Monitoring Tokens, Latency & Cost in Real Time with Requesty Live Logs

In the rapidly evolving world of AI applications, deploying large language models (LLMs) in production is just the beginning. The real challenge? Keeping them running efficiently, cost-effectively, and reliably at scale. Without proper monitoring, your LLM-powered application can quickly become a black box that burns through budgets, frustrates users with slow responses, or worse—fails silently while you're none the wiser.

That's where real-time monitoring comes in. By tracking tokens, latency, and costs as they happen, you gain the visibility needed to optimize performance, control spending, and deliver exceptional user experiences. Let's explore how Requesty Live Logs makes this critical task not just possible, but surprisingly straightforward.

Why Real-Time LLM Monitoring Is Non-Negotiable

Think of LLM monitoring as the dashboard in your car. You wouldn't drive cross-country without knowing your speed, fuel level, or engine temperature. Similarly, running production LLMs without monitoring is asking for trouble:

  • Unexpected cost spikes can turn a $500 monthly budget into a $30,000 surprise bill

  • Performance degradation might go unnoticed until users start complaining

  • Compliance violations could expose sensitive data without your knowledge

  • Model failures may cascade through your application, creating poor user experiences

The three pillars of LLM observability—tokens, latency, and cost—form the foundation of operational excellence. Master these, and you'll have the insights needed to build reliable, efficient AI applications.

Understanding the Core Metrics

Token Usage: The Currency of AI

Tokens are the fundamental units that LLMs process—think of them as the "words" your AI reads and writes. Every API call consumes tokens, and every token costs money. Monitoring token usage helps you:

  • Identify inefficient prompts that waste tokens

  • Spot verbose model outputs that could be condensed

  • Track usage patterns across different users or features

  • Predict and control costs before they spiral

With Requesty's unified gateway, you can monitor token usage across 160+ models from a single dashboard, making it easy to compare efficiency between different providers like Claude 4, GPT-4o, or DeepSeek R1.

Latency: The Speed of Thought

Latency measures how quickly your LLM responds to requests. But here's the catch—averages lie. A service might average 500ms response times while some users wait 5 seconds. That's why monitoring tail latencies (P95, P99) is crucial.

Key latency metrics to track:

  • Time to first token (critical for streaming responses)

  • Total response time

  • P95/P99 latencies (what your slowest users experience)

  • Latency by model and provider

Requesty's smart routing automatically directs requests to the fastest available models, ensuring optimal latency while maintaining quality.

Cost: The Bottom Line

Every token processed translates directly to dollars spent. Real-time cost monitoring helps you:

  • Set and enforce budget limits

  • Identify cost-heavy operations or users

  • Compare pricing across different models

  • Optimize prompt engineering for cost efficiency

Through Requesty's routing optimizations, teams typically see up to 80% cost savings by intelligently routing requests to the most cost-effective models without sacrificing quality.

What Makes Requesty Live Logs Different

Traditional logging solutions weren't built for the unique challenges of LLM applications. Requesty Live Logs provides purpose-built monitoring that captures:

  • Comprehensive Request Data: Every prompt, response, token count, and timing metric

  • Real-Time Visibility: See what's happening now, not what happened yesterday

  • Intelligent Filtering: Quickly find specific requests by user, model, endpoint, or custom metadata

  • Cost Attribution: Know exactly how much each user, feature, or experiment costs

  • Error Tracking: Categorize and analyze failures, timeouts, and model-specific issues

Advanced Monitoring Patterns

Multi-Layer Observability

Effective monitoring happens at multiple levels:

  • Client Layer: Basic request tracking and user attribution

  • Gateway Layer: Rich logging of all LLM interactions (where Requesty shines)

  • Backend Layer: Application-specific metrics and business logic monitoring

By positioning monitoring at the gateway level, Requesty captures comprehensive data without requiring changes to your application code.

Proactive Anomaly Detection

Don't wait for problems to find you. Set up alerts for:

  • Token usage spikes (catch runaway prompts early)

  • Latency degradation (maintain user experience)

  • Error rate increases (identify reliability issues)

  • Cost threshold breaches (protect your budget)

Requesty's enterprise features include advanced alerting and budget controls, ensuring you're always in control.

Security and Compliance Monitoring

With Requesty's security guardrails, you can automatically:

  • Scan for PII and sensitive data in requests and responses

  • Detect potential prompt injection attacks

  • Ensure compliance with data residency requirements

  • Track and audit all LLM interactions for regulatory purposes

Practical Implementation Tips

Start with the Basics

Begin by monitoring these essential metrics:

  • Total tokens per request (input + output)

  • Response latency (P50, P95, P99)

  • Cost per request

  • Error rates by type

Requesty's quickstart guide gets you up and running in minutes with OpenAI-compatible SDKs.

Use Request Metadata Effectively

Tag your requests with custom metadata to enable powerful analytics:

```

  • user_id: Track per-user costs and usage

  • feature_name: Attribute costs to specific features

  • experiment_id: Compare different prompt versions

  • environment: Separate dev/staging/production metrics

```

Request metadata in Requesty enables granular tracking and analysis.

Implement Cost Controls

Prevent budget overruns with these strategies:

  • Set up real-time cost alerts

  • Implement per-user or per-API-key spending limits

  • Use cheaper models for non-critical tasks

  • Cache common responses to reduce API calls

Requesty's API spend limits and auto-caching features make cost control automatic.

Real-World Success Stories

Teams using Requesty Live Logs have achieved remarkable results:

  • A SaaS startup reduced their monthly LLM costs by 73% after identifying and optimizing inefficient prompts

  • An enterprise customer improved P95 latency by 2.3x using smart routing across multiple providers

  • A healthcare app ensured HIPAA compliance by implementing automated PII detection in their logs

  • An e-commerce platform prevented a $15,000 cost overrun by catching a recursive prompt bug within minutes

Best Practices for Long-Term Success

Treat Prompts as Code

Version your prompts and monitor their performance over time. Track metrics for each version to understand the impact of changes on cost, latency, and quality.

Monitor at Scale

As your application grows, ensure your monitoring solution can handle:

  • High request volumes (thousands per second)

  • Multiple models and providers

  • Complex routing logic

  • Team collaboration needs

Requesty's enterprise platform scales with your needs, supporting everything from startups to Fortune 500 companies.

Integrate with Your Existing Stack

Requesty works seamlessly with popular frameworks and tools:

Getting Started with Requesty Live Logs

Ready to take control of your LLM operations? Here's how to get started:

1. Sign up for Requesty (free tier available) 2. Follow the quickstart guide to integrate with your application 3. Configure your monitoring preferences and alerts 4. Start seeing real-time insights into your LLM usage

With Requesty's unified gateway handling routing, caching, failover, and monitoring, you can focus on building great AI experiences while we handle the operational complexity.

Conclusion

Real-time monitoring of tokens, latency, and cost isn't just a nice-to-have—it's essential for any production LLM deployment. Without it, you're flying blind, risking budget overruns, performance issues, and compliance violations.

Requesty Live Logs provides the comprehensive observability you need, combined with powerful routing and optimization features that can reduce costs by up to 80%. By monitoring at the gateway level, you get complete visibility across all 160+ supported models while benefiting from intelligent routing, automatic failover, and enterprise-grade security.

Don't let your LLM costs spiral out of control or your users suffer from poor performance. Join the 15,000+ developers who trust Requesty to route, secure, and optimize their LLM traffic. Your future self (and your CFO) will thank you.

Start monitoring with Requesty today and experience the peace of mind that comes with complete LLM observability.