diff --git a/README.md b/README.md
index 6dbf03d..775a589 100644
--- a/README.md
+++ b/README.md
@@ -213,6 +213,15 @@ telecom-platform/
 |   |-- charging-engine/     # Rust: OCS Real-time Credit Control
 |   |-- packet-gateway/      # Rust: eBPF UPF Data Plane
 |   |-- web-dashboard/       # TypeScript: Next.js Frontend
+|-- sdk/
+|   |-- go/                  # Go SDK
+|   |-- python/              # Python SDK
+|   |-- typescript/          # TypeScript SDK
+|   |-- kotlin/              # Kotlin SDK
+|   |-- ruby/                # Ruby SDK
+|   |-- swift/               # Swift SDK
+|   |-- rust/                # Rust SDK
+|   |-- elixir/              # Elixir SDK
 |-- libs/
 |   |-- shared-ts-sdk/       # TypeScript: Drop-in Widget SDK
 |   |-- proto/               # Shared Protobufs
@@ -223,6 +232,7 @@ telecom-platform/
 |   |-- traefik.yml          # Static configuration
 |   |-- dynamic/             # Dynamic middleware config
 |-- docs/                    # Architecture & API docs
+|   |-- sdk-usage.md         # Multi-language SDK documentation
 |   |-- gateway-quickstart.md # API Gateway guide
 |   |-- api-gateway.md       # Gateway implementation details
 |-- scripts/                 # Automation scripts
@@ -338,6 +348,53 @@ The API Gateway provides:
 
 For detailed setup, see [Gateway Quickstart Guide](./docs/gateway-quickstart.md)
 
+## API Endpoints
+
+### Analytics API
+
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| POST | `/api/v1/analytics/churn/predict` | Predict churn for a profile |
+| GET | `/api/v1/analytics/churn/metrics` | Get churn metrics |
+| GET | `/api/v1/analytics/churn/at-risk` | Get at-risk customers |
+| GET | `/api/v1/analytics/market/metrics` | Get market metrics |
+| GET | `/api/v1/analytics/market/competitors` | Get competitor analysis |
+| GET | `/api/v1/analytics/market/opportunities` | Get market opportunities |
+| GET | `/api/v1/analytics/maintenance/metrics` | Get maintenance metrics |
+| GET | `/api/v1/analytics/maintenance/assets` | Get assets health |
+| GET | `/api/v1/analytics/maintenance/alerts` | Get maintenance alerts |
+| POST | `/api/v1/analytics/maintenance/predict/:asset_id` | Predict asset failure |
+| GET | `/api/v1/analytics/pricing/metrics` | Get pricing metrics |
+| POST | `/api/v1/analytics/pricing/optimize` | Optimize pricing |
+| GET | `/api/v1/analytics/pricing/elasticity` | Get price elasticity |
+
+### Security API
+
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| POST | `/api/v1/security/fraud/analyze` | Analyze transaction for fraud |
+| POST | `/api/v1/security/fraud/alerts` | Get fraud alerts |
+| PUT | `/api/v1/security/fraud/alerts/:id` | Update alert status |
+| GET | `/api/v1/security/fraud/metrics` | Get fraud metrics |
+| GET | `/api/v1/security/fraud/patterns` | Get fraud patterns |
+| POST | `/api/v1/security/simswap/verify` | Verify SIM swap |
+| GET | `/api/v1/security/simswap/history/:profile_id` | Get SIM swap history |
+
+### Currency & Billing API
+
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| POST | `/api/v1/currency/convert` | Convert currency |
+| GET | `/api/v1/currency/exchange/:from/:to` | Get exchange rate |
+| GET | `/api/v1/currency/exchange/:from/:to/history` | Get exchange rate history |
+| GET | `/api/v1/currency/currencies` | List supported currencies |
+| POST | `/api/v1/currency/exchange/refresh` | Refresh exchange rates |
+| POST | `/api/v1/currency/billing` | Process billing |
+| GET | `/api/v1/currency/billing/history/:profile_id` | Get billing history |
+| GET | `/api/v1/currency/billing/summary/:profile_id` | Get billing summary |
+| POST | `/api/v1/currency/billing/refund/:transaction_id` | Process refund |
+| GET | `/api/v1/currency/billing/analytics` | Get billing analytics |
+
 ## Environment Variables
 
 Create `.env` files in each service directory:
diff --git a/docs/sdk-usage.md b/docs/sdk-usage.md
new file mode 100644
index 0000000..505c8bf
--- /dev/null
+++ b/docs/sdk-usage.md
@@ -0,0 +1,547 @@
+# TaaS Platform SDK Documentation
+
+Multi-language SDK documentation for integrating with the Telecom-as-a-Service Platform.
