diff --git a/packages/api/src/router/estimate-demand-lines.ts b/packages/api/src/router/estimate-demand-lines.ts
new file mode 100644
index 0000000..1682e09
--- /dev/null
+++ b/packages/api/src/router/estimate-demand-lines.ts
@@ -0,0 +1,160 @@
+import { normalizeEstimateDemandLine, summarizeEstimateDemandLines } from "@capakraken/engine";
+import { CreateEstimateSchema } from "@capakraken/shared";
+import { z } from "zod";
+import { lookupRate } from "../lib/rate-card-lookup.js";
+
+function buildComputedMetrics(
+  demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"],
+) {
+  const summary = summarizeEstimateDemandLines(demandLines);
+
+  return [
+    {
+      key: "total_hours",
+      label: "Total Hours",
+      metricGroup: "summary",
+      valueDecimal: summary.totalHours,
+      metadata: {},
+    },
+    {
+      key: "total_cost",
+      label: "Total Cost",
+      metricGroup: "summary",
+      valueDecimal: summary.totalCostCents / 100,
+      valueCents: summary.totalCostCents,
+      currency: demandLines[0]?.currency ?? "EUR",
+      metadata: {},
+    },
+    {
+      key: "total_price",
+      label: "Total Price",
+      metricGroup: "summary",
+      valueDecimal: summary.totalPriceCents / 100,
+      valueCents: summary.totalPriceCents,
+      currency: demandLines[0]?.currency ?? "EUR",
+      metadata: {},
+    },
+    {
+      key: "margin",
+      label: "Margin",
+      metricGroup: "summary",
+      valueDecimal: summary.marginCents / 100,
+      valueCents: summary.marginCents,
+      currency: demandLines[0]?.currency ?? "EUR",
+      metadata: {},
+    },
+    {
+      key: "margin_percent",
+      label: "Margin %",
+      metricGroup: "summary",
+      valueDecimal: summary.marginPercent,
+      metadata: {},
+    },
+  ];
+}
+
+function normalizeDemandLines<
+  T extends {
+    demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
+    resourceSnapshots: z.infer<typeof CreateEstimateSchema>["resourceSnapshots"];
+  },
+>(input: T, baseCurrency: string) {
+  const snapshotsByResourceId = new Map(
+    input.resourceSnapshots
+      .filter(
+        (snapshot): snapshot is (typeof input.resourceSnapshots)[number] & {
+          resourceId: string;
+        } => typeof snapshot.resourceId === "string" && snapshot.resourceId.length > 0,
+      )
+      .map((snapshot) => [snapshot.resourceId, snapshot]),
+  );
+
+  return input.demandLines.map((line) =>
+    normalizeEstimateDemandLine(line, {
+      resourceSnapshot:
+        line.resourceId != null ? snapshotsByResourceId.get(line.resourceId) : null,
+      defaultCurrency: baseCurrency,
+    }),
+  );
+}
+
+export function withComputedMetrics<
+  T extends {
+    demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
+    resourceSnapshots: z.infer<typeof CreateEstimateSchema>["resourceSnapshots"];
+    metrics: z.infer<typeof CreateEstimateSchema>["metrics"];
+  },
+>(input: T, baseCurrency: string) {
+  const normalizedDemandLines = normalizeDemandLines(input, baseCurrency);
+  const computedMetrics = buildComputedMetrics(normalizedDemandLines);
+  const computedKeys = new Set(computedMetrics.map((metric) => metric.key));
+
+  return {
+    ...input,
+    demandLines: normalizedDemandLines,
+    metrics: [
+      ...input.metrics.filter((metric) => !computedKeys.has(metric.key)),
+      ...computedMetrics,
+    ],
+  };
+}
+
+export async function autoFillDemandLineRates(
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  db: any,
+  demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"],
+  projectId?: string | null,
+): Promise<{
+  demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
+  autoFilledIndices: number[];
+}> {
+  let clientId: string | null = null;
+  if (projectId) {
+    const project = await db.project.findUnique({
+      where: { id: projectId },
+      select: { clientId: true },
