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docs/requirements/Component-AuditLog.md

@@ -881,3 +881,20 @@ orphaned entries) and in the CLI's `audit tree` output.
   reusing the existing audit-KPI reads; the resulting `totalEventsLastHour` /
   `errorEventsLastHour` / `backlogTotal` series render as trends on the Audit Log
   page via `KpiTrendChart`.
+
+### Serialized-byte budgets for telemetry and reconciliation (2026-09-09)
+
+The audit-only drain, combined cached telemetry drain, and site reconciliation responses use
+`AuditWireBudget`: the complete protobuf row (including error message/detail, summaries, extra,
+provenance and nested operational fields), repeated-message tag/length prefixes, five-byte gRPC
+frame and the continuation flag must fit a normal **2 MiB** budget. A drain sends a prefix and
+marks only acknowledged rows forwarded. A byte-limited pull returns `MoreAvailable = true`;
+its cursor advances from the last returned row, so unreturned rows remain available.
+
+A single row exceeding 2 MiB is sent alone if it fits the coordinated **32 MiB** channel ceiling.
+A row exceeding that ceiling is never truncated, falsely acknowledged or silently skipped:
+the operation reports `ResourceExhausted` with its row identifier and required byte count, and
+the row remains durable locally. Good rows preceding it can still advance. Operators must
+reduce that oversized payload or deploy coordinated larger limits to resume past it; repeated
+drain failures are logged. A lost response retains the existing at-least-once retry/cursor
+semantics. The separate Flow Debugger trace pull remains governed by its own contract.