diff --git a/packages/api/package.json b/packages/api/package.json
new file mode 100644
index 0000000..42c7511
--- /dev/null
+++ b/packages/api/package.json
@@ -0,0 +1,10 @@
+{
+  "name": "@trails-cool/api",
+  "private": true,
+  "version": "0.0.1",
+  "type": "module",
+  "main": "src/index.ts",
+  "dependencies": {
+    "zod": "^3.25.0"
+  }
+}
diff --git a/packages/api/src/activities.ts b/packages/api/src/activities.ts
new file mode 100644
index 0000000..479fbc6
--- /dev/null
+++ b/packages/api/src/activities.ts
@@ -0,0 +1,45 @@
+import { z } from "zod";
+
+/** Activity summary for list views */
+export const ActivitySummarySchema = z.object({
+  id: z.string().uuid(),
+  name: z.string(),
+  description: z.string(),
+  routeId: z.string().uuid().nullable(),
+  routeName: z.string().nullable(),
+  distance: z.number().nullable(),
+  duration: z.number().nullable(),
+  elevationGain: z.number().nullable(),
+  elevationLoss: z.number().nullable(),
+  startedAt: z.string().datetime().nullable(),
+  geojson: z.string().nullable(),
+  createdAt: z.string().datetime(),
+});
+
+/** Full activity detail */
+export const ActivityDetailSchema = ActivitySummarySchema.extend({
+  gpx: z.string().nullable(),
+  photos: z.array(z.string().url()),
+});
+
+/** Paginated activity list response */
+export const ActivityListResponseSchema = z.object({
+  activities: z.array(ActivitySummarySchema),
+  nextCursor: z.string().nullable(),
+});
+
+/** Create activity request */
+export const CreateActivityRequestSchema = z.object({
+  name: z.string().min(1).max(200),
+  description: z.string().max(5000).default(""),
+  gpx: z.string().optional(),
+  routeId: z.string().uuid().optional(),
+  startedAt: z.string().datetime().optional(),
+  duration: z.number().optional(),
+  distance: z.number().optional(),
+});
+
+export type ActivitySummary = z.infer<typeof ActivitySummarySchema>;
+export type ActivityDetail = z.infer<typeof ActivityDetailSchema>;
+export type ActivityListResponse = z.infer<typeof ActivityListResponseSchema>;
+export type CreateActivityRequest = z.infer<typeof CreateActivityRequestSchema>;
diff --git a/packages/api/src/auth.ts b/packages/api/src/auth.ts
new file mode 100644
index 0000000..8440738
--- /dev/null
+++ b/packages/api/src/auth.ts
@@ -0,0 +1,35 @@
+import { z } from "zod";
+
+export const TokenExchangeRequestSchema = z.object({
+  grant_type: z.enum(["authorization_code", "refresh_token"]),
+  code: z.string().optional(),
+  code_verifier: z.string().optional(),
+  refresh_token: z.string().optional(),
+  client_id: z.string(),
+  redirect_uri: z.string().optional(),
+  device_name: z.string().max(100).optional(),
+});
+
+export const TokenResponseSchema = z.object({
+  access_token: z.string(),
+  refresh_token: z.string(),
+  token_type: z.literal("Bearer"),
+  expires_in: z.number(),
+});
+
+export const DeviceSchema = z.object({
+  id: z.string(),
+  deviceName: z.string().nullable(),
+  lastActiveAt: z.string().datetime(),
+  createdAt: z.string().datetime(),
+  isCurrent: z.boolean(),
+});
+
+export const DeviceListResponseSchema = z.object({
+  devices: z.array(DeviceSchema),
+});
+
+export type TokenExchangeRequest = z.infer<typeof TokenExchangeRequestSchema>;