+    });
+    clientId = project?.clientId ?? null;
+  }
+
+  const autoFilledIndices: number[] = [];
+  const enriched = await Promise.all(
+    demandLines.map(async (line, index) => {
+      const isDefaultRate = line.costRateCents === 0 && line.billRateCents === 0;
+      const hasExplicitSource = line.rateSource != null && line.rateSource.length > 0;
+      if (!isDefaultRate || hasExplicitSource) {
+        return line;
+      }
+
+      const result = await lookupRate(db, {
+        clientId,
+        chapter: line.chapter ?? null,
+        roleId: line.roleId ?? null,
+      });
+      if (!result) {
+        return line;
+      }
+
+      autoFilledIndices.push(index);
+      const existingMetadata = (line.metadata ?? {}) as Record<string, unknown>;
+      return {
+        ...line,
+        costRateCents: result.costRateCents,
+        billRateCents: result.billRateCents,
+        currency: result.currency,
+        rateSource: `rate-card:${result.rateCardId}`,
+        metadata: {
+          ...existingMetadata,
+          autoAppliedRateCard: {
+            rateCardId: result.rateCardId,
+            rateCardLineId: result.rateCardLineId,
+            rateCardName: result.rateCardName,
+            appliedAt: new Date().toISOString(),
+          },
+        },
+      };
+    }),
+  );
+
+  return { demandLines: enriched, autoFilledIndices };
+}
diff --git a/packages/api/src/router/estimate.ts b/packages/api/src/router/estimate.ts
index 2cf93eb..6c108f5 100644
--- a/packages/api/src/router/estimate.ts
+++ b/packages/api/src/router/estimate.ts
@@ -7,10 +7,6 @@ import {
   updateEstimateDraft,
 } from "@capakraken/application";
 import type { Prisma } from "@capakraken/db";
-import {
-  normalizeEstimateDemandLine,
-  summarizeEstimateDemandLines,
-} from "@capakraken/engine";
 import {
   CloneEstimateSchema,
   CreateEstimateExportSchema,
@@ -31,6 +27,10 @@ import {
 } from "../trpc.js";
 import { emitAllocationCreated } from "../sse/event-bus.js";
 import { estimateCommercialProcedures } from "./estimate-commercial.js";
+import {
+  autoFillDemandLineRates,
+  withComputedMetrics,
+} from "./estimate-demand-lines.js";
 import { estimatePhasingProcedures } from "./estimate-phasing.js";
 import { estimateReadProcedures } from "./estimate-read.js";
 import { estimateVersionWorkflowProcedures } from "./estimate-version-workflow.js";
@@ -67,171 +67,6 @@ function rethrowEstimateRouterError(
   throw error;
 }
 
-function buildComputedMetrics(
-  demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"],
-) {
-  const summary = summarizeEstimateDemandLines(demandLines);
-
-  return [
-    {
-      key: "total_hours",
-      label: "Total Hours",
-      metricGroup: "summary",
-      valueDecimal: summary.totalHours,
-      metadata: {},
-    },
-    {
-      key: "total_cost",
-      label: "Total Cost",
-      metricGroup: "summary",
-      valueDecimal: summary.totalCostCents / 100,
-      valueCents: summary.totalCostCents,
-      currency: demandLines[0]?.currency ?? "EUR",
-      metadata: {},
-    },
-    {
-      key: "total_price",
-      label: "Total Price",
-      metricGroup: "summary",
-      valueDecimal: summary.totalPriceCents / 100,
-      valueCents: summary.totalPriceCents,
-      currency: demandLines[0]?.currency ?? "EUR",
-      metadata: {},
-    },
-    {
-      key: "margin",
-      label: "Margin",
-      metricGroup: "summary",
-      valueDecimal: summary.marginCents / 100,
-      valueCents: summary.marginCents,
-      currency: demandLines[0]?.currency ?? "EUR",
-      metadata: {},
-    },
-    {
-      key: "margin_percent",
-      label: "Margin %",
-      metricGroup: "summary",
-      valueDecimal: summary.marginPercent,
-      metadata: {},
-    },
-  ];
-}
-
-function normalizeDemandLines<
-  T extends {
-    demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