+
+## Table of Contents
+
+- [Overview](#overview)
+- [Installation](#installation)
+- [Authentication](#authentication)
+- [Go SDK](#go-sdk)
+- [Python SDK](#python-sdk)
+- [TypeScript SDK](#typescript-sdk)
+- [Analytics API](#analytics-api)
+- [Security API](#security-api)
+- [Currency & Billing API](#currency--billing-api)
+
+---
+
+## Overview
+
+The TaaS Platform provides SDKs for multiple programming languages to simplify integration with platform services:
+
+| Language | Package | Status |
+|----------|---------|--------|
+| Go | `github.com/nutcas3/telecom-platform/sdk/go` | ✅ Stable |
+| Python | `telecom-sdk` | ✅ Stable |
+| TypeScript | `@taas/sdk` | ✅ Stable |
+| Kotlin | `com.taas:sdk` | 🚧 Beta |
+| Ruby | `taas-sdk` | 🚧 Beta |
+| Swift | `TaaSSDK` | 🚧 Beta |
+| Rust | `taas-sdk` | 🚧 Beta |
+| Elixir | `taas_sdk` | 🚧 Beta |
+
+---
+
+## Installation
+
+### Go
+
+```bash
+go get github.com/nutcas3/telecom-platform/sdk/go
+```
+
+### Python
+
+```bash
+pip install telecom-sdk
+```
+
+### TypeScript/JavaScript
+
+```bash
+npm install @taas/sdk
+# or
+pnpm add @taas/sdk
+```
+
+---
+
+## Authentication
+
+All SDKs use JWT-based authentication. Obtain an API key from the dashboard or use username/password authentication.
+
+### API Key Authentication
+
+```go
+// Go
+client := taas.NewClient(taas.WithAPIKey("your-api-key"))
+```
+
+```python
+# Python
+from telecom_sdk import TelecomClient
+client = TelecomClient(api_key="your-api-key")
+```
+
+```typescript
+// TypeScript
+import { TelecomClient } from '@taas/sdk';
+const client = new TelecomClient({ apiKey: 'your-api-key' });
+```
+
+---
+
+## Go SDK
+
+### Basic Usage
+
+```go
+package main
+
+import (
+    "context"
+    "fmt"
+    "log"
+
+    taas "github.com/nutcas3/telecom-platform/sdk/go"
+)
+
+func main() {
+    // Initialize client
+    client := taas.NewClient(
+        taas.WithBaseURL("https://api.telecom.com"),
+        taas.WithAPIKey("your-api-key"),
+    )
+
+    // Create a subscriber
+    subscriber, err := client.Subscribers.Create(context.Background(), &taas.CreateSubscriberRequest{
+        MSISDN:    "+1234567890",
+        FirstName: "John",
+        LastName:  "Doe",
+        Email:     "john@example.com",
+        PlanID:    1,
+    })
+    if err != nil {
+        log.Fatal(err)
+    }
+    fmt.Printf("Created subscriber: %s\n", subscriber.ID)
+}
+```
+
+### Analytics API
+
+```go
+// Churn Prediction
+analyticsAPI := taas.NewAnalyticsAPI(client.HTTPClient)
+
+// Predict churn for a profile
+prediction, err := analyticsAPI.PredictChurn(ctx, "profile-123")
+if err != nil {
+    log.Fatal(err)
+}
+fmt.Printf("Churn Risk: %s (Score: %.2f)\n", prediction.RiskLevel, prediction.RiskScore)
+
+// Get churn metrics
+metrics, err := analyticsAPI.GetChurnMetrics(ctx, "monthly")
+if err != nil {
+    log.Fatal(err)
+}
+fmt.Printf("Monthly Churn Rate: %.2f%%\n", metrics.MonthlyChurnRate)
+
+// Get at-risk customers
+atRisk, err := analyticsAPI.GetAtRiskCustomers(ctx, taas.ChurnRiskHigh, 100)
+if err != nil {
+    log.Fatal(err)
+}
+fmt.Printf("Found %d high-risk customers\n", len(atRisk))
+
+// Market metrics
+marketMetrics, err := analyticsAPI.GetMarketMetrics(ctx, "quarterly")
+if err != nil {
+    log.Fatal(err)
+}
+fmt.Printf("Market Share: %.2f%%\n", marketMetrics.MarketShare)
+```
+
+### Security API
+
+```go
+// Fraud Detection
+securityAPI := taas.NewSecurityAPI(client.HTTPClient)
+
+// Analyze a transaction
+alert, err := securityAPI.AnalyzeTransaction(ctx, map[string]interface{}{
