prompt-cachinglisted

# Prompt Caching Cache LLM prompt prefixes for 90% token savings. ## Supported Models (2026) | Provider | Models | |----------|--------| | Claude | Opus 4.1, Opus 4, Sonnet 4.5, Sonnet 4, Sonnet 3.7, Haiku 4.5, Haiku 3.5, Haiku 3 | | OpenAI | gpt-4o, gpt-4o-mini, o1, o1-mini (automatic caching) | ## Claude Prompt Caching ```python def build_cached_messages( system_prompt: str, few_shot_examples: str | None, user_content: str, use_extended_cache: bool = False ) -> list[dict]: """Build messages with cache breakpoints. Cache structure (processing order: tools → system → messages): 1. System prompt (cached) 2. Few-shot examples (cached) ─────── CACHE BREAKPOINT ─────── 3. User content (NOT cached) """ # TTL: "5m" (default, 1.25x write cost) or "1h" (extended, 2x write cost) ttl = "1h" if use_extended_cache else "5m" content_parts = [] # Breakpoint 1: System prompt content_parts.append({ "type": "text", "text": system_prompt, "cache_control": {"type": "ephemeral", "ttl": ttl} }) # Breakpoint 2: Few-shot examples (up to 4 breakpoints allowed) if few_shot_examples: content_parts.append({ "type": "text", "text": few_shot_examples, "cache_control": {"type": "ephemeral", "ttl": ttl} }) # Dynamic content (NOT cached) content_parts.append({ "type": "text", "text": user_content }) return [{"role":