first commit

ui/app/workspace/routing-rules/tree/views/celParser.ts

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+/**
+ * CEL (Common Expression Language) parsing and evaluation helpers.
+ *
+ * Only handles the subset of CEL actually used in routing rule conditions:
+ * equality/inequality, startsWith, contains, in-list, header access, and
+ * simple numeric comparisons.
+ */
+
+/**
+ * Evaluate a single normalised CEL clause against a resolved variable map.
+ * Only handles simple equality/inequality patterns (field == "v", "v" == field,
+ * field != "v", "v" != field). Returns null when too complex to evaluate.
+ */
+export function evalChainCondition(cond: string, vars: Record<string, string>): boolean | null {
+	const s = cond.trim();
+	let m: RegExpMatchArray | null;
+
+	// Simple equality: field == "v" or "v" == field
+	m = s.match(/^(\w+)\s*==\s*["']([^"']*)["']$/);
+	if (m && m[1] in vars) return vars[m[1]] === m[2];
+	m = s.match(/^["']([^"']*)['"]\s*==\s*(\w+)$/);
+	if (m && m[2] in vars) return vars[m[2]] === m[1];
+
+	// Inequality: field != "v" or "v" != field
+	m = s.match(/^(\w+)\s*!=\s*["']([^"']*)["']$/);
+	if (m && m[1] in vars) return vars[m[1]] !== m[2];
+	m = s.match(/^["']([^"']*)['"]\s*!=\s*(\w+)$/);
+	if (m && m[2] in vars) return vars[m[2]] !== m[1];
+
+	// startsWith: field.startsWith("prefix")
+	m = s.match(/^(\w+)\.startsWith\(["']([^"']*)["']\)$/);
+	if (m && m[1] in vars) return vars[m[1]].startsWith(m[2]);
+
+	// contains: field.contains("sub")
+	m = s.match(/^(\w+)\.contains\(["']([^"']*)["']\)$/);
+	if (m && m[1] in vars) return vars[m[1]].includes(m[2]);
+
+	// in list: field in ["a","b","c"]
+	m = s.match(/^(\w+)\s+in\s+\[([^\]]*)\]$/);
+	if (m && m[1] in vars) {
+		const items = m[2].split(",").map((x) => x.trim().replace(/^["']|["']$/g, ""));
+		return items.includes(vars[m[1]]);
+	}
+
+	// headers["key"] == "value"
+	m = s.match(/^headers\[["']([^"']*)["']\]\s*==\s*["']([^"']*)["']$/);
+	if (m) {
+		const hVal = vars[`headers.${m[1]}`] ?? vars[`header_${m[1]}`];
+		if (hVal !== undefined) return hVal === m[2];
+	}
+
+	// Numeric comparisons: field >= n, field <= n, field > n, field < n
+	m = s.match(/^(\w+)\s*(>=|<=|>|<)\s*(\d+(?:\.\d+)?)$/);
+	if (m && m[1] in vars) {
+		const lv = parseFloat(vars[m[1]]);
+		const rv = parseFloat(m[3]);
+		if (!isNaN(lv)) {
+			if (m[2] === ">") return lv > rv;
+			if (m[2] === "<") return lv < rv;
+			if (m[2] === ">=") return lv >= rv;
+			if (m[2] === "<=") return lv <= rv;
+		}
+	}
+
+	return null; // too complex — skip
+}
+
+function isWrappedInParens(s: string): boolean {
+	if (!s.startsWith("(") || !s.endsWith(")")) return false;
+	let d = 0;
+	for (let i = 0; i < s.length; i++) {
+		if (s[i] === "(") d++;
+		else if (s[i] === ")") d--;
+		if (d === 0 && i < s.length - 1) return false;
+	}
+	return true;
+}
+
+function splitOn(expr: string, op: "&&" | "||"): string[] {
+	const trimmed = expr.trim();
+	const s = isWrappedInParens(trimmed) ? trimmed.slice(1, -1) : trimmed;
+	const parts: string[] = [];
+	let depth = 0,
+		current = "";
+	for (let i = 0; i < s.length; i++) {
+		const ch = s[i];
+		if (ch === "(" || ch === "[") depth++;
+		else if (ch === ")" || ch === "]") depth--;
+		else if (depth === 0 && s.slice(i, i + 2) === op) {
+			const p = current.trim();
+			if (p) parts.push(p);
+			current = "";
+			i++;
+			continue;
+		}
+		current += ch;
+	}
+	const last = current.trim();
+	if (last) parts.push(last);
+	if (parts.length < 2) return [expr.trim()];
+	return parts;
+}
+
+/** Cartesian product of two arrays of string arrays. */
+function cartesian(a: string[][], b: string[][]): string[][] {
+	const result: string[][] = [];
+	for (const x of a) for (const y of b) result.push([...x, ...y]);
+	return result;
+}
+
+/** Expand a CEL string into one or more condition lists, fanning out on OR.
+ *  Handles nested disjunctions such as `a && (b || c)` → [["a","b"],["a","c"]].
+ */
+export function expandCEL(cel: string): string[][] {
+	const trimmed = cel?.trim() || "";
+	if (!trimmed) return [[]];
+	// OR has lower precedence than AND → split on || first (outer level)
+	const orBranches = splitOn(trimmed, "||");
+	const result: string[][] = [];
+	for (const branch of orBranches) {
+		const andParts = splitOn(branch.trim(), "&&")
+			.map((p) => p.trim())
+			.filter(Boolean);
+		if (!andParts.length) {
+			result.push([branch.trim()]);
+			continue;
+		}
+
+		// For each AND part, check if it is a parenthesized OR — expand recursively
+		// and Cartesian-product with the accumulated combinations so far.
+		let combinations: string[][] = [[]];
+		for (const part of andParts) {
+			if (isWrappedInParens(part)) {
+				const inner = part.slice(1, -1).trim();
+				const innerBranches = splitOn(inner, "||");
+				if (innerBranches.length > 1) {
+					const innerExpanded = innerBranches.flatMap((b) => expandCEL(b.trim()));
+					combinations = cartesian(combinations, innerExpanded);
+					continue;
+				}
+			}
+			combinations = combinations.map((c) => [...c, part]);
+		}
+		result.push(...combinations);
+	}
+	return result.length ? result : [[]];
+}
+
+/**
+ * Normalize a CEL condition token for trie key comparison.
+ * Collapses whitespace around operators so "a == b" and "a==b" are the same key.
+ */
+export function normalizeCond(cond: string): string {
+	return cond
+		.trim()
+		.replace(/\s*(==|!=|>=|<=|>|<)\s*/g, (_, op) => ` ${op} `)
+		.replace(/\s+/g, " ");
+}

ui/app/workspace/routing-rules/tree/views/constants.ts

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+// ─── Scope config ──────────────────────────────────────────────────────────
+
+export const SCOPE_CONFIG = {
+	virtual_key: { label: "Virtual Key", color: "#7c3aed", headerClass: "bg-purple-100 dark:bg-purple-900/30" },
+	team: { label: "Team", color: "#2563eb", headerClass: "bg-blue-100 dark:bg-blue-900/30" },
+	customer: { label: "Customer", color: "#16a34a", headerClass: "bg-green-100 dark:bg-green-900/30" },
+	global: { label: "Global", color: "#6b7280", headerClass: "bg-gray-100 dark:bg-gray-800/30" },
+} as const;
+
+export type ScopeKey = keyof typeof SCOPE_CONFIG;
+
+export const SCOPE_ORDER = ["virtual_key", "team", "customer", "global"] as const;
+
+// ─── Layout constants (LR: W = horizontal, H = vertical) ──────────────────
+
+export const SRC_W = 260;
+export const SRC_H = 80;
+export const COND_W = 310;
+export const COND_H = 76;
+export const RULE_W = 220;
+export const RULE_H = 106;
+/** Baseline horizontal spacing intent (Dagre uses ranksep for rank-to-rank gaps). */
+export const H_GAP = 280;
+/** Baseline vertical spacing intent (Dagre uses nodesep within a rank). */
+export const V_GAP = 36;
+
+/** Dagre: minimum horizontal gap between layers (LR ranks / columns). Higher = calmer graph. */
+export const DAGRE_RANKSEP = 300;
+/** Dagre: minimum vertical gap between nodes sharing a rank. */
+export const DAGRE_NODESEP = 52;
+/** Dagre: margin around the laid-out bounding box. */
+export const DAGRE_MARGIN = 48;
+
+/** Default padding when fitting the graph to the viewport (fraction of viewport). */
+export const FIT_VIEW_PADDING = 0.14;

