{"version":"2.1.314","anchor":"billing-header-adds-previous-message-info-after-compaction","canonical_anchor":"billing-header-adds-previous-message-info-after-compaction","heading":"Attribution header gains previous-message fields after compaction","tier":"internal","area":"Compaction","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.314\/e\/billing-header-adds-previous-message-info-after-compaction","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.314","markdown":"### Attribution header gains previous-message fields after compaction\n\nAfter compaction, the attribution header can now carry cc_prev_msg, cc_prev_prompt_index and cc_prev_turn_index for first-party providers\n\n**What**\n\nCompaction is when Claude Code shortens a long conversation by summarising it. With each request, Claude Code sends an attribution header, extra information attached to the request about where it came from. With first-party providers, that header can now include three new fields taken from the response before compaction:\n\n- `cc_prev_msg`\n\n- `cc_prev_prompt_index`\n\n- `cc_prev_turn_index`\n\nThe pattern Claude Code uses to strip these attribution fields out of headers now also matches the three new fields. Before, it matched only `prev_req`, `prompt_id`, `turn_origin`, `prompt_index`, `turn_index` and `workload`.\n\n**Why**\n\nRequests sent after compaction can now be linked back to the conversation before it. If you inspect request headers, expect these extra fields.\n\n- Area: Compaction\n- Tier: Under the hood\n- Useful: 1\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}