Reddit Automation via Rube MCP

Automate Reddit operations through Composio's Reddit toolkit via Rube MCP.

Toolkit docs: composio.dev/toolkits/reddit

Prerequisites

• Rube MCP must be connected (RUBE_SEARCH_TOOLS available)

• Active Reddit connection via RUBE_MANAGE_CONNECTIONS with toolkit reddit

• Always call RUBE_SEARCH_TOOLS first to get current tool schemas

Setup

Get Rube MCP: Add https://rube.app/mcp as an MCP server in your client configuration. No API keys needed — just add the endpoint and it works.

• Verify Rube MCP is available by confirming RUBE_SEARCH_TOOLS responds

• Call RUBE_MANAGE_CONNECTIONS with toolkit reddit

• If connection is not ACTIVE, follow the returned auth link to complete Reddit OAuth

• Confirm connection status shows ACTIVE before running any workflows

Core Workflows

1. Search Reddit

When to use: User wants to find posts across subreddits

Tool sequence:

• REDDIT_SEARCH_ACROSS_SUBREDDITS
• Search for posts matching a query [Required]

Key parameters:

• query : Search terms

• subreddit : Limit search to a specific subreddit (optional)

• sort : Sort results by 'relevance', 'hot', 'top', 'new', 'comments'

• time_filter : Time range ('hour', 'day', 'week', 'month', 'year', 'all')

• limit : Number of results to return

Pitfalls:

• Search results may not include very recent posts due to indexing delay

• The time_filter parameter only works with certain sort options

• Results are paginated; use after/before tokens for additional pages

• NSFW content may be filtered based on account settings

2. Create Posts

When to use: User wants to submit a new post to a subreddit

Tool sequence:

• REDDIT_LIST_SUBREDDIT_POST_FLAIRS

• Get available post flairs [Optional]

• REDDIT_CREATE_REDDIT_POST

• Submit the post [Required]

Key parameters:

• subreddit : Target subreddit name (without 'r/' prefix)

• title : Post title

• text : Post body text (for text posts)

• url : Link URL (for link posts)

• flair_id : Flair ID from the subreddit's flair list

Pitfalls:

• Some subreddits require flair; use LIST_SUBREDDIT_POST_FLAIRS first

• Subreddit posting rules vary widely; karma/age restrictions may apply

• Text and URL are mutually exclusive; a post is either text or link

• Rate limits apply; avoid rapid successive post creation

• The subreddit name should not include 'r/' prefix

3. Manage Comments

When to use: User wants to comment on posts or manage existing comments

Tool sequence:

• REDDIT_RETRIEVE_POST_COMMENTS

• Get comments on a post [Optional]

• REDDIT_POST_REDDIT_COMMENT

• Add a comment to a post or reply to a comment [Required]

• REDDIT_EDIT_REDDIT_COMMENT_OR_POST

• Edit an existing comment [Optional]

• REDDIT_DELETE_REDDIT_COMMENT

• Delete a comment [Optional]

Key parameters:

• post_id : ID of the post (for retrieving or commenting on)

• parent_id : Full name of the parent (e.g., 't3_abc123' for post, 't1_xyz789' for comment)

• body : Comment text content

• thing_id : Full name of the item to edit or delete

Pitfalls:

• Reddit uses 'fullname' format: 't1_' prefix for comments, 't3_' for posts

• Editing replaces the entire comment body; include all desired content

• Deleted comments show as '[deleted]' but the tree structure remains

• Comment depth limits may apply in some subreddits

4. Browse Subreddit Content

When to use: User wants to view top or trending content from a subreddit

Tool sequence:

• REDDIT_GET_R_TOP

• Get top posts from a subreddit [Required]

• REDDIT_GET

• Get posts from a subreddit endpoint [Alternative]

• REDDIT_RETRIEVE_REDDIT_POST

• Get full details for a specific post [Optional]

Key parameters:

• subreddit : Subreddit name

• time_filter : Time range for top posts ('hour', 'day', 'week', 'month', 'year', 'all')

