| name | ai-building-chatbots |
| description | Build a conversational AI assistant with memory and state. Use when you need a customer support chatbot, helpdesk bot, onboarding assistant, sales qualification bot, FAQ assistant, or any multi-turn conversational AI. Also used for chatbot remember previous messages, conversational AI keeps forgetting context, build a helpdesk bot that actually works, chatbot drops context after a few turns, Intercom bot alternative, Zendesk AI alternative, build WhatsApp bot, Slack bot with AI, chatbot escalation to human agent, LangChain chatbot but simpler, chatbot for SaaS onboarding flow. |
Build a Conversational AI Chatbot
Guide the user through building a multi-turn chatbot that remembers context, follows conversation flows, and produces high-quality responses. Uses DSPy for optimizable response generation and LangGraph for conversation state, memory, and flow control.
Step 1: Define the conversation
Ask the user:
- What does the bot do? (answer questions, resolve issues, qualify leads, guide onboarding?)
- What states can the conversation be in? (greeting, gathering info, resolving, escalating, closing?)
- When should the bot escalate to a human? (complex issues, angry users, sensitive topics?)
- What docs or data should it draw from? (help articles, product docs, FAQs, database?)
Step 2: Build the response module (DSPy)
The core of your chatbot is a DSPy module that generates responses given conversation history and context.
lm = dspy.LM("openai/gpt-4o-mini")
dspy.configure(lm=lm)
Basic response module
import dspy
class ChatResponse(dspy.Signature):
"""Generate a helpful, on-brand response to the user's message."""
conversation_history: str = dspy.InputField(desc="Previous messages in the conversation")
context: str = dspy.InputField(desc="Relevant information from docs or database")
user_message: str = dspy.InputField(desc="The user's latest message")
response: str = dspy.OutputField(desc="Helpful response to the user")
class ChatBot(dspy.Module):
def __init__(self):
self.respond = dspy.ChainOfThought(ChatResponse)
def forward(self, conversation_history, context, user_message):
return self.respond(
conversation_history=conversation_history,
context=context,
user_message=user_message,
)
With intent classification
Route different intents to specialized handlers:
from typing import Literal
class ClassifyIntent(dspy.Signature):
"""Classify the user's intent from their message."""
conversation_history: str = dspy.InputField()
user_message: str = dspy.InputField()
intent: Literal["question", "complaint", "request", "greeting", "goodbye"] = dspy.OutputField()
class ChatBotWithRouting(dspy.Module):
def __init__(self):
self.classify = dspy.Predict(ClassifyIntent)
self.respond_question = dspy.ChainOfThought(AnswerQuestion)
self.respond_complaint = dspy.ChainOfThought(HandleComplaint)
self.respond_request = dspy.ChainOfThought(HandleRequest)
self.respond_greeting = dspy.Predict(Greeting)
def forward(self, conversation_history, context, user_message):
intent = self.classify(
conversation_history=conversation_history,
user_message=user_message,
).intent
handler = {
"question": self.respond_question,
"complaint": self.respond_complaint,
"request": self.respond_request,
"greeting": self.respond_greeting,
}.get(intent, self.respond_question)
return handler(
conversation_history=conversation_history,
context=context,
user_message=user_message,
)
Step 3: Add conversation state (LangGraph)
LangGraph manages the conversation flow — what state the bot is in, when to transition, and when to escalate.
Define conversation state
from langgraph.graph import StateGraph, START, END
from typing import TypedDict, Annotated
import operator
class ConversationState(TypedDict):
messages: Annotated[list[dict], operator.add]
current_intent: str
context: str
escalate: bool
resolved: bool
turn_count: int
Build the conversation graph
import dspy
classifier = dspy.Predict(ClassifyIntent)
responder = dspy.ChainOfThought(ChatResponse)
def classify_node(state: ConversationState) -> dict:
"""Classify the user's intent."""
history = format_history(state["messages"][:-1])
user_msg = state["messages"][-1]["content"]
result = classifier(conversation_history=history, user_message=user_msg)
return {"current_intent": result.intent}
def retrieve_node(state: ConversationState) -> dict:
"""Retrieve relevant docs for the current message."""
user_msg = state["messages"][-1]["content"]
docs = retrieve_relevant_docs(user_msg)
return {"context": "\n".join(docs)}
def respond_node(state: ConversationState) -> dict:
"""Generate a response using DSPy."""
history = format_history(state["messages"][:-1])
user_msg = state["messages"][-1]["content"]
result = responder(
conversation_history=history,
context=state["context"],
user_message=user_msg,
)
return {
"messages": [{"role": "assistant", "content": result.response}],
"turn_count": state["turn_count"] + 1,
}
def check_escalation(state: ConversationState) -> dict:
"""Decide if this needs human handoff."""
