California Generative AI: Training Data Transparency

Summary

California AB 2013 — the Generative AI Training Data Transparency Act, also searched as "CA AB 2013" or "AB 2013 California" — is codified at Civil Code Title 15.2, Sections 3110 and 3111. It requires a developer of a generative AI (GenAI) system or service that was released on or after January 1, 2022 and made publicly available to Californians to publish training-data documentation on the developer's public website. AB 2013 regulates developers, not deployers or end users: the disclosure duty falls on the entity that designs, codes, produces, or substantially modifies the GenAI system or service.

AB 2013's training-data documentation duty is one part of California's generative-AI transparency regime; it operates alongside California SB 942, the AI Transparency Act, which governs disclosure of AI-generated image, video, and audio content, and California SB 53 (TFAIA), which imposes safety-framework and critical-incident-reporting duties on frontier-model developers.

Who must comply with AB 2013

The statute reaches a developer that makes a covered GenAI system or service available to people in California, regardless of where the developer is located. A "developer" includes a person that substantially modifies a GenAI system or service, so fine-tuning or materially retraining a third-party model can bring an organization into scope.

Required training-data documentation (Civil Code § 3111)

The developer must post a high-level summary of the datasets used to develop the GenAI system or service. The summary must address each of the following:

• Sources or owners of the datasets
• How the datasets further the intended purpose of the AI system or service
• The number of data points in the datasets (general ranges and estimates are permitted)
• The types of data points, with a general description for unstructured data
• Whether the datasets include data protected by copyright, trademark, or patent, or are entirely in the public domain
• Whether the datasets were purchased or licensed by the developer
• Whether the datasets include personal information as defined in Civil Code § 1798.140
• Whether the datasets include aggregate consumer information as defined in Civil Code § 1798.140
• Whether there was any cleaning, processing, or other modification of the datasets by the developer, including the intended purpose of those alterations
• The dates the datasets were first used during development
• The time period over which the data was collected, including a notice if collection is ongoing
• Whether the GenAI system or service used or continuously uses synthetic data generation (a description of the functional need or operational outcome may be included)

When the documentation must be posted

The first posting deadline is January 1, 2026. Because the requirement is keyed to public availability, a developer that releases a new covered model — or substantially modifies an existing one — after that date must post updated documentation before that release or modification reaches Californians. The obligation is therefore continuous, not a one-time filing.

Exclusions

Civil Code § 3110 excludes a GenAI system or service whose sole purpose is to help ensure security and integrity, the operation of aircraft in the national airspace, or that is developed for national security, military, or defense purposes and is made available only to a federal entity.

Penalties and enforcement

Civil Code §§ 3110–3111 do not state a standalone civil-penalty amount or create an express private right of action. The Atlas therefore records no fixed statutory penalty for AB 2013 rather than importing a dollar amount or enforcement theory from another California law.

Primary sources: California Civil Code Title 15.2, §§ 3110–3111, leginfo.legislature.ca.gov, and the chaptered AB 2013 text — retrieved July 27, 2026.