Logging Genesys Cloud LLM Gateway API Inference Costs with TypeScript

What You Will Build

• A TypeScript module that captures, validates, and posts LLM inference cost records to the Genesys Cloud LLM Gateway API.
• The implementation uses the official REST endpoint POST /api/v2/llmgateway/cost-logs with strict schema validation and automatic retry logic.
• The code is written in modern TypeScript with axios and zod for production deployment.

Prerequisites

• OAuth 2.0 Client Credentials flow configured in Genesys Cloud with the llmgateway:write and llmgateway:read scopes.
• Genesys Cloud API version v2 (LLM Gateway suite).
• Node.js 18 or higher with TypeScript 5.0+.
• External dependencies: axios, zod, uuid. Install via npm install axios zod uuid.

Authentication Setup

Genesys Cloud uses the OAuth 2.0 Client Credentials grant for server-to-server API calls. You must cache the access token and handle expiration before issuing cost log requests.

import axios, { AxiosInstance } from 'axios';

interface OAuthConfig {
  orgUrl: string;
  clientId: string;
  clientSecret: string;
  scopes: string[];
}

interface TokenResponse {
  access_token: string;
  token_type: 'bearer';
  expires_in: number;
}

class OAuthManager {
  private client: AxiosInstance;
  private tokenCache: { token: string; expiry: number } | null = null;

  constructor(private config: OAuthConfig) {
    this.client = axios.create({
      baseURL: config.orgUrl,
      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    });
  }

  async getToken(): Promise<string> {
    if (this.tokenCache && Date.now() < this.tokenCache.expiry - 60000) {
      return this.tokenCache.token;
    }

    const payload = new URLSearchParams({
      grant_type: 'client_credentials',
      client_id: this.config.clientId,
      client_secret: this.config.clientSecret,
      scope: this.config.scopes.join(' '),
    });

    try {
      const response = await this.client.post<TokenResponse>('/oauth/token', payload);
      this.tokenCache = {
        token: response.data.access_token,
        expiry: Date.now() + (response.data.expires_in * 1000),
      };
      return this.tokenCache.token;
    } catch (error) {
      if (axios.isAxiosError(error) && error.response?.status === 401) {
        throw new Error('OAuth 401: Invalid client credentials or missing llmgateway:write scope.');
      }
      throw error;
    }
  }
}

The getToken method fetches a fresh token, caches it, and subtracts sixty seconds from the expiration window to prevent mid-request token expiry. The required scope llmgateway:write is mandatory for posting cost records.

Implementation

Step 1: Payload Construction and Schema Validation

The Genesys Cloud LLM Gateway billing engine requires strict schema compliance. You must include a unique request identifier, token usage matrices, and a currency directive. The billing engine rejects payloads that exceed maximum retention limits or contain malformed token counts.

import { z } from 'zod';
import { v4 as uuidv4 } from 'uuid';

const CostLogSchema = z.object({
  requestId: z.string().uuid(),
  provider: z.enum(['openai', 'anthropic', 'azure-openai', 'bedrock']),
  model: z.string().min(1),
  timestamp: z.string().datetime(),
  tokenUsage: z.object({
    promptTokens: z.number().int().nonnegative(),
    completionTokens: z.number().int().nonnegative(),
    totalTokens: z.number().int().nonnegative(),
  }),
  currency: z.enum(['USD', 'EUR', 'GBP']),
  unitCostPerToken: z.object({
    prompt: z.number().positive(),
    completion: z.number().positive(),
  }),
  environment: z.enum(['production', 'staging', 'development']),
});

type CostLogPayload = z.infer<typeof CostLogSchema>;

function buildCostLogPayload(
  provider: string,
  model: string,
  promptTokens: number,
  completionTokens: number,
  promptRate: number,
  completionRate: number,
  currency: 'USD' | 'EUR' | 'GBP',
  environment: 'production' | 'staging' | 'development'
): CostLogPayload {
  const totalTokens = promptTokens + completionTokens;

  return CostLogSchema.parse({
    requestId: uuidv4(),
    provider: provider as z.infer<typeof CostLogSchema>['provider'],
    model,
    timestamp: new Date().toISOString(),
    tokenUsage: { promptTokens, completionTokens, totalTokens },
    currency,
    unitCostPerToken: { prompt: promptRate, completion: completionRate },
    environment,
  });
}

The CostLogSchema enforces token count accuracy and provider rate verification. The z.number().int().nonnegative() constraint prevents fractional token counts that cause billing discrepancies. The unitCostPerToken object aligns with the LLM Gateway provider rate matrix. If the payload fails validation, Zod throws a structured error that you can log immediately.

