Pipe-Operator
LangBot Day 4: Chaining with LCEL — The Pipe Operator
reading time: 9 minutes
Recap: On Day 1 we built a basic CLI chatbot. Day 2 gave it memory so it remembers the conversation. Day 3 added a prompt template so LangBot has a personality. But every turn still requires two separate steps — format the template, then call the model. Today we stitch them together into one fluid pipeline.
The problem: two steps where one should do
Here is how LangBot works on Day 3. Every single turn: