AI Token & LLM Cost Engineering Guides
Deep-dive technical documentation written for engineers architecting, evaluating, and scaling production AI systems. No fluff—just equations, code examples, and verified benchmarks.
AI Cost Automation: CLI, CI/CD Token Budgets & Embeds
Shift LLM cost governance left: automate token limits in GitHub Actions with npx @tokenmath/tokenmath, embed live calculator widgets, and schedule diurnal off-peak jobs.
AI Token Optimization & Cost Reduction: The Complete Blueprint
Master prompt caching, Batch API discounts, multimodal video/audio tokenomics, and RAG chunking to reduce LLM API spending by up to 80%.
How AI Tokenization Works: BPE vs SentencePiece
An engineer's breakdown of Byte-Pair Encoding, byte fallbacks, subword vocabularies, and why character counts never equal token counts.
Tokens vs Words: The Definitive Conversion Guide
Exact conversion rules for natural English prose, source code indentation, JSON payloads, and multi-page PDF documents.
Multimodal Vision Token Math: OpenAI 512px Tiles, Claude & Gemini
Detailed tiling formulas, patch dimensions, and video frame-per-second token costs across OpenAI, Anthropic, and Google.
The Engineer's Guide to Reasoning Tokens: o3, o3-pro & Claude Thinking
How invisible chain-of-thought tokens are billed at output rates, managing reasoning_effort, and preventing runaway costs.
Batch API Processing: 50% Discounts, Queues & Evaluation Architecture
Cut token costs in half using asynchronous JSONL queues. 24-hour SLAs, retry semantics, and stacking with prompt caching.
Prompt Caching Economics: How KV Caching Saves Up to 90%
Deep dive into Key-Value attention cache reuse, write-cache amortizations, TTL lifetimes, and breakeven hit-rate formulas.
LLM API Pricing Explained: Input vs Output & Reasoning Tokens
Why generation tokens cost 3x-5x more than input tokens, how internal chain-of-thought tokens are billed, and how to compute blended rates.
RAG Cost Architecture: Ingestion, Chunking & Vector Retrieval
A complete economic blueprint for Retrieval-Augmented Generation: embedding corpus costs, vector database searches, and top-k context sizing.
AI Agent Cost Modeling: Loops, Tool Calls & Context Bloat
How multi-turn autonomous loops compound token consumption across multi-step execution loops, and how prompt caching mitigates ballooning agent expenses.
Managed API vs Self-Hosted GPU TCO: The 50M–150M Token Threshold
The definitive Total Cost of Ownership equation: H100 hourly rates, vLLM throughput, and the 30% idle compute tax.
Input vs Output Tokens: Why Output Costs 3x to 5x More
Hardware bottlenecks: parallel prefill vs autoregressive decode, memory bandwidth limits, and KV cache pressure.
Cached Input Tokens: Mechanics, Break-Evens & Provider Rules
Deep dive into prompt caching across Anthropic, Google, OpenAI, DeepSeek, and Cohere. Break-even hit rate math.
LLM Context Windows: Attention Complexity & Memory Limits
Quadratic attention O(N^2), FlashAttention-3, RoPE frequency scaling, and needle-in-a-haystack retrieval bounds.
AI API Pricing Models: Per-Token, Provisioned & GPU TCO
Complete procurement taxonomy: serverless per-token, Provisioned Throughput Units (PTUs), and dedicated clusters.
Multimodal Token Pricing: Vision Tiles, Audio & Video Math
How 512px image tiles, 1 fps video frames, and Whisper speech audio minutes convert to billable token units.
Token Efficiency: Why Vocabulary Size Changes Your Real Bill
How 200k vs 65k vs 131k vs 152k BPE vocabularies change real-world token counts for code and multilingual text.
Long-Context Pricing: Tier Multipliers & Budget Traps
How Google Gemini 3.1 Pro 2x price multipliers above 200k tokens work, and how to prune context to avoid spikes.
10 Architectural Patterns to Cut LLM API Costs by 50% to 80%
Production playbook: multi-model routing cascades, prefix freezing, semantic caching, and schema compression.
How to Estimate AI Infrastructure Costs for SaaS Applications
Enterprise forecasting framework: DAU unit economics, peak concurrency multipliers, retry buffers, and RAG IOPS.
LLM FinOps: Unit Economics & Anomaly Governance
Marginal cost per user (COGS), automated circuit breakers, token runaway detection, and multi-tenant chargebacks.