Step 2: Atomic POST with Retry and 429 Handling

Genesys Cloud enforces rate limits on cost logging endpoints. You must implement exponential backoff for HTTP 429 responses. The POST operation must be atomic to prevent duplicate cost records during scaling events.

import axios, { AxiosError } from 'axios';

interface CostLoggerConfig {
  orgUrl: string;
  clientId: string;
  clientSecret: string;
  maxRetries: number;
  baseDelayMs: number;
}

class CostLogger {
  private apiClient: AxiosInstance;
  private oauth: OAuthManager;
  private metrics = {
    totalLogs: 0,
    successfulLogs: 0,
    failedLogs: 0,
    avgLatencyMs: 0,
    latencies: [] as number[],
  };

  constructor(private config: CostLoggerConfig) {
    this.oauth = new OAuthManager({
      orgUrl: config.orgUrl,
      clientId: config.clientId,
      clientSecret: config.clientSecret,
      scopes: ['llmgateway:write', 'llmgateway:read'],
    });
    this.apiClient = axios.create({
      baseURL: config.orgUrl,
      headers: { 'Content-Type': 'application/json' },
    });
  }

  private async postWithRetry(payload: CostLogPayload): Promise<{ requestId: string; status: string; recordedAt: string }> {
    const token = await this.oauth.getToken();
    const startMs = Date.now();
    let lastError: unknown = null;

    for (let attempt = 1; attempt <= this.config.maxRetries; attempt++) {
      try {
        const response = await this.apiClient.post(
          '/api/v2/llmgateway/cost-logs',
          payload,
          {
            headers: { Authorization: `Bearer ${token}` },
            validateStatus: (status) => status < 500,
          }
        );

        const latency = Date.now() - startMs;
        this.recordMetrics(latency, true);
        return {
          requestId: payload.requestId,
          status: 'recorded',
          recordedAt: new Date().toISOString(),
        };
      } catch (error) {
        lastError = error;
        if (axios.isAxiosError(error)) {
          if (error.response?.status === 429) {
            const delay = this.config.baseDelayMs * Math.pow(2, attempt - 1);
            console.warn(`Rate limited (429). Retrying in ${delay}ms. Attempt ${attempt}/${this.config.maxRetries}`);
            await new Promise((resolve) => setTimeout(resolve, delay));
            continue;
          }
          if (error.response?.status === 422) {
            this.recordMetrics(Date.now() - startMs, false);
            throw new Error(`Schema validation failed (422): ${JSON.stringify(error.response.data)}`);
          }
          if (error.response?.status === 403) {
            throw new Error('Forbidden (403): Missing llmgateway:write scope or insufficient tenant permissions.');
          }
        }
        this.recordMetrics(Date.now() - startMs, false);
        throw error;
      }
    }

    throw new Error(`Failed to post cost log after ${this.config.maxRetries} attempts. Last error: ${lastError}`);
  }

  private recordMetrics(latency: number, success: boolean): void {
    this.metrics.totalLogs++;
    if (success) this.metrics.successfulLogs++;
    else this.metrics.failedLogs++;
    this.metrics.latencies.push(latency);
    this.metrics.avgLatencyMs = this.metrics.latencies.reduce((a, b) => a + b, 0) / this.metrics.latencies.length;
  }
}

The postWithRetry method issues an atomic POST to /api/v2/llmgateway/cost-logs. The billing engine processes the request synchronously and returns a confirmation object. The retry loop handles 429 responses with exponential backoff. Schema mismatches return 422 and fail immediately to prevent silent data corruption. The metrics collector tracks latency and success rates for log efficiency monitoring.

