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

# Technical Overview

> How SubstackAPI provides reliable, high-performance access to Substack publication data.

<Card title="SubstackAPI on GitHub" icon="github" href="https://github.com/Noah-Bjorner/SubstackAPI">
  SubstackAPI is open source and available on GitHub.
</Card>

### Challenge

Substack does not offer a public API. There are currently two ways to access data from a Substack publication:

1. Use the Substack publication RSS feed
2. Use the Substack unofficial/internal API

Both of these options come with their own set of pros and cons.

RSS Feed:

* ✓ Publicly available and stable
* ✓ Official support from Substack
* ✗ Limited data access
* ✗ Slower query performance

Unofficial API:

* ✓ Rich data access
* ✓ Fast query performance
* ✗ No official support
* ✗ Could break without notice
* ✗ Restrictive rate limits

Neither option alone provides a complete solution for content creators to access their data reliably and efficiently.

### Solution

To address these limitations, SubstackAPI implements a hybrid approach:

```mermaid
flowchart LR
Client[API Client]
Cache[(Redis Cache)]
API[Unofficial API]
RSS[RSS Feed]
Client --> Cache
Cache -- "Cache Miss" --> API
API -- "Error" --> RSS
API --> Cache
RSS --> Cache
Cache --> Client
```

1. **Primary Data Source**: Unofficial API
   * Used to fetch publication data
   * Rate limiting handled through minimizing requests

2. **Fallback Mechanism**: RSS Feed
   * Provides backup data access
   * Ensures service continuity if unofficial API changes

3. **Caching Layer**: Redis
   * Minimizes calls to the unofficial API
   * Provides fast, low-latency data access
   * Handles large amounts of requests efficiently

This architecture ensures:

* Reliable and unlimited access to publication data
* Minimal dependency on the unofficial API
* Fast response times
* High availability through fallback mechanisms

The main tradeoff with this solution is a potential delay of up to a few hours for the latest publication updates due to caching.

If you are interested in seeing the source code, you can view it on [GitHub](https://github.com/Noah-Bjorner/SubstackAPI).