diff --git a/src/domain/analysisView/EnvironmentStateWriteSimulation.ts b/src/domain/analysisView/EnvironmentStateWriteSimulation.ts
index 42dda20728..48c0e72f5b 100644
--- a/src/domain/analysisView/EnvironmentStateWriteSimulation.ts
+++ b/src/domain/analysisView/EnvironmentStateWriteSimulation.ts
@@ -19,21 +19,23 @@ import {
   checkDocumentRead,
   checkItemRead,
   checkListRead,
-  checkedLines,
   collectionTarget,
   entityTarget,
   isAbsence,
-  servedLine,
   succeeded,
   withBodies,
   writtenFieldChecks,
   SimulatedState,
   WriteEffects,
   type CheckOutcome,
-  type CheckedLines,
   type TouchedTargets,
-  type ServedLine,
 } from "./environmentStateWriteChecks.js";
+import {
+  checkedLines,
+  servedLine,
+  type CheckedLines,
+  type ServedLine,
+} from "./environmentStateCheckedLines.js";
 import { applyCreate } from "./environmentStateWriteCreate.js";
 import {
   applyDelete,
diff --git a/src/domain/analysisView/environmentStateCheckedLines.ts b/src/domain/analysisView/environmentStateCheckedLines.ts
new file mode 100644
index 0000000000..c3d057be6a
--- /dev/null
+++ b/src/domain/analysisView/environmentStateCheckedLines.ts
@@ -0,0 +1,110 @@
+import {
+  compareUnicodeCodePoints as compare,
+  compositeKey,
+} from "../unicodeCodePointOrder.js";
+import { iterateUrlQueryParameters } from "../recordedTransportUrl.js";
+import {
+  decodedSegment,
+  isParam,
+  segmentsOf,
+  type StateRecordFacts,
+  type StateToolFacts,
+  type StateView,
+} from "./environmentStateRules.js";
+
+/** A query as replay compares a call's: decoded values by name, in any order. A query repeating a name, which no call's arguments can carry, keeps its spelling. */
+const queryKey = (query: string | undefined): string => {
+  const pairs = [...iterateUrlQueryParameters(query ?? "")];
+  return new Set(pairs.map(([name]) => name)).size === pairs.length
+    ? compositeKey(pairs.sort(([left], [right]) => compare(left, right)))
+    : compositeKey([query ?? ""]);
+};
+
+/** A list or document view's checked lines, by query, in the tool's recorded order, and which path segments are the tool's parameters. */
+export interface CheckedLines {
+  readonly params: ReadonlySet<number>;
+  readonly byQuery: ReadonlyMap<
+    string,
+    readonly {
+      readonly ordinal: number;
+      readonly segments: readonly string[];
+    }[]
+  >;
+}
+
+/** The line a read's call is answered from, and the collection serving lists for it. */
+export interface ServedLine {
+  readonly ordinal: number;
+  readonly collection: string;
+}
+
+/** Each list or document view's checked lines. */
+export const checkedLines = (input: {
+  readonly tools: readonly StateToolFacts[];
+  readonly records: readonly StateRecordFacts[];
+  readonly views: ReadonlyMap<string, StateView>;
+}): Map<string, CheckedLines> => {
+  const byOrdinal = new Map(
+    input.records.map((record) => [record.ordinal, record]),
+  );
+  const tools = new Map(input.tools.map((tool) => [tool.name, tool]));
+  const byView = new Map<string, CheckedLines>();
+  for (const view of input.views.values()) {
+    const tool = tools.get(view.tool);
+    if (view.shape === "recorded" || view.shape === "item" || !tool) continue;
+    const checked = new Set(view.checked_record_ordinals);
+    const byQuery = new Map<
+      string,
+      { readonly ordinal: number; readonly segments: readonly string[] }[]
+    >();
+    for (const ordinal of tool.record_ordinals) {
+      const record = byOrdinal.get(ordinal);
+      if (!checked.has(ordinal) || record === undefined) continue;
+      const key = queryKey(record.query);
+      const lines = byQuery.get(key) ?? [];
+      lines.push({ ordinal, segments: segmentsOf(record.path) });
+      byQuery.set(key, lines);
+    }
+    const params = new Set(
+      segmentsOf(tool.path_template).flatMap((segment, index) =>
+        isParam(segment) ? [index] : [],
+      ),
+    );
+    byView.set(view.tool, { params, byQuery });
+  }
+  return byView;
+};
+
+/**
+ * The checked line serving answers a read's call from, ranked as replay ranks lines: every
+ * parameter the read's value verbatim or once percent-decoded and the query the read's, then the
+ * most verbatim parameters, then recorded order.