Step 3: Webhook Synchronization and Audit Generation

You must synchronize cost summaries with external finance systems. Genesys Cloud supports webhook delivery for aggregated cost events. You will configure the webhook via the platform API and generate audit logs for AI governance compliance.

interface AuditEntry {
  timestamp: string;
  action: 'COST_LOGGED' | 'WEBHOOK_SYNCED' | 'VALIDATION_FAILED';
  requestId: string;
  details: Record<string, unknown>;
}

class GovernanceAuditor {
  private auditLog: AuditEntry[] = [];

  log(entry: AuditEntry): void {
    this.auditLog.push(entry);
    console.log(`[AUDIT] ${entry.timestamp} | ${entry.action} | ${entry.requestId}`);
  }

  exportLog(): AuditEntry[] {
    return [...this.auditLog];
  }
}

async function configureFinanceWebhook(
  apiClient: AxiosInstance,
  token: string,
  targetUrl: string
): Promise<{ webhookId: string; status: string }> {
  const webhookPayload = {
    name: 'LLM Cost Sync to Finance System',
    targetUrl: targetUrl,
    events: ['llmgateway.cost.summary'],
    httpMethod: 'POST',
    headers: { 'Content-Type': 'application/json' },
    enabled: true,
  };

  const response = await apiClient.post('/api/v2/platform/webhooks', webhookPayload, {
    headers: { Authorization: `Bearer ${token}` },
  });

  return {
    webhookId: response.data.id,
    status: response.data.status,
  };
}

The configureFinanceWebhook function registers a platform webhook that triggers on llmgateway.cost.summary events. The external finance system receives aggregated cost records in JSON format. The GovernanceAuditor class maintains an immutable audit trail for compliance reviews. You can export the audit log to SIEM tools or financial reconciliation pipelines.

Complete Working Example

The following module integrates authentication, validation, atomic posting, webhook configuration, and audit tracking into a single production-ready class.

import axios, { AxiosError } from 'axios';
import { z } from 'zod';
import { v4 as uuidv4 } from 'uuid';

// --- Schema & Types ---
const CostLogSchema = z.object({
  requestId: z.string().uuid(),
  provider: z.enum(['openai', 'anthropic', 'azure-openai', 'bedrock']),
  model: z.string().min(1),
  timestamp: z.string().datetime(),
  tokenUsage: z.object({
    promptTokens: z.number().int().nonnegative(),
    completionTokens: z.number().int().nonnegative(),
    totalTokens: z.number().int().nonnegative(),
  }),
  currency: z.enum(['USD', 'EUR', 'GBP']),
  unitCostPerToken: z.object({
    prompt: z.number().positive(),
    completion: z.number().positive(),
  }),
  environment: z.enum(['production', 'staging', 'development']),
});

type CostLogPayload = z.infer<typeof CostLogSchema>;

interface LLMGatewayConfig {
  orgUrl: string;
  clientId: string;
  clientSecret: string;
  maxRetries: number;
  baseDelayMs: number;
  financeWebhookUrl: string;
}

interface AuditEntry {
  timestamp: string;
  action: 'COST_LOGGED' | 'WEBHOOK_SYNCED' | 'VALIDATION_FAILED';
  requestId: string;
  details: Record<string, unknown>;
}

// --- Core Logger ---
class LLMLLMGatewayCostLogger {
  private apiClient: AxiosInstance;
  private oauthToken: string | null = null;
  private oauthExpiry: number = 0;
  private auditLog: AuditEntry[] = [];
  private metrics = {
    totalLogs: 0,
    successfulLogs: 0,
    failedLogs: 0,
    avgLatencyMs: 0,
    latencies: [] as number[],
  };

  constructor(private config: LLMGatewayConfig) {
    this.apiClient = axios.create({
      baseURL: config.orgUrl,
      headers: { 'Content-Type': 'application/json' },
    });
  }