-    resourceSnapshots: z.infer<typeof CreateEstimateSchema>["resourceSnapshots"];
-  },
->(input: T, baseCurrency: string) {
-  const snapshotsByResourceId = new Map(
-    input.resourceSnapshots
-      .filter(
-        (snapshot): snapshot is (typeof input.resourceSnapshots)[number] & {
-          resourceId: string;
-        } => typeof snapshot.resourceId === "string" && snapshot.resourceId.length > 0,
-      )
-      .map((snapshot) => [snapshot.resourceId, snapshot]),
-  );
-
-  return input.demandLines.map((line) =>
-    normalizeEstimateDemandLine(line, {
-      resourceSnapshot:
-        line.resourceId != null ? snapshotsByResourceId.get(line.resourceId) : null,
-      defaultCurrency: baseCurrency,
-    }),
-  );
-}
-
-function withComputedMetrics<
-  T extends {
-    demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
-    resourceSnapshots: z.infer<typeof CreateEstimateSchema>["resourceSnapshots"];
-    metrics: z.infer<typeof CreateEstimateSchema>["metrics"];
-  },
->(input: T, baseCurrency: string) {
-  const normalizedDemandLines = normalizeDemandLines(input, baseCurrency);
-  const computedMetrics = buildComputedMetrics(normalizedDemandLines);
-  const computedKeys = new Set(computedMetrics.map((metric) => metric.key));
-
-  return {
-    ...input,
-    demandLines: normalizedDemandLines,
-    metrics: [
-      ...input.metrics.filter((metric) => !computedKeys.has(metric.key)),
-      ...computedMetrics,
-    ],
-  };
-}
-
-/**
- * Auto-fill rate card rates into demand lines that have default (zero) rates.
- * A line is eligible for auto-fill when both costRateCents and billRateCents
- * are 0 (the Zod default) and rateSource is not explicitly set.
- *
- * Returns the enriched demand lines and a list of line indices that were auto-filled.
- */
-async function autoFillDemandLineRates(
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  db: any,
-  demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"],
-  projectId?: string | null,
-): Promise<{
-  demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
-  autoFilledIndices: number[];
-}> {
-  // Resolve clientId from the linked project
-  let clientId: string | null = null;
-  if (projectId) {
-    const project = await db.project.findUnique({
-      where: { id: projectId },
-      select: { clientId: true },
-    });
-    clientId = project?.clientId ?? null;
-  }
-
-  const autoFilledIndices: number[] = [];
-
-  const enriched = await Promise.all(
-    demandLines.map(async (line, index) => {
-      // Only auto-fill if both rates are at default (0) and no explicit rateSource
-      const isDefaultRate = line.costRateCents === 0 && line.billRateCents === 0;
-      const hasExplicitSource = line.rateSource != null && line.rateSource.length > 0;
-
-      if (!isDefaultRate || hasExplicitSource) return line;
-
-      const result = await lookupRate(db, {
-        clientId,
-        chapter: line.chapter ?? null,
-        roleId: line.roleId ?? null,
-      });
-
-      if (!result) return line;
-
-      autoFilledIndices.push(index);
-
-      const existingMetadata = (line.metadata ?? {}) as Record<string, unknown>;
-      return {
-        ...line,
-        costRateCents: result.costRateCents,
-        billRateCents: result.billRateCents,
-        currency: result.currency,
-        rateSource: `rate-card:${result.rateCardId}`,
-        metadata: {
-          ...existingMetadata,
-          autoAppliedRateCard: {
-            rateCardId: result.rateCardId,
-            rateCardLineId: result.rateCardLineId,
-            rateCardName: result.rateCardName,
-            appliedAt: new Date().toISOString(),
-          },
-        },
-      };
-    }),
-  );
-
-  return { demandLines: enriched, autoFilledIndices };
-}
-
 export const estimateRouter = createTRPCRouter({
   ...estimateReadProcedures,
   ...estimateCommercialProcedures,