diff --git a/frontend/package.json b/frontend/package.json
index 9af9949..6c17171 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -4,8 +4,9 @@
   "description": "PredictIQ Landing Page with WCAG 2.1 AA Compliance",
   "private": true,
   "scripts": {
+    "generate-client": "openapi-typescript ../../services/api/openapi.yaml -o src/lib/api/schema.d.ts",
     "dev": "next dev",
-    "build": "next build",
+    "build": "npm run generate-client && next build",
     "start": "next start",
     "lint": "next lint",
     "test": "jest",
@@ -51,6 +52,7 @@
     "jest-environment-jsdom": "^29.7.0",
     "lighthouse": "^11.4.0",
     "pa11y": "^7.0.0",
+    "openapi-typescript": "^7.0.0",
     "typescript": "^5.3.3"
   },
   "engines": {
diff --git a/frontend/src/lib/api/client.ts b/frontend/src/lib/api/client.ts
new file mode 100644
index 0000000..98fed97
--- /dev/null
+++ b/frontend/src/lib/api/client.ts
@@ -0,0 +1,131 @@
+/**
+ * Type-safe API client generated from the OpenAPI schema.
+ * Run `npm run generate-client` to regenerate `schema.d.ts` after API changes.
+ */
+
+const BASE_URL =
+  process.env.NEXT_PUBLIC_API_URL?.replace(/\/$/, "") ?? "http://localhost:3001";
+
+type HttpMethod = "GET" | "POST" | "DELETE";
+
+async function request<T>(
+  method: HttpMethod,
+  path: string,
+  options: { body?: unknown; params?: Record<string, string | number | undefined> } = {}
+): Promise<T> {
+  let url = `${BASE_URL}${path}`;
+
+  if (options.params) {
+    const qs = new URLSearchParams();
+    for (const [k, v] of Object.entries(options.params)) {
+      if (v !== undefined) qs.set(k, String(v));
+    }
+    const str = qs.toString();
+    if (str) url += `?${str}`;
+  }
+
+  const res = await fetch(url, {
+    method,
+    headers: { "Content-Type": "application/json" },
+    body: options.body !== undefined ? JSON.stringify(options.body) : undefined,
+  });
+
+  if (!res.ok) {
+    const err = await res.json().catch(() => ({ message: res.statusText }));
+    throw new Error(err?.message ?? `HTTP ${res.status}`);
+  }
+
+  // 204 / empty body
+  const text = await res.text();
+  return text ? (JSON.parse(text) as T) : (undefined as unknown as T);
+}
+
+// ---------------------------------------------------------------------------
+// Public endpoints
+// ---------------------------------------------------------------------------
+
+export const api = {
+  health: () => request<string>("GET", "/health"),
+
+  getStatistics: () => request<Record<string, unknown>>("GET", "/api/statistics"),
+
+  getFeaturedMarkets: () =>
+    request<
+      Array<{
+        id: number;
+        title: string;
+        volume: number;
+        ends_at: string;
+        onchain_volume: string;
+        resolved_outcome?: number | null;
+      }>
+    >("GET", "/api/markets/featured"),
+
+  getContent: (params?: { page?: number; page_size?: number }) =>
+    request<Record<string, unknown>>("GET", "/api/content", { params }),
+
+  // Blockchain
+  getBlockchainHealth: () =>
+    request<Record<string, unknown>>("GET", "/api/blockchain/health"),
+
+  getBlockchainMarket: (marketId: number | string) =>
+    request<Record<string, unknown>>("GET", `/api/blockchain/markets/${marketId}`),
+
+  getBlockchainStats: () =>
+    request<Record<string, unknown>>("GET", "/api/blockchain/stats"),
+
+  getUserBets: (user: string, params?: { page?: number; page_size?: number }) =>
+    request<Record<string, unknown>>("GET", `/api/blockchain/users/${user}/bets`, { params }),
+
+  getOracleResult: (marketId: number | string) =>
+    request<Record<string, unknown>>("GET", `/api/blockchain/oracle/${marketId}`),
+
+  getTransactionStatus: (txHash: string) =>
+    request<Record<string, unknown>>("GET", `/api/blockchain/tx/${txHash}`),
+
+  // Newsletter
+  newsletterSubscribe: (body: { email: string; source?: string }) =>
+    request<{ success: boolean; message: string }>("POST", "/api/v1/newsletter/subscribe", { body }),
+
+  newsletterConfirm: (token: string) =>
+    request<{ success: boolean; message: string }>("GET", `/api/v1/newsletter/confirm`, {
+      params: { token },
+    }),
+
+  newsletterUnsubscribe: (email: string) =>
+    request<{ success: boolean; message: string }>("DELETE", "/api/v1/newsletter/unsubscribe", {
+      body: { email },
+    }),
+
+  newsletterGdprExport: (email: string) =>
+    request<{ success: boolean; data: Record<string, unknown> }>(
