Preto.ai Blog https://preto.ai/blog/ LLM cost optimization & OpenAI cost tracking en-us Fri, 24 Apr 2026 00:00:00 GMT GPT-5 vs Claude Sonnet 4: Price and Performance for Production Workloads https://preto.ai/blog/gpt-5-vs-claude-sonnet-4/ Real per-task cost math, head-to-head benchmark results, and the gotchas that don't show up on the pricing page. Plus: what changes when Sonnet 4 deprecates June 15, 2026 and you're choosing between GPT-5 and Sonnet 4.6 for the workload that's actually shipping. Fri, 24 Apr 2026 00:00:00 GMT https://preto.ai/blog/gpt-5-vs-claude-sonnet-4/ gaurav@preto.ai My AI Startup's Gross Margin Was 72%. Then I Counted LLM Costs. https://preto.ai/blog/ai-startup-margin-llm-costs/ The number on the board deck was 72% gross margin. Then I moved LLM API spend from 'infrastructure' to COGS where it belongs. The real number was 31%. Here's the math, the levers I pulled, and why this is happening to almost every AI founder. Wed, 22 Apr 2026 00:00:00 GMT https://preto.ai/blog/ai-startup-margin-llm-costs/ gaurav@preto.ai We Analyzed 1M API Requests — Here Are the 7 Changes That Cut OpenAI Costs 40-60% https://preto.ai/blog/reduce-openai-costs/ Seven sourced, primary-research-backed tactics that cut production OpenAI bills 40–60% — model routing, prompt caching, semantic caching, prompt compression, output token reduction, batch API, and proxy-layer budget enforcement. Every number cited. Sun, 19 Apr 2026 00:00:00 GMT https://preto.ai/blog/reduce-openai-costs/ gaurav@preto.ai Your Cost-Per-Request Is the Number You Should Be Losing Sleep Over https://preto.ai/blog/cost-per-request/ Total LLM spend tells you what you owe. Cost-per-request tells you whether your product makes economic sense. Here's how to calculate it across tokens, retries, infrastructure, and the multi-call workflows that hide most of the bill. Fri, 17 Apr 2026 00:00:00 GMT https://preto.ai/blog/cost-per-request/ gaurav@preto.ai LLM API Costs for Healthcare SaaS: HIPAA Compliance and Token Economics https://preto.ai/blog/ai-costs-healthcare-saas/ HIPAA-bound LLM workloads pay for what consumer AI gets free: PHI redaction, restricted caching, audit logging, and BAA-tier endpoints. Here's the real per-encounter cost math for scribing, clinical decision support, and prior authorization. Wed, 15 Apr 2026 00:00:00 GMT https://preto.ai/blog/ai-costs-healthcare-saas/ gaurav@preto.ai The Unit Economics Nobody Shows on Their AI SaaS Pitch Deck https://preto.ai/blog/ai-saas-unit-economics/ Most AI SaaS founders model LLM costs as fixed infrastructure. They're not — they're variable COGS that scales with engagement. Here's what the real gross margin looks like after LLM costs, and the five metrics that actually matter. Tue, 14 Apr 2026 00:00:00 GMT https://preto.ai/blog/ai-saas-unit-economics/ gaurav@preto.ai AI Costs for Legal Tech: What Law Firms Actually Spend on LLM APIs https://preto.ai/blog/ai-costs-legal-tech/ Document review, contract analysis, and legal research drive the largest LLM bills in legal tech — and contract analysis routinely runs 5–7x over budget because teams estimate volume but miss token count. Here's the breakdown. Mon, 13 Apr 2026 00:00:00 GMT https://preto.ai/blog/ai-costs-legal-tech/ gaurav@preto.ai AI Costs for Fintech: LLM Spending Patterns in Financial Services https://preto.ai/blog/ai-costs-fintech/ Fraud detection, KYC, and compliance monitoring are the three biggest LLM cost drivers in fintech — and fraud detection routinely runs 4x over budget. Here's why, and what to do about it. Sun, 12 Apr 2026 00:00:00 GMT https://preto.ai/blog/ai-costs-fintech/ gaurav@preto.ai Your AI Costs Will 3x This Year. Here's How to Survive It. https://preto.ai/blog/ai-costs-saas-3x/ LLM prices dropped 80% last year. Your bill still went up. Here's why AI costs triple even as models get cheaper — and the 5-part plan that keeps them under control. Sat, 11 Apr 2026 00:00:00 GMT https://preto.ai/blog/ai-costs-saas-3x/ gaurav@preto.ai How to Build Automatic Model Routing for LLM APIs https://preto.ai/blog/llm-model-routing/ Most teams send every request to GPT-4o. Classification tasks cost 100x more than they should. Here's the complexity estimator, routing decision tree, and Go implementation that fixes it. Fri, 10 Apr 2026 00:00:00 GMT https://preto.ai/blog/llm-model-routing/ gaurav@preto.ai LLM Gateway vs LLM Proxy vs LLM Router: What's the Difference? https://preto.ai/blog/llm-gateway-vs-proxy-vs-router/ Everyone calls their product a gateway now. Here's a precise technical definition of each term — proxy, router, gateway — with Go code examples for each layer, and what you actually need at your scale. Thu, 09 Apr 2026 00:00:00 GMT https://preto.ai/blog/llm-gateway-vs-proxy-vs-router/ gaurav@preto.ai Streaming SSE Proxying for LLM APIs: The Hard Parts https://preto.ai/blog/streaming-sse-proxy/ SSE proxying looks simple until you hit production. Here are the four failure modes — chunk corruption, token leaks on disconnect, backpressure, and mid-stream errors — and the Go patterns that fix them. Thu, 09 Apr 2026 00:00:00 GMT https://preto.ai/blog/streaming-sse-proxy/ gaurav@preto.ai Prompt Hashing for Duplicate Detection: Cutting LLM Waste With SHA-256 https://preto.ai/blog/prompt-hashing-duplicate-detection/ The average production app sends 15-30% duplicate LLM requests. SHA-256 prompt hashing catches the exact ones. Here's the canonical hash key, the Go implementation, and real duplicate rates from anonymized production data. Wed, 08 Apr 2026 00:00:00 GMT https://preto.ai/blog/prompt-hashing-duplicate-detection/ gaurav@preto.ai How We Log LLM Requests at Sub-50ms Latency Using ClickHouse https://preto.ai/blog/clickhouse-llm-logging/ We switched from PostgreSQL to ClickHouse for LLM request logging. Query latency dropped 10x. Here's the schema, the materialized views, and the async write path that keeps logging under 2ms p95. Tue, 07 Apr 2026 00:00:00 GMT https://preto.ai/blog/clickhouse-llm-logging/ gaurav@preto.ai Semantic Caching for LLM APIs: Architecture and Real-World Hit Rates https://preto.ai/blog/semantic-caching-llm/ Semantic caching promises 90%+ cost savings on LLM APIs. Production data shows hit rates of 20-45%, not 95%. Here's what actually works and what doesn't. Wed, 01 Apr 2026 00:00:00 GMT https://preto.ai/blog/semantic-caching-llm/ gaurav@preto.ai Building an LLM Proxy in Go: Why We Chose Go Over Rust and Python https://preto.ai/blog/llm-proxy-golang/ We evaluated Go, Rust, and Python to build our LLM proxy. Go won — and not for the reason you'd expect. Here's the engineering trade-off breakdown. Tue, 31 Mar 2026 00:00:00 GMT https://preto.ai/blog/llm-proxy-golang/ gaurav@preto.ai The Architecture Behind LLM Proxies: What Happens to Your API Request in 47ms https://preto.ai/blog/llm-proxy-architecture/ How LLM proxies route, cache, and optimize every API request in under 50ms. A full technical breakdown of the 7 layers your request passes through before reaching OpenAI. Tue, 24 Mar 2026 00:00:00 GMT https://preto.ai/blog/llm-proxy-architecture/ gaurav@preto.ai The Real Cost of Every LLM API in 2026 https://preto.ai/blog/llm-api-pricing-2026/ A complete pricing breakdown of every major LLM API in 2026 — GPT-5, Claude, Gemini, Llama, and more. Real per-request costs, hidden fees, and how teams cut their AI bill by 40–60%. Sun, 15 Mar 2026 00:00:00 GMT https://preto.ai/blog/llm-api-pricing-2026/ gaurav@preto.ai