• limit : Number of posts to retrieve

• post_id : Specific post ID for full details

Pitfalls:

• Top posts with time_filter='all' returns all-time top content

• Post details include the body text but comments require a separate call

• Some posts may be removed or hidden based on subreddit rules

• NSFW posts are included unless filtered at the account level

5. Manage Posts

When to use: User wants to edit or delete their own posts

Tool sequence:

• REDDIT_EDIT_REDDIT_COMMENT_OR_POST

• Edit a post's text content [Optional]

• REDDIT_DELETE_REDDIT_POST

• Delete a post [Optional]

• REDDIT_GET_USER_FLAIR

• Get user's flair in a subreddit [Optional]

Key parameters:

• thing_id : Full name of the post (e.g., 't3_abc123')

• body : New text content (for editing)

• subreddit : Subreddit name (for flair)

Pitfalls:

• Only text posts can have their body edited; link posts cannot be modified

• Post titles cannot be edited after submission

• Deletion is permanent; deleted posts show as '[deleted]'

• User flair is per-subreddit and may be restricted

Common Patterns

Reddit Fullname Format

Prefixes:

t1_ = Comment (e.g., 't1_abc123') t2_ = Account (e.g., 't2_xyz789') t3_ = Post/Link (e.g., 't3_def456') t4_ = Message t5_ = Subreddit

Usage:

1. Retrieve a post to get its fullname (t3_XXXXX)
2. Use fullname as parent_id when commenting
3. Use fullname as thing_id when editing/deleting

Pagination

• Reddit uses cursor-based pagination with 'after' and 'before' tokens

• Set limit for items per page (max 100)

• Check response for after token

• Pass after value in subsequent requests to get next page

Flair Resolution

1. Call REDDIT_LIST_SUBREDDIT_POST_FLAIRS with subreddit name
2. Find matching flair by text or category
3. Extract flair_id
4. Include flair_id when creating the post

Known Pitfalls

Rate Limits:

• Reddit enforces rate limits per account and per OAuth app

• Posting is limited to approximately 1 post per 10 minutes for new accounts

• Commenting has similar but less restrictive limits

• 429 errors should trigger exponential backoff

Content Rules:

• Each subreddit has its own posting rules and requirements

• Some subreddits are restricted or private

• Karma requirements may prevent posting in certain subreddits

• Auto-moderator rules may remove posts that match certain patterns

ID Formats:

• Always use fullname format (with prefix) for parent_id and thing_id

• Raw IDs without prefix will cause 'Invalid ID' errors

• Post IDs from search results may need 't3_' prefix added

Text Formatting:

• Reddit uses Markdown for post and comment formatting

• Code blocks, tables, and headers are supported

• Links use text format

• Mention users with u/username , subreddits with r/subreddit

Quick Reference

Task Tool Slug Key Params

Search Reddit REDDIT_SEARCH_ACROSS_SUBREDDITS query, subreddit, sort, time_filter

Create post REDDIT_CREATE_REDDIT_POST subreddit, title, text/url

Get post comments REDDIT_RETRIEVE_POST_COMMENTS post_id

Add comment REDDIT_POST_REDDIT_COMMENT parent_id, body

Edit comment/post REDDIT_EDIT_REDDIT_COMMENT_OR_POST thing_id, body

Delete comment REDDIT_DELETE_REDDIT_COMMENT thing_id

Delete post REDDIT_DELETE_REDDIT_POST thing_id

Get top posts REDDIT_GET_R_TOP subreddit, time_filter, limit

Browse subreddit REDDIT_GET subreddit

Get post details REDDIT_RETRIEVE_REDDIT_POST post_id

Get specific comment REDDIT_RETRIEVE_SPECIFIC_COMMENT comment_id

List post flairs REDDIT_LIST_SUBREDDIT_POST_FLAIRS subreddit

Get user flair REDDIT_GET_USER_FLAIR subreddit

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