# Single Post
Source: https://substackapi.dev/api-reference/endpoint/post

GET /post
Get a single post from your publication by slug.



# Latest Posts
Source: https://substackapi.dev/api-reference/endpoint/posts-latest

GET /posts/latest
Get the latest posts from your publication.



# Search Posts
Source: https://substackapi.dev/api-reference/endpoint/posts-search

GET /posts/search
Search for posts in your publication.



# Top Posts
Source: https://substackapi.dev/api-reference/endpoint/posts-top

GET /posts/top
Get the most popular posts from your publication.



# FAQ
Source: https://substackapi.dev/faq

Frequently asked questions about the API.

<AccordionGroup>
  <Accordion title="Is this the official API for Substack?">
    No, this is not the official Substack API. This is a community-driven project to provide a free and easy-to-use API for Substack content creators. This API is not affiliated with Substack.
  </Accordion>

  <Accordion title="Is this API free?">
    Yes, this API is free to use.
  </Accordion>

  <Accordion title="How do I get started?">
    To get started, please refer to the [Quickstart guide](./quickstart).
  </Accordion>

  <Accordion title="How do I get an API key?">
    You can get an API key by visiting the [API Key Generator](https://auth.substackapi.dev) and following the instructions.
  </Accordion>

  <Accordion title="Can I access any Substack publication?">
    While all Substack publications are available, you can only access data from publications you own or have explicit permission to access. Each API key is linked to one specific Substack publication and can only access data from that publication.
  </Accordion>

  <Accordion title="Do you collect any data?">
    Yes, we collect data about API usage. This helps us understand how the API is used and how we can improve it. However, we do not collect any data related to the content of Substack publications.
  </Accordion>

  <Accordion title="Is this project open source?">
    Yes, the project is open source and the code is available on [GitHub](https://github.com/Noah-Bjorner/SubstackAPI).
  </Accordion>

  <Accordion title="How do I get support?">
    If you need help, please reach out via email at [bjornernoah@gmail.com](mailto:bjornernoah@gmail.com).
  </Accordion>

  <Accordion title="Who made this?">
    This API was created by [Noah Bjorner](https://github.com/Noah-Bjorner). If you wish to reach out, please contact me at [bjornernoah@gmail.com](mailto:bjornernoah@gmail.com).
  </Accordion>
</AccordionGroup>


# Introduction
Source: https://substackapi.dev/introduction

Welcome to Substack API, the unofficial open-source API for Substack publications.

<img alt="Hero Light" />

<img alt="Hero Dark" />

## What is Substack API?

Substack API allows Substack publications to access their content and display it on their own websites or applications. The API provides:

* Fast and reliable access to your publication's content
* Simple authentication using API keys
* Free to use with generous rate limits

## Available Endpoints

<CardGroup>
  <Card title="Latest Posts" icon="clock" href="/api-reference/endpoint/posts-latest">
    Get the latest posts from your publication.
  </Card>

  <Card title="Top Posts" icon="trophy" href="/api-reference/endpoint/posts-top">
    Get the most popular posts from your publication.
  </Card>

  <Card title="Search Posts" icon="magnifying-glass" href="/api-reference/endpoint/posts-search">
    Search for posts in your publication.
  </Card>

  <Card title="Single Post" icon="newspaper" href="/api-reference/endpoint/post">
    Get a single post from your publication by slug.
  </Card>
</CardGroup>

## How to get started

<Steps>
  <Step title="Generate an API Key">
    Visit the [API Key Generator](https://auth.substackapi.dev) to create your API key. You'll need your Substack publication URL.
  </Step>

  <Step title="Use the API Key">
    Include your API key in the `X-API-Key` header when making requests to the API.
  </Step>

  <Step title="Explore the API">
    Refer to the [API Reference](/api-reference) for detailed endpoint documentation and examples.
  </Step>
</Steps>

<Tip>
  You can try out the API without an API key using the [Try it](/api-reference/endpoint/posts-latest) feature available for all endpoints.
</Tip>

<Note>
  For a detailed walkthrough, check out our video tutorial and step-by-step guide in the [Quickstart](/quickstart) page.
</Note>

## Need Help?

* Check out our [FAQ](/faq) for common questions
* View the technical details in our [Technical Overview](/technical-overview)
* Contact the developer at [bjornernoah@gmail.com](mailto:bjornernoah@gmail.com)
* View the source code on [GitHub](https://github.com/Noah-Bjorner/SubstackAPI)


# Quickstart
Source: https://substackapi.dev/quickstart

Learn how to use the Substack API.

<video />

## Step by Step Guide

Get started with SubstackAPI in just a few simple steps:

<Steps>
  <Step title="Generate an API Key">
    Go to the [API Key Generator](https://auth.substackapi.dev) to create your unique API key. You'll need:

    * Your email address
    * Your Substack publication URL (access will be limited to this publication)
  </Step>

  <Step title="Explore API Endpoints">
    Browse the API documentation to find available endpoints, including their URLs, parameters, and responses. Use the interactive "Try it" feature to test requests and verify your implementation before integrating.
  </Step>

  <Step title="Integrate with Your Application">
    With your API key and endpoint information ready, you can now authenticate your requests, make API calls from your application.
  </Step>
</Steps>


# Technical Overview
Source: https://substackapi.dev/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 theme={null}
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).


# Usage & Limits
Source: https://substackapi.dev/usage-limits

API request limits and intended usage guidelines.

## Intended Use

This API is intended exclusively for:

* Content owners accessing their own Substack publication data
* Applications authorized by publication owners to interact with their content
* Legitimate integrations with Substack publications by copyright holders

<Warning>
  This API is not intended for:

  * Unauthorized scraping of Substack content
  * Accessing publications without explicit permission from the content owner
  * Mass collection or aggregation of Substack content without authorization
</Warning>

Violation of these usage guidelines may result in immediate API access termination.

## Rate Limits

| Endpoint      | Rate Limit             |
| ------------- | ---------------------- |
| /posts/latest | 10 requests per minute |
| /posts/top    | 10 requests per minute |
| /posts/search | 20 requests per minute |
| /post         | 15 requests per minute |

* Production API keys use the limits shown above, while test API keys are limited to 3 requests per minute for all endpoints.
* Rate limits are tracked by the **client's IP address**, not by API key.
* Exceeding these limits will result in a `429 Too Many Requests` response.

## Authentication

<Info>
  Authentication is handled via the `X-API-Key` header. Each API key is linked to one Substack publication and can only access its data.
</Info>

### API Key Format

* Production keys start with `sk_live_`
* Test keys start with `sk_test_`

### Using Your API Key

Include your API key in all requests using the `X-API-Key` header:

```bash theme={null}
curl https://api.substackapi.dev/api_key/validate \
-H "X-API-Key: sk_live_your_key_here"
```