diff --git a/docs/spec/revit-csv-phase-14-audit-and-plan.md b/docs/spec/revit-csv-phase-14-audit-and-plan.md
index 88ef0cb..8ce675b 100644
--- a/docs/spec/revit-csv-phase-14-audit-and-plan.md
+++ b/docs/spec/revit-csv-phase-14-audit-and-plan.md
@@ -2,9 +2,10 @@
 
 ## Status
 
-Phase 14.0 ist abgeschlossen. Dieses Dokument beschreibt den gegen den aktuellen
-Code geprüften Zielzuschnitt. Die Laufzeitimplementierung beginnt gemäß der
-verbindlichen Revit-Spezifikation erst nach Freigabe dieses Audits.
+Phase 14.0 ist abgeschlossen und freigegeben. Dieses Dokument beschreibt den
+gegen den aktuellen Code geprüften Zielzuschnitt. Phase 14.1 befindet sich in
+Umsetzung; ihre reinen Transportverträge und Konfigurationsvalidatoren sind
+vorhanden.
 
 Fachliche Quelle bleibt
 [Revit-CSV-Integration – Anforderungen und Implementierungsanweisung](revit-csv-integration-requirements.md).
@@ -240,7 +241,8 @@ keine Projektrevision und laufen über einen eigenen Audit-Store.
 ### 14.1 – CSV-Konfiguration und reine Vorschau
 
 1. Transport-Domainverträge, Dialekt- und Mappingvalidatoren sowie kleine
-   synthetische Fixtures ergänzen.
+   synthetische Fixtures ergänzen. **Erledigt:** Verträge und Validatoren;
+   Parser-Fixtures folgen gemeinsam mit dem Parser.
 2. Zustandsfreien Parser und Serializer mit Round-trip-Tests für UTF-8-BOM,
    CRLF, Semikolon, vollständige Quotierung, Kopfzeile in Zeile 2 sowie
    Titel-, Leer-, Objekt- und Passthrough-Zeilen implementieren.
diff --git a/src/external-model/csv/external-csv-configuration.ts b/src/external-model/csv/external-csv-configuration.ts
new file mode 100644
index 0000000..83e1c24
--- /dev/null
+++ b/src/external-model/csv/external-csv-configuration.ts
@@ -0,0 +1,185 @@
+import {
+  externalCsvConfigurationSchemaVersion,
+  type ExternalCsvConfiguration,
+  type ExternalCsvDisplayNameSuggestion,
+  type ExternalCsvQuantityRule,
+} from "./external-csv-contracts.js";
+
+const supportedCategories = new Set([
+  "lighting",
+  "single_phase",
+  "three_phase",
+]);
+
+const requiredColumnKeys = [
+  "ifcGuid",
+  "roomNumber",
+  "roomName",
+  "familyAndType",
+  "selectionMarker",
+  "circuitIdentifier",
+  "power",
+  "quantity",
+] as const;
+
+export function assertExternalCsvConfiguration(
+  value: unknown
+): asserts value is ExternalCsvConfiguration {
+  if (!isRecord(value)) {
+    throw new Error("External CSV configuration must be an object.");
+  }
+  if (value.schemaVersion !== externalCsvConfigurationSchemaVersion) {
+    throw new Error("Unsupported external CSV configuration schema version.");
+  }
+  if (value.encoding !== "utf-8") {
+    throw new Error("External CSV encoding must be utf-8.");
+  }
+  if (value.delimiter !== ";" && value.delimiter !== "," && value.delimiter !== "\t") {
+    throw new Error("External CSV delimiter is unsupported.");
+  }
+  if (value.decimalSeparator !== "," && value.decimalSeparator !== ".") {
+    throw new Error("External CSV decimal separator is unsupported.");
+  }
+  if (value.powerUnit !== "W" && value.powerUnit !== "kW") {
+    throw new Error("External CSV power unit is unsupported.");
+  }
+  assertPositiveFiniteNumber(value.wattsPerSourceUnit, "wattsPerSourceUnit");
+
+  if (!isRecord(value.columns)) {
+    throw new Error("External CSV columns must be an object.");
+  }
+  const mappedColumns = new Set<string>();
+  for (const key of requiredColumnKeys) {
+    const columnName = assertTrimmedString(value.columns[key], `columns.${key}`);
+    if (mappedColumns.has(columnName)) {
+      throw new Error(`External CSV column is mapped more than once: ${columnName}`);
+    }
+    mappedColumns.add(columnName);
+  }
+
+  if (!Array.isArray(value.additionalSourceMappings)) {
+    throw new Error("External CSV additional source mappings must be an array.");
+  }
+  const targetFields = new Set<string>();
