Layer stack · Diagram Design
AI app stack · Where the work actually happens
AI app stack · Where the work actually happens
Layer stack showing model weights, SDK, prompts, agent harness, and UI surface, with the agent harness highlighted as the focal layer.
ABSTRACTION
SILICON
L5
UI surface
chat, editor, canvas
L4
Agent harness
tools, memory, loop
L3
Prompt layer
system, few-shot, caching
L2
SDK / client
auth, retries, streaming
L1
Model weights
opus, sonnet, haiku
FOCAL LAYER
The harness is where most product differentiation actually lives — tools, memory, and the loop that stitches model calls into useful work.