---
title: "LLM calls with no tracing or cost tracking | Metacenta"
description: "Language-model calls bill per use and get worse without raising an error. How we spot projects with no tracing or cost observability declared."
url: "https://metacenta.com/rules/ai-llm-without-observability"
updated: "2026-10-14"
tokens: 487
---

AI lifecycle · rule ai-llm-without-observability

# LLM calls with no tracing or cost tracking

A Metacenta review checks this under the rule **Model calls are traced and costed**. Everything below applies whether or not you ever commission one.

## What this rule checks

Where a project declares a language-model SDK, this rule checks that a tracing or cost-observability library such as Langfuse or LangSmith is declared too. It reports once for the project.

## Why it matters

Inference is the one dependency that bills per use and degrades without an error. Untraced, a prompt that grew twice as long shows up in next month's bill rather than on the day it shipped.

## How to fix it

**Trace and cost every model call.** Log tokens, latency and model id for every call, and keep the totals. Those figures are what make the next conversation about cost short.

## When it is fine to leave

Spend and latency tracked elsewhere, such as through a gateway or the provider's own usage dashboard broken down by feature, cover this in practice. We report it at medium confidence for that reason.

## What we need to check it

The dependency manifests in your repository. We reason from what they declare, so the finding is medium confidence at most.

[Ask about a review](https://metacenta.com/enquire?src=rule-ai-llm-without-observability&via=md)

## Related pages

- [Unpinned AI and ML library versions](https://metacenta.com/rules/ai-dependency-unpinned)
- [Model training with no experiment tracking](https://metacenta.com/rules/ai-training-without-tracking)
- [LLM apps with no evaluation suite](https://metacenta.com/rules/ai-llm-without-evaluation)
- [Jupyter notebooks committed with outputs](https://metacenta.com/rules/ai-notebook-outputs-committed)
- [A sample review, as a client reads it](https://metacenta.com/sample)
- [All published rules](https://metacenta.com/rules)
- [How a review is assessed](https://metacenta.com/standard)