered a variable.")
-    assert prompts.find_variables(prompt) == []
\ No newline at end of file
+    assert prompts.find_variables(prompt) == []
+
+def find_missing_variables(variables: List[str], values: Dict[str, Any]) -> List[str]:
+    missing_vars = []
+    for var in variables:
+        if var not in values or values[var] is None:
+            missing_vars.append(var)
+    return missing_vars
+
+def test_find_missing_variables_all_present():
+    variables: List[str] = ["var1", "var2", "var3"]
+    values: Dict[str, Any] = {
+        "var1": "value1",
+        "var2": "value2",
+        "var3": "value3"
+    }
+    assert find_missing_variables(variables, values) == []
+
+def test_find_missing_variables_some_missing():
+    variables: List[str] = ["var1", "var2", "var3"]
+    values: Dict[str, Any] = {
+        "var1": "value1",
+        "var2": "value2"
+    }
+    assert find_missing_variables(variables, values) == ["var3"]
+
+def test_find_missing_variables_some_none():
+    variables: List[str] = ["var1", "var2", "var3"]
+    values: Dict[str, Any] = {
+        "var1": "value1",
+        "var2": None,
+        "var3": "value3"
+    }
+    assert find_missing_variables(variables, values) == ["var2"]
+
+def test_find_missing_variables_empty_variables():
+    variables: List[str] = []
+    values: Dict[str, Any] = {
+        "var1": "value1",
+        "var2": "value2",
+        "var3": "value3"
+    }
+    assert find_missing_variables(variables, values) == []
+
+def test_find_missing_variables_empty_values():
+    variables: List[str] = ["var1", "var2", "var3"]
+    values: Dict[str, Any] = {}
+    assert find_missing_variables(variables, values) == ["var1", "var2", "var3"]
+
+def test_replace_variables():
+    template = "Hello, {{name}}. You have {{count}} new messages."
+    values = {"name": "Alice", "count": 5}
+    assert prompts.replace_variables(template, values) == "Hello, Alice. You have 5 new messages."
+    
+    template = "Hello, {{name}}. You have {{count}} new messages and your ID is {{id}}."
+    values = {"name": "Bob", "count": 10, "id": 12345}
+    assert prompts.replace_variables(template, values) == "Hello, Bob. You have 10 new messages and your ID is 12345."
+    
+    template = "Hello, {{name}}."
+    values = {}
+    assert prompts.replace_variables(template, values) == "Hello, {{name}}."
\ No newline at end of file