# Atlas coding convention drift detection > Atlas Convention Drift reconciles your declared coding conventions against recently changed code and flags violations without spending a single token. Atlas Convention Drift compares the coding standards you wrote down against what your code actually does. When a recently changed file breaks a rule you declared, such as one concern per file or no em-dashes in client-facing copy, Atlas surfaces the violation in a sidebar panel while it is fresh. The scan contains no LLM calls at all, so it costs nothing to run. The engine ships in Atlas today behind the paid tier, and Atlas Pro is not yet on sale. ## Key takeaways - Built and running in Atlas. Included in the paid tier, which is not yet on sale. - Contains zero LLM calls. The scan is fully deterministic and costs nothing to run. - Scoped to files changed since the last pass, so it flags new drift, not legacy debt. - First run uses a 14-day window by default, so it does not dump your backlog at you. - Surfaces violations in a sidebar panel with file and line. It never edits your code. ## Standards you declared, quietly contradicted You write down how the code should be built, and then it drifts 1 file at a time, until review or never. Convention Drift treats each declared convention as a claim and your recently changed code as reality. When a new change breaks a rule, that violation surfaces while you can still fix it cheaply, instead of accumulating unseen until someone reads the whole diff. ## Zero tokens, by design The entire scan runs with 0 LLM calls, which is unusual enough in 2026 to be worth stating plainly. Each convention is a deterministic checker: regex rules such as no em-dashes and no emoji, count rules such as file-too-long, and structural heuristics such as one concern per file. Because none of it calls a model, Atlas can run the check continuously without metering you. Deriving new conventions from your project guide's prose would need a model, and that part is designed but not yet built. ## New drift, not old debt Flagging an entire codebase at once is noise, so the first run looks back only 14 days by default. After that, Convention Drift scopes its checks to files changed since the last watermark, so the nudges are about fresh drift you just introduced rather than a backlog you already know about. Each violation carries a stable identity, so acknowledging one keeps it quiet while a genuine reintroduction fires again. ## Availability Convention Drift is 1 of the 8 record engines in Atlas, and it sits behind the paid tier. The engine is built and running in the product, gated to Atlas Pro. Pro has no checkout yet, so it is not something you can buy today. Shipped, the automated work log, is the one record engine available free right now. ## FAQ ### Is Atlas convention drift detection available now? The engine is built and running in Atlas, but it sits behind the paid tier and Atlas Pro is not yet on sale, so you cannot purchase access today. ### Where do the conventions come from? Built-in checkers for common rules, plus an optional conventions file in your project. Deriving conventions from your project guide's prose is designed but not yet built. ### Does it check my whole codebase? No. The first run looks back 14 days by default, and after that it scopes checks to files changed since the last pass, so it flags new drift rather than legacy debt. ### Does it use an LLM? No. The scan contains zero LLM calls and is fully deterministic, which is why it can run continuously without costing you anything. ### Will it edit my code to fix violations? No. It surfaces violations with file and line in a sidebar panel. You decide what to change. --- Canonical HTML: https://runatlas.sh/resources/features/convention-drift-detection Source of truth: aeo_pages row `/resources/features/convention-drift-detection` (segment: Platform) (this file is generated from it, never hand-edited). Licence: Atlas is proprietary with a free core. It is not open source and there is no public source repository.