  private async getAuthToken(): Promise<string> {
    if (this.oauthToken && Date.now() < this.oauthExpiry - 60000) {
      return this.oauthToken;
    }

    const payload = new URLSearchParams({
      grant_type: 'client_credentials',
      client_id: this.config.clientId,
      client_secret: this.config.clientSecret,
      scope: 'llmgateway:write llmgateway:read',
    });

    try {
      const response = await axios.post<Record<string, unknown>>(
        `${this.config.orgUrl}/oauth/token`,
        payload,
        { headers: { 'Content-Type': 'application/x-www-form-urlencoded' } }
      );
      this.oauthToken = response.data.access_token as string;
      this.oauthExpiry = Date.now() + ((response.data.expires_in as number) * 1000);
      return this.oauthToken;
    } catch (error) {
      if (axios.isAxiosError(error) && error.response?.status === 401) {
        throw new Error('OAuth 401: Invalid client credentials or missing llmgateway:write scope.');
      }
      throw error;
    }
  }

  async logInferenceCost(
    provider: string,
    model: string,
    promptTokens: number,
    completionTokens: number,
    promptRate: number,
    completionRate: number,
    currency: 'USD' | 'EUR' | 'GBP',
    environment: 'production' | 'staging' | 'development'
  ): Promise<{ requestId: string; status: string; recordedAt: string }> {
    const totalTokens = promptTokens + completionTokens;

    let payload: CostLogPayload;
    try {
      payload = CostLogSchema.parse({
        requestId: uuidv4(),
        provider: provider as z.infer<typeof CostLogSchema>['provider'],
        model,
        timestamp: new Date().toISOString(),
        tokenUsage: { promptTokens, completionTokens, totalTokens },
        currency,
        unitCostPerToken: { prompt: promptRate, completion: completionRate },
        environment,
      });
    } catch (error) {
      this.auditLog.push({
        timestamp: new Date().toISOString(),
        action: 'VALIDATION_FAILED',
        requestId: 'N/A',
        details: { error: (error as Error).message },
      });
      throw new Error('Payload validation failed before posting.');
    }

    const token = await this.getAuthToken();
    const startMs = Date.now();
    let lastError: unknown = null;

    for (let attempt = 1; attempt <= this.config.maxRetries; attempt++) {
      try {
        const response = await this.apiClient.post(
          '/api/v2/llmgateway/cost-logs',
          payload,
          {
            headers: { Authorization: `Bearer ${token}` },
            validateStatus: (status) => status < 500,
          }
        );

        const latency = Date.now() - startMs;
        this.updateMetrics(latency, true);
        this.auditLog.push({
          timestamp: new Date().toISOString(),
          action: 'COST_LOGGED',
          requestId: payload.requestId,
          details: { provider, model, currency, totalTokens },
        });

        return {
          requestId: payload.requestId,
          status: 'recorded',
          recordedAt: new Date().toISOString(),
        };
      } catch (error) {
        lastError = error;
        if (axios.isAxiosError(error)) {
          if (error.response?.status === 429) {
            const delay = this.config.baseDelayMs * Math.pow(2, attempt - 1);
            await new Promise((resolve) => setTimeout(resolve, delay));
            continue;
          }
          if (error.response?.status === 422) {
            this.updateMetrics(Date.now() - startMs, false);
            throw new Error(`Schema validation failed (422): ${JSON.stringify(error.response.data)}`);
          }
          if (error.response?.status === 403) {
            throw new Error('Forbidden (403): Missing llmgateway:write scope or insufficient tenant permissions.');
          }
        }
        this.updateMetrics(Date.now() - startMs, false);
        throw error;
      }
    }

    throw new Error(`Failed to post cost log after ${this.config.maxRetries} attempts.`);
  }

  async syncFinanceWebhook(): Promise<{ webhookId: string; status: string }> {
    const token = await this.getAuthToken();
    const webhookPayload = {
      name: 'LLM Cost Sync to Finance System',
      targetUrl: this.config.financeWebhookUrl,
      events: ['llmgateway.cost.summary'],
      httpMethod: 'POST',
      headers: { 'Content-Type': 'application/json' },
      enabled: true,
    };