+  for (const [index, mapping] of value.additionalSourceMappings.entries()) {
+    if (!isRecord(mapping)) {
+      throw new Error(`additionalSourceMappings.${index} must be an object.`);
+    }
+    const sourceColumn = assertTrimmedString(
+      mapping.sourceColumn,
+      `additionalSourceMappings.${index}.sourceColumn`
+    );
+    const targetField = assertTrimmedString(
+      mapping.targetField,
+      `additionalSourceMappings.${index}.targetField`
+    );
+    if (mappedColumns.has(sourceColumn)) {
+      throw new Error(`External CSV column is mapped more than once: ${sourceColumn}`);
+    }
+    if (targetFields.has(targetField)) {
+      throw new Error(`External target field is mapped more than once: ${targetField}`);
+    }
+    mappedColumns.add(sourceColumn);
+    targetFields.add(targetField);
+  }
+
+  if (!Array.isArray(value.familyTypeRules)) {
+    throw new Error("External CSV family/type rules must be an array.");
+  }
+  const exactFamilyValues = new Set<string>();
+  for (const [index, rule] of value.familyTypeRules.entries()) {
+    if (!isRecord(rule)) {
+      throw new Error(`familyTypeRules.${index} must be an object.`);
+    }
+    const exactFamilyAndType = assertTrimmedString(
+      rule.exactFamilyAndType,
+      `familyTypeRules.${index}.exactFamilyAndType`
+    );
+    if (exactFamilyValues.has(exactFamilyAndType)) {
+      throw new Error(
+        `External CSV family/type rule is duplicated: ${exactFamilyAndType}`
+      );
+    }
+    exactFamilyValues.add(exactFamilyAndType);
+    assertTrimmedString(
+      rule.internalDeviceType,
+      `familyTypeRules.${index}.internalDeviceType`
+    );
+    if (rule.connectionKind !== null) {
+      assertTrimmedString(
+        rule.connectionKind,
+        `familyTypeRules.${index}.connectionKind`
+      );
+    }
+    if (typeof rule.category !== "string" || !supportedCategories.has(rule.category)) {
+      throw new Error(`familyTypeRules.${index}.category is unsupported.`);
+    }
+    assertQuantityRule(rule.quantityRule, index);
+    assertDisplayNameSuggestion(rule.displayNameSuggestion, index);
+  }
+}
+
+export function validateExternalCsvConfiguration(
+  value: unknown
+): { success: true; data: ExternalCsvConfiguration } | { success: false; error: string } {
+  try {
+    assertExternalCsvConfiguration(value);
+    return { success: true, data: value };
+  } catch (error) {
+    return {
+      success: false,
+      error: error instanceof Error ? error.message : "Invalid external CSV configuration.",
+    };
+  }
+}
+
+function assertQuantityRule(value: unknown, index: number): asserts value is ExternalCsvQuantityRule {
+  if (!isRecord(value)) {
+    throw new Error(`familyTypeRules.${index}.quantityRule must be an object.`);
+  }
+  if (value.kind === "mapped-column") {
+    return;
+  }
+  if (value.kind === "fixed") {
+    assertPositiveFiniteNumber(value.quantity, `familyTypeRules.${index}.quantityRule.quantity`);
+    return;
+  }
+  throw new Error(`familyTypeRules.${index}.quantityRule is unsupported.`);
+}
+
+function assertDisplayNameSuggestion(
+  value: unknown,
+  index: number
+): asserts value is ExternalCsvDisplayNameSuggestion | null {
+  if (value === null) {
+    return;
+  }
+  if (!isRecord(value)) {
+    throw new Error(`familyTypeRules.${index}.displayNameSuggestion must be an object or null.`);
+  }
+  if (value.kind === "selection-marker" || value.kind === "family-and-type") {
+    return;
+  }
+  if (value.kind === "fixed") {
+    assertTrimmedString(value.value, `familyTypeRules.${index}.displayNameSuggestion.value`);
+    return;
+  }
+  throw new Error(`familyTypeRules.${index}.displayNameSuggestion is unsupported.`);
+}
+
+function assertPositiveFiniteNumber(value: unknown, field: string) {
+  if (typeof value !== "number" || !Number.isFinite(value) || value <= 0) {