+    "profile_id":  "profile-123",
+    "amount":      99.99,
+    "ip_address":  "192.168.1.1",
+    "device_id":   "device-456",
+    "transaction": "payment",
+})
+if err != nil {
+    log.Fatal(err)
+}
+if alert != nil {
+    fmt.Printf("Fraud Alert: %s (Severity: %s)\n", alert.Type, alert.Severity)
+}
+
+// Get fraud alerts
+alerts, err := securityAPI.GetFraudAlerts(ctx, taas.FraudAlertFilter{
+    Severity: taas.FraudSeverityHigh,
+    Status:   "new",
+    Limit:    50,
+})
+if err != nil {
+    log.Fatal(err)
+}
+fmt.Printf("Found %d fraud alerts\n", len(alerts))
+
+// Get fraud metrics
+fraudMetrics, err := securityAPI.GetFraudMetrics(ctx, "monthly")
+if err != nil {
+    log.Fatal(err)
+}
+fmt.Printf("Resolution Rate: %.2f%%\n", fraudMetrics.ResolutionRate)
+```
+
+---
+
+## Python SDK
+
+### Basic Usage
+
+```python
+from telecom_sdk import TelecomClient
+from telecom_sdk.types import CreateSubscriberRequest
+
+# Initialize client
+client = TelecomClient(
+    base_url="https://api.telecom.com",
+    api_key="your-api-key"
+)
+
+# Create a subscriber
+subscriber = client.subscribers.create(CreateSubscriberRequest(
+    msisdn="+1234567890",
+    first_name="John",
+    last_name="Doe",
+    email="john@example.com",
+    plan_id=1
+))
+print(f"Created subscriber: {subscriber.id}")
+```
+
+### Analytics API
+
+```python
+from telecom_sdk import TelecomClient
+from telecom_sdk.types import ChurnRiskLevel
+
+client = TelecomClient(api_key="your-api-key")
+
+# Churn Prediction
+prediction = client.analytics.predict_churn("profile-123")
+print(f"Churn Risk: {prediction.risk_level} (Score: {prediction.risk_score:.2f})")
+
+# Get churn metrics
+metrics = client.analytics.get_churn_metrics("monthly")
+print(f"Monthly Churn Rate: {metrics.monthly_churn_rate:.2f}%")
+
+# Get at-risk customers
+at_risk = client.analytics.get_at_risk_customers(
+    risk_level=ChurnRiskLevel.HIGH,
+    limit=100
+)
+print(f"Found {len(at_risk)} high-risk customers")
+
+# Market metrics
+market = client.analytics.get_market_metrics("quarterly")
+print(f"Market Share: {market.market_share_pct:.2f}%")
+```
+
+### Security API
+
+```python
+from telecom_sdk import TelecomClient
+from telecom_sdk.types import FraudType, FraudSeverity, FraudAlertFilter
+
+client = TelecomClient(api_key="your-api-key")
+
+# Analyze transaction
+alert = client.security.analyze_transaction({
+    "profile_id": "profile-123",
+    "amount": 99.99,
+    "ip_address": "192.168.1.1",
+    "device_id": "device-456",
+    "transaction": "payment"
+})
+if alert:
+    print(f"Fraud Alert: {alert.type} (Severity: {alert.severity})")
+
+# Get fraud alerts
+alerts = client.security.get_fraud_alerts(FraudAlertFilter(
+    severity=FraudSeverity.HIGH,
+    status="new",
+    limit=50
+))
+print(f"Found {len(alerts)} fraud alerts")
+
+# Get fraud metrics
+fraud_metrics = client.security.get_fraud_metrics("monthly")
+print(f"Resolution Rate: {fraud_metrics.resolution_rate_pct:.2f}%")
+```
+
+---
+
+## TypeScript SDK
+
+### Basic Usage
+
+```typescript
+import { TelecomClient, CreateSubscriberRequest } from '@taas/sdk';
+
+// Initialize client
+const client = new TelecomClient({
+  baseUrl: 'https://api.telecom.com',
+  apiKey: 'your-api-key'
+});
+
+// Create a subscriber
+const subscriber = await client.subscribers.create({
+  msisdn: '+1234567890',
+  firstName: 'John',
+  lastName: 'Doe',
+  email: 'john@example.com',
+  planId: 1
+});
+console.log(`Created subscriber: ${subscriber.id}`);
