---
title: "ai.txt"
slug: "ai-txt"
category: "glossary"
tags: ["glossary", "seo", "ai-txt", "ai-agents", "licensing"]
status: "stable"
last_updated: 2026-05-14
summary: "ai.txt is an optional plain-text manifest served at /ai.txt that declares a site's preferences for AI training and inference access to its content."
related:
  [
    "[[seo/ai-txt]]",
    "[[glossary/llms-txt]]",
    "[[seo/llms-txt]]",
    "[[meta/for-ai-agents]]",
    "[[meta/llm-info-standard]]",
    "[[seo/technical]]",
  ]
---

## Overview

This page is the atomic definition. The deep-dive lives at [[seo/ai-txt]].

## Definition

ai.txt is an optional plain-text manifest served at `/ai.txt` that declares a site's content-licensing preferences for AI systems. The format mirrors `robots.txt`: user-agent groups (Bytespider, GPTBot, ClaudeBot, and others) and `Allow`/`Disallow` directives, with extensions for training versus inference and for opt-in licensing terms. It is a soft signal; honoring it depends on the AI vendor. Spawning AI's Source.Plus initiative and the IETF AI Preferences Working Group are converging on more formal standards.

## When it applies

Ship ai.txt when the site has a deliberate policy on AI training (allow, deny, or license-required). Sites with no policy can skip it; the default for most crawlers is to fetch unless blocked.

## Example

A publisher's `/ai.txt` declares `User-Agent: GPTBot` followed by `Disallow: /` to opt out of OpenAI training, and a separate `User-Agent: ClaudeBot` block with `Allow: /` that permits Anthropic's crawler.

## Related concepts

- [[seo/ai-txt]] - the deep-dive with format rules and vendor support.
- [[glossary/llms-txt]] - the parallel manifest for agent-readable site indexing.
- [[meta/for-ai-agents]] - the agent-onboarding page on this site.
- [[meta/llm-info-standard]] - the broader LLM-info standards survey.
- [[seo/technical]] - the technical SEO checklist that touches crawler directives.

## Citing this term

> See [[glossary/ai-txt|ai.txt]] (llmbestpractices.com/glossary/ai-txt).

## Related

- [[seo/ai-txt]]
- [[seo/llms-txt]]
- [[meta/for-ai-agents]]
- [[glossary/llms-txt]]
- [[meta/llm-info-standard]]