+    throw new Error(`${field} must be a positive finite number.`);
+  }
+}
+
+function assertTrimmedString(value: unknown, field: string) {
+  if (typeof value !== "string" || !value.trim() || value !== value.trim()) {
+    throw new Error(`${field} must be a non-empty trimmed string.`);
+  }
+  return value;
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return value !== null && typeof value === "object" && !Array.isArray(value);
+}
diff --git a/src/external-model/csv/external-csv-contracts.ts b/src/external-model/csv/external-csv-contracts.ts
new file mode 100644
index 0000000..e2d033c
--- /dev/null
+++ b/src/external-model/csv/external-csv-contracts.ts
@@ -0,0 +1,106 @@
+import type { CircuitGroupCategory } from "../../shared/constants/circuit-group.js";
+
+export const externalCsvConfigurationSchemaVersion = 1 as const;
+
+export type ExternalCsvEncoding = "utf-8";
+export type ExternalCsvDelimiter = ";" | "," | "\t";
+export type ExternalCsvDecimalSeparator = "," | ".";
+export type ExternalCsvPowerUnit = "W" | "kW";
+
+export interface ExternalCsvColumnMapping {
+  ifcGuid: string;
+  roomNumber: string;
+  roomName: string;
+  familyAndType: string;
+  selectionMarker: string;
+  circuitIdentifier: string;
+  power: string;
+  quantity: string;
+}
+
+export interface ExternalCsvAdditionalSourceMapping {
+  sourceColumn: string;
+  targetField: string;
+}
+
+export type ExternalCsvQuantityRule =
+  | { kind: "fixed"; quantity: number }
+  | { kind: "mapped-column" };
+
+export type ExternalCsvDisplayNameSuggestion =
+  | { kind: "fixed"; value: string }
+  | { kind: "selection-marker" }
+  | { kind: "family-and-type" };
+
+export interface ExternalCsvFamilyTypeRule {
+  exactFamilyAndType: string;
+  internalDeviceType: string;
+  connectionKind: string | null;
+  category: CircuitGroupCategory;
+  quantityRule: ExternalCsvQuantityRule;
+  displayNameSuggestion: ExternalCsvDisplayNameSuggestion | null;
+}
+
+export interface ExternalCsvConfiguration {
+  schemaVersion: typeof externalCsvConfigurationSchemaVersion;
+  encoding: ExternalCsvEncoding;
+  delimiter: ExternalCsvDelimiter;
+  decimalSeparator: ExternalCsvDecimalSeparator;
+  powerUnit: ExternalCsvPowerUnit;
+  wattsPerSourceUnit: number;
+  columns: ExternalCsvColumnMapping;
+  additionalSourceMappings: ExternalCsvAdditionalSourceMapping[];
+  familyTypeRules: ExternalCsvFamilyTypeRule[];
+}
+
+export type ExternalCsvLineEnding = "\r\n" | "\n" | "\r";
+
+export interface ExternalCsvDialect {
+  encoding: ExternalCsvEncoding;
+  hasBom: boolean;
+  delimiter: ExternalCsvDelimiter;
+  lineEnding: ExternalCsvLineEnding;
+  quoteCharacter: '"';
+  quoteAllFields: boolean;
+  hasTrailingLineEnding: boolean;
+}
+
+export interface ExternalCsvCell {
+  value: string;
+  wasQuoted: boolean;
+}
+
+export type ExternalCsvRowClassification =
+  | "metadata"
+  | "header"
+  | "passthrough"
+  | "object"
+  | "suspect-object";
+
+export interface ExternalCsvRow {
+  index: number;
+  cells: ExternalCsvCell[];
+  classification: ExternalCsvRowClassification;
+}
+
+export interface ExternalCsvDocument {
+  dialect: ExternalCsvDialect;
+  headerRowIndex: number;
+  rows: ExternalCsvRow[];
+}
+
+export function createDefaultExternalCsvConfiguration(
+  columns: ExternalCsvColumnMapping
+): ExternalCsvConfiguration {
+  return {
+    schemaVersion: externalCsvConfigurationSchemaVersion,
+    encoding: "utf-8",
+    delimiter: ";",
+    decimalSeparator: ",",
+    powerUnit: "W",
+    wattsPerSourceUnit: 1,
+    columns,
+    additionalSourceMappings: [],
+    familyTypeRules: [],
+  };
+}
diff --git a/tests/external-csv-configuration.test.ts b/tests/external-csv-configuration.test.ts
new file mode 100644
index 0000000..19411ee
--- /dev/null
+++ b/tests/external-csv-configuration.test.ts
@@ -0,0 +1,112 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import {
