David Breunig System Prompt Interactive Map
- Entity ID:
ent-20260419-d0e1f2a3b4c5 - Type:
document - Scope:
shared - Status:
active - Aliases: dbreunig system prompt map, How Claude Code Builds a System Prompt
Description
Interactive analysis by David Breunig (dbreunig.com, April 4 2026) reconstructing the entire Claude Code system prompt assembly from the leaked source. Identifies: 7 always-included sections (Intro, System Rules, Doing Tasks, Executing Actions, Using Your Tools, Tone and Style, Output Efficiency), 13 conditional sections with activation flags, the Cache Boundary Marker as invisible-to-model, and the Anthropic-vs-external asymmetry. Most precise public map of conditional prompt assembly to date.
Key claims
- Broadcom SEC filing hedges Anthropic consumption on continued commercial success
- Anthropic ARR grew 3.3x in four months from $9B to $30B
- Cache Boundary Marker is invisible to the model
Relations
- CLAUDE_CODE_AUTO_COMPACT_WINDOW --[depends_on]--> David Breunig System Prompt Interactive Map
- David Breunig System Prompt Interactive Map --[summarizes]--> System Prompt Assembly
- David Breunig System Prompt Interactive Map --[summarizes]--> 4-Layer Prompt Pipeline