Langfuse v4 + Ollama: Tracing Local LLMs Without Mocks or Monkey-Patches

Disclosure: I learn topics like this through LLM dialogue. The prompts are mine, the depth comes from the model, the verification comes back to me, and I publish the result so others don't have to start from zero. Four files, one wrapper import, and every local Ollama chat turn lands in Langfuse with session_id, user_id, tags, token counts, and reconstructed stream chunks — no custom OTLP exporter, no monkey-patching of the Ollama client, no manual span management. The trick is that Ollama alr...