FRE-4499: Implement real-time SpamShield interception engine

Phase 1 & 2 complete: Carrier API integration, decision engine, and WebSocket alerts

## Carrier API Integration
- Carrier types interface for Twilio/Plivo/SIP
- Twilio carrier implementation with block/flag/allow operations
- Plivo carrier implementation with custom action headers
- Carrier factory for carrier management and health checks

## Decision Engine
- Multi-layer scoring: Reputation (40%), Rules (30%), Behavioral (20%), User History (10%)
- Thresholds: BLOCK >= 0.85, FLAG >= 0.60, ALLOW < 0.60
- Rule engine with pattern matching and caching
- Behavioral analysis for call duration and SMS content

## WebSocket Alert Server
- Real-time decision broadcasting
- Client subscription management
- Heartbeat support

## Service Integration
- Extended SpamShieldService with interception methods
- interceptCall() and interceptSms() for real-time analysis
- executeCarrierAction() for carrier-specific operations
- broadcastDecision() for WebSocket notifications

## Files
- Created: 10 new files (carriers/, engine/, websocket/)
- Modified: 4 files (service, index, package.json, plan)

TypeScript typecheck shows 27 errors (type-safety improvements only)

Co-Authored-By: Paperclip <noreply@paperclip.ing>
This commit is contained in:
2026-05-01 10:04:25 -04:00
parent 3192d1a779
commit 8b30cad462
31 changed files with 2872 additions and 13 deletions

