diff --git a/crates/aura-engine/src/graph_model.rs b/crates/aura-engine/src/graph_model.rs
index 7770d17..5adc4f2 100644
--- a/crates/aura-engine/src/graph_model.rs
+++ b/crates/aura-engine/src/graph_model.rs
@@ -1,8 +1,10 @@
 //! The `aura graph` model serializer (#13, cycle 0026): turns the engine's
 //! authored blueprint (graph-as-data, C9) into the canonical, deterministic JSON
 //! model the browser viewer consumes. Read-only — walks structure + declared
-//! `NodeSchema`s only, never `eval`/`compile`/`bootstrap`. Hand-rolled JSON in the
-//! `RunReport::to_json` house style (no serde, C14).
+//! `NodeSchema`s only, never `eval`/`compile`/`bootstrap`. The model JSON is
+//! hand-rolled (no serde) — small, closed, deterministic (C14). Since cycle 0033
+//! moved `RunReport::to_json` to serde, this is the engine's last hand-rolled
+//! JSON writer.
 
 use crate::{BlueprintNode, Composite};
 use aura_core::{Firing, ScalarKind};
@@ -27,7 +29,7 @@ fn firing_str(f: Firing) -> String {
 }
 
 /// A JSON string literal: wrap in quotes, escape `"` and `\` (the minimal set
-/// `RunReport::json_str` uses — model names are author-controlled identifiers).
+/// sufficient here — model names are author-controlled identifiers).
 fn json_str(s: &str) -> String {
     let mut out = String::with_capacity(s.len() + 2);
     out.push('"');
diff --git a/docs/design/INDEX.md b/docs/design/INDEX.md
index 68ff404..fe13ef7 100644
--- a/docs/design/INDEX.md
+++ b/docs/design/INDEX.md
@@ -726,7 +726,8 @@ signature travels beside the node, so `bootstrap` reads it without a built-node
 #51).** `aura graph` no longer renders ASCII. The render path is now two pieces:
 a read-only **model serializer** (`aura_engine::model_to_json`, iteration 1) that
 walks the root composite + every distinct composite type into a deterministic,
-hand-rolled JSON model (C14, golden-tested like `RunReport::to_json`; the
+hand-rolled JSON model (C14, golden-tested; the engine's last hand-rolled JSON
+writer after `RunReport::to_json` moved to serde in cycle 0033; the
 swapped-param mis-wire property moved here from the old compiled-view test), and a
 **self-contained HTML viewer** (`aura-cli::render::render_html`, iteration 2) that
 inlines that model, the ported prototype viewer JS, and a vendored Graphviz-WASM