Prompt caching correctly — the variable input goes LAST — step 5 of 9

You're marking the system prompt as cacheable. Anthropic's default TTL is 5 minutes — the 1-hour tier is an explicit opt-in — so always pass ttl explicitly. Fill in the cache_control value for a 1-hour cache.

Expected output:

{'type': 'ephemeral', 'ttl': '1h'}