+      "GET",
+      "/api/v1/newsletter/gdpr/export",
+      { params: { email } }
+    ),
+
+  newsletterGdprDelete: (email: string) =>
+    request<{ success: boolean; message: string }>("DELETE", "/api/v1/newsletter/gdpr/delete", {
+      body: { email },
+    }),
+
+  // Admin / email
+  resolveMarket: (marketId: number | string) =>
+    request<{ invalidated_keys: number }>("POST", `/api/markets/${marketId}/resolve`),
+
+  emailPreview: (templateName: string) =>
+    request<Record<string, unknown>>("GET", `/api/v1/email/preview/${templateName}`),
+
+  emailSendTest: (body: { recipient: string; template_name: string }) =>
+    request<{ success: boolean; message: string; message_id: string }>(
+      "POST",
+      "/api/v1/email/test",
+      { body }
+    ),
+
+  getEmailAnalytics: (params?: { template_name?: string; days?: number }) =>
+    request<Record<string, unknown>>("GET", "/api/v1/email/analytics", { params }),
+
+  getEmailQueueStats: () =>
+    request<Record<string, unknown>>("GET", "/api/v1/email/queue/stats"),
+};
diff --git a/services/api/openapi.yaml b/services/api/openapi.yaml
new file mode 100644
index 0000000..214baef
--- /dev/null
+++ b/services/api/openapi.yaml
@@ -0,0 +1,556 @@
+openapi: 3.0.3
+info:
+  title: PredictIQ API
+  version: 1.0.0
+  description: REST API for the PredictIQ prediction markets platform
+
+servers:
+  - url: http://localhost:3001
+    description: Local development
+
+tags:
+  - name: health
+  - name: markets
+  - name: blockchain
+  - name: newsletter
+  - name: email
+  - name: webhooks
+
+paths:
+  /health:
+    get:
+      tags: [health]
+      operationId: getHealth
+      summary: Health check
+      responses:
+        "200":
+          description: Service is healthy
+          content:
+            text/plain:
+              schema:
+                type: string
+                example: ok
+
+  /api/statistics:
+    get:
+      tags: [markets]
+      operationId: getStatistics
+      summary: Platform statistics
+      responses:
+        "200":
+          description: Statistics payload
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/markets/featured:
+    get:
+      tags: [markets]
+      operationId: getFeaturedMarkets
+      summary: List featured markets
+      responses:
+        "200":
+          description: Array of featured markets
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/FeaturedMarketView"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/content:
+    get:
+      tags: [markets]
+      operationId: getContent
+      summary: Paginated content feed
+      parameters:
+        - $ref: "#/components/parameters/page"
+        - $ref: "#/components/parameters/pageSize"
+      responses:
+        "200":
+          description: Content payload
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/markets/{market_id}/resolve:
+    post:
+      tags: [markets]
+      operationId: resolveMarket
+      summary: Resolve a market and invalidate caches (admin)
+      parameters:
+        - $ref: "#/components/parameters/marketId"
+      responses:
+        "200":
+          description: Cache invalidation result
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/InvalidationResult"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/blockchain/health:
+    get:
+      tags: [blockchain]
+      operationId: getBlockchainHealth
+      summary: Blockchain node health
+      responses:
+        "200":
+          description: Health data
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/blockchain/markets/{market_id}:
+    get:
+      tags: [blockchain]
+      operationId: getBlockchainMarket
+      summary: On-chain market data
+      parameters:
+        - $ref: "#/components/parameters/marketId"
+      responses:
+        "200":
+          description: Market chain data
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/blockchain/stats:
+    get:
+      tags: [blockchain]
+      operationId: getBlockchainStats
+      summary: Platform on-chain statistics
+      responses:
+        "200":
+          description: Platform stats
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/blockchain/users/{user}/bets:
+    get:
+      tags: [blockchain]
+      operationId: getUserBets
+      summary: Bets placed by a user
+      parameters:
+        - name: user
+          in: path
