> ## Documentation Index
> Fetch the complete documentation index at: https://docs.reduce.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Core Concepts

> Understand the building blocks of Reduce

## Newsletter

A newsletter is the top-level container for a specific topic or interest area. Each newsletter has:

* A **name** and optional **description**
* One or more **sources** (where content comes from)
* One or more **sections** (what content to extract)
* A **cadence** (delivery schedule)
* An **active/paused** state

You can create multiple newsletters for different topics — for example, one for AI coding and another for crypto news.

## Source

A source is a content feed from a supported platform. Sources provide the raw content that sections process.

**Supported platforms:**

| Platform    | Source type        | Example                                           | Availability |
| ----------- | ------------------ | ------------------------------------------------- | ------------ |
| YouTube     | Channel            | @fireship, @anthropic-ai                          | Free & Pro   |
| Reddit      | Subreddit          | r/ClaudeAI, r/LocalLLaMA                          | Free & Pro   |
| X/Twitter   | Account            | @AnthropicAI, @OpenAI                             | Free & Pro   |
| RSS         | Feed               | Any RSS/Atom feed URL                             | Pro only     |
| Podcast     | Feed               | Podcast RSS feed URL                              | Pro only     |
| Email Inbox | Forwarding address | Forward newsletters to your unique Reduce address | Pro only     |

<Note>
  X/Twitter sources have a separate limit: **4 on Free**, **50 on Pro**. All other sources share a pool of **20 on Free** and **100 on Pro**.
</Note>

**Coming soon:** Hacker News, GitHub, Discord, and more.

Sources are shared across the newsletter — every section has access to content from all sources in its parent newsletter.

## Section

A section is a filtered view of your newsletter's content, defined by a custom prompt. Free users get **1 section** with a default prompt; Pro users can create up to **10 sections** with custom prompts. Each section has:

* A **name** (displayed as a heading in the newsletter)
* A **prompt** (tells the AI what to extract and how to summarize)

The prompt is the key to getting exactly the content you want. Be specific about what you're looking for.

**Good prompts:**

* "New AI coding tools, extensions, and IDE integrations released this week"
* "Breaking changes, deprecations, and migration guides for popular frameworks"
* "Practical tutorials and how-to guides for using Claude in development workflows"

**Vague prompts (avoid):**

* "Interesting stuff"
* "AI news"
* "Updates"

## Cadence

The cadence defines when your newsletter is delivered. Free users are limited to **weekly** delivery. Pro users can choose any schedule:

| Cadence       | Description                   | Availability |
| ------------- | ----------------------------- | ------------ |
| Weekly        | Once per week on a chosen day | Free & Pro   |
| Daily         | Every day at a specified time | Pro only     |
| Every X days  | Every 2, 3, or N days         | Pro only     |
| Specific days | e.g., Monday and Thursday     | Pro only     |

## Delivery

A delivery is a single instance of your newsletter being sent. Each delivery:

* Contains only **new content** published since the previous delivery
* Includes all sections with their AI-generated summaries
* Links back to original source content
* Is stored in your delivery history for reference

<Note>
  If no new content is available from your sources, Reduce will let you know rather than sending an empty newsletter.
</Note>

## Content freshness

Reduce tracks what content has already been delivered. Each delivery includes **only content published since the last delivery**, which means:

* No duplicate content across deliveries
* Every email contains fresh, relevant information
* Newsletters stay concise and actionable