+export type TokenResponse = z.infer<typeof TokenResponseSchema>;
+export type Device = z.infer<typeof DeviceSchema>;
+export type DeviceListResponse = z.infer<typeof DeviceListResponseSchema>;
diff --git a/packages/api/src/discovery.ts b/packages/api/src/discovery.ts
new file mode 100644
index 0000000..9680a9a
--- /dev/null
+++ b/packages/api/src/discovery.ts
@@ -0,0 +1,10 @@
+import { z } from "zod";
+
+export const DiscoveryResponseSchema = z.object({
+  apiVersion: z.string(),
+  instanceName: z.string(),
+  apiBaseUrl: z.string().url(),
+  tileUrl: z.string().url().optional(),
+});
+
+export type DiscoveryResponse = z.infer<typeof DiscoveryResponseSchema>;
diff --git a/packages/api/src/endpoints.ts b/packages/api/src/endpoints.ts
new file mode 100644
index 0000000..a45d84e
--- /dev/null
+++ b/packages/api/src/endpoints.ts
@@ -0,0 +1,35 @@
+/** Typed API endpoint path constants */
+export const ENDPOINTS = {
+  discovery: "/.well-known/trails-cool",
+
+  auth: {
+    token: "/api/v1/auth/token",
+    devices: "/api/v1/auth/devices",
+    device: (id: string) => `/api/v1/auth/devices/${id}` as const,
+  },
+
+  routes: {
+    list: "/api/v1/routes",
+    create: "/api/v1/routes",
+    detail: (id: string) => `/api/v1/routes/${id}` as const,
+    update: (id: string) => `/api/v1/routes/${id}` as const,
+    delete: (id: string) => `/api/v1/routes/${id}` as const,
+    compute: "/api/v1/routes/compute",
+  },
+
+  activities: {
+    list: "/api/v1/activities",
+    create: "/api/v1/activities",
+    detail: (id: string) => `/api/v1/activities/${id}` as const,
+    delete: (id: string) => `/api/v1/activities/${id}` as const,
+  },
+
+  uploads: {
+    presign: "/api/v1/uploads",
+  },
+
+  push: {
+    subscribe: "/api/v1/push/subscribe",
+    unsubscribe: "/api/v1/push/unsubscribe",
+  },
+} as const;
diff --git a/packages/api/src/errors.ts b/packages/api/src/errors.ts
new file mode 100644
index 0000000..7d7fb88
--- /dev/null
+++ b/packages/api/src/errors.ts
@@ -0,0 +1,26 @@
+import { z } from "zod";
+
+export const FieldErrorSchema = z.object({
+  field: z.string(),
+  message: z.string(),
+});
+
+export const ApiErrorResponseSchema = z.object({
+  error: z.string(),
+  code: z.string(),
+  fields: z.array(FieldErrorSchema).optional(),
+});
+
+export type FieldError = z.infer<typeof FieldErrorSchema>;
+export type ApiErrorResponse = z.infer<typeof ApiErrorResponseSchema>;
+
+/** Standard error codes */
+export const ERROR_CODES = {
+  VALIDATION_ERROR: "VALIDATION_ERROR",
+  NOT_FOUND: "NOT_FOUND",
+  UNAUTHORIZED: "UNAUTHORIZED",
+  FORBIDDEN: "FORBIDDEN",
+  CONFLICT: "CONFLICT",
+  RATE_LIMITED: "RATE_LIMITED",
+  INTERNAL_ERROR: "INTERNAL_ERROR",
+} as const;
diff --git a/packages/api/src/index.test.ts b/packages/api/src/index.test.ts
new file mode 100644
index 0000000..1283c01
--- /dev/null
+++ b/packages/api/src/index.test.ts
@@ -0,0 +1,318 @@
+import { describe, it, expect } from "vitest";
+import {
+  API_VERSION,
+  ENDPOINTS,
+  // Errors
+  ApiErrorResponseSchema,
+  ERROR_CODES,
+  // Pagination
+  PaginationQuerySchema,
+  // Discovery
+  DiscoveryResponseSchema,
+  // Auth
+  TokenExchangeRequestSchema,
+  TokenResponseSchema,
+  DeviceSchema,
+  DeviceListResponseSchema,
+  // Routes