+```
+
+### Analytics API
+
+```typescript
+import { TelecomClient, ChurnRiskLevel } from '@taas/sdk';
+import { AnalyticsAPI } from '@taas/sdk/analytics';
+
+const client = new TelecomClient({ apiKey: 'your-api-key' });
+const analytics = new AnalyticsAPI(client.httpClient);
+
+// Churn Prediction
+const prediction = await analytics.predictChurn('profile-123');
+console.log(`Churn Risk: ${prediction.riskLevel} (Score: ${prediction.riskScore.toFixed(2)})`);
+
+// Get churn metrics
+const metrics = await analytics.getChurnMetrics('monthly');
+console.log(`Monthly Churn Rate: ${metrics.monthlyChurnRate.toFixed(2)}%`);
+
+// Get at-risk customers
+const atRisk = await analytics.getAtRiskCustomers(ChurnRiskLevel.High, 100);
+console.log(`Found ${atRisk.length} high-risk customers`);
+
+// Market metrics
+const market = await analytics.getMarketMetrics('quarterly');
+console.log(`Market Share: ${market.marketSharePct.toFixed(2)}%`);
+```
+
+### Security API
+
+```typescript
+import { TelecomClient, FraudSeverity, FraudAlertFilter } from '@taas/sdk';
+import { SecurityAPI } from '@taas/sdk/security';
+
+const client = new TelecomClient({ apiKey: 'your-api-key' });
+const security = new SecurityAPI(client.httpClient);
+
+// Analyze transaction
+const alert = await security.analyzeTransaction({
+  profileId: 'profile-123',
+  amount: 99.99,
+  ipAddress: '192.168.1.1',
+  deviceId: 'device-456',
+  transaction: 'payment'
+});
+if (alert) {
+  console.log(`Fraud Alert: ${alert.type} (Severity: ${alert.severity})`);
+}
+
+// Get fraud alerts
+const alerts = await security.getFraudAlerts({
+  severity: FraudSeverity.High,
+  status: 'new',
+  limit: 50
+});
+console.log(`Found ${alerts.length} fraud alerts`);
+
+// Get fraud metrics
+const fraudMetrics = await security.getFraudMetrics('monthly');
+console.log(`Resolution Rate: ${fraudMetrics.resolutionRatePct.toFixed(2)}%`);
+```
+
+---
+
+## Analytics API
+
+### Endpoints
+
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| POST | `/api/v1/analytics/churn/predict` | Predict churn for a profile |
+| GET | `/api/v1/analytics/churn/metrics` | Get churn metrics |
+| GET | `/api/v1/analytics/churn/at-risk` | Get at-risk customers |
+| GET | `/api/v1/analytics/market/metrics` | Get market metrics |
+| GET | `/api/v1/analytics/maintenance/metrics` | Get predictive maintenance metrics |
+| GET | `/api/v1/analytics/pricing/metrics` | Get pricing metrics |
+| POST | `/api/v1/analytics/pricing/optimize` | Optimize pricing for rate plans |
+
+### Churn Risk Levels
+
+- `low` - Low risk of churn (< 25% probability)
+- `medium` - Medium risk of churn (25-50% probability)
+- `high` - High risk of churn (50-75% probability)
+- `critical` - Critical risk of churn (> 75% probability)
+
+---
+
+## Security API
+
+### Endpoints
+
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| POST | `/api/v1/security/fraud/analyze` | Analyze transaction for fraud |
+| POST | `/api/v1/security/fraud/alerts` | Get fraud alerts with filters |
+| PUT | `/api/v1/security/fraud/alerts/:id` | Update alert status |
+| GET | `/api/v1/security/fraud/metrics` | Get fraud metrics |
+
+### Fraud Types
+
+- `account_takeover` - Unauthorized account access
+- `subscription_fraud` - Fraudulent subscription creation
+- `payment_fraud` - Fraudulent payment transactions
+- `usage_anomaly` - Abnormal usage patterns
+- `sim_swap` - Unauthorized SIM swap attempts
+
+### Fraud Severity Levels
+
+- `low` - Low severity, monitor only