ui/app/workspace/routing-rules/tree/views/graphBuilder.ts

@@ -0,0 +1,487 @@
+/**
+ * Converts a list of RoutingRules into a React Flow node/edge graph.
+ *
+ * Pipeline:
+ *   rules → buildTrie → mergeSubtrees → collectDAGStructure → Dagre LR layout → buildGraph
+ */
+
+import { RoutingRule } from "@/lib/types/routingRules";
+import dagre from "@dagrejs/dagre";
+import type { Edge, Node } from "@xyflow/react";
+import { evalChainCondition, expandCEL, normalizeCond } from "./celParser";
+import {
+	COND_H,
+	COND_W,
+	DAGRE_MARGIN,
+	DAGRE_NODESEP,
+	DAGRE_RANKSEP,
+	RULE_H,
+	RULE_W,
+	SCOPE_CONFIG,
+	SRC_H,
+	SRC_W,
+	type ScopeKey,
+} from "./constants";
+
+// ─── Color mixing ──────────────────────────────────────────────────────────
+
+function hexToRgb(hex: string): [number, number, number] {
+	const n = parseInt(hex.slice(1), 16);
+	return [(n >> 16) & 255, (n >> 8) & 255, n & 255];
+}
+function rgbToHex(r: number, g: number, b: number): string {
+	return "#" + [r, g, b].map((v) => Math.round(v).toString(16).padStart(2, "0")).join("");
+}
+/** Weighted-blend hex colours. weights default to equal if omitted. */
+function blendColors(colors: string[], weights?: number[]): string {
+	if (colors.length === 1) return colors[0];
+	const w = weights ?? colors.map(() => 1);
+	const total = w.reduce((s, v) => s + v, 0);
+	const [r, g, b] = colors
+		.map((c, i) => hexToRgb(c).map((ch) => ch * (w[i] / total)) as [number, number, number])
+		.reduce(([ar, ag, ab], [cr, cg, cb]) => [ar + cr, ag + cg, ab + cb], [0, 0, 0]);
+	return rgbToHex(r, g, b);
+}
+
+// ─── Trie / DAG types ─────────────────────────────────────────────────────
+
+export interface TrieNode {
+	id: string;
+	condition: string | null;
+	children: Map<string, TrieNode>;
+	terminals: RoutingRule[];
+}
+
+interface LNode {
+	id: string;
+	kind: "source" | "condition" | "rule" | "target";
+	data: any;
+	w: number;
+	h: number;
+}
+interface LEdge {
+	source: string;
+	target: string;
+	label?: string;
+	color?: string;
+	isChainBack?: boolean;
+	isChainWeak?: boolean;
+	sourceHandle?: string;
+	targetHandle?: string;
+}
+
+// ─── Trie construction ────────────────────────────────────────────────────
+
+export function buildTrie(rules: RoutingRule[]): TrieNode {
+	let uid = 0;
+	const mkNode = (c: string | null): TrieNode => ({
+		id: c === null ? "root" : `n${++uid}`,
+		condition: c,
+		children: new Map(),
+		terminals: [],
+	});
+	const root = mkNode(null);
+
+	// Pre-collect all (rule, normalized-path) pairs so we can compute frequencies.
+	const allPaths: { rule: RoutingRule; path: string[] }[] = [];
+	for (const rule of rules) {
+		for (const path of expandCEL(rule.cel_expression ?? "")) {
+			allPaths.push({ rule, path: path.map(normalizeCond) });
+		}
+	}
+
+	// Count how many paths each condition appears in.
+	// Conditions shared by more paths sort earlier → maximum prefix sharing.
+	const freq = new Map<string, number>();
+	for (const { path } of allPaths) {
+		for (const cond of new Set(path)) {
+			freq.set(cond, (freq.get(cond) ?? 0) + 1);
+		}
+	}
+
+	// Insert into trie with paths sorted by frequency desc, then alphabetically.
+	for (const { rule, path } of allPaths) {
+		const sorted = [...path].sort((a, b) => {
+			const d = (freq.get(b) ?? 0) - (freq.get(a) ?? 0);
+			return d !== 0 ? d : a.localeCompare(b);
+		});
+		let node = root;
+		for (const cond of sorted) {
+			if (!node.children.has(cond)) node.children.set(cond, mkNode(cond));
+			node = node.children.get(cond)!;
+		}
+		if (!node.terminals.find((r) => r.id === rule.id)) node.terminals.push(rule);
+	}
+
+	return root;
+}
+
+/** Merge structurally identical subtrees so OR-expanded duplicates share one node. */
+export function mergeSubtrees(root: TrieNode): void {
+	const registry = new Map<string, TrieNode>();
+	const nodeCanon = new Map<string, string>();
+
+	function canon(node: TrieNode, seen = new Set<string>()): string {
+		if (nodeCanon.has(node.id)) return nodeCanon.get(node.id)!;
+		if (seen.has(node.id)) return node.id;
+		seen.add(node.id);
+		const termKey = node.terminals
+			.map((r) => r.id)
+			.sort()
+			.join(",");
+		const childKey = Array.from(node.children.entries())
+			.map(([c, ch]) => `${c}:${canon(ch, new Set(seen))}`)
+			.sort()
+			.join("|");
+		const key = `${node.condition}::${termKey}::${childKey}`;
+		nodeCanon.set(node.id, key);
+		if (!registry.has(key)) registry.set(key, node);
+		return key;
+	}
+
+	function postOrder(node: TrieNode, seen = new Set<string>()): void {
+		if (seen.has(node.id)) return;
+		seen.add(node.id);
+		for (const ch of node.children.values()) postOrder(ch, seen);
+		canon(node);
+	}
+	postOrder(root);
+
+	function replace(node: TrieNode, seen = new Set<string>()): void {
+		if (seen.has(node.id)) return;
+		seen.add(node.id);
+		for (const [cond, ch] of Array.from(node.children.entries())) {
+			const canonical = registry.get(nodeCanon.get(ch.id)!)!;
+			if (canonical.id !== ch.id) node.children.set(cond, canonical);
+			replace(canonical, seen);
+		}
+	}
+	replace(root);
+}
+
+// ─── Scope colour helpers ──────────────────────────────────────────────────
+
+function collectTerminals(node: TrieNode, seen = new Set<string>()): RoutingRule[] {
+	if (seen.has(node.id)) return [];
+	seen.add(node.id);
+	const acc = [...node.terminals];
+	for (const ch of node.children.values()) acc.push(...collectTerminals(ch, seen));
+	return acc;
+}
+
+function nodeColor(node: TrieNode, cache?: Map<string, string | null>): string | null {
+	if (cache?.has(node.id)) return cache.get(node.id)!;
+	const rules = collectTerminals(node);
+	if (!rules.length) {
+		cache?.set(node.id, null);
+		return null;
+	}
+	// Deduplicate by rule.id before counting — collectTerminals returns one entry
+	// per OR-expanded path, so a multi-branch rule would otherwise be over-counted.
+	const uniqueRules = [...new Map(rules.map((r) => [r.id, r])).values()];
+	// Count rules per scope to produce a weighted blend.
+	const counts = new Map<string, number>();
+	for (const r of uniqueRules) counts.set(r.scope, (counts.get(r.scope) ?? 0) + 1);
+	const entries = [...counts.entries()]
+		.map(([scope, count]): { color: string | undefined; count: number } => ({
+			color: SCOPE_CONFIG[scope as ScopeKey]?.color,
+			count,
+		}))
+		.filter((e): e is { color: string; count: number } => !!e.color);
+	const result = entries.length
+		? blendColors(
+				entries.map((e) => e.color),
+				entries.map((e) => e.count),
+			)
+		: null;
+	cache?.set(node.id, result);
+	return result;
+}
+
+// ─── DAG structure collection ─────────────────────────────────────────────
+
+function collectDAGStructure(root: TrieNode): { lNodes: LNode[]; lEdges: LEdge[] } {
+	const colorCache = new Map<string, string | null>();
+	const lNodes: LNode[] = [{ id: "source", kind: "source", data: {}, w: SRC_W, h: SRC_H }];
+	const lEdges: LEdge[] = [];
+	const addedNodes = new Set<string>(["source"]);
+	const addedEdges = new Set<string>();
+	const processed = new Set<string>();
+	const chainQueue: { ruleId: string; rule: RoutingRule; sc: string }[] = [];
+
+	function addEdge(src: string, tgt: string, label?: string, color?: string, opts?: Partial<LEdge>) {
+		const key = `${src}→${tgt}${opts?.isChainBack ? ":chain" : ""}`;
+		if (addedEdges.has(key)) return;
+		addedEdges.add(key);
+		lEdges.push({ source: src, target: tgt, label, color, ...opts });
+	}
+
+	function traverse(node: TrieNode, parentId: string) {
+		const isRoot = node.condition === null;
+		const selfId = isRoot ? "source" : node.id;
+
+		if (!isRoot) {
+			if (!addedNodes.has(selfId)) {
+				const color = nodeColor(node, colorCache);
+				const terminalRules = collectTerminals(node);
+				const scopes = [...new Set(terminalRules.map((r) => r.scope))];
+				lNodes.push({ id: selfId, kind: "condition", data: { condition: node.condition, color, scopes }, w: COND_W, h: COND_H });
+				addedNodes.add(selfId);
+			}
+			addEdge(parentId, selfId, undefined, nodeColor(node, colorCache) ?? undefined);
+		}
+
+		// Don't re-traverse a shared node's subtree from a second parent
+		if (!isRoot && processed.has(selfId)) return;
+		processed.add(selfId);
+
+		for (const ch of node.children.values()) traverse(ch, selfId);
+
+		for (const rule of node.terminals) {
+			const ruleId = `rule-${rule.id}`;
+			const sc = SCOPE_CONFIG[rule.scope as ScopeKey]?.color ?? "#9ca3af";
+			if (!addedNodes.has(ruleId)) {
+				lNodes.push({ id: ruleId, kind: "rule", data: { rule, scopeColor: sc }, w: RULE_W, h: RULE_H });