+  RouteSummarySchema,
+  RouteDetailSchema,
+  RouteListResponseSchema,
+  CreateRouteRequestSchema,
+  UpdateRouteRequestSchema,
+  ComputeRouteRequestSchema,
+  // Activities
+  ActivitySummarySchema,
+  ActivityDetailSchema,
+  ActivityListResponseSchema,
+  CreateActivityRequestSchema,
+  // Uploads
+  PresignedUploadRequestSchema,
+  PresignedUploadResponseSchema,
+} from "./index.ts";
+
+describe("API_VERSION", () => {
+  it("is a valid semver string", () => {
+    expect(API_VERSION).toMatch(/^\d+\.\d+\.\d+$/);
+  });
+});
+
+describe("ENDPOINTS", () => {
+  it("has correct static paths", () => {
+    expect(ENDPOINTS.discovery).toBe("/.well-known/trails-cool");
+    expect(ENDPOINTS.routes.list).toBe("/api/v1/routes");
+    expect(ENDPOINTS.activities.list).toBe("/api/v1/activities");
+    expect(ENDPOINTS.auth.token).toBe("/api/v1/auth/token");
+    expect(ENDPOINTS.uploads.presign).toBe("/api/v1/uploads");
+  });
+
+  it("has correct dynamic paths", () => {
+    expect(ENDPOINTS.routes.detail("abc-123")).toBe("/api/v1/routes/abc-123");
+    expect(ENDPOINTS.activities.delete("xyz")).toBe("/api/v1/activities/xyz");
+    expect(ENDPOINTS.auth.device("dev-1")).toBe("/api/v1/auth/devices/dev-1");
+  });
+});
+
+describe("ApiErrorResponseSchema", () => {
+  it("accepts valid error", () => {
+    const result = ApiErrorResponseSchema.parse({
+      error: "Not found",
+      code: "NOT_FOUND",
+    });
+    expect(result.code).toBe("NOT_FOUND");
+  });
+
+  it("accepts error with field errors", () => {
+    const result = ApiErrorResponseSchema.parse({
+      error: "Validation failed",
+      code: ERROR_CODES.VALIDATION_ERROR,
+      fields: [{ field: "name", message: "Required" }],
+    });
+    expect(result.fields).toHaveLength(1);
+  });
+
+  it("rejects missing error field", () => {
+    expect(() => ApiErrorResponseSchema.parse({ code: "X" })).toThrow();
+  });
+});
+
+describe("PaginationQuerySchema", () => {
+  it("defaults limit to 20", () => {
+    const result = PaginationQuerySchema.parse({});
+    expect(result.limit).toBe(20);
+    expect(result.cursor).toBeUndefined();
+  });
+
+  it("coerces string limit", () => {
+    const result = PaginationQuerySchema.parse({ limit: "50" });
+    expect(result.limit).toBe(50);
+  });
+
+  it("rejects limit > 100", () => {
+    expect(() => PaginationQuerySchema.parse({ limit: 101 })).toThrow();
+  });
+});
+
+describe("DiscoveryResponseSchema", () => {
+  it("accepts valid discovery", () => {
+    const result = DiscoveryResponseSchema.parse({
+      apiVersion: "1.0.0",
+      instanceName: "trails.cool",
+      apiBaseUrl: "https://trails.cool/api/v1",
+    });
+    expect(result.apiVersion).toBe("1.0.0");
+  });
+
+  it("accepts optional tileUrl", () => {
+    const result = DiscoveryResponseSchema.parse({
+      apiVersion: "1.0.0",
+      instanceName: "my-instance",
+      apiBaseUrl: "https://example.com/api/v1",
+      tileUrl: "https://tiles.example.com/{z}/{x}/{y}.pbf",
+    });
+    expect(result.tileUrl).toBeDefined();
+  });
+});
+
+describe("TokenExchangeRequestSchema", () => {
+  it("accepts authorization_code grant", () => {
+    const result = TokenExchangeRequestSchema.parse({
+      grant_type: "authorization_code",
