Migrating from PRAW to Devvit Web

Devvit Web is how you ship the same kind of automation on Reddit’s platform. This guide will outline the basics

note

This guide assumes you have basic familiarity with Python and PRAW (e.g., pip, requirements.txt, and praw.Reddit(...)). The sections below focus on what changes on Devvit.

This guide is a PRAW → Devvit mapping: same workflows, different runtime. For Devvit setup, start with the app quickstart or mod tool quickstart.

Topic	Devvit
Architecture and limits	Devvit Web overview
`devvit.json`	Configure your app

1. Project layout and auth

PRAW	Devvit
`pip` / `requirements.txt`	`npm` / `package.json`
`praw.Reddit(...)` + env	`devvit.json` + `permissions.reddit`
`python bot.py` on your server	`npm run dev` (playtest on Reddit); handlers are HTTP routes, not a forever loop

Devvit (typical new project)

npm install && npm run dev

devvit.json (excerpt)
{
  "name": "my-app",
  "server": {
    "entry": "dist/server/index.cjs"
  },
  "permissions": {
    "reddit": true
  },
  "triggers": {
    "onAppInstall": "/internal/triggers/on-app-install"
  }
}

src/server/index.ts (excerpt)
import { Hono } from "hono";
import type { TriggerResponse } from "@devvit/web/shared";

const app = new Hono();

app.post("/internal/triggers/on-app-install", async (c) => {
  return c.json<TriggerResponse>({ status: "ok" });
});

export default app;

2. `praw.Reddit` → `reddit` and `context`

PRAW	Devvit
`reddit.subreddit(...)`, `reddit.comment(...)`, `reddit.submission(...)`	Import `reddit` from `@devvit/web/server`. Load: `getSubredditInfoByName`, `getCurrentSubreddit`, `getCommentById`, `getPostById`. Submit: `submitPost`, `submitComment`. See `RedditAPIClient`.
Hard-coded subreddit / “current” thing from your script	`context` from `@devvit/web/server` — `subredditName`, `subredditId`, `postId`, `commentId` (menu/form/post surfaces), `postData`. See `BaseContext`.
Thing id from a menu or form action	`context.commentId`, `context.postId` — mod tool quickstart
Subreddit secrets / config in your script	Import `settings` from `@devvit/web/server` (`settings.get(...)`)
Event payload from a stream or webhook	`await c.req.json<OnCommentCreateRequest>()` (and similar types from `@devvit/web/shared`) — Triggers (see Streams → triggers below)

PRAW

for comment in reddit.subreddit("learnpython").stream.comments(skip_existing=True):
    print(comment.author, comment.body)

Devvit — declare a trigger in devvit.json, then handle the event (same idea as Streams → triggers below):

devvit.json (excerpt)
{
  "triggers": {
    "onCommentCreate": "/internal/triggers/on-comment-create"
  }
}

src/server/index.ts
import { Hono } from "hono";
import { context } from "@devvit/web/server";
import type { OnCommentCreateRequest, TriggerResponse } from "@devvit/web/shared";

const app = new Hono();

app.post("/internal/triggers/on-comment-create", async (c) => {
  const { subredditName } = context;
  const input = await c.req.json<OnCommentCreateRequest>();
  const commentId = input.comment?.id;
  const postId = input.comment?.postId;
  if (subredditName && commentId) {
    console.log(`r/${subredditName} new comment (${commentId}) on ${postId}: ${input.comment?.body}`);
  }
  return c.json<TriggerResponse>({ status: "ok" });
});

export default app;

3. Streams → triggers

Your subreddit.stream / mod.stream loops do not have a direct Devvit equivalent. Declare triggers in devvit.json; Reddit POSTs one event per handler invocation (onCommentSubmit, onPostCreate, onModAction, onModMail, …).