+				addedNodes.add(ruleId);
+			}
+			addEdge(selfId, ruleId, undefined, sc);
+			if (rule.chain_rule) chainQueue.push({ ruleId, rule, sc });
+		}
+	}
+
+	traverse(root, "");
+
+	// ── Second pass: chain edges to specific matching condition nodes ──────
+	// For each chain rule, evaluate its resolved targets against every
+	// condition node reachable from source. Connect to the first satisfied
+	// condition in each path so the edge shows exactly where the chain lands.
+	if (chainQueue.length > 0) {
+		// Build an adjacency list (forward edges only, by definition at this point)
+		const childrenOf = new Map<string, string[]>();
+		for (const e of lEdges) {
+			if (!childrenOf.has(e.source)) childrenOf.set(e.source, []);
+			childrenOf.get(e.source)!.push(e.target);
+		}
+		const nodeById = new Map(lNodes.map((n) => [n.id, n]));
+
+		/** Walk forward from `startIds`, following only condition nodes, and
+		 *  return the deepest node in each branch whose condition evaluates to
+		 *  true for `vars`. Only emits a node if none of its condition children
+		 *  also evaluate to true (deepest satisfied entry point semantics).
+		 *
+		 *  Each result carries a `strong` flag: true when every condition on the
+		 *  path evaluated to `true` (static chain), false when any condition was
+		 *  `null` / too complex to evaluate (dynamic chain). */
+		function findEntries(startIds: string[], vars: Record<string, string>): Array<{ id: string; strong: boolean }> {
+			const results: Array<{ id: string; strong: boolean }> = [];
+			const visited = new Set<string>();
+
+			/** Returns true if this node (or any descendant condition) matched.
+			 *  `strong` is false once we have passed through any `null` hop. */
+			function explore(id: string, strong: boolean): boolean {
+				if (visited.has(id)) return false;
+				visited.add(id);
+				const node = nodeById.get(id);
+				if (!node || node.kind !== "condition") return false;
+
+				const result = evalChainCondition(node.data.condition as string, vars);
+				if (result === false) return false; // branch blocked
+
+				if (result === true) {
+					// Continue into children — prefer the deepest static match
+					let hasDeeper = false;
+					for (const childId of childrenOf.get(id) ?? []) {
+						if (explore(childId, strong)) hasDeeper = true;
+					}
+					if (!hasDeeper) results.push({ id, strong });
+					return true;
+				}
+
+				// result === null (too complex) — explore children but mark as weak
+				let anyMatch = false;
+				for (const childId of childrenOf.get(id) ?? []) {
+					if (explore(childId, false)) anyMatch = true;
+				}
+				return anyMatch;
+			}
+
+			for (const id of startIds) explore(id, true);
+			return results;
+		}
+
+		for (const { ruleId, rule, sc } of chainQueue) {
+			// Collect unique (provider, model) pairs across all targets
+			const seen = new Set<string>();
+			for (const t of rule.targets) {
+				const vars: Record<string, string> = {};
+				if (t.provider) vars.provider = t.provider;
+				if (t.model) vars.model = t.model;
+				if (!Object.keys(vars).length) {
+					// passthrough target — chain loops back to source (static: we know the input is unchanged)
+					addEdge(ruleId, "source", "↺", sc, { isChainBack: true, isChainWeak: false, sourceHandle: "chain-out" });
+					continue;
+				}
+				const key = JSON.stringify(vars);
+				if (seen.has(key)) continue;
+				seen.add(key);
+
+				const entries = findEntries(childrenOf.get("source") ?? [], vars);
+				if (entries.length === 0) {
+					// resolved vars match no condition node — fall back to source
+					addEdge(ruleId, "source", "↺", sc, { isChainBack: true, isChainWeak: false, sourceHandle: "chain-out" });
+				}
+				for (const { id: condId, strong } of entries) {
+					addEdge(ruleId, condId, "↺", sc, { isChainBack: true, isChainWeak: !strong, sourceHandle: "chain-out" });
+				}
+			}
+		}
+	}
+
+	return { lNodes, lEdges };
+}
+
+// ─── Dagre layered layout (LR) ───────────────────────────────────────────
+//
+// Uses @dagrejs/dagre with the network-simplex ranker for crossing reduction and
+// consistent rank spacing. Chain-back edges are excluded — they are drawn after.
+
+function computeLRLayout(lNodes: LNode[], lEdges: LEdge[]): Map<string, { x: number; y: number }> {
+	const g = new dagre.graphlib.Graph({ multigraph: false });
+	g.setGraph({
+		rankdir: "LR",
+		// Network-simplex tends to produce cleaner orderings than longest-path on DAGs.
+		ranker: "network-simplex",
+		ranksep: DAGRE_RANKSEP,
+		nodesep: DAGRE_NODESEP,
+		edgesep: 16,
+		marginx: DAGRE_MARGIN,
+		marginy: DAGRE_MARGIN,
+		align: "UL",
+	});
+	g.setDefaultEdgeLabel(() => ({}));
+
+	for (const n of lNodes) {
+		g.setNode(n.id, { width: n.w, height: n.h });
+	}
+
+	const forward = lEdges.filter((e) => !e.isChainBack);
+	const edgeKey = new Set<string>();
+	for (const e of forward) {
+		const k = `${e.source}\0${e.target}`;
+		if (edgeKey.has(k)) continue;
+		edgeKey.add(k);
+		if (g.hasNode(e.source) && g.hasNode(e.target)) {
+			g.setEdge(e.source, e.target);
+		}
+	}
+
+	dagre.layout(g);
+
+	const positions = new Map<string, { x: number; y: number }>();
+	for (const n of lNodes) {
+		const laid = g.node(n.id);
+		if (laid === undefined) continue;
+		// Dagre uses x,y as the centre of each node.
+		positions.set(n.id, {
+			x: laid.x - n.w / 2,
+			y: laid.y - n.h / 2,
+		});
+	}
+
+	// Dagre pins the first rank to the top of the layout; shift "source" so its
+	// vertical centre matches the midpoint of every *other* node's bounding box.
+	centerSourceVertically(positions, lNodes);
+
+	// Pull the source node an extra gap to the left so it visually breathes
+	// away from the first condition column.
+	const sourcePos = positions.get("source");
+	if (sourcePos) sourcePos.x -= 200;
+
+	return positions;
+}
+
+/** Move the source node so it sits at the vertical centre of the rest of the graph. */
+function centerSourceVertically(positions: Map<string, { x: number; y: number }>, lNodes: LNode[]): void {
+	const sourceEntry = lNodes.find((n) => n.id === "source");
+	const sourcePos = positions.get("source");
+	if (!sourceEntry || !sourcePos) return;
+
+	const others = lNodes.filter((n) => n.id !== "source");
+	if (others.length === 0) return;
+
+	let minTop = Infinity;
+	let maxBottom = -Infinity;
+	for (const n of others) {
+		const p = positions.get(n.id);
+		if (!p) continue;
+		minTop = Math.min(minTop, p.y);
+		maxBottom = Math.max(maxBottom, p.y + n.h);
+	}
+	if (!Number.isFinite(minTop) || !Number.isFinite(maxBottom)) return;
+
+	const midY = (minTop + maxBottom) / 2;
+	sourcePos.y = midY - sourceEntry.h / 2;
+}
+
+// ─── Build React Flow graph ────────────────────────────────────────────────
+
+export function buildGraph(rules: RoutingRule[]): { nodes: Node[]; edges: Edge[] } {
+	const trie = buildTrie(rules);
+	mergeSubtrees(trie);
+	const { lNodes, lEdges } = collectDAGStructure(trie);
+	// Chain-back edges form cycles — exclude them from layout (forward edges only).
+	const positions = computeLRLayout(
+		lNodes,
+		lEdges.filter((e) => !e.isChainBack),
+	);
+
+	const kindType: Record<string, string> = {
+		source: "rfSource",
+		condition: "rfCondition",
+		rule: "rfRule",
+	};
+
+	const rfNodes: Node[] = lNodes.map((ln) => ({
+		id: ln.id,
+		type: kindType[ln.kind],
+		position: positions.get(ln.id) ?? { x: 0, y: 0 },
+		data: ln.data,
+		draggable: true,
+		selectable: true,
+		connectable: false,
+	}));
+
+	const rfEdges: Edge[] = lEdges.map((le) => {
+		const base = {
+			id: `e-${le.source}-${le.target}${le.isChainBack ? "-chain" : ""}`,
+			source: le.source,
+			target: le.target,
+			...(le.sourceHandle ? { sourceHandle: le.sourceHandle } : {}),
+			...(le.targetHandle ? { targetHandle: le.targetHandle } : {}),
+		};
+		if (le.isChainBack) {
+			// Both dashed: longer dashes (static) vs shorter dashes (dynamic). Mid-arrow in rfChainEdge.
+			const weak = le.isChainWeak;
+			return {
+				...base,
+				type: "rfChain",
+				data: { chainWeak: weak },
+				animated: false,
+				...(weak ? { className: "rf-chain-edge-dynamic" } : {}),
+				style: {
+					stroke: le.color,
+					strokeWidth: 1.5,
+					strokeLinecap: "round",
+					...(weak ? {} : { strokeDasharray: "14 10" }),
+				},
+			};
+		}
+		return {
+			...base,
+			type: "simplebezier",
+			style: { stroke: le.color ?? "var(--border)", strokeWidth: le.color ? 1.5 : 1 },
+		};
+	});
+
+	return { nodes: rfNodes, edges: rfEdges };
+}

