A memory bank is the set of general context documents for a codebase that an AI coding agent is given across all sessions — things like rules files or high-level descriptions of the product and the codebase. In Understanding Spec-Driven-Development: Kiro, spec-kit, and Tessl, Birgitta Böckeler adopts the name, which she says some tools use for this context, to draw a line between it and specs in Spec-driven development: memory bank files are relevant to every AI coding session in the codebase, whereas specs are relevant only to the tasks that create or change the particular functionality they describe.
Usage
The article’s examples of memory bank files include AGENTS.md, a project description and an architecture description. It also maps the concept onto three SDD tools: in Kiro the memory bank is called “steering”, and asking Kiro to generate steering documents creates product.md, structure.md and tech.md by default, though its workflow does not seem to rely on any specific files being present; in GitHub Spec Kit it is the “constitution”, a prerequisite of the workflow meant to hold high-level, “immutable” principles applied to every change — in the author’s words, a very powerful rules file; and in the Tessl Framework (Tessl) it included a framework folder together with KNOWLEDGE.md and AGENTS.md files. The author reports that “How do I structure my memory bank?” is among the questions she hears most often from practitioners.