+          required: true
+          schema:
+            type: string
+          description: Stellar address of the user
+        - $ref: "#/components/parameters/page"
+        - $ref: "#/components/parameters/pageSize"
+      responses:
+        "200":
+          description: User bets
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/blockchain/oracle/{market_id}:
+    get:
+      tags: [blockchain]
+      operationId: getOracleResult
+      summary: Oracle result for a market
+      parameters:
+        - $ref: "#/components/parameters/marketId"
+      responses:
+        "200":
+          description: Oracle result
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/blockchain/tx/{tx_hash}:
+    get:
+      tags: [blockchain]
+      operationId: getTransactionStatus
+      summary: Transaction status by hash
+      parameters:
+        - name: tx_hash
+          in: path
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: Transaction status
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/v1/newsletter/subscribe:
+    post:
+      tags: [newsletter]
+      operationId: newsletterSubscribe
+      summary: Subscribe to newsletter
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/NewsletterSubscribeRequest"
+      responses:
+        "200":
+          $ref: "#/components/responses/NewsletterResponse"
+        "400":
+          $ref: "#/components/responses/NewsletterResponse"
+        "409":
+          $ref: "#/components/responses/NewsletterResponse"
+        "429":
+          $ref: "#/components/responses/NewsletterResponse"
+
+  /api/v1/newsletter/confirm:
+    get:
+      tags: [newsletter]
+      operationId: newsletterConfirm
+      summary: Confirm newsletter subscription via token
+      parameters:
+        - name: token
+          in: query
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          $ref: "#/components/responses/NewsletterResponse"
+        "400":
+          $ref: "#/components/responses/NewsletterResponse"
+        "404":
+          $ref: "#/components/responses/NewsletterResponse"
+
+  /api/v1/newsletter/unsubscribe:
+    delete:
+      tags: [newsletter]
+      operationId: newsletterUnsubscribe
+      summary: Unsubscribe from newsletter
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/EmailRequest"
+      responses:
+        "200":
+          $ref: "#/components/responses/NewsletterResponse"
+        "400":
+          $ref: "#/components/responses/NewsletterResponse"
+
+  /api/v1/newsletter/gdpr/export:
+    get:
+      tags: [newsletter]
+      operationId: newsletterGdprExport
+      summary: GDPR data export for a subscriber
+      parameters:
+        - name: email
+          in: query
+          required: true
+          schema:
+            type: string
+            format: email
+      responses:
+        "200":
+          description: Subscriber data
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/NewsletterExportResponse"
+        "400":
+          $ref: "#/components/responses/NewsletterResponse"
+        "404":
+          $ref: "#/components/responses/NewsletterResponse"
+
+  /api/v1/newsletter/gdpr/delete:
+    delete:
+      tags: [newsletter]
+      operationId: newsletterGdprDelete
+      summary: GDPR data deletion for a subscriber
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/EmailRequest"
+      responses:
+        "200":
+          $ref: "#/components/responses/NewsletterResponse"
+        "400":
+          $ref: "#/components/responses/NewsletterResponse"
+
+  /api/v1/email/preview/{template_name}:
+    get:
+      tags: [email]
+      operationId: emailPreview
+      summary: Preview a rendered email template (admin)
+      parameters:
+        - name: template_name
+          in: path
+          required: true
+          schema:
+            type: string
+            enum:
+              - newsletter_confirmation
+              - waitlist_confirmation
+              - contact_form_auto_response
+              - welcome_email
+      responses:
+        "200":
+          description: Rendered email preview
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/v1/email/test:
+    post:
+      tags: [email]
+      operationId: emailSendTest
+      summary: Send a test email (admin)
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/EmailTestRequest"
+      responses:
+        "200":
+          description: Test email result