ui/app/workspace/routing-rules/tree/views/node/rfConditionNode.tsx

@@ -0,0 +1,50 @@
+import { cn } from "@/lib/utils";
+import { Position } from "@xyflow/react";
+import { COND_H, COND_W, SCOPE_CONFIG, type ScopeKey } from "../constants";
+import { RFEdgeHandle } from "./rfEdgeHandle";
+
+/** Width of the left scope-color strip (matches common “start node” accent bars). */
+const ACCENT_STRIP_CLASS = "w-2.5";
+
+export function RFConditionNode({ data }: { data: any }) {
+	const condition = data.condition as string;
+	const color = data.color as string | null;
+	const scopes = (data.scopes as string[] | undefined) ?? [];
+	const accent = color ?? undefined;
+
+	return (
+		<div className="relative" style={{ width: COND_W, minHeight: COND_H }}>
+			<RFEdgeHandle type="target" position={Position.Left} accentColor={accent ?? "var(--muted-foreground)"} />
+			<RFEdgeHandle type="source" position={Position.Right} accentColor={accent ?? "var(--muted-foreground)"} />
+			<div
+				className="dark:bg-card relative z-10 flex w-full cursor-grab overflow-hidden rounded-lg border bg-white shadow-sm active:cursor-grabbing"
+				style={{ minHeight: COND_H, borderColor: accent }}
+			>
+				<div
+					className={cn("shrink-0 self-stretch", ACCENT_STRIP_CLASS, !accent && "bg-muted")}
+					style={accent ? { backgroundColor: accent } : undefined}
+					aria-hidden
+				/>
+				<div className="flex min-w-0 flex-1 flex-col gap-4 px-3 py-2.5">
+					<code className="text-foreground flex-1 font-mono text-[12px] leading-snug break-all">{condition}</code>
+					{scopes.length > 0 && (
+						<div className="flex flex-wrap gap-1">
+							{scopes.map((sc) => {
+								const cfg = SCOPE_CONFIG[sc as ScopeKey];
+								return cfg ? (
+									<span
+										key={sc}
+										className="rounded px-1 py-0 text-[9px] font-semibold"
+										style={{ backgroundColor: `${cfg.color}18`, color: cfg.color }}
+									>
+										{cfg.label}
+									</span>
+								) : null;
+							})}
+						</div>
+					)}
+				</div>
+			</div>
+		</div>
+	);
+}

ui/app/workspace/routing-rules/tree/views/node/rfEdgeHandle.tsx

@@ -0,0 +1,28 @@
+import { cn } from "@/lib/utils";
+import { Handle, type HandleProps } from "@xyflow/react";
+
+/** Visual diameter; React Flow’s default is ~6px — larger so half the disc reads clearly past the node edge. */
+export const RF_HANDLE_SIZE_PX = 14;
+
+export type RFEdgeHandleProps = Omit<HandleProps, "className"> & {
+	className?: string;
+	accentColor?: string;
+};
+
+export function RFEdgeHandle({ className, accentColor, style, ...rest }: RFEdgeHandleProps) {
+	return (
+		<Handle
+			className={cn(
+				"!pointer-events-auto !z-0",
+				"!h-[14px] !min-h-[14px] !w-[14px] !min-w-[14px]",
+				"!rounded-full !border-0 !border-none !p-0 !shadow-none",
+				className,
+			)}
+			style={{
+				...style,
+				...(accentColor ? { background: accentColor } : {}),
+			}}
+			{...rest}
+		/>
+	);
+}