+      code: "abc123",
+      code_verifier: "verifier",
+      client_id: "trails-cool-mobile",
+      redirect_uri: "trailscool://auth/callback",
+    });
+    expect(result.grant_type).toBe("authorization_code");
+  });
+
+  it("accepts refresh_token grant", () => {
+    const result = TokenExchangeRequestSchema.parse({
+      grant_type: "refresh_token",
+      refresh_token: "refresh-abc",
+      client_id: "trails-cool-mobile",
+    });
+    expect(result.grant_type).toBe("refresh_token");
+  });
+
+  it("rejects invalid grant_type", () => {
+    expect(() => TokenExchangeRequestSchema.parse({
+      grant_type: "password",
+      client_id: "x",
+    })).toThrow();
+  });
+});
+
+describe("TokenResponseSchema", () => {
+  it("accepts valid token response", () => {
+    const result = TokenResponseSchema.parse({
+      access_token: "at-123",
+      refresh_token: "rt-456",
+      token_type: "Bearer",
+      expires_in: 3600,
+    });
+    expect(result.token_type).toBe("Bearer");
+  });
+});
+
+describe("CreateRouteRequestSchema", () => {
+  it("accepts minimal route", () => {
+    const result = CreateRouteRequestSchema.parse({ name: "My Route" });
+    expect(result.name).toBe("My Route");
+    expect(result.description).toBe("");
+  });
+
+  it("accepts route with GPX", () => {
+    const result = CreateRouteRequestSchema.parse({
+      name: "Berlin Tour",
+      description: "A nice ride",
+      gpx: "<gpx>...</gpx>",
+      routingProfile: "fastbike",
+    });
+    expect(result.gpx).toBeDefined();
+  });
+
+  it("rejects empty name", () => {
+    expect(() => CreateRouteRequestSchema.parse({ name: "" })).toThrow();
+  });
+
+  it("rejects name over 200 chars", () => {
+    expect(() => CreateRouteRequestSchema.parse({ name: "x".repeat(201) })).toThrow();
+  });
+});
+
+describe("UpdateRouteRequestSchema", () => {
+  it("accepts partial update", () => {
+    const result = UpdateRouteRequestSchema.parse({ name: "New Name" });
+    expect(result.name).toBe("New Name");
+    expect(result.gpx).toBeUndefined();
+  });
+
+  it("accepts GPX-only update", () => {
+    const result = UpdateRouteRequestSchema.parse({ gpx: "<gpx>...</gpx>" });
+    expect(result.gpx).toBeDefined();
+  });
+});
+
+describe("ComputeRouteRequestSchema", () => {
+  it("accepts valid waypoints", () => {
+    const result = ComputeRouteRequestSchema.parse({
+      waypoints: [
+        { lat: 52.52, lon: 13.405 },
+        { lat: 52.51, lon: 13.39 },
+      ],
+    });
+    expect(result.waypoints).toHaveLength(2);
+    expect(result.profile).toBe("fastbike");
+  });
+
+  it("rejects fewer than 2 waypoints", () => {
+    expect(() => ComputeRouteRequestSchema.parse({
+      waypoints: [{ lat: 52.52, lon: 13.405 }],
+    })).toThrow();
+  });
+});
+
+describe("RouteSummarySchema", () => {
+  const validRoute = {
+    id: "550e8400-e29b-41d4-a716-446655440000",
+    name: "Berlin Tour",
+    description: "",
+    distance: 42000,
+    elevationGain: 340,
+    elevationLoss: 320,
+    routingProfile: "fastbike",
+    dayBreaks: [2],
+    geojson: null,
+    createdAt: "2026-04-12T10:00:00.000Z",
+    updatedAt: "2026-04-12T12:00:00.000Z",
+  };
+
+  it("accepts valid route summary", () => {
