{"version":"2.1.248","anchor":"prompt-cache-markers-skip-ephemeral-messages","canonical_anchor":"prompt-cache-markers-skip-ephemeral-messages","heading":"Prompt cache markers skip ephemeral messages","tier":"notice","area":"Compaction","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248\/e\/prompt-cache-markers-skip-ephemeral-messages","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248","markdown":"### Prompt cache markers skip ephemeral messages\n\nShort-lived messages no longer invalidate the prompt cache, so more context gets reused.\n\n**What**\n\nCache markers, which decide how much of a conversation the model can reuse between requests, now step over ephemeral user messages when placing themselves, so short-lived messages do not invalidate the cache.\n\n**Details**\n\n- Ephemeral user messages are treated like system entries during the backwards walk.\n- The trailing-system optimisation is refused if an ephemeral user message sits in between.\n- Fork-point pinning is skipped entirely when a top-level cache control is supplied.\n\n**Evidence**\n\n`(fe.type === \"user\" && fe.ephemeral === !0)`\n\n- Area: Compaction\n- Tier: You'll notice\n- Useful: 3\/5\n- Signal: 2\/5"}