- Guard `currentActive` against a stale window: a model/window switch on the
current branch left the live snapshot outranking the projection (G1 didn't
fire). Now defers to the projection unless streaming or the window matches.
- Scope branch lookups to the authenticated user (`getMessages` filter +
injected `userId`) — was loading any conversation by id (IDOR).
- Recount messages with no stored `tokenCount` via the tokenizer instead of
charging 0, so snapshot-less/imported histories don't under-report.
- Fall back (null) for already-summarized branches rather than projecting from
the full raw parent chain (the next call would send summary + tail); the
client's summary-baseline-aware estimate handles them until a follow-up
replays the summary boundary.
POST /api/endpoints/context-projection → resolveContextProjection (packages/api):
reconstructs the viewed branch (parent-chain walk from messageId), resolves the
agent config (instructions/provider/model/maxContextTokens), reuses LibreChat's
stored per-message tokenCounts as the index map (no re-tokenizing), and calls
the agents SDK projectAgentContextUsage — no model call. Thin controller injects
db.getMessages/db.getAgent; route mirrors /token-config.
First cut targets message-windowing accuracy; tool-schema tokens are deferred to
a follow-up that reuses the full initializeAgent path.