+    const result = RouteSummarySchema.parse(validRoute);
+    expect(result.name).toBe("Berlin Tour");
+  });
+
+  it("accepts nullable fields as null", () => {
+    const result = RouteSummarySchema.parse({
+      ...validRoute,
+      distance: null,
+      elevationGain: null,
+      elevationLoss: null,
+      routingProfile: null,
+    });
+    expect(result.distance).toBeNull();
+  });
+});
+
+describe("RouteListResponseSchema", () => {
+  it("accepts paginated response", () => {
+    const result = RouteListResponseSchema.parse({
+      routes: [],
+      nextCursor: "abc123",
+    });
+    expect(result.nextCursor).toBe("abc123");
+  });
+
+  it("accepts null nextCursor (last page)", () => {
+    const result = RouteListResponseSchema.parse({
+      routes: [],
+      nextCursor: null,
+    });
+    expect(result.nextCursor).toBeNull();
+  });
+});
+
+describe("CreateActivityRequestSchema", () => {
+  it("accepts minimal activity", () => {
+    const result = CreateActivityRequestSchema.parse({ name: "Morning Ride" });
+    expect(result.name).toBe("Morning Ride");
+  });
+
+  it("accepts activity with all fields", () => {
+    const result = CreateActivityRequestSchema.parse({
+      name: "Morning Ride",
+      description: "Nice weather",
+      gpx: "<gpx>...</gpx>",
+      routeId: "550e8400-e29b-41d4-a716-446655440000",
+      startedAt: "2026-04-12T07:00:00.000Z",
+      duration: 3600,
+      distance: 25000,
+    });
+    expect(result.routeId).toBeDefined();
+  });
+});
+
+describe("PresignedUploadRequestSchema", () => {
+  it("accepts valid upload request", () => {
+    const result = PresignedUploadRequestSchema.parse({
+      filename: "photo.jpg",
+      contentType: "image/jpeg",
+      resourceType: "route",
+      resourceId: "550e8400-e29b-41d4-a716-446655440000",
+    });
+    expect(result.resourceType).toBe("route");
+  });
+
+  it("rejects invalid resource type", () => {
+    expect(() => PresignedUploadRequestSchema.parse({
+      filename: "x.jpg",
+      contentType: "image/jpeg",
+      resourceType: "user",
+      resourceId: "550e8400-e29b-41d4-a716-446655440000",
+    })).toThrow();
+  });
+});
+
+describe("DeviceSchema", () => {
+  it("accepts valid device", () => {
+    const result = DeviceSchema.parse({
+      id: "dev-1",
+      deviceName: "iPhone 16e",
+      lastActiveAt: "2026-04-12T10:00:00.000Z",
+      createdAt: "2026-04-10T08:00:00.000Z",
+      isCurrent: true,
+    });
+    expect(result.deviceName).toBe("iPhone 16e");
+  });
+});
diff --git a/packages/api/src/index.ts b/packages/api/src/index.ts
new file mode 100644
index 0000000..8f7e100
--- /dev/null
+++ b/packages/api/src/index.ts
@@ -0,0 +1,56 @@
+export { API_VERSION } from "./version.ts";
+export { ENDPOINTS } from "./endpoints.ts";
+
+// Error schemas
+export {
+  ApiErrorResponseSchema, FieldErrorSchema, ERROR_CODES,
+  type ApiErrorResponse, type FieldError,
+} from "./errors.ts";
+
+// Pagination
+export {
+  PaginationQuerySchema, PaginatedResponseSchema,
+  type PaginationQuery, type PaginatedResponse,
+} from "./pagination.ts";
+
+// Discovery
+export {
+  DiscoveryResponseSchema,
+  type DiscoveryResponse,
+} from "./discovery.ts";
+
+// Auth
+export {
+  TokenExchangeRequestSchema, TokenResponseSchema,