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/EmailTestResponse"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/v1/email/analytics:
+    get:
+      tags: [email]
+      operationId: getEmailAnalytics
+      summary: Email analytics (admin)
+      parameters:
+        - name: template_name
+          in: query
+          required: false
+          schema:
+            type: string
+        - name: days
+          in: query
+          required: false
+          schema:
+            type: integer
+            minimum: 1
+            maximum: 365
+            default: 30
+      responses:
+        "200":
+          description: Analytics data
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /api/v1/email/queue/stats:
+    get:
+      tags: [email]
+      operationId: getEmailQueueStats
+      summary: Email queue statistics (admin)
+      responses:
+        "200":
+          description: Queue stats
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/AnyObject"
+        "500":
+          $ref: "#/components/responses/ApiError"
+
+  /webhooks/sendgrid:
+    post:
+      tags: [webhooks]
+      operationId: sendgridWebhook
+      summary: SendGrid event webhook receiver
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: array
+              items:
+                $ref: "#/components/schemas/AnyObject"
+      responses:
+        "200":
+          description: Webhook processed
+
+components:
+  parameters:
+    marketId:
+      name: market_id
+      in: path
+      required: true
+      schema:
+        type: integer
+        format: int64
+    page:
+      name: page
+      in: query
+      required: false
+      schema:
+        type: integer
+        format: int64
+        minimum: 1
+        default: 1
+    pageSize:
+      name: page_size
+      in: query
+      required: false
+      schema:
+        type: integer
+        format: int64
+        minimum: 1
+        maximum: 100
+        default: 20
+
+  schemas:
+    AnyObject:
+      type: object
+      additionalProperties: true
+
+    ApiError:
+      type: object
+      required: [message]
+      properties:
+        message:
+          type: string
+
+    FeaturedMarketView:
+      type: object
+      required: [id, title, volume, ends_at, onchain_volume]
+      properties:
+        id:
+          type: integer
+          format: int64
+        title:
+          type: string
+        volume:
+          type: number
+          format: double
+        ends_at:
+          type: string
+          format: date-time
+        onchain_volume:
+          type: string
+        resolved_outcome:
+          type: integer
+          format: int32
+          nullable: true
+
+    InvalidationResult:
+      type: object
+      required: [invalidated_keys]
+      properties:
+        invalidated_keys:
+          type: integer
+
+    NewsletterSubscribeRequest:
+      type: object
+      required: [email]
+      properties:
+        email:
+          type: string
+          format: email
+        source:
+          type: string
+          maxLength: 64
+
+    EmailRequest:
+      type: object
+      required: [email]
+      properties:
+        email:
+          type: string
+          format: email
+
+    NewsletterResponse:
+      type: object
+      required: [success, message]
+      properties:
+        success:
+          type: boolean
+        message:
+          type: string
+
+    NewsletterExportResponse:
+      type: object
+      required: [success, data]
+      properties:
+        success:
+          type: boolean
+        data:
+          $ref: "#/components/schemas/AnyObject"
+
+    EmailTestRequest:
+      type: object
+      required: [recipient, template_name]
+      properties:
+        recipient:
+          type: string
+          format: email
+        template_name:
+          type: string
+
+    EmailTestResponse:
+      type: object
+      required: [success, message, message_id]
+      properties:
+        success:
+          type: boolean
+        message:
+          type: string
+        message_id:
+          type: string
+
+  responses:
+    ApiError:
+      description: Internal server error
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/ApiError"
+    NewsletterResponse:
+      description: Newsletter operation result
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/NewsletterResponse"