should_escalate = (
state["current_intent"] == "complaint"
and state["turn_count"] > 3
)
return {"escalate": should_escalate}
def format_history(messages: list[dict]) -> str:
return "\n".join(f"{m['role']}: {m['content']}" for m in messages[-10:])
graph = StateGraph(ConversationState)
graph.add_node("classify", classify_node)
graph.add_node("retrieve", retrieve_node)
graph.add_node("respond", respond_node)
graph.add_node("check_escalation", check_escalation)
graph.add_edge(START, "classify")
graph.add_edge("classify", "retrieve")
graph.add_edge("retrieve", "respond")
graph.add_edge("respond", "check_escalation")
def route_after_escalation_check(state: ConversationState) -> str:
if state["escalate"]:
return "escalate"
return "done"
graph.add_conditional_edges(
"check_escalation",
route_after_escalation_check,
{"escalate": END, "done": END},
)
app = graph.compile()
Run a conversation turn
result = app.invoke({
"messages": [{"role": "user", "content": "How do I reset my password?"}],
"current_intent": "",
"context": "",
"escalate": False,
"resolved": False,
"turn_count": 0,
})
print(result["messages"][-1]["content"])
Step 4: Add memory
Session memory with checkpointing
LangGraph's checkpointer persists conversation state across requests:
from langgraph.checkpoint.memory import MemorySaver
checkpointer = MemorySaver()
app = graph.compile(checkpointer=checkpointer)
config = {"configurable": {"thread_id": "user-abc-123"}}
result = app.invoke(
{"messages": [{"role": "user", "content": "Hi, I need help with billing"}],
"current_intent": "", "context": "", "escalate": False, "resolved": False, "turn_count": 0},
config=config,
)
result = app.invoke(
{"messages": [{"role": "user", "content": "I was charged twice last month"}]},
config=config,
)
For production, use a persistent backend:
from langgraph.checkpoint.postgres import PostgresSaver
checkpointer = PostgresSaver(conn_string="postgresql://user:pass@localhost/chatbot")
app = graph.compile(checkpointer=checkpointer)
Conversation summary for long chats
When conversations get long, summarize older messages to stay within token limits:
class SummarizeConversation(dspy.Signature):
"""Summarize the conversation so far, preserving key details."""
conversation: str = dspy.InputField()
summary: str = dspy.OutputField(desc="Concise summary of the conversation so far")
summarizer = dspy.Predict(SummarizeConversation)
def maybe_summarize(state: ConversationState) -> dict:
"""Summarize if conversation is getting long."""
if len(state["messages"]) > 20:
history = format_history(state["messages"][:-5])
summary = summarizer(conversation=history).summary
return {
"messages": [
{"role": "system", "content": f"Summary of earlier conversation: {summary}"},
*state["messages"][-5:],
]
}
return {}
Step 5: Ground responses in docs
Retrieve relevant documents each turn to keep responses factual.
class DocGroundedResponse(dspy.Signature):
"""Answer the user's question based on the provided documentation.
Only use information from the docs. If the docs don't cover it, say so."""
conversation_history: str = dspy.InputField()
docs: list[str] = dspy.InputField(desc="Relevant documentation passages")
user_message: str = dspy.InputField()
response: str = dspy.OutputField()
class GroundedChatBot(dspy.Module):
def __init__(self, retriever):
self.retriever = retriever
self.respond = dspy.ChainOfThought(DocGroundedResponse)
def forward(self, conversation_history, user_message):
docs = self.retriever(user_message).passages
return self.respond(
conversation_history=conversation_history,
docs=docs,
user_message=user_message,
)
See /ai-searching-docs for setting up retrievers and vector stores, including loading data from PDFs, Notion, and other sources with LangChain document loaders.
Step 6: Add guardrails
Response quality with dspy.Refine
Use dspy.Refine with a reward function to enforce guardrails on chatbot responses:
class GroundedChatBotInner(dspy.Module):
def __init__(self, retriever):
self.retriever = retriever
self.respond = dspy.ChainOfThought(DocGroundedResponse)
def forward(self, conversation_history, user_message):
docs = self.retriever(user_message).passages
return self.respond(
conversation_history=conversation_history,
docs=docs,
user_message=user_message,
)
def chatbot_response_reward(args, pred):
"""Score chatbot response quality. Returns 0.0-1.0."""
