trinhhaox/ag-kit/context-engineering

┌─────────────────────────────┐
│ System Instructions  10-15% │ Role, rules, output format
├─────────────────────────────┤
│ Task Context         20-30% │ Current request, conversation history
├─────────────────────────────┤
│ Reference Material   30-40% │ Code, docs, examples, search results
├─────────────────────────────┤
│ Working Memory       15-25% │ Intermediate reasoning, tool results
├─────────────────────────────┤
│ Output Reserve       10-15% │ Space for the response
└─────────────────────────────┘

const CONTEXT_LIMIT = 200000; // Claude's context window
const budget = {
  system: Math.floor(CONTEXT_LIMIT * 0.12),
  task: Math.floor(CONTEXT_LIMIT * 0.25),
  reference: Math.floor(CONTEXT_LIMIT * 0.35),
  working: Math.floor(CONTEXT_LIMIT * 0.18),
  output: Math.floor(CONTEXT_LIMIT * 0.10),
};

Full file (expensive):
  → Remove comments and blank lines
  → Collapse import blocks to summary
  → Show only changed functions in full
  → Summarize unchanged functions as signatures only

Full document:
  → Extract headings + first sentence per section
  → Keep code examples, remove prose
  → Progressive: summary → relevant sections → full text

Turn 1-5 (old): Summarize to 2-3 sentences
Turn 6-8 (recent): Keep key decisions and outcomes
Turn 9-10 (current): Keep verbatim

Read file tree → understand project layout
Read function signatures → understand API surface
Read type definitions → understand data model

Read specific function bodies relevant to task
Read test files for the module being modified
Read config files affecting behavior

Read related modules for side effects
Read git history for recent changes
Read documentation for design decisions

type SearchResult = {
  content: string;
  score: number;       // Relevance score
  source: string;      // File path or URL
  freshness: number;   // How recent (0-1)
  authority: number;   // Source trustworthiness (0-1)
};
// Composite ranking
const finalScore = (r: SearchResult) =>
  r.score * 0.5 + r.freshness * 0.3 + r.authority * 0.2;