Community notes API uses AI to suggest helpful post context on X
Community-Driven API and AI Writer Design for Openly Scaling Community Notes
Social and Information NetworksArtificial Intelligence
Summary
It can be hard to know the full story behind posts on social platforms like X. The authors describe how Community Notes lets users add extra information to posts. They built an AI tool that helps by writing note suggestions when people ask for them. Humans still decide which notes are shown, keeping control away from the AI or the platform. Their AI tool speeds up writing notes and adds coverage where people are less likely to write them themselves.
What this means in practice
- •For social media platform teams: Integrate an AI-powered API that generates crowd-sourced context notes while keeping human control of final note visibility.
- •For online community managers: Boost coverage and speed of context-providing notes on user posts by combining AI suggestions with human review.
Authors
Brad Miller, Jay Baxter, Jiansong Chao, Keith Coleman, Sophie Hilgard, Daniel Ortiz
Abstract
Community Notes is a crowd-sourced approach for adding context to posts on X. Contributors propose and rate notes, forming the inputs to an open-source, open-data algorithm that determines which notes show broadly to users. Since September 2025, Community Notes' AI Note Writer API has provided an open, public interface for using AI to propose notes, while adhering to the founding principle that users, not the platform or an AI, control which notes show on X. Explicit note requests and user posts on X determine the AI API post feeds, ensuring that AI note writing responds to demand from X users. We present the design, operation and impact of the AI API, including analysis of the interaction between AI and human generated notes across topics. Unless otherwise stated, measurements and system description reflect June 2-29, 2026. The Community Writer is the largest AI API client and contributes the bulk of AI API output, generating 52% of notes selected as Helpful and shown broadly on X. The writer is guided by community input during both training and operation to prioritize, draft, evaluate and delete proposed notes. Beyond scale, the writer also offers speed, submitting the first proposed, non-deleted note on 60% of posts when compared to other writers. AI note writing is additive on top of human note writers, extending coverage of Community Notes on X. Among posts that have Helpful notes, 42% have only AI notes, indicating human raters did not feel motivated to propose an alternative. In contrast, 30% have only human notes, reflecting contribution beyond the scope of AI writing. The Community Writer is open-source software released under the Apache 2.0 license.