Codex

A self-hosted OpenTelemetry stack for LLM usage, built as an OpenObserve experiment for customers who keep telemetry on prem: two months of getting the numbers wrong, 118,469 spans of which 118 were useful, and what Rosenberg's learning by using says about why the price list told me nothing.

How we restored the Chat Completions wire API in a Codex fork, so one coding agent drives local Ollama models, OpenRouter, Azure OpenAI with Entra auth, or any EU-hosted provider. The three patches that made it usable, the branch model that keeps the rebases to an hour, and why Baldwin & Clark's design rules say the interface was the thing to fight for.