+- `medium` - Medium severity, review required
+- `high` - High severity, immediate action needed
+- `critical` - Critical severity, block transaction
+
+---
+
+## Currency & Billing API
+
+### Endpoints
+
+| Method | Endpoint | Description |
+|--------|----------|-------------|
+| POST | `/api/v1/currency/convert` | Convert currency |
+| GET | `/api/v1/currency/exchange/:from/:to` | Get exchange rate |
+| GET | `/api/v1/currency/exchange/:from/:to/history` | Get exchange rate history |
+| GET | `/api/v1/currency/currencies` | List supported currencies |
+| POST | `/api/v1/currency/exchange/refresh` | Refresh exchange rates |
+| POST | `/api/v1/currency/billing` | Process billing |
+| GET | `/api/v1/currency/billing/history/:profile_id` | Get billing history |
+| GET | `/api/v1/currency/billing/summary/:profile_id` | Get billing summary |
+| POST | `/api/v1/currency/billing/refund/:transaction_id` | Process refund |
+| GET | `/api/v1/currency/billing/analytics` | Get billing analytics |
+
+### Example: Currency Conversion
+
+```typescript
+// TypeScript
+const result = await client.currency.convert({
+  from: 'USD',
+  to: 'EUR',
+  amount: 100.00
+});
+console.log(`${result.amount} ${result.to} = ${result.converted} ${result.from}`);
+```
+
+```python
+# Python
+result = client.currency.convert(
+    from_currency="USD",
+    to_currency="EUR",
+    amount=100.00
+)
+print(f"{result.amount} {result.to_currency} = {result.converted} {result.from_currency}")
+```
+
+```go
+// Go
+result, err := client.Currency.Convert(ctx, &taas.ConvertRequest{
+    From:   "USD",
+    To:     "EUR",
+    Amount: 100.00,
+})
+fmt.Printf("%f %s = %f %s\n", result.Amount, result.To, result.Converted, result.From)
+```
+
+---
+
+## Error Handling
+
+All SDKs provide consistent error handling:
+
+### Go
+
+```go
+subscriber, err := client.Subscribers.Get(ctx, "invalid-id")
+if err != nil {
+    if apiErr, ok := err.(*taas.APIError); ok {
+        fmt.Printf("API Error: %s (Code: %d)\n", apiErr.Message, apiErr.StatusCode)
+    } else {
+        fmt.Printf("Network Error: %v\n", err)
+    }
+}
+```
+
+### Python
+
+```python
+from telecom_sdk.exceptions import APIError, NetworkError
+
+try:
+    subscriber = client.subscribers.get("invalid-id")
+except APIError as e:
+    print(f"API Error: {e.message} (Code: {e.status_code})")
+except NetworkError as e:
+    print(f"Network Error: {e}")
+```
+
+### TypeScript
+
+```typescript
+import { APIError, NetworkError } from '@taas/sdk';
+
+try {
+  const subscriber = await client.subscribers.get('invalid-id');
+} catch (error) {
+  if (error instanceof APIError) {
+    console.log(`API Error: ${error.message} (Code: ${error.statusCode})`);
+  } else if (error instanceof NetworkError) {
+    console.log(`Network Error: ${error.message}`);
+  }
+}
+```
+
+---
+
+## Rate Limiting
+
+The API enforces rate limits per user:
+- **Default**: 100 requests per minute
+- **Burst**: Up to 200 requests in short bursts
+
+SDKs automatically handle rate limiting with exponential backoff:
+
+```typescript
+const client = new TelecomClient({
+  apiKey: 'your-api-key',
+  retryConfig: {
+    maxRetries: 3,
+    retryDelay: 1000, // 1 second
+    retryOnRateLimit: true
+  }
+});
+```
+
+---
+
+## Support
+
+- **Documentation**: [https://docs.telecom-platform.com](https://docs.telecom-platform.com)
+- **GitHub Issues**: [https://github.com/nutcas3/telecom-platform/issues](https://github.com/nutcas3/telecom-platform/issues)
+- **Email**: sdk-support@telecom-platform.com