+  createDefaultExternalCsvConfiguration,
+  type ExternalCsvColumnMapping,
+} from "../src/external-model/csv/external-csv-contracts.js";
+import {
+  assertExternalCsvConfiguration,
+  validateExternalCsvConfiguration,
+} from "../src/external-model/csv/external-csv-configuration.js";
+
+const columns: ExternalCsvColumnMapping = {
+  ifcGuid: "IfcGUID",
+  roomNumber: "Raumnummer",
+  roomName: "Raumname",
+  familyAndType: "Familie und Typ",
+  selectionMarker: "CAx_Auswahlkenner",
+  circuitIdentifier: "Stromkreis",
+  power: "Elektrische Leistung",
+  quantity: "Anzahl",
+};
+
+describe("external CSV configuration", () => {
+  it("creates the agreed UTF-8, semicolon and watt defaults", () => {
+    const configuration = createDefaultExternalCsvConfiguration(columns);
+
+    assert.doesNotThrow(() => assertExternalCsvConfiguration(configuration));
+    assert.equal(configuration.encoding, "utf-8");
+    assert.equal(configuration.delimiter, ";");
+    assert.equal(configuration.powerUnit, "W");
+    assert.equal(configuration.wattsPerSourceUnit, 1);
+  });
+
+  it("accepts exact family/type rules and additional source mappings", () => {
+    const configuration = createDefaultExternalCsvConfiguration(columns);
+    configuration.additionalSourceMappings.push({
+      sourceColumn: "Montageart",
+      targetField: "mountingType",
+    });
+    configuration.familyTypeRules.push({
+      exactFamilyAndType: "_E_CAx Mehrfachsteckdose: Doppelsteckdose",
+      internalDeviceType: "Steckdose",
+      connectionKind: "socket",
+      category: "single_phase",
+      quantityRule: { kind: "mapped-column" },
+      displayNameSuggestion: { kind: "selection-marker" },
+    });
+
+    assert.deepEqual(validateExternalCsvConfiguration(configuration), {
+      success: true,
+      data: configuration,
+    });
+  });
+
+  it("rejects ambiguous column and family/type mappings", () => {
+    const duplicateColumn = createDefaultExternalCsvConfiguration({
+      ...columns,
+      quantity: columns.power,
+    });
+    assert.match(
+      validateFailure(duplicateColumn),
+      /column is mapped more than once/
+    );
+
+    const duplicateRule = createDefaultExternalCsvConfiguration(columns);
+    duplicateRule.familyTypeRules = [
+      {
+        exactFamilyAndType: "Leuchte: Standard",
+        internalDeviceType: "Leuchte",
+        connectionKind: null,
+        category: "lighting",
+        quantityRule: { kind: "fixed", quantity: 1 },
+        displayNameSuggestion: null,
+      },
+      {
+        exactFamilyAndType: "Leuchte: Standard",
+        internalDeviceType: "Leuchte",
+        connectionKind: null,
+        category: "lighting",
+        quantityRule: { kind: "fixed", quantity: 1 },
+        displayNameSuggestion: null,
+      },
+    ];
+    assert.match(
+      validateFailure(duplicateRule),
+      /family\/type rule is duplicated/
+    );
+  });
+
+  it("rejects unsupported transport values and invalid fixed quantities", () => {
+    const configuration = createDefaultExternalCsvConfiguration(columns) as unknown as Record<string, unknown>;
+    configuration.encoding = "ansi";
+    assert.match(validateFailure(configuration), /encoding must be utf-8/);
+
+    const invalidQuantity = createDefaultExternalCsvConfiguration(columns);
+    invalidQuantity.familyTypeRules.push({
+      exactFamilyAndType: "Steckdose: Standard",
+      internalDeviceType: "Steckdose",
+      connectionKind: null,
+      category: "single_phase",
+      quantityRule: { kind: "fixed", quantity: 0 },
+      displayNameSuggestion: { kind: "fixed", value: "Steckdose" },
+    });
+    assert.match(validateFailure(invalidQuantity), /positive finite number/);
+  });
+});
+
+function validateFailure(value: unknown) {
+  const result = validateExternalCsvConfiguration(value);
+  assert.equal(result.success, false);
+  return result.error;
+}