+  DeviceSchema, DeviceListResponseSchema,
+  type TokenExchangeRequest, type TokenResponse,
+  type Device, type DeviceListResponse,
+} from "./auth.ts";
+
+// Routes
+export {
+  RouteSummarySchema, RouteDetailSchema, RouteVersionSchema,
+  RouteListResponseSchema,
+  CreateRouteRequestSchema, UpdateRouteRequestSchema,
+  ComputeRouteRequestSchema,
+  type RouteSummary, type RouteDetail, type RouteVersion,
+  type RouteListResponse,
+  type CreateRouteRequest, type UpdateRouteRequest,
+  type ComputeRouteRequest,
+} from "./routes.ts";
+
+// Activities
+export {
+  ActivitySummarySchema, ActivityDetailSchema,
+  ActivityListResponseSchema,
+  CreateActivityRequestSchema,
+  type ActivitySummary, type ActivityDetail,
+  type ActivityListResponse,
+  type CreateActivityRequest,
+} from "./activities.ts";
+
+// Uploads
+export {
+  PresignedUploadRequestSchema, PresignedUploadResponseSchema,
+  type PresignedUploadRequest, type PresignedUploadResponse,
+} from "./uploads.ts";
diff --git a/packages/api/src/pagination.ts b/packages/api/src/pagination.ts
new file mode 100644
index 0000000..649792f
--- /dev/null
+++ b/packages/api/src/pagination.ts
@@ -0,0 +1,16 @@
+import { z } from "zod";
+
+/** Cursor-based pagination query params */
+export const PaginationQuerySchema = z.object({
+  cursor: z.string().optional(),
+  limit: z.coerce.number().min(1).max(100).default(20),
+});
+
+export type PaginationQuery = z.infer<typeof PaginationQuerySchema>;
+
+/** Paginated response wrapper — extend with your items */
+export const PaginatedResponseSchema = z.object({
+  nextCursor: z.string().nullable(),
+});
+
+export type PaginatedResponse = z.infer<typeof PaginatedResponseSchema>;
diff --git a/packages/api/src/routes.ts b/packages/api/src/routes.ts
new file mode 100644
index 0000000..b9e64e5
--- /dev/null
+++ b/packages/api/src/routes.ts
@@ -0,0 +1,73 @@
+import { z } from "zod";
+
+/** Route summary for list views */
+export const RouteSummarySchema = z.object({
+  id: z.string().uuid(),
+  name: z.string(),
+  description: z.string(),
+  distance: z.number().nullable(),
+  elevationGain: z.number().nullable(),
+  elevationLoss: z.number().nullable(),
+  routingProfile: z.string().nullable(),
+  dayBreaks: z.array(z.number()),
+  geojson: z.string().nullable(),
+  createdAt: z.string().datetime(),
+  updatedAt: z.string().datetime(),
+});
+
+/** Route version info */
+export const RouteVersionSchema = z.object({
+  version: z.number(),
+  changeDescription: z.string().nullable(),
+  createdAt: z.string().datetime(),
+});
+
+/** Full route detail */
+export const RouteDetailSchema = RouteSummarySchema.extend({
+  gpx: z.string().nullable(),
+  versions: z.array(RouteVersionSchema),
+});
+
+/** Paginated route list response */
+export const RouteListResponseSchema = z.object({
+  routes: z.array(RouteSummarySchema),
+  nextCursor: z.string().nullable(),
+});
+
+/** Create route request */
+export const CreateRouteRequestSchema = z.object({
+  name: z.string().min(1).max(200),
+  description: z.string().max(5000).default(""),
+  gpx: z.string().optional(),
+  routingProfile: z.string().optional(),
+});
+
+/** Update route request */
+export const UpdateRouteRequestSchema = z.object({