ui/app/workspace/routing-rules/tree/views/node/rfRuleNode.tsx

@@ -0,0 +1,144 @@
+import { Badge } from "@/components/ui/badge";
+import { ProviderIconType, RenderProviderIcon } from "@/lib/constants/icons";
+import { getProviderLabel } from "@/lib/constants/logs";
+import { RoutingRule } from "@/lib/types/routingRules";
+import { Position } from "@xyflow/react";
+import { Link2 } from "lucide-react";
+import { useState } from "react";
+import { RULE_W, SCOPE_CONFIG, type ScopeKey } from "../constants";
+import { RFEdgeHandle } from "./rfEdgeHandle";
+
+export function RFRuleNode({ data }: { data: any }) {
+	const rule = data.rule as RoutingRule;
+	const scopeColor = data.scopeColor as string;
+	const cfg = SCOPE_CONFIG[rule.scope as ScopeKey];
+	const multi = rule.targets.length > 1;
+	const [hovered, setHovered] = useState(false);
+
+	return (
+		<div
+			className="relative"
+			style={{ width: RULE_W }}
+			tabIndex={0}
+			role="button"
+			aria-haspopup="true"
+			aria-expanded={hovered}
+			onMouseEnter={() => setHovered(true)}
+			onMouseLeave={() => setHovered(false)}
+			onFocus={() => setHovered(true)}
+			onBlur={() => setHovered(false)}
+			onClick={() => setHovered((v) => !v)}
+			onKeyDown={(e) => {
+				if (e.key === "Enter" || e.key === " ") {
+					e.preventDefault();
+					setHovered((v) => !v);
+				}
+			}}
+		>
+			<RFEdgeHandle type="target" position={Position.Left} accentColor={scopeColor} />
+			{rule.chain_rule && <RFEdgeHandle type="source" id="chain-out" position={Position.Right} accentColor={scopeColor} />}
+			<div
+				className="dark:bg-card relative z-10 cursor-grab rounded-lg border-2 bg-white shadow-sm active:cursor-grabbing"
+				style={{ borderColor: scopeColor, borderStyle: rule.chain_rule ? "dashed" : "solid" }}
+			>
+				{/* scope header */}
+				<div className={`flex items-center gap-1.5 rounded-t-[6px] px-3 py-1.5 ${cfg?.headerClass ?? "bg-gray-100 dark:bg-gray-800/30"}`}>
+					<span className="h-1.5 w-1.5 flex-shrink-0 rounded-full" style={{ backgroundColor: scopeColor }} />
+					<span className="text-[10px] font-semibold" style={{ color: scopeColor }}>
+						{cfg?.label ?? rule.scope}
+					</span>
+					<div className="ml-auto flex items-center gap-1">
+						{rule.chain_rule && <Link2 className="h-3 w-3" style={{ color: scopeColor }} />}
+						{!rule.enabled && (
+							<Badge variant="secondary" className="px-1 py-0 text-[9px]">
+								Off
+							</Badge>
+						)}
+					</div>
+				</div>
+
+				{/* rule name */}
+				<div className="px-3 py-2">
+					<p className="text-foreground truncate text-xs font-semibold">{rule.name}</p>
+					{rule.priority > 0 && <p className="text-muted-foreground mt-0.5 text-[10px]">Priority {rule.priority}</p>}
+				</div>
+
+				{/* targets footer */}
+				<div
+					className="flex items-center gap-1.5 rounded-b-[6px] border-t px-3 py-1.5"
+					style={{ borderColor: `${scopeColor}40`, backgroundColor: `${scopeColor}08` }}
+				>
+					<div className="flex items-center gap-1">
+						{rule.targets
+							.slice(0, 4)
+							.map((t, i) =>
+								t.provider ? (
+									<RenderProviderIcon key={i} provider={t.provider as ProviderIconType} size={12} />
+								) : (
+									<span key={i} className="bg-muted-foreground/30 h-2 w-2 rounded-full" />
+								),
+							)}
+						{rule.targets.length > 4 && <span className="text-muted-foreground text-[9px]">+{rule.targets.length - 4}</span>}
+					</div>
+					<span className="text-muted-foreground ml-auto text-[10px]">
+						{rule.targets.length} target{rule.targets.length !== 1 ? "s" : ""}
+					</span>
+				</div>
+
+				{/* hover popover */}
+				{hovered && (
+					<div
+						className="nodrag nowheel dark:bg-card absolute top-0 left-full z-50 ml-3 min-w-[190px] rounded-lg border-2 bg-white py-1.5 shadow-xl"
+						style={{ borderColor: scopeColor }}
+					>
+						{rule.scope !== "global" && rule.scope_id && (
+							<div className="mb-1 border-b px-3 pb-1.5">
+								<p className="text-muted-foreground text-[10px]">
+									<span className="font-semibold" style={{ color: scopeColor }}>
+										{cfg?.label ?? rule.scope}:{" "}
+									</span>
+									<span className="text-foreground font-medium">{rule.scope_id}</span>
+								</p>
+							</div>
+						)}
+						{rule.chain_rule && (
+							<div className="mb-1 flex items-start gap-2 border-b px-3 pb-1.5">
+								<Link2 className="mt-0.5 h-3 w-3 shrink-0" style={{ color: scopeColor }} />
+								<p className="text-muted-foreground text-[10px] leading-snug">
+									Chain rule — resolved provider/model feeds back as the new input and the full scope chain re-evaluates.
+								</p>
+							</div>
+						)}
+						<p className="mb-1 px-3 text-[10px] font-semibold tracking-wide uppercase" style={{ color: scopeColor }}>
+							{rule.chain_rule ? "Resolved target (new input)" : "Targets"}
+						</p>
+						{rule.targets.map((t, i) => {
+							const isPassthrough = !t.provider && !t.model;
+							return (
+								<div key={i} className="hover:bg-muted flex items-center gap-2 px-3 py-1.5">
+									{t.provider ? (
+										<RenderProviderIcon provider={t.provider as ProviderIconType} size={13} />
+									) : (
+										<span className="bg-muted-foreground/30 h-3 w-3 flex-shrink-0 rounded-full" />
+									)}
+									<div className="min-w-0 flex-1">
+										<p className="text-foreground truncate text-xs font-medium">
+											{isPassthrough ? "Passthrough" : t.provider ? getProviderLabel(t.provider) : t.model}
+										</p>
+										{t.model && t.provider && <p className="text-muted-foreground truncate font-mono text-[10px]">{t.model}</p>}
+										{isPassthrough && <p className="text-muted-foreground/60 text-[10px] italic">original provider &amp; model</p>}
+									</div>
+									{multi && (
+										<span className="ml-1 shrink-0 text-[11px] font-semibold" style={{ color: scopeColor }}>
+											{Math.round(t.weight * 100)}%
+										</span>
+									)}
+								</div>
+							);
+						})}
+					</div>
+				)}
+			</div>
+		</div>
+	);
+}

ui/app/workspace/routing-rules/tree/views/node/rfSourceNode.tsx

@@ -0,0 +1,19 @@
+import { Position } from "@xyflow/react";
+import { Network } from "lucide-react";
+import { SRC_H, SRC_W } from "../constants";
+import { RFEdgeHandle } from "./rfEdgeHandle";
+
+export function RFSourceNode() {
+	return (
+		<div className="relative" style={{ width: SRC_W, height: SRC_H }}>
+			<RFEdgeHandle type="source" position={Position.Right} accentColor="var(--primary)" />
+			<div className="border-primary dark:bg-card relative z-10 flex h-full cursor-grab flex-col justify-center rounded-xl border-2 bg-white px-5 shadow-md active:cursor-grabbing">
+				<div className="text-foreground flex items-center gap-2 font-semibold">
+					<Network className="text-primary h-4 w-4" />
+					Incoming Request
+				</div>
+				<p className="text-muted-foreground mt-0.5 text-[11px]">provider · model · headers · params · limits</p>
+			</div>
+		</div>
+	);
+}

ui/app/workspace/routing-rules/tree/views/positionPersistence.ts

@@ -0,0 +1,17 @@
+import { RoutingRule } from "@/lib/types/routingRules";
+
+export const POSITIONS_COOKIE = "bf-routing-tree-positions";
+
+export interface PositionCookie {
+	fingerprint: string;
+	positions: Record<string, { x: number; y: number }>;
+	viewport?: { x: number; y: number; zoom: number };
+}
+
+/** Changes whenever any rule is added, edited, or deleted. */
+export function computeFingerprint(rules: RoutingRule[]): string {
+	return rules
+		.map((r) => `${r.id}:${r.updated_at}`)
+		.sort()
+		.join("|");
+}