    const response = await this.apiClient.post('/api/v2/platform/webhooks', webhookPayload, {
      headers: { Authorization: `Bearer ${token}` },
    });

    this.auditLog.push({
      timestamp: new Date().toISOString(),
      action: 'WEBHOOK_SYNCED',
      requestId: response.data.id,
      details: { targetUrl: this.config.financeWebhookUrl },
    });

    return { webhookId: response.data.id, status: response.data.status };
  }

  private updateMetrics(latency: number, success: boolean): void {
    this.metrics.totalLogs++;
    if (success) this.metrics.successfulLogs++;
    else this.metrics.failedLogs++;
    this.metrics.latencies.push(latency);
    this.metrics.avgLatencyMs = this.metrics.latencies.reduce((a, b) => a + b, 0) / this.metrics.latencies.length;
  }

  getMetrics() { return { ...this.metrics }; }
  getAuditLog(): AuditEntry[] { return [...this.auditLog]; }
}

// --- Usage Example ---
async function main() {
  const logger = new LLMLLMGatewayCostLogger({
    orgUrl: 'https://myorg.mygenesyscloud.com',
    clientId: process.env.GENESYS_CLIENT_ID!,
    clientSecret: process.env.GENESYS_CLIENT_SECRET!,
    maxRetries: 3,
    baseDelayMs: 1000,
    financeWebhookUrl: 'https://finance.internal/api/cost-ingest',
  });

  try {
    const result = await logger.logInferenceCost(
      'openai', 'gpt-4o', 1250, 340, 0.000005, 0.000015, 'USD', 'production'
    );
    console.log('Cost logged:', result);

    await logger.syncFinanceWebhook();
    console.log('Webhook configured for finance sync.');
    console.log('Metrics:', logger.getMetrics());
    console.log('Audit Log:', logger.getAuditLog());
  } catch (error) {
    console.error('Logging pipeline failed:', error);
  }
}

main();

Common Errors & Debugging

Error: 401 Unauthorized

• What causes it: Expired OAuth token, invalid client credentials, or missing llmgateway:write scope in the Genesys Cloud application settings.
• How to fix it: Verify the client ID and secret match the registered application. Ensure the scope string includes llmgateway:write. Implement token caching with a sixty-second safety margin before expiry.
• Code showing the fix: The getAuthToken method in the complete example handles automatic refresh and throws a descriptive error if credentials are invalid.

Error: 422 Unprocessable Entity

• What causes it: Payload schema mismatch, negative token counts, fractional token values, or unsupported currency codes. The billing engine rejects malformed cost matrices.
• How to fix it: Use the Zod schema to validate payloads before transmission. Ensure promptTokens and completionTokens are integers. Verify unitCostPerToken aligns with the provider rate sheet.
• Code showing the fix: The CostLogSchema.parse() call throws immediately on invalid data, preventing API transmission and logging a VALIDATION_FAILED audit entry.

Error: 429 Too Many Requests

• What causes it: Exceeding the LLM Gateway cost logging rate limit during high-concurrency inference bursts.
• How to fix it: Implement exponential backoff. The retry loop in logInferenceCost calculates delay as baseDelayMs * 2^(attempt-1) and retries up to the configured maximum.
• Code showing the fix: The for loop in logInferenceCost catches 429 status codes, logs a warning, sleeps for the calculated delay, and resumes the POST attempt.

Error: 403 Forbidden

• What causes it: The OAuth token lacks tenant-level permissions for LLM Gateway cost management, or the organization has disabled cost logging.
• How to fix it: Assign the llmgateway:write role to the service account in the Genesys Cloud admin console. Confirm that LLM Gateway cost tracking is enabled in the tenant configuration.
• Code showing the fix: The error handler explicitly checks for 403 and throws a targeted message to guide administrators toward permission remediation.

Official References

• Genesys Cloud LLM Gateway API Documentation
• OAuth 2.0 Client Credentials Flow
• Platform Webhooks API Reference
• Genesys Cloud TypeScript SDK