+ */
+export const servedLine = (
+  lines: CheckedLines | undefined,
+  record: StateRecordFacts,
+): ServedLine | undefined => {
+  const read = segmentsOf(record.path);
+  let best: { line: ServedLine; verbatim: number } | undefined;
+  for (const { ordinal, segments } of lines?.byQuery.get(
+    queryKey(record.query),
+  ) ?? []) {
+    if (segments.length !== read.length) continue;
+    let verbatim = 0;
+    const matches = segments.every((segment, index) => {
+      if (segment === read[index]) {
+        if (lines!.params.has(index)) verbatim += 1;
+        return true;
+      }
+      return (
+        lines!.params.has(index) && decodedSegment(segment) === read[index]
+      );
+    });
+    if (matches && (best === undefined || verbatim > best.verbatim))
+      best = {
+        line: { ordinal, collection: `/${segments.join("/")}` },
+        verbatim,
+      };
+  }
+  return best?.line;
+};
diff --git a/src/domain/analysisView/environmentStateWriteChecks.ts b/src/domain/analysisView/environmentStateWriteChecks.ts
index ac6ba7e5c5..a99fb07ec8 100644
--- a/src/domain/analysisView/environmentStateWriteChecks.ts
+++ b/src/domain/analysisView/environmentStateWriteChecks.ts
@@ -1,15 +1,9 @@
 import type { JsonValue } from "../jsonValue.js";
-import { iterateUrlQueryParameters } from "../recordedTransportUrl.js";
-import {
-  compareUnicodeCodePoints as compare,
-  compositeKey,
-} from "../unicodeCodePointOrder.js";
+import { compositeKey } from "../unicodeCodePointOrder.js";
 import {
   at,
   collectionPathOf,
-  decodedSegment,
   isObject,
-  isParam,
   lastSegmentValue,
   listItems,
   missingRequiredFields,
@@ -18,115 +12,15 @@ import {
   replaceAt,
   same,
   scalarText,
-  segmentsOf,
   type JsonObject,
   type StateDocument,
   type StateEntity,
   type StateItemView,
   type StateListView,
   type StateRecordFacts,
-  type StateToolFacts,
-  type StateView,
 } from "./environmentStateRules.js";
 import { answerQuery, renderQueryList } from "./environmentStateListQuery.js";
 
-/** A query as replay compares a call's: decoded values by name, in any order. A query repeating a name, which no call's arguments can carry, keeps its spelling. */
-const queryKey = (query: string | undefined): string => {
-  const pairs = [...iterateUrlQueryParameters(query ?? "")];
-  return new Set(pairs.map(([name]) => name)).size === pairs.length
-    ? compositeKey(pairs.sort(([left], [right]) => compare(left, right)))
-    : compositeKey([query ?? ""]);
-};
-
-/** A list or document view's checked lines, by query, in the tool's recorded order, and which path segments are the tool's parameters. */
-export interface CheckedLines {
-  readonly params: ReadonlySet<number>;
-  readonly byQuery: ReadonlyMap<
-    string,
-    readonly {
-      readonly ordinal: number;
-      readonly segments: readonly string[];
-    }[]
-  >;
-}
-
-/** The line a read's call is answered from, and the collection serving lists for it. */
-export interface ServedLine {
-  readonly ordinal: number;
-  readonly collection: string;
-}
-
-/** Each list or document view's checked lines. */
-export const checkedLines = (input: {
-  readonly tools: readonly StateToolFacts[];
-  readonly records: readonly StateRecordFacts[];
-  readonly views: ReadonlyMap<string, StateView>;
-}): Map<string, CheckedLines> => {
-  const byOrdinal = new Map(
-    input.records.map((record) => [record.ordinal, record]),
-  );
-  const tools = new Map(input.tools.map((tool) => [tool.name, tool]));
-  const byView = new Map<string, CheckedLines>();
-  for (const view of input.views.values()) {
-    const tool = tools.get(view.tool);
-    if (view.shape === "recorded" || view.shape === "item" || !tool) continue;
-    const checked = new Set(view.checked_record_ordinals);
-    const byQuery = new Map<
-      string,
-      { readonly ordinal: number; readonly segments: readonly string[] }[]
-    >();
-    for (const ordinal of tool.record_ordinals) {
-      const record = byOrdinal.get(ordinal);
-      if (!checked.has(ordinal) || record === undefined) continue;
-      const key = queryKey(record.query);
-      const lines = byQuery.get(key) ?? [];
-      lines.push({ ordinal, segments: segmentsOf(record.path) });
-      byQuery.set(key, lines);
-    }
-    const params = new Set(
-      segmentsOf(tool.path_template).flatMap((segment, index) =>
-        isParam(segment) ? [index] : [],
-      ),
-    );
-    byView.set(view.tool, { params, byQuery });
-  }
-  return byView;
-};
-
-/**
- * The checked line serving answers a read's call from, ranked as replay ranks lines: every
- * parameter the read's value verbatim or once percent-decoded and the query the read's, then the
- * most verbatim parameters, then recorded order.
- */
-export const servedLine = (
-  lines: CheckedLines | undefined,
-  record: StateRecordFacts,
-): ServedLine | undefined => {
-  const read = segmentsOf(record.path);
-  let best: { line: ServedLine; verbatim: number } | undefined;
-  for (const { ordinal, segments } of lines?.byQuery.get(
-    queryKey(record.query),
-  ) ?? []) {
-    if (segments.length !== read.length) continue;
-    let verbatim = 0;
-    const matches = segments.every((segment, index) => {
-      if (segment === read[index]) {
-        if (lines!.params.has(index)) verbatim += 1;
-        return true;
-      }
-      return (
-        lines!.params.has(index) && decodedSegment(segment) === read[index]
-      );
-    });
-    if (matches && (best === undefined || verbatim > best.verbatim))
-      best = {
-        line: { ordinal, collection: `/${segments.join("/")}` },
-        verbatim,
-      };
-  }
-  return best?.line;
-};
-
 /** Modelled writes per target since its last check, with the fields each wrote (null: all). */
 export type TouchedTargets = Map<string, Map<string, readonly string[] | null>>;