https://aikeys.co/blog/Guides to calling frontier models through one API key, and to what per-token pricing costs.enhttps://aikeys.co/blog/chat-completions-vs-messages-vs-responses/https://aikeys.co/blog/chat-completions-vs-messages-vs-responses/The three request formats behind most LLM APIs, side by side: required fields, where the system prompt goes, how to read the reply, and when to pick each.Tue, 13 Oct 2026 00:00:00 GMThttps://aikeys.co/blog/claude-fable-opus-sonnet-haiku-api-cost/https://aikeys.co/blog/claude-fable-opus-sonnet-haiku-api-cost/What one task costs on each Claude tier, for three task shapes, with October 2026 list prices. Plus a simple rule for picking the tier.Tue, 13 Oct 2026 00:00:00 GMThttps://aikeys.co/blog/handle-429-503-llm-api-errors/https://aikeys.co/blog/handle-429-503-llm-api-errors/Which LLM API errors to retry, how long to wait, and how to fall back to another model when there is no capacity. With Python code for the OpenAI SDK.Tue, 13 Oct 2026 00:00:00 GMThttps://aikeys.co/blog/llm-api-pricing-explained/https://aikeys.co/blog/llm-api-pricing-explained/How input and output token prices add up, a worked monthly estimate for Claude, GPT and Gemini, and five ways to cut the bill.Tue, 13 Oct 2026 00:00:00 GMThttps://aikeys.co/blog/one-api-key-claude-gpt-gemini/https://aikeys.co/blog/one-api-key-claude-gpt-gemini/Point the OpenAI or Anthropic SDK at one base URL, pick a model id, and call Claude, GPT and Gemini models with the same key. Python, TypeScript and cURL.Tue, 13 Oct 2026 00:00:00 GMT