PRAW

for comment in reddit.subreddit("your_sub").stream.comments(skip_existing=True):
    if "spam phrase" in (comment.body or "").lower():
        comment.mod.remove(spam=True)

Devvit

devvit.json
{
  "triggers": {
    "onCommentSubmit": "/internal/triggers/on-comment-submit"
  }
}

src/server/index.ts
import { Hono } from "hono";
import { reddit } from "@devvit/web/server";
import type { OnCommentSubmitRequest, TriggerResponse } from "@devvit/web/shared";

const app = new Hono();

app.post("/internal/triggers/on-comment-submit", async (c) => {
  const input = await c.req.json<OnCommentSubmitRequest>();
  const body = (input.comment?.body ?? "").toLowerCase();
  const id = input.comment?.id;
  if (id && body.includes("spam phrase"))
    await reddit.remove(id, true);
  return c.json<TriggerResponse>({ status: "ok" });
});

export default app;

note

Handlers should return quickly (limitations). Defer heavy work to the scheduler or an allow-listed fetch.

4. Scheduler, Redis, and HTTP

PRAW	Devvit
`while True`, `time.sleep`, cron job	Scheduler — cron in `devvit.json` and/or `scheduler.runJob` (recurring scheduler tasks)
SQLite / JSON files / pickle on disk	Redis (per subreddit)
`requests.get` to any URL	Server-side HTTP fetch — `fetch` to domains in `permissions.http.domains`

Redis (replaces local SQLite / JSON files):

src/server/index.ts (excerpt)
import { redis } from "@devvit/web/server";
import type { OnPostSubmitRequest, TriggerResponse } from "@devvit/web/shared";

app.post("/internal/triggers/on-post-submit", async (c) => {
  const input = await c.req.json<OnPostSubmitRequest>();
  const authorId = input.author?.id;
  if (!authorId) return c.json<TriggerResponse>({ status: "ignored" });

  const count = await redis.incrBy(`post_count:${authorId}`, 1);
  console.log(`User ${authorId} has submitted ${count} posts.`);
  return c.json<TriggerResponse>({ status: "ok" });
});

Scheduler (replaces time.sleep / cron; declare the task in devvit.json first):

src/server/index.ts (excerpt)
import { scheduler } from "@devvit/web/server";

await scheduler.runJob({
  name: "my-delayed-task",
  data: { message: "Reminder in one hour" },
  runAt: new Date(Date.now() + 60 * 60 * 1000),
});

HTTP fetch (HTTPS only; domain must be allow-listed):

devvit.json — HTTP allow-list
{
  "permissions": {
    "http": {
      "enable": true,
      "domains": [
        "api.example.com"
      ]
    }
  }
}

const res = await fetch("https://api.example.com/v1/status");
const data = await res.json();

5. Posts, comments, moderation

Same Reddit actions you already call from PRAW. Devvit’s client is async. PRAW loads comments and posts by base36 id; Devvit APIs use fullnames (t1_, t3_) — see Reddit thing IDs.

Posts

PRAW — subreddit.submit(...)

reddit.subreddit("learnpython").submit(
    "Weekly thread",
    selftext="Discussion goes here.",
)

Devvit — submitPost / submitCustomPost; prefer context.subredditName over hard-coding the sub name.

src/server/index.ts
import { context, reddit } from "@devvit/web/server";

export async function createWeeklyThread() {
  const { subredditName } = context;
  if (!subredditName) throw new Error("subredditName is required");

  return await reddit.submitPost({
    subredditName,
    title: "Weekly thread",
    text: "Discussion goes here.",
  });
}

Acting as the logged-in user (not the app account): runAs: "USER".

Comments

Get post and comment fullnames from the current request — do not hard-code t1_ / t3_ ids in app code.

PRAW	Devvit
`comment.id` / `submission.id` on a loaded object	`.id` on `Post`, `Comment`, or the return value of `submitComment`
Hard-coded id in a long-running script	`context.postId`, `context.commentId` (`reddit` and `context`)
Id from a streamed or webhook event	`input.post?.id`, `input.comment?.id` in the JSON body (Streams → triggers)

PRAW — .reply() on a Comment / Submission

reddit.comment("abc123").reply("Thanks for the context.")
comment_reply = reddit.submission("def456").reply("Pinned notice.")
comment_reply.distinguish(True)  # to pin comment

Devvit — either pattern works: pass the fullname to reddit.* (e.g. submitComment), or fetch a Comment / Post and call methods on it (like PRAW). Fetching first adds an extra API round trip — prefer the id-only reddit.* path when you only need a single action; fetch when you will chain several methods on the same thing.