ui/app/workspace/routing-rules/tree/views/rfChainEdge.tsx

@@ -0,0 +1,81 @@
+import { BaseEdge, type EdgeProps } from "@xyflow/react";
+import { memo, useMemo } from "react";
+
+export type RfChainEdgeData = {
+	/** When true, the chain is "dynamic" — static analysis could not fully prove the re-entry path. */
+	chainWeak?: boolean;
+};
+
+/**
+ * Builds a cubic Bézier path for a chain-back edge.
+ *
+ * Because the source handle exits to the RIGHT and the target is often to the
+ * LEFT (the edge loops back), the standard `getSimpleBezierPath` control-point
+ * formula places both control points between source and target, causing the
+ * edge to immediately swing left from a right-facing handle.
+ *
+ * Instead we always push cp1 rightward past the source and cp2 leftward past
+ * the target, creating a clear outward loop before the edge arrives at the
+ * condition node's left handle.
+ */
+function buildChainPath(
+	sx: number,
+	sy: number,
+	tx: number,
+	ty: number,
+): { path: string; labelX: number; labelY: number; angleDeg: number } {
+	// Offset scales with horizontal distance so the loop expands when nodes
+	// are far apart, but stays legible when they are close.
+	const hDist = Math.abs(sx - tx);
+	const offset = Math.max(80, hDist * 0.25);
+
+	const cp1x = sx + offset; // always to the right of the source
+	const cp1y = sy;
+	const cp2x = tx - offset; // always to the left of the target
+	const cp2y = ty;
+
+	const path = `M${sx},${sy} C${cp1x},${cp1y} ${cp2x},${cp2y} ${tx},${ty}`;
+
+	// Midpoint of cubic Bézier at t = 0.5
+	const labelX = sx / 8 + (3 * cp1x) / 8 + (3 * cp2x) / 8 + tx / 8;
+	const labelY = sy / 8 + (3 * cp1y) / 8 + (3 * cp2y) / 8 + ty / 8;
+
+	// Tangent direction at t = 0.5 for the mid-edge arrow orientation
+	const dx = 0.75 * (cp1x - sx) + 1.5 * (cp2x - cp1x) + 0.75 * (tx - cp2x);
+	const dy = 0.75 * (cp1y - sy) + 1.5 * (cp2y - cp1y) + 0.75 * (ty - cp2y);
+	const angleDeg = (Math.atan2(dy, dx) * 180) / Math.PI;
+
+	return { path, labelX, labelY, angleDeg };
+}
+
+function RfChainEdgeImpl({ id, sourceX, sourceY, targetX, targetY, style, interactionWidth, data }: EdgeProps) {
+	const weak = (data as RfChainEdgeData | undefined)?.chainWeak === true;
+	const strokeColor = typeof style?.stroke === "string" && style.stroke.length > 0 ? style.stroke : "var(--foreground)";
+
+	const { path, labelX, labelY, angleDeg } = useMemo(
+		() => buildChainPath(sourceX, sourceY, targetX, targetY),
+		[sourceX, sourceY, targetX, targetY],
+	);
+
+	return (
+		<>
+			<BaseEdge id={id} path={path} style={style} interactionWidth={interactionWidth ?? 12} />
+			<g transform={`translate(${labelX}, ${labelY}) rotate(${angleDeg})`} className="pointer-events-none" aria-hidden>
+				{weak ? (
+					<polyline
+						points="-6,-4 6,0 -6,4"
+						fill="none"
+						stroke={strokeColor}
+						strokeWidth={1.75}
+						strokeLinecap="round"
+						strokeLinejoin="round"
+					/>
+				) : (
+					<polygon points="8,0 -6,-5 -6,5" fill={strokeColor} />
+				)}
+			</g>
+		</>
+	);
+}
+
+export const RfChainEdge = memo(RfChainEdgeImpl);