+  name: z.string().min(1).max(200).optional(),
+  description: z.string().max(5000).optional(),
+  gpx: z.string().optional(),
+});
+
+/** Compute route request (BRouter proxy) */
+export const ComputeRouteRequestSchema = z.object({
+  waypoints: z.array(z.object({
+    lat: z.number(),
+    lon: z.number(),
+  })).min(2),
+  profile: z.string().default("fastbike"),
+  noGoAreas: z.array(z.object({
+    points: z.array(z.object({
+      lat: z.number(),
+      lon: z.number(),
+    })),
+  })).optional(),
+});
+
+export type RouteSummary = z.infer<typeof RouteSummarySchema>;
+export type RouteVersion = z.infer<typeof RouteVersionSchema>;
+export type RouteDetail = z.infer<typeof RouteDetailSchema>;
+export type RouteListResponse = z.infer<typeof RouteListResponseSchema>;
+export type CreateRouteRequest = z.infer<typeof CreateRouteRequestSchema>;
+export type UpdateRouteRequest = z.infer<typeof UpdateRouteRequestSchema>;
+export type ComputeRouteRequest = z.infer<typeof ComputeRouteRequestSchema>;
diff --git a/packages/api/src/uploads.ts b/packages/api/src/uploads.ts
new file mode 100644
index 0000000..98f8927
--- /dev/null
+++ b/packages/api/src/uploads.ts
@@ -0,0 +1,17 @@
+import { z } from "zod";
+
+export const PresignedUploadRequestSchema = z.object({
+  filename: z.string(),
+  contentType: z.string(),
+  resourceType: z.enum(["route", "activity"]),
+  resourceId: z.string().uuid(),
+});
+
+export const PresignedUploadResponseSchema = z.object({
+  uploadUrl: z.string().url(),
+  storageKey: z.string(),
+  expiresAt: z.string().datetime(),
+});
+
+export type PresignedUploadRequest = z.infer<typeof PresignedUploadRequestSchema>;
+export type PresignedUploadResponse = z.infer<typeof PresignedUploadResponseSchema>;
diff --git a/packages/api/src/version.ts b/packages/api/src/version.ts
new file mode 100644
index 0000000..5ef45ad
--- /dev/null
+++ b/packages/api/src/version.ts
@@ -0,0 +1,7 @@
+/**
+ * API version following semver.
+ * - Patch: bug fixes
+ * - Minor: new endpoints, new optional fields (backwards compatible)
+ * - Major: breaking changes
+ */
+export const API_VERSION = "1.0.0";
diff --git a/packages/api/tsconfig.json b/packages/api/tsconfig.json
new file mode 100644
index 0000000..5285d28
--- /dev/null
+++ b/packages/api/tsconfig.json
@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "dist"
+  },
+  "include": ["src"]
+}
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 9f75fd4..42d9ac7 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -410,6 +410,12 @@ importers:
         specifier: 'catalog:'
         version: 8.0.8(@types/node@25.5.2)(esbuild@0.27.4)(jiti@2.6.1)(tsx@4.21.0)
 
+  packages/api:
+    dependencies:
+      zod:
+        specifier: ^3.25.0
+        version: 3.25.76
+
   packages/db:
     dependencies:
       drizzle-orm:
@@ -4102,6 +4108,9 @@ packages:
     resolution: {integrity: sha512-rVksvsnNCdJ/ohGc6xgPwyN8eheCxsiLM8mxuE/t/mOVqJewPuO1miLpTHQiRgTKCLexL4MeAFVagts7HmNZ2Q==}
     engines: {node: '>=10'}
 
+  zod@3.25.76:
+    resolution: {integrity: sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==}
+
 snapshots:
 
   '@adobe/css-tools@4.4.4': {}
@@ -7620,3 +7629,5 @@ snapshots:
       lib0: 0.2.117
 
   yocto-queue@0.1.0: {}
+
+  zod@3.25.76: {}