Reddit API Overview

The Reddit API allows you to read and write Reddit content such as posts / comments / upvotes, in order to integrate your app's behavior with the content of the community it's installed in.

note

Unlike traditional Reddit API usage, you don't need to create an app at reddit.com/prefs/apps or manage API keys. Devvit handles authentication automatically when you enable the reddit permission in your app.

Private user data

Devvit apps cannot access certain private user data. This data is private to the logged-in user and is not exposed through the Devvit platform:

• Subscribed subreddits - The list of subreddits a user is subscribed to
• Upvoted and downvoted content - Posts and comments the user has voted on
• Saved content - Posts and comments the user has saved
• Recently viewed posts - The user's browsing history
• Private profile information - Any profile data that is not publicly visible
• Follows and friends - The list of users someone follows (on reddit.com) or has friended (on Old Reddit)

The Reddit client

Here's how to obtain a reference to the Reddit client

Devvit Web

devvit.json

{
  "permissions": {
    "reddit": true
  }
}

server/index.ts

import { reddit } from '@devvit/reddit';

Devvit Blocks / Mod Tools

devvit.tsx

import { Devvit } from '@devvit/public-api';

Devvit.configure({
  redditAPI: true,
});

//Then, in any function that has a reference to Devvit.Context:
const reddit = context.reddit;

Reddit Thing IDs

Reddit uses prefixed IDs (called "things") to identify different types of content:

Prefix	Type	Example	Description
t1_	Comment	t1_abc123	A comment on a post or reply to another comment
t2_	User	t2_xyz789	A Reddit user account
t3_	Post	t3_def456	A post
t4_	Message	t4_ghi012	A private message
t5_	Subreddit	t5_jkl345	A subreddit community

These IDs are returned by API methods and used when referencing specific content:

// Get a post by its full ID
const post = await reddit.getPostById('t3_abc123');

// Get a comment by its full ID  
const comment = await reddit.getCommentById('t1_xyz789');

// A comment's parentId can be either a post (t3_) or another comment (t1_)
const parentId = comment.parentId; // 't3_abc123' or 't1_def456'

Example usage

Submitting a post

Devvit Web

import { Devvit } from '@devvit/public-api';
import { context, reddit } from '@devvit/web/server';

export const createPost = async () => {
const { subredditName } = context;
if (!subredditName) {
  throw new Error('subredditName is required');
}

return await reddit.submitCustomPost({
  userGeneratedContent: {
    text: 'Hello there! This is a post from a Devvit app',
  },
  subredditName: subredditName,
  title: 'New Post',
  entry: 'default',
});
};

Devvit Blocks / Mod Tools

import { Devvit } from '@devvit/public-api';

Devvit.configure({
  redditAPI: true,
});

function createPost(context: Devvit.Context) {
  const currentSubreddit = context.reddit.getCurrentSubreddit();
  if (!currentSubreddit) {
    throw new Error('No subreddit found');
  }

  return context.reddit.submitPost({
    title: 'My custom post',
    subredditName: currentSubreddit.name,
    preview: (
      <vstack height="100%" width="100%" alignment="middle center">
        <text size="large">Loading...</text>
      </vstack>
    ),
  });
}

Submitting a comment

note

Auto-comments should be used to spark conversation in the post comments, but you should avoid lower-signal updates (e.g., level/progress pings).

Devvit Web

    import { context, reddit } from '@devvit/web/server';

    export const createComment = async () => {
        const { subredditName } = context;
        if (!subredditName) {
            throw new Error('subredditName is required');
        }

        reddit.submitComment({
            postId: 't3_123456', // Replace with the actual post ID
            text: 'This is a comment from a Devvit app',
            runAs: 'USER' // Optional: specify the user to run as
        });
    };

Devvit Blocks / Mod Tools

    import { Devvit } from '@devvit/public-api';

    Devvit.configure({
        redditAPI: true,
    });

    function createComment(context: Devvit.Context) {
        const { reddit } = context;

        reddit.submitComment({
            postId: 't3_123456', // Replace with the actual post ID
            text: 'This is a comment from a Devvit app',
            runAs: RunAs.USER, // Optional: specify the user to run as
        });
    };