src/server/index.ts — reply on a comment, id only (preferred)
import { context, reddit } from "@devvit/web/server";

const { commentId } = context;
if (!commentId) throw new Error("Run on a comment.");

await reddit.submitComment({ id: commentId, text: "Thanks for the context.", runAs: "APP" });

src/server/index.ts — reply on a comment via Comment.reply()
import { context, reddit } from "@devvit/web/server";

const { commentId } = context;
if (!commentId) throw new Error("Run on a comment.");

const comment = await reddit.getCommentById(commentId);
await comment.reply({ text: "Thanks for the context.", runAs: "APP" });

src/server/index.ts — reply on a post, id only (preferred)
import { context, reddit } from "@devvit/web/server";

const { postId } = context;
if (!postId) throw new Error("Run on a post.");

const pinned = await reddit.submitComment({
  postId,
  text: "Pinned notice.",
  runAs: "APP",
});
await pinned.distinguish(true); // sticky mod comment (maps to PRAW distinguish(True))

src/server/index.ts — reply on a post via Post.addComment()
import { context, reddit } from "@devvit/web/server";

const { postId } = context;
if (!postId) throw new Error("Run on a post.");

const post = await reddit.getPostById(postId);
const pinned = await post.addComment({ text: "Pinned notice.", runAs: "APP" });
await pinned.distinguish(true);

In a trigger handler, use ids from the event payload (see Streams → triggers) — input.comment?.id, input.post?.id — with either approach.

Moderation

PRAW — .mod.lock(), .mod.remove(), .mod.approve(), subreddit.banned.add, Modmail via subreddit.modmail, …

submission = reddit.submission("def456")
submission.mod.lock()
comment = reddit.comment("abc123")
comment.mod.remove(spam=False)
comment.mod.approve()

Devvit — same choice as comments: prefer reddit.* with fullnames when that covers the action (remove, approve, …). Fetch Post / Comment when you need object-only methods (e.g. lock) or several calls on the same thing — each getPostById / getCommentById is an extra round trip.

src/server/index.ts — moderate a comment (reddit.* with ids)
import { context, reddit } from "@devvit/web/server";

const { commentId } = context;
if (!commentId) throw new Error("Run this action on a comment.");

await reddit.remove(commentId, false);
await reddit.approve(commentId);

src/server/index.ts — lock post and moderate comment (object methods)
import { context, reddit } from "@devvit/web/server";

const { commentId } = context;
if (!commentId) throw new Error("Run this action on a comment.");

const comment = await reddit.getCommentById(commentId);
const post = await reddit.getPostById(comment.postId);
await post.lock();
await comment.remove(false);
await comment.approve();

More: RedditAPIClient, ModMailService. Mod tools often set permissions.reddit.scope to "moderator" — permissions.

6. Gaps: what your PRAW bot may do that Devvit does not

PRAW	Devvit	Notes
`redditor.subreddits`, saved, upvoted, friends, …	Private user data not available	Public data only
Infinite `stream` / open socket to Reddit	No in-process stream; short-lived handlers	Triggers + scheduler
`requests` to any host	Allow-listed `fetch` only	HTTP fetch; request domains early
Local SQLite / arbitrary files	No general `fs` persistence	Redis; settings
One bot process across all of Reddit from your VPS	Per-installation, hosted app	Design for subreddit-scoped installs
Your own OAuth app from prefs	Platform-managed Reddit access	`permissions.reddit` in `devvit.json`

Most subreddit moderation and engagement flows you built with PRAW still map cleanly; the shift is event-driven hosting and installation scope, not relearning Reddit’s content model.

References

Devvit

App quickstart · Mod tool quickstart
Triggers · Scheduler · Redis · HTTP fetch
Reddit API overview · RedditAPIClient · User actions

PRAW

PRAW documentation

1. Project layout and auth​

2. praw.Reddit → reddit and context​

3. Streams → triggers​

4. Scheduler, Redis, and HTTP​

5. Posts, comments, moderation​

Posts​

Comments​

Moderation​

6. Gaps: what your PRAW bot may do that Devvit does not​

References​

1. Project layout and auth

2. `praw.Reddit` → `reddit` and `context`

3. Streams → triggers

4. Scheduler, Redis, and HTTP

5. Posts, comments, moderation

Posts

Comments

Moderation

6. Gaps: what your PRAW bot may do that Devvit does not

References