ui/app/workspace/routing-rules/tree/views/routingTreeView.tsx

@@ -0,0 +1,536 @@
+/**
+ * Routing Tree View — left-to-right flow lane.
+ *
+ * Source → conditions (shared prefix / OR merge) → rule node → target node(s)
+ *
+ * OR branches are split into parallel paths that converge on the same
+ * shared child via subtree-hash deduplication.  Each rule target gets its
+ * own leaf node.  Nodes are draggable for exploration; nothing is editable.
+ */
+
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
+import { useGetRoutingRulesQuery } from "@/lib/store/apis/routingRulesApi";
+import { useNavigate } from "@tanstack/react-router";
+import type { Node, NodeChange } from "@xyflow/react";
+import { Background, BackgroundVariant, Controls, Panel, ReactFlow, useEdgesState, useNodesState } from "@xyflow/react";
+import "@xyflow/react/dist/style.css";
+import { AlertCircle, ArrowLeft, GitBranch, Info, Link2, Loader2, RotateCcw, Search } from "lucide-react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import { useCookies } from "react-cookie";
+import { FIT_VIEW_PADDING, SCOPE_CONFIG, SCOPE_ORDER } from "./constants";
+import { buildGraph } from "./graphBuilder";
+import { RFConditionNode } from "./node/rfConditionNode";
+import { RFRuleNode } from "./node/rfRuleNode";
+import { RFSourceNode } from "./node/rfSourceNode";
+import { POSITIONS_COOKIE, PositionCookie, computeFingerprint } from "./positionPersistence";
+import { RfChainEdge } from "./rfChainEdge";
+
+// ─── Node types (stable reference) ────────────────────────────────────────
+
+const nodeTypes = {
+	rfSource: RFSourceNode,
+	rfCondition: RFConditionNode,
+	rfRule: RFRuleNode,
+};
+
+const edgeTypes = { rfChain: RfChainEdge };
+
+// ─── Main component ────────────────────────────────────────────────────────
+
+export function RoutingTreeView() {
+	const navigate = useNavigate();
+	const { data, isLoading, isError } = useGetRoutingRulesQuery({ limit: 500 });
+	const rules = data?.rules ?? [];
+
+	// ── Position persistence ───────────────────────────────────────────────
+	const [cookies, setCookie, removeCookie] = useCookies([POSITIONS_COOKIE]);
+
+	// React Flow instance — captured via onInit so we can call fitView imperatively.
+	// eslint-disable-next-line @typescript-eslint/no-explicit-any
+	const rfInstanceRef = useRef<any>(null);
+	const resetTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+	useEffect(
+		() => () => {
+			if (resetTimeoutRef.current) clearTimeout(resetTimeoutRef.current);
+		},
+		[],
+	);
+
+	// Capture cookie value once on mount so re-saves don't trigger re-renders.
+	const [initialCookie] = useState<PositionCookie | undefined>(() => cookies[POSITIONS_COOKIE] as PositionCookie | undefined);
+
+	const fingerprint = useMemo(() => computeFingerprint(rules), [rules]);
+
+	const { baseNodes, baseEdges } = useMemo(() => {
+		const g = buildGraph(rules);
+		return { baseNodes: g.nodes, baseEdges: g.edges };
+	}, [rules]);
+
+	// If the cookie fingerprint matches current rules, restore saved positions.
+	const { mergedNodes, positionsRestored } = useMemo(() => {
+		if (initialCookie?.fingerprint === fingerprint && initialCookie?.positions && Object.keys(initialCookie.positions).length > 0) {
+			return {
+				mergedNodes: baseNodes.map((n) => ({
+					...n,
+					position: initialCookie.positions[n.id] ?? n.position,
+				})),
+				positionsRestored: true,
+			};
+		}
+		return { mergedNodes: baseNodes, positionsRestored: false };
+	}, [baseNodes, fingerprint, initialCookie]);
+
+	const [nodes, setNodes, onNodesChange] = useNodesState(mergedNodes);
+	const [edges, setEdges, onEdgesChange] = useEdgesState(baseEdges);
+
+	useEffect(() => {
+		setNodes(mergedNodes);
+	}, [mergedNodes, setNodes]);
+	useEffect(() => {
+		setEdges(baseEdges);
+	}, [baseEdges, setEdges]);
+
+	// Always reflect the latest nodes in a ref so the save handler is not stale.
+	const nodesRef = useRef(nodes);
+	nodesRef.current = nodes;
+
+	// Tracks the last data written so position-save and viewport-save don't clobber each other.
+	const cookieDataRef = useRef<Omit<PositionCookie, "fingerprint">>({ positions: {}, viewport: undefined });
+
+	// Once positions are known to be restored, seed the ref so viewport-only saves keep positions.
+	useEffect(() => {
+		if (positionsRestored && initialCookie) {
+			cookieDataRef.current = { positions: initialCookie.positions, viewport: initialCookie.viewport };
+		}
+	}, [positionsRestored, initialCookie]);
+
+	const writeCookie = useCallback(
+		(update: Partial<Omit<PositionCookie, "fingerprint">>) => {
+			cookieDataRef.current = { ...cookieDataRef.current, ...update };
+			setCookie(POSITIONS_COOKIE, { fingerprint, ...cookieDataRef.current } satisfies PositionCookie, {
+				path: "/",
+				maxAge: 30 * 24 * 60 * 60, // 30 days
+			});
+		},
+		[fingerprint, setCookie],
+	);
+
+	// Save positions to cookie when a drag ends.
+	const handleNodesChange = useCallback(
+		(changes: NodeChange[]) => {
+			onNodesChange(changes);
+			const hasDragEnd = changes.some((c) => c.type === "position" && c.dragging === false);
+			if (!hasDragEnd) return;
+
+			const posMap: Record<string, { x: number; y: number }> = {};
+			for (const n of nodesRef.current) posMap[n.id] = n.position;
+			// Apply the final positions from the change events themselves (state not yet flushed).
+			for (const c of changes) {
+				if (c.type === "position" && c.dragging === false && c.position) {
+					posMap[c.id] = c.position;
+				}
+			}
+			writeCookie({ positions: posMap });
+		},
+		[onNodesChange, writeCookie],
+	);
+
+	// Save viewport (pan + zoom) when the user stops moving.
+	const handleMoveEnd = useCallback(
+		(_: unknown, viewport: { x: number; y: number; zoom: number }) => {
+			writeCookie({ viewport });
+		},
+		[writeCookie],
+	);
+
+	// Reset all saved positions and re-fit to the computed default layout.
+	const handleResetLayout = useCallback(() => {
+		removeCookie(POSITIONS_COOKIE, { path: "/" });
+		cookieDataRef.current = { positions: {}, viewport: undefined };
+		setNodes(baseNodes);
+		setSelectedNodeId(null);
+		setSelectedEdgeId(null);
+		if (resetTimeoutRef.current) clearTimeout(resetTimeoutRef.current);
+		resetTimeoutRef.current = setTimeout(() => rfInstanceRef.current?.fitView({ padding: FIT_VIEW_PADDING, duration: 300 }), 50);
+	}, [baseNodes, removeCookie, setNodes]);
+
+	// ── Selection / path highlight ────────────────────────────────────────
+	const [selectedNodeId, setSelectedNodeId] = useState<string | null>(null);
+	const [selectedEdgeId, setSelectedEdgeId] = useState<string | null>(null);
+
+	/**
+	 * BFS up (forward edges only — skips chain-backs) to find all ancestors,
+	 * and BFS down (all edges including chain-backs) to find all descendants.
+	 * Chain-back edges are identified by their id ending in "-chain".
+	 */
+	const selectedHighlightIds = useMemo<Set<string> | null>(() => {
+		// Edge selection: highlight only the two endpoint nodes + the edge itself.
+		if (selectedEdgeId) {
+			const edge = edges.find((e) => e.id === selectedEdgeId);
+			if (!edge) return null;
+			return new Set<string>([edge.source, edge.target]);
+		}
+
+		if (!selectedNodeId) return null;
+
+		const childrenOf = new Map<string, string[]>();
+		const parentsOf = new Map<string, string[]>();
+		for (const e of edges) {
+			if (!childrenOf.has(e.source)) childrenOf.set(e.source, []);
+			childrenOf.get(e.source)!.push(e.target);
+			// Exclude chain-back edges from the ancestor map (they reverse flow direction).
+			if (!e.id.endsWith("-chain")) {
+				if (!parentsOf.has(e.target)) parentsOf.set(e.target, []);
+				parentsOf.get(e.target)!.push(e.source);
+			}
+		}
+
+		const highlighted = new Set<string>([selectedNodeId]);
+
+		const upQ = [selectedNodeId];
+		while (upQ.length) {
+			const id = upQ.pop()!;
+			for (const p of parentsOf.get(id) ?? []) {
+				if (!highlighted.has(p)) {
+					highlighted.add(p);
+					upQ.push(p);
+				}
+			}
+		}
+
+		const downQ = [selectedNodeId];
+		while (downQ.length) {
+			const id = downQ.pop()!;
+			for (const c of childrenOf.get(id) ?? []) {
+				if (!highlighted.has(c)) {
+					highlighted.add(c);
+					downQ.push(c);
+				}
+			}
+		}
+
+		return highlighted;
+	}, [selectedNodeId, selectedEdgeId, edges]);
+
+	const handleNodeClick = useCallback((_: React.MouseEvent, node: Node) => {
+		setSelectedEdgeId(null);
+		setSelectedNodeId((prev) => (prev === node.id ? null : node.id));
+	}, []);
+
+	const handleEdgeClick = useCallback((_: React.MouseEvent, edge: { id: string }) => {
+		setSelectedNodeId(null);
+		setSelectedEdgeId((prev) => (prev === edge.id ? null : edge.id));
+	}, []);
+
+	const handlePaneClick = useCallback(() => {
+		setSelectedNodeId(null);
+		setSelectedEdgeId(null);
+	}, []);
+
+	// ── Search / highlight ─────────────────────────────────────────────────
+	const [search, setSearch] = useState("");
+
+	/**
+	 * Returns null when search is empty (no filtering).
+	 * Returns an empty Set when there are no matches (dim everything).
+	 * Otherwise returns the set of node IDs that should stay visible:
+	 *   directly matching nodes + all their ancestors + all their descendants.
+	 */
+	const highlightedIds = useMemo<Set<string> | null>(() => {
+		const q = search.trim().toLowerCase();
+		if (!q) return null;
+
+		const childrenOf = new Map<string, string[]>();
+		const parentsOf = new Map<string, string[]>();
+		for (const e of edges) {
+			if (!childrenOf.has(e.source)) childrenOf.set(e.source, []);
+			childrenOf.get(e.source)!.push(e.target);
+			if (!parentsOf.has(e.target)) parentsOf.set(e.target, []);
+			parentsOf.get(e.target)!.push(e.source);
+		}
+
+		const matched = new Set<string>();
