41.4 Context packing: selecting the best chunks under budget

The Token Budget

You have limited context space. Don't just take top-K; select chunks that maximize information under the budget.

Optimal Packing

function packContext(chunks: Chunk[], tokenBudget: number): Chunk[] {
  // Sort by relevance score
  const sorted = chunks.sort((a, b) => b.score - a.score);
  
  const selected: Chunk[] = [];
  let tokensUsed = 0;
  
  for (const chunk of sorted) {
    if (tokensUsed + chunk.tokens <= tokenBudget) {
      // Avoid duplicates
      if (!selected.some(s => s.documentId === chunk.documentId)) {
        selected.push(chunk);
        tokensUsed += chunk.tokens;
      }
    }
  }
  
  return selected;
}

// Prefer diversity: don't include 5 chunks from same doc
// when you could include 1 each from 5 docs

Where to go next

• 41.5 Answer with provenance