Prompt Templates
Definition
Prompt templates are reusable prompt structures with placeholder variables that can be filled in dynamically, enabling consistent and maintainable prompt engineering across applications.
Why It Matters
As AI applications grow, managing prompts becomes challenging. Prompt templates provide structure and consistency: define the template once, then inject different data for each use case. This makes prompts easier to test, version, and maintain across your codebase.
How It Works
A template defines the structure with variables:
Summarize the following {document_type} in {num_points} bullet points.
Focus on: {focus_areas}
Document:
{content}
Summary:Your code fills in the variables at runtime. Frameworks like LangChain and LlamaIndex provide template utilities with features like partial filling, validation, and composition.
When to Use
Use prompt templates when: the same prompt structure applies to multiple inputs, you need to maintain prompts across a team, you want version control for prompt iterations, or you’re building production applications. For one-off queries or experimentation, direct prompting is simpler.