--- name: cost-latency-optimizer description: Reduces LLM costs and improves response times through caching, model selection, batching, and prompt optimization. Provides cost breakdowns, latency hotspots, and configuration recommendations. Use for "cost reduction", "performance optimization", "latency improvement", or "efficiency". ---
Cost & Latency Optimizer
Optimize LLM applications for cost and performance.
Cost Breakdown Analysis
class CostAnalyzer:
def __init__(self):
self.costs = {
"llm_calls": 0,
"embeddings": 0,
"tool_calls": 0,
}
self.counts = {
"llm_calls": 0,
"embeddings": 0,
}def track_llm_call(self, tokens_in: int, tokens_out: int): # GPT-4 pricing cost = (tokens_in / 1000) * 0.03 + (tokens_out / 1000) * 0.06 self.costs["llm_calls"] += cost self.counts["llm_calls"] += 1
def report(self): return { "total_cost": sum(self.costs.values()), "breakdown": self.costs, "avg_cost_per_call": self.costs["llm_calls"] / self.counts["llm_calls"], } ```
Caching Strategy
import hashlib
from functools import lru_cacheclass LLMCache: def __init__(self, redis_client): self.cache = redis_client self.ttl = 3600 # 1 hour
def get_cache_key(self, prompt: str, model: str) -> str: content = f"{model}:{prompt}" return f"llm_cache:{hashlib.sha256(content.encode()).hexdigest()}"
def get(self, prompt: str, model: str): key = self.get_cache_key(prompt, model) return self.cache.get(key)
def set(self, prompt: str, model: str, response: str): key = self.get_cache_key(prompt, model) self.cache.setex(key, self.ttl, response)
Usage
cache = LLMCache(redis_client)
def cached_llm_call(prompt: str, model: str = "gpt-4"): # Check cache cached = cache.get(prompt, model) if cached: return cached
Call LLM
response = llm(prompt, model=model)
Cache result
cache.set(prompt, model, response)
return response ```
Model Selection
MODEL_PRICING = {
"gpt-4": {"input": 0.03, "output": 0.06},
"gpt-3.5-turbo": {"input": 0.0005, "output": 0.0015},
"claude-3-opus": {"input": 0.015, "output": 0.075},
"claude-3-sonnet": {"input": 0.003, "output": 0.015},
}def select_model_by_complexity(query: str) -> str: """Use cheaper models for simple queries""" # Classify complexity complexity = classify_complexity(query)
if complexity == "simple": return "gpt-3.5-turbo" # 60x cheaper elif complexity == "medium": return "claude-3-sonnet" else: return "gpt-4"
def classify_complexity(query: str) -> str: # Simple heuristics if len(query) < 100 and "?" in query: return "simple" elif any(word in query.lower() for word in ["analyze", "complex", "detailed"]): return "complex" return "medium" ```
Prompt Optimization
def optimize_prompt(prompt: str) -> str:
"""Reduce token count while preserving meaning"""
optimizations = [
# Remove extra whitespace
lambda p: re.sub(r'\s+', ' ', p),Remove examples if not critical
lambda p: p.split("Examples:")[0] if "Examples:" in p else p,
Use abbreviations
lambda p: p.replace("For example", "E.g."), ]
for optimize in optimizations: prompt = optimize(prompt)
return prompt.strip()
Example: 500 tokens → 350 tokens = 30% cost reduction
`
Batching
async def batch_llm_calls(prompts: List[str], batch_size: int = 5):
"""Process multiple prompts in parallel"""
results = []for i in range(0, len(prompts), batch_size): batch = prompts[i:i + batch_size]
Parallel execution
batch_results = await asyncio.gather(*[ llm_async(prompt) for prompt in batch ])
results.extend(batch_results)
return results
10 sequential calls: ~30 seconds
# 10 batched calls (5 parallel): ~6 seconds ```
Latency Hotspot Analysis
import timeclass LatencyTracker: def __init__(self): self.timings = {}
def track(self, operation: str): def decorator(func): def wrapper(*args, **kwargs): start = time.time() result = func(*args, **kwargs) duration = time.time() - start
if operation not in self.timings: self.timings[operation] = [] self.timings[operation].append(duration)
return result return wrapper return decorator
def report(self): return { op: { "count": len(times), "total": sum(times), "avg": sum(times) / len(times), "p95": sorted(times)[int(len(times) * 0.95)] } for op, times in self.timings.items() }
Usage
tracker = LatencyTracker()
@tracker.track("llm_call") def call_llm(prompt): return llm(prompt)
After 100 calls
print(tracker.report()) # {"llm_call": {"avg": 2.3, "p95": 4.1, ...}} ```
Optimization Recommendations
def generate_recommendations(cost_analysis, latency_analysis):
recs = []High LLM costs
if cost_analysis["costs"]["llm_calls"] > 10: recs.append({ "issue": "High LLM costs", "recommendation": "Implement caching for repeated queries", "impact": "50-80% cost reduction", })
if cost_analysis["avg_cost_per_call"] > 0.01: recs.append({ "issue": "Using expensive model for all queries", "recommendation": "Use gpt-3.5-turbo for simple queries", "impact": "60% cost reduction", })
High latency
if latency_analysis["llm_call"]["avg"] > 3: recs.append({ "issue": "High LLM latency", "recommendation": "Batch parallel calls, use streaming", "impact": "50% latency reduction", })
return recs ```
Streaming for Faster TTFB
async def streaming_llm(prompt: str):
"""Stream tokens as they're generated"""
async for chunk in llm_stream(prompt):
yield chunk
# User sees partial response immediatelyTime to First Byte: ~200ms (streaming) vs ~2s (waiting for full response)
`
Best Practices
- Cache aggressively: Identical queries cached
- Model selection: Use cheaper models when possible
- Prompt optimization: Reduce unnecessary tokens
- Batching: Parallel execution for throughput
- Streaming: Faster perceived latency
- Monitor costs: Track per-user, per-feature
- Set budgets: Alert on anomalies
Output Checklist
- Cost tracking implementation
- Caching layer
- Model selection logic
- Prompt optimization
- Batching for parallel calls
- Latency tracking
- Hotspot analysis
- Optimization recommendations
- Budget alerts
- Performance dashboard