# TryFast documentation

TryFast runs A/B tests on your website. You add one line to your pages, change a headline, a button or a whole page for some of your visitors, and TryFast tells you in plain words when a result is safe to act on. Everything you can do in the app, your AI agent can do through the MCP server and your scripts through the REST API. TryFast is hosted in Germany.

## How TryFast is organized

- A **workspace** holds your projects, team members, connected AI agents, API keys and plan. You can start one without an account and save it to an account later ([Workspaces and accounts](account.md)).
- A **project** is one website (one or more domains) with one **snippet**, the line you paste into your pages ([Install the snippet](install.md)).
- An **experiment** tests an idea on a project: the **control** (your page as it is, letter A) against one or more **variations** (B, C and so on), shown to a share of your visitors ([Experiments](experiments/index.md)).
- A **goal** defines what counts as a conversion: a click, a page visit, a form, a purchase with revenue ([Goals](goals.md)).
- A **visitor** is one browser with a random TryFast id. Visitors are split between the control and the variations and keep their variation on later visits.
- The **results** compare the conversion rate of each variation with the control and give a verdict: ship it, keep the original, keep collecting, or check your data ([Statistics](statistics.md)).

## Start here

1. [Install the snippet](install.md) and connect your cookie banner.
2. [Create your first experiment](experiments/index.md) with the [visual editor](experiments/visual-editor.md), with code, or by asking your AI agent.
3. [Define a goal](goals.md) and [preview every variation](experiments/qa-and-preview.md) on your live site.
4. Launch it and [read the results](statistics.md) whenever you like: the statistics stay valid however often you look.

## Work with AI agents

- [Connect an AI agent](ai-agents.md): Claude Code, Claude, ChatGPT, Cursor, VS Code and any other MCP client, through `https://tryfast.eu/mcp`.
- [MCP server reference](mcp.md): every tool, prompt and resource, and how approvals keep you in control of launches.

## Developer reference

- [REST API](api.md): authentication, conventions and [error codes](api.md#errors). The machine-readable description is at `https://tryfast.eu/api/openapi.yaml`.
- [JavaScript API](javascript-api.md): `window.tryfast`, window events, URL parameters and the code contract for variation JavaScript.
- [Integrations](integrations.md): Google Tag Manager and the data layer, DOM events, and cookie banner recipes.

## Experiments in depth

[Variations](experiments/variations.md) (changes, CSS, JavaScript, redirects), [Visual editor](experiments/visual-editor.md), [Targeting](experiments/targeting.md) (pages, triggers, audiences), [Traffic](experiments/traffic.md), [Lifecycle and approvals](experiments/lifecycle.md), [QA and preview](experiments/qa-and-preview.md).

## Privacy, limits and the inspector

- [Privacy and consent](privacy-and-consent.md): what the snippet stores in your visitors' browsers, the consent modes, retention and how to erase one visitor.
- [Limitations](limitations.md): what TryFast does not do yet, and the limits every client-side testing tool shares.
- [The TryFast inspector](inspect.md): what our page checker fetches and how it identifies itself.

## Company and legal

[About us](about-us.md) describes who builds and operates TryFast. Legal and compliance information is at [/legal/](../legal/index.md). Every docs and legal page is also available as raw markdown: add `.md` to its address (this page is `/docs/index.md`). An index for AI agents is at `https://tryfast.eu/llms.txt`.

Questions: support@tryfast.eu.