Who Wrote This Line? New Tool Traces Every Edit Back to Human or AI
Human vs. AI – Diff-based line-level provenance for text under agentic editing
A new open-source tool, us-vs-them, determines whether each line of a text was written by a human or an AI agent, using only version history—no markup required. It's designed for agentic coding and editing, where preserving human-authored code is crucial. The tool outputs 'islands' of human-authored lines within a 'sea' of machine-generated text, with scores indicating the degree of human authorship. It works as a library or CLI tool and can be used in any git repository.
Text a human wrote or edited should be considered close to sacred: an agent should be hesitant and have a very good reason to touch it.
- hamandcheese
I'm curious why people care about such tracking? I hardly use an editor anymore, and I'm not alone. All that matters is who is signing off on the commit.
> Text a human wrote or edited should be considered close to sacred: an agent should be hesitant and have a very good reason to touch it.
Not sure I agree (particularly with code, not prose). If code is risky to change for reasons that aren't obvious, it should be commented as such. It doesn't matter how the bytes were generated.
> Another use case: the README.md, originally generated, where you rewrite the opening paragraphs. The agent should feel free to redo or append parts further downwards but should really think twice changing anything in the opener.
This, I understand.
- spuz
> A git repository is already a history of versions each carrying a provenance marker — every revision of the file, in order, with the author of the change that made it.
Maybe I'm missing how people use AI these days but when I have an agent working locally, all git commits have my authorship attached.
- alansaber
Cool, we do the same thing, but we also denote when a line is "AI generated but was modified by a human" (aka human made anything upwards of a 1 character change).