Declarative AI Applications

Declarative means you describe what the app should do (its data model, its business logic, its knowledge) rather than programming the execution steps. Upjack reads these declarations and builds the application. Change the declaration, the app changes. No deploy cycle, no engineer required.

Teams building production AI applications who want faster delivery and easier maintenance. Developers use it to skip boilerplate. Domain experts use it to define business logic directly. Organizations use it to capture institutional knowledge in a format that survives team changes.

LangChain is an imperative library for chaining LLM calls (you write Python. CrewAI is a role-based framework) you define agents as code. Upjack is declarative, you define apps as schemas and skills. Different architectural models for different needs. Upjack excels when non-engineers need to maintain the system.