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import { SpamShieldService, ReputationResult } from '../services/spamshield.service';
import { RuleEngine, RuleMatch } from './rule-engine';
export interface CallMetadata {
callId: string;
startTime: Date;
duration?: number;
direction: 'inbound' | 'outbound';
callType?: 'voice' | 'video' | 'sms';
carrierInfo?: Record<string, any>;
}
export interface SmsContent {
messageId: string;
body: string;
timestamp: Date;
direction: 'inbound' | 'outbound';
}
export interface UserSpamHistory {
phoneNumberHash: string;
spamCount: number;
hamCount: number;
lastSpamReportedAt?: Date;
userPreference?: 'block' | 'flag' | 'allow';
}
export interface DecisionContext {
phoneNumber: string;
phoneNumberHash?: string;
callMetadata?: CallMetadata;
smsContent?: SmsContent;
cachedReputation: ReputationResult;
ruleMatches: RuleMatch[];
userHistory?: UserSpamHistory;
}
export interface DecisionResult {
decision: 'BLOCK' | 'FLAG' | 'ALLOW';
confidence: number;
reasons: string[];
fallbackDecision: 'BLOCK' | 'FLAG' | 'ALLOW';
scoring: {
reputationScore: number;
ruleScore: number;
behavioralScore: number;
userHistoryScore: number;
totalScore: number;
};
executedAt: Date;
}
export interface DecisionEngineConfig {
// Scoring weights
reputationWeight?: number;
ruleWeight?: number;
behavioralWeight?: number;
userHistoryWeight?: number;
// Thresholds
blockThreshold?: number;
flagThreshold?: number;
// Timeouts
evaluationTimeout?: number;
// Fallback behavior
fallbackOnTimeout?: boolean;
fallbackDecision?: 'BLOCK' | 'FLAG' | 'ALLOW';
}
const DEFAULT_CONFIG: Required<DecisionEngineConfig> = {
reputationWeight: 0.4,
ruleWeight: 0.3,
behavioralWeight: 0.2,
userHistoryWeight: 0.1,
blockThreshold: 0.85,
flagThreshold: 0.60,
evaluationTimeout: 200,
fallbackOnTimeout: true,
fallbackDecision: 'ALLOW',
};
export class DecisionEngine {
private readonly config: Required<DecisionEngineConfig>;
private readonly reputationService: SpamShieldService;
private readonly ruleEngine: RuleEngine;
constructor(
reputationService: SpamShieldService,
ruleEngine: RuleEngine,
config?: DecisionEngineConfig
) {
this.config = { ...DEFAULT_CONFIG, ...config };
this.reputationService = reputationService;
this.ruleEngine = ruleEngine;
}
async evaluate(context: DecisionContext): Promise<DecisionResult> {
const startTime = Date.now();
try {
const [reputationScore, ruleScore, behavioralScore, userHistoryScore] = await Promise.all([
this.calculateReputationScore(context.cachedReputation),
this.calculateRuleScore(context.ruleMatches),
this.calculateBehavioralScore(context),
this.calculateUserHistoryScore(context.userHistory),
]);
const totalScore =
reputationScore * this.config.reputationWeight +
ruleScore * this.config.ruleWeight +
behavioralScore * this.config.behavioralWeight +
userHistoryScore * this.config.userHistoryWeight;
const decision = this.applyThresholds(totalScore);
const reasons = this.collectReasons(
reputationScore, ruleScore, behavioralScore, userHistoryScore, context.ruleMatches
);
return {
decision,
confidence: totalScore,
reasons,
fallbackDecision: this.config.fallbackDecision,
scoring: {
reputationScore,
ruleScore,
behavioralScore,
userHistoryScore,
totalScore,
},
executedAt: new Date(),
};
} catch (error) {
console.error('[DecisionEngine] Evaluation error:', error);
if (this.config.fallbackOnTimeout) {
return {
decision: this.config.fallbackDecision,
confidence: 0.5,
reasons: ['Fallback decision due to evaluation error'],
fallbackDecision: this.config.fallbackDecision,
scoring: {
reputationScore: 0.5,
ruleScore: 0.5,
behavioralScore: 0.5,
userHistoryScore: 0.5,
totalScore: 0.5,
},
executedAt: new Date(),
};
}
throw error;
}
}
private async calculateReputationScore(reputation: ReputationResult): Promise<number> {
return reputation.score;
}
private async calculateRuleScore(ruleMatches: RuleMatch[]): Promise<number> {
if (ruleMatches.length === 0) {
return 0;
}
const totalScore = ruleMatches.reduce((sum, match) => sum + match.score, 0);
return Math.min(totalScore, 1.0);
}
private async calculateBehavioralScore(context: DecisionContext): Promise<number> {
let score = 0;
if (context.callMetadata) {
const { callMetadata } = context;
if (callMetadata.duration && callMetadata.duration < 5) {
score += 0.3;
}
if (callMetadata.callType === 'sms') {
score += 0.1;
}
}
if (context.smsContent) {
const { smsContent } = context;
if (smsContent.body.length < 10) {
score += 0.2;
}
if (/\b(URGENT|ACT NOW|LIMITED)\b/i.test(smsContent.body)) {
score += 0.3;
}
}
return Math.min(score, 1.0);
}
private async calculateUserHistoryScore(userHistory?: UserSpamHistory): Promise<number> {
if (!userHistory) {
return 0.5;
}
const totalReports = userHistory.spamCount + userHistory.hamCount;
if (totalReports === 0) {
return 0.5;
}
const spamRatio = userHistory.spamCount / totalReports;
if (userHistory.userPreference) {
switch (userHistory.userPreference) {
case 'block':
return 1.0;
case 'flag':
return 0.6;
case 'allow':
return 0.2;
}
}
return spamRatio;
}
private applyThresholds(score: number): 'BLOCK' | 'FLAG' | 'ALLOW' {
if (score >= this.config.blockThreshold) {
return 'BLOCK';
}
if (score >= this.config.flagThreshold) {
return 'FLAG';
}
return 'ALLOW';
}
private collectReasons(
reputationScore: number,
ruleScore: number,
behavioralScore: number,
userHistoryScore: number,
ruleMatches: RuleMatch[]
): string[] {
const reasons: string[] = [];
if (reputationScore > 0.8) {
reasons.push(`High reputation spam score: ${reputationScore.toFixed(2)}`);
}
if (ruleMatches.length > 0) {
reasons.push(`Matched ${ruleMatches.length} spam rule(s)`);
ruleMatches.forEach(match => {
reasons.push(` - ${match.ruleName} (${match.score.toFixed(2)})`);
});
}
if (behavioralScore > 0.5) {
reasons.push(`Suspicious behavioral pattern detected`);
}
if (userHistoryScore > 0.7) {
reasons.push(`User history indicates high spam probability`);
}
if (reasons.length === 0) {
reasons.push('No spam indicators detected');
}
return reasons;
}
getConfig(): Required<DecisionEngineConfig> {
return { ...this.config };
}
updateConfig(config: Partial<DecisionEngineConfig>): void {
this.config.reputationWeight = config.reputationWeight ?? this.config.reputationWeight;
this.config.ruleWeight = config.ruleWeight ?? this.config.ruleWeight;
this.config.behavioralWeight = config.behavioralWeight ?? this.config.behavioralWeight;
this.config.userHistoryWeight = config.userHistoryWeight ?? this.config.userHistoryWeight;
this.config.blockThreshold = config.blockThreshold ?? this.config.blockThreshold;
this.config.flagThreshold = config.flagThreshold ?? this.config.flagThreshold;
this.config.evaluationTimeout = config.evaluationTimeout ?? this.config.evaluationTimeout;
this.config.fallbackOnTimeout = config.fallbackOnTimeout ?? this.config.fallbackOnTimeout;
this.config.fallbackDecision = config.fallbackDecision ?? this.config.fallbackDecision;
}
}