+		for (const n of nodes) {
+			const d = n.data as any;
+			const cond = (d?.condition as string | undefined)?.toLowerCase();
+			const ruleName = (d?.rule?.name as string | undefined)?.toLowerCase();
+			const ruleCel = (d?.rule?.cel_expression as string | undefined)?.toLowerCase();
+			if (cond?.includes(q) || ruleName?.includes(q) || ruleCel?.includes(q)) {
+				matched.add(n.id);
+			}
+		}
+
+		if (matched.size === 0) return new Set();
+
+		const highlighted = new Set<string>(matched);
+
+		// BFS upstream → source
+		const upQ = [...matched];
+		while (upQ.length) {
+			const id = upQ.pop()!;
+			for (const p of parentsOf.get(id) ?? []) {
+				if (!highlighted.has(p)) {
+					highlighted.add(p);
+					upQ.push(p);
+				}
+			}
+		}
+
+		// BFS downstream → rule leaves
+		const downQ = [...matched];
+		while (downQ.length) {
+			const id = downQ.pop()!;
+			for (const c of childrenOf.get(id) ?? []) {
+				if (!highlighted.has(c)) {
+					highlighted.add(c);
+					downQ.push(c);
+				}
+			}
+		}
+
+		return highlighted;
+	}, [search, nodes, edges]);
+
+	const matchCount = useMemo(() => {
+		if (!highlightedIds) return 0;
+		return nodes.filter((n) => n.type === "rfRule" && highlightedIds.has(n.id)).length;
+	}, [highlightedIds, nodes]);
+
+	// Selection takes priority; search acts as fallback when nothing is selected.
+	const activeHighlightIds = selectedHighlightIds ?? highlightedIds;
+
+	// Derived display nodes/edges — keeps opacity layered on top without
+	// disturbing drag state (positions stay in the underlying `nodes` state).
+	const displayNodes = useMemo(() => {
+		const h = activeHighlightIds;
+		const dimOpacity = selectedNodeId ? 0.12 : 0.25;
+		return nodes.map((n) => {
+			const isSelected = n.id === selectedNodeId;
+			if (!h) return { ...n, selected: isSelected };
+			const active = h.size > 0;
+			return {
+				...n,
+				selected: isSelected,
+				style: {
+					...n.style,
+					opacity: active && !h.has(n.id) ? dimOpacity : 1,
+					transition: "opacity 0.15s",
+				},
+			};
+		});
+	}, [nodes, activeHighlightIds, selectedNodeId]);
+
+	const displayEdges = useMemo(() => {
+		const h = activeHighlightIds;
+		const dimOpacity = selectedNodeId || selectedEdgeId ? 0.1 : 0.2;
+		if (!h) return edges;
+		const active = h.size > 0;
+		return edges.map((e) => {
+			const endpointsLit = h.has(e.source) && h.has(e.target);
+			const isSelectedEdge = e.id === selectedEdgeId;
+			const lit = endpointsLit || isSelectedEdge;
+			return {
+				...e,
+				style: {
+					...e.style,
+					opacity: active && !lit ? dimOpacity : 1,
+					transition: "opacity 0.15s",
+				},
+			};
+		});
+	}, [edges, activeHighlightIds, selectedNodeId, selectedEdgeId]);
+
+	if (isLoading) {
+		return (
+			<div className="flex h-full items-center justify-center">
+				<Loader2 className="text-muted-foreground h-6 w-6 animate-spin" />
+			</div>
+		);
+	}
+	if (isError) {
+		return (
+			<div className="text-muted-foreground flex h-full items-center justify-center gap-2">
+				<AlertCircle className="h-5 w-5" />
+				<span className="text-sm">Failed to load routing rules</span>
+			</div>
+		);
+	}
+	if (rules.length === 0) {
+		return (
+			<div className="text-muted-foreground flex h-full flex-col items-center justify-center gap-3">
+				<GitBranch className="h-10 w-10 opacity-20" />
+				<p className="text-sm">No routing rules to display</p>
+				<Button
+					variant="outline"
+					size="sm"
+					data-testid="routing-tree-back-empty-btn"
+					onClick={() => navigate({ to: "/workspace/routing-rules" })}
+				>
+					<ArrowLeft className="mr-1.5 h-4 w-4" />
+					Back to rules
+				</Button>
+			</div>
+		);
+	}
+
+	return (
+		<ReactFlow
+			nodes={displayNodes}
+			edges={displayEdges}
+			onNodesChange={handleNodesChange}
+			onEdgesChange={onEdgesChange}
+			onNodeClick={handleNodeClick}
+			onEdgeClick={handleEdgeClick}
+			onPaneClick={handlePaneClick}
+			onInit={(instance) => {
+				rfInstanceRef.current = instance;
+			}}
+			nodeTypes={nodeTypes}
+			edgeTypes={edgeTypes}
+			fitView={!positionsRestored}
+			fitViewOptions={{ padding: FIT_VIEW_PADDING }}
+			defaultViewport={positionsRestored ? (initialCookie?.viewport ?? { x: 0, y: 0, zoom: 1 }) : undefined}
+			onMoveEnd={handleMoveEnd}
+			nodesDraggable={true}
+			nodesConnectable={false}
+			elementsSelectable={true}
+			zoomOnDoubleClick={false}
+			proOptions={{ hideAttribution: true }}
+		>
+			<Background variant={BackgroundVariant.Dots} gap={20} size={1} color="var(--border)" />
+			<Controls showInteractive={false} />
+
+			<Panel position="top-left">
+				<div className="flex flex-col gap-2">
+					{/* Main toolbar */}
+					<div className="dark:bg-card flex items-center gap-3 rounded-md border bg-white px-4 py-2.5 shadow-sm">
+						<Button
+							variant="ghost"
+							size="sm"
+							className="-ml-1 gap-1.5 !pl-0 hover:bg-transparent"
+							data-testid="routing-tree-back-toolbar-btn"
+							onClick={() => navigate({ to: "/workspace/routing-rules" })}
+						>
+							<ArrowLeft className="h-4 w-4" />
+							Back
+						</Button>
+						<div className="bg-border h-5 w-px" />
+						<div className="flex items-center gap-2">
+							<GitBranch className="text-muted-foreground h-4 w-4" />
+							<p className="text-foreground text-sm leading-tight font-semibold">Routing Tree</p>
+							<p className="text-muted-foreground text-[11px]">
+								{search
+									? highlightedIds && highlightedIds.size > 0
+										? `${matchCount} rule${matchCount !== 1 ? "s" : ""}`
+										: "no match"
+									: `${rules.length} rule${rules.length !== 1 ? "s" : ""}`}
+							</p>
+						</div>
+						<div className="bg-border h-5 w-px" />
+						<div className="relative">
+							<Search className="text-muted-foreground absolute top-1/2 left-2.5 h-3.5 w-3.5 -translate-y-1/2" />
+							<Input
+								value={search}
+								onChange={(e) => setSearch(e.target.value)}
+								placeholder="Search conditions or rules…"
+								className="h-8 w-56 pl-8 text-sm"
+							/>
+						</div>
+						<div className="bg-border h-5 w-px" />
+						<Button
+							variant="ghost"
+							size="sm"
+							className="text-muted-foreground hover:text-foreground gap-1.5"
+							onClick={handleResetLayout}
+							title="Reset to default layout"
+							data-testid="routing-tree-reset-layout-btn"
+						>
+							<RotateCcw className="h-3.5 w-3.5" />
+							Reset layout
+						</Button>
+					</div>
+					{/* Scope + edge legend — floats below */}
+					<div className="dark:bg-card flex items-center gap-3 rounded-md border bg-white px-3 py-1.5 shadow-sm">
+						{SCOPE_ORDER.map((s) => (
+							<div key={s} className="flex items-center gap-1.5">
+								<span className="h-2 w-2 rounded-full" style={{ backgroundColor: SCOPE_CONFIG[s].color }} />
+								<span className="text-muted-foreground text-[10px] font-medium">{SCOPE_CONFIG[s].label}</span>
+							</div>
+						))}
+						<div className="bg-border h-3 w-px" />
+						<div className="flex items-center gap-1.5">
+							<Link2 className="text-muted-foreground h-2.5 w-2.5" />
+							<span className="text-muted-foreground text-[10px] font-medium">Chain rule</span>
+						</div>
+						<div className="bg-border h-3 w-px" />
+						{/* Chain edge styles — both dashed (long = static, short = dynamic); arrows at path midpoint */}
+						<div className="flex items-center gap-1.5">
+							<svg width="40" height="12" className="shrink-0" aria-hidden>
+								<line
+									x1="2"
+									y1="6"
+									x2="38"
+									y2="6"
+									stroke="var(--muted-foreground)"
+									strokeWidth="1.5"
+									strokeDasharray="14 10"
+									strokeLinecap="round"
+								/>
+								<polygon points="20,6 14,2.5 14,9.5" fill="var(--muted-foreground)" />
+							</svg>
+							<span className="text-muted-foreground text-[10px] font-medium">Static chain</span>
+							<Tooltip>
+								<TooltipTrigger asChild>
+									<Info
+										className="text-muted-foreground/60 h-2.5 w-2.5 cursor-default"
+										data-testid="routing-tree-static-chain-info-trigger"
+									/>
+								</TooltipTrigger>
+								<TooltipContent side="top" className="max-w-[200px] text-center">
+									Re-entry point is fully proven by static analysis — every condition on the path evaluated to a known value.
+								</TooltipContent>
+							</Tooltip>
+						</div>
+						<div className="flex items-center gap-1.5">
+							<svg width="40" height="12" className="shrink-0 overflow-visible" aria-hidden>
+								<line
+									className="rf-chain-legend-dynamic-dash"
+									x1="2"
+									y1="6"
+									x2="38"
+									y2="6"
+									stroke="var(--muted-foreground)"
+									strokeWidth="1.5"
+									strokeDasharray="3 5"
+									strokeLinecap="round"
+								/>
+								<polyline
+									points="14,2.5 26,6 14,9.5"
+									fill="none"
+									stroke="var(--muted-foreground)"
+									strokeWidth="1.5"
+									strokeLinecap="round"
+									strokeLinejoin="round"
+								/>
+							</svg>
+							<span className="text-muted-foreground text-[10px] font-medium">Dynamic chain</span>
+							<Tooltip>
+								<TooltipTrigger asChild>
+									<Info
+										className="text-muted-foreground/60 h-2.5 w-2.5 cursor-default"
+										data-testid="routing-tree-dynamic-chain-info-trigger"
+									/>
+								</TooltipTrigger>
+								<TooltipContent side="top" className="max-w-[200px] text-center">
+									Re-entry point is a conditional — one or more conditions on the path are not fully evaluated at build time.
+								</TooltipContent>
+							</Tooltip>
+						</div>
+					</div>
+				</div>
+			</Panel>
+		</ReactFlow>
+	);
+}