response = pred.response
score = 1.0
if "I am an AI" in response:
return 0.0
if len(response.split()) >= 200:
score -= 0.2
condescending = ["obviously", "clearly", "simply"]
if any(word in response.lower() for word in condescending):
score -= 0.1
return max(score, 0.0)
def make_guarded_chatbot(retriever):
return dspy.Refine(
module=GroundedChatBotInner(retriever),
N=3,
reward_fn=chatbot_response_reward,
threshold=0.8,
)
Human-in-the-loop for sensitive actions
Use LangGraph's interrupt to pause before the bot takes real actions:
app = graph.compile(
checkpointer=checkpointer,
interrupt_before=["execute_refund", "cancel_account"],
)
result = app.invoke(input_state, config)
result = app.invoke(None, config)
Step 7: Optimize and evaluate
Conversation-level metrics
def chatbot_metric(example, prediction, trace=None):
"""Score a single conversation turn."""
judge = dspy.Predict(JudgeTurn)
result = judge(
user_message=example.user_message,
expected_response=example.response,
actual_response=prediction.response,
conversation_history=example.conversation_history,
)
return result.is_good
class JudgeTurn(dspy.Signature):
"""Judge if the chatbot response is helpful, accurate, and on-topic."""
user_message: str = dspy.InputField()
expected_response: str = dspy.InputField()
actual_response: str = dspy.InputField()
conversation_history: str = dspy.InputField()
is_good: bool = dspy.OutputField()
Build a training set from real conversations
trainset = []
for convo in real_conversations:
for turn in convo["turns"]:
trainset.append(
dspy.Example(
conversation_history=turn["history"],
user_message=turn["user_message"],
context=turn["context"],
response=turn["response"],
).with_inputs("conversation_history", "user_message", "context")
)
Optimize
optimizer = dspy.MIPROv2(metric=chatbot_metric, auto="medium")
optimized_bot = optimizer.compile(chatbot, trainset=trainset)
optimized_bot.save("chatbot_optimized.json")
Key patterns
- DSPy for response generation, LangGraph for flow control — DSPy modules handle what the bot says; LangGraph handles conversation state and routing
- Checkpointing is your memory — use LangGraph's checkpointer so conversations persist across HTTP requests
- Retrieve every turn — don't assume context from earlier turns is still relevant; re-retrieve each time
- Summarize long conversations — once past ~20 messages, summarize older context to stay within token limits
- Classify intent early — knowing the user's intent lets you route to specialized handlers
- Interrupt before real actions — use LangGraph's
interrupt_before so humans approve refunds, cancellations, etc.
- Optimize on real conversations — collect actual chat logs to build training data for DSPy optimization
Gotchas
- Claude puts conversation flow logic inside DSPy modules. DSPy modules should only handle LM calls (classify, respond, summarize). State transitions, routing, and memory belong in LangGraph nodes and edges. If you catch yourself writing
if/else chains inside forward() to manage conversation state, move that logic to LangGraph.
- Claude passes full message history every turn. This works for short conversations but blows up token usage on long ones. After ~20 messages, summarize older messages and keep only the summary + last 5 messages. Use the
maybe_summarize pattern from Step 4.
- Claude forgets
with_inputs() when building conversation training data. Every dspy.Example for chatbot training needs .with_inputs("conversation_history", "user_message", "context") — without it, the optimizer treats all fields as outputs and optimization silently produces garbage.
- Claude defines a single monolithic
ChatResponse signature for all intents. Different intents need different handling — a complaint needs empathy and escalation logic, a question needs retrieval accuracy, a greeting needs brevity. Use ClassifyIntent + separate handler modules per intent rather than one signature trying to do everything.
- Claude skips the escalation check. Chatbots that can't hand off to humans are a liability. Always include an escalation path — at minimum, a turn-count threshold combined with intent detection for complaints or sensitive topics.
Additional resources
- For worked examples (support bot, FAQ assistant), see examples.md
Cross-references
Install any skill: npx skills add lebsral/DSPy-Programming-not-prompting-LMs-skills --skill <name>
- Search docs for grounding — see
/ai-searching-docs
- Bot takes actions (APIs, tools) — see
/ai-taking-actions
- Multiple bots working together — see
/ai-coordinating-agents
- Measure and improve chatbot accuracy — see
/ai-improving-accuracy
- Multi-step AI pipeline design — see
/ai-building-pipelines
- Composing DSPy modules — see
/dspy-modules
- Iterative refinement with reward functions — see
/dspy-refine
- ReAct for tool-using chatbots — see
/dspy-react
- Install
/ai-do if you do not have it — it routes any AI problem to the right skill and is the fastest way to work: npx skills add lebsral/DSPy-Programming-not-prompting-LMs-skills --skill ai-do