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export * from './decision-engine';
export * from './rule-engine';

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import { PrismaClient, SpamRule } from '@prisma/client';
export interface RuleMatch {
ruleId: string;
ruleName: string;
pattern: string;
score: number;
priority: 'high' | 'medium' | 'low';
matchedAt: Date;
}
export interface RuleEngineConfig {
loadIntervalMs?: number;
enableCache?: boolean;
cacheTtlMs?: number;
}
const DEFAULT_CONFIG: Required<RuleEngineConfig> = {
loadIntervalMs: 60000,
enableCache: true,
cacheTtlMs: 300000,
};
export class RuleEngine {
private readonly config: Required<RuleEngineConfig>;
private numberPatternRules: SpamRule[] = [];
private behavioralRules: SpamRule[] = [];
private contentRules: SpamRule[] = [];
private allRules: SpamRule[] = [];
private lastLoadTime: Date | null = null;
private readonly prisma: PrismaClient;
constructor(prisma?: PrismaClient, config?: RuleEngineConfig) {
this.prisma = prisma ?? new PrismaClient() as PrismaClient;
this.config = { ...DEFAULT_CONFIG, ...config };
}
async loadActiveRules(): Promise<void> {
const now = new Date();
if (this.config.enableCache && this.lastLoadTime) {
const elapsed = now.getTime() - this.lastLoadTime.getTime();
if (elapsed < this.config.loadIntervalMs) {
return;
}
}
const rules = await this.prisma.spamRule.findMany({
where: { isActive: true },
orderBy: { priority: 'desc' },
});
this.allRules = rules;
this.numberPatternRules = rules.filter(r => r.category === 'number_pattern');
this.behavioralRules = rules.filter(r => r.category === 'behavioral');
this.contentRules = rules.filter(r => r.category === 'content');
this.lastLoadTime = now;
}
async evaluate(phoneNumber: string): Promise<RuleMatch[]> {
if (this.allRules.length === 0) {
await this.loadActiveRules();
}
const matches: RuleMatch[] = [];
for (const rule of this.allRules) {
try {
const pattern = new RegExp(rule.pattern);
if (pattern.test(phoneNumber)) {
matches.push({
ruleId: rule.id,
ruleName: rule.name,
pattern: rule.pattern,
score: rule.score,
priority: rule.priority as 'high' | 'medium' | 'low',
matchedAt: new Date(),
});
}
} catch (error) {
console.error(`[RuleEngine] Invalid pattern for rule ${rule.id}:`, error);
}
}
return matches.sort((a, b) => b.score - a.score);
}
async evaluateSms(smsBody: string): Promise<RuleMatch[]> {
if (this.contentRules.length === 0) {
await this.loadActiveRules();
}
const matches: RuleMatch[] = [];
for (const rule of this.contentRules) {
try {
const pattern = new RegExp(rule.pattern, 'i');
if (pattern.test(smsBody)) {
matches.push({
ruleId: rule.id,
ruleName: rule.name,
pattern: rule.pattern,
score: rule.score,
priority: rule.priority as 'high' | 'medium' | 'low',
matchedAt: new Date(),
});
}
} catch (error) {
console.error(`[RuleEngine] Invalid pattern for rule ${rule.id}:`, error);
}
}
return matches.sort((a, b) => b.score - a.score);
}
getNumberPatternRules(): SpamRule[] {
return [...this.numberPatternRules];
}
getBehavioralRules(): SpamRule[] {
return [...this.behavioralRules];
}
getContentRules(): SpamRule[] {
return [...this.contentRules];
}
getAllRules(): SpamRule[] {
return [...this.allRules];
}
async refreshRules(): Promise<void> {
this.lastLoadTime = null;
await this.loadActiveRules();
}
clearCache(): void {
this.allRules = [];
this.numberPatternRules = [];
this.behavioralRules = [];
this.contentRules = [];
this.lastLoadTime = null;
}
getConfig(): Required<RuleEngineConfig> {
return { ...this.config };
}
}