Reddit MCP Server

Instructions

Implementation Reference

• src/tools/post-tools.ts:131-210 (handler)

  Primary MCP tool handler for 'create_post'. Takes parameters, calls RedditClient.createPost, formats response with post details and links, handles errors with localized messages.
  export async function createPost(params: { subreddit: string; title: string; content: string; is_self?: boolean; }) { const { subreddit, title, content, is_self = true } = params; const client = getRedditClient(); if (!client) { throw new McpError( ErrorCode.InternalError, "Reddit client not initialized" ); } try { console.log( `[Tool] Creating ${is_self ? "text" : "link"} post in r/${subreddit}: "${title}"` ); const startTime = Date.now(); const post = await client.createPost(subreddit, title, content, is_self); const endTime = Date.now(); console.log(`[Tool] Post creation took ${endTime - startTime}ms`); const formattedPost = formatPostInfo(post); return { content: [ { type: "text", text: ` # ✅ Post créé avec succès ! ## 📝 Détails du post - **Titre**: ${formattedPost.title} - **Subreddit**: r/${formattedPost.subreddit} - **Type**: ${formattedPost.type} - **ID**: ${post.id} - **Auteur**: u/${formattedPost.author} ## 🔗 Liens - **Lien complet**: ${formattedPost.links.fullPost} - **Permalink**: https://reddit.com${post.permalink} ## ⏰ Statut Votre post a été **publié avec succès** sur r/${formattedPost.subreddit} ! ${is_self ? `**Contenu**: ${content.substring(0, 200)}${content.length > 200 ? '...' : ''}` : `**URL**: ${content}` } `, }, ], }; } catch (error: any) { console.error(`[Error] Error creating post: ${error}`); // Provide more specific error messages let errorMessage = `Échec de la création du post: ${error.message}`; if (error.message.includes('timeout')) { errorMessage = `⏰ Timeout lors de la création du post. Le post a peut-être été créé malgré tout - vérifiez votre profil Reddit.`; } else if (error.message.includes('authentication')) { errorMessage = `🔐 Problème d'authentification. Vérifiez vos credentials Reddit dans le fichier .env`; } else if (error.message.includes('rate limit')) { errorMessage = `⏱️ Limite de fréquence atteinte. Attendez quelques minutes avant de réessayer.`; } else if (error.message.includes('submission')) { errorMessage = `📝 Erreur de soumission. Vérifiez que le subreddit existe et que vous avez les permissions.`; } throw new McpError( ErrorCode.InternalError, errorMessage ); } }
• src/index.ts:180-207 (registration)

  Tool registration in MCP server's listTools response, defining name, description, and input schema with required parameters subreddit, title, content.
  name: "create_post", description: "Create a new post in a subreddit", inputSchema: { type: "object", properties: { subreddit: { type: "string", description: "Name of the subreddit to post in", }, title: { type: "string", description: "Title of the post", }, content: { type: "string", description: "Content of the post (text for self posts, URL for link posts)", }, is_self: { type: "boolean", description: "Whether this is a self (text) post (true) or link post (false)", default: true, }, }, required: ["subreddit", "title", "content"], }, },
• src/index.ts:454-462 (registration)

  Dispatch handler in MCP server's CallToolRequestSchema switch statement, routing 'create_post' calls to tools.createPost with typed parameters.
  case "create_post": return await tools.createPost( toolParams as { subreddit: string; title: string; content: string; is_self?: boolean; } );
• src/client/reddit-client.ts:270-352 (helper)

  Core RedditClient helper method implementing the actual Reddit API submission for creating posts, handling authentication, API call to /api/submit, and post retrieval.
  async createPost( subreddit: string, title: string, content: string, isSelf: boolean = true ): Promise<RedditPost> { await this.authenticate(); if (!this.username || !this.password) { throw new Error("User authentication required for posting"); } try { console.log(`[Post] Creating post in r/${subreddit}: "${title}"`); const kind = isSelf ? "self" : "link"; const params = new URLSearchParams(); params.append("sr", subreddit); params.append("kind", kind); params.append("title", title); params.append(isSelf ? "text" : "url", content); const response = await this.api.post("/api/submit", params, { headers: { "Content-Type": "application/x-www-form-urlencoded", }, timeout: 30000, // 30 seconds timeout }); console.log(`[Post] Reddit API response:`, response.data); if (response.data.success) { const postId = response.data.data.id; const postName = response.data.data.name; console.log(`[Post] Post created successfully! ID: ${postId}, Name: ${postName}`); try { // Try to get the newly created post const newPost = await this.getPost(postId); console.log(`[Post] Successfully retrieved created post`); return newPost; } catch (getError) { console.log(`[Post] Could not retrieve post details, but post was created successfully`); // Return a basic post object if we can't retrieve the full details return { id: postId, title: title, author: this.username!, subreddit: subreddit, selftext: isSelf ? content : "", url: isSelf ? "" : content, score: 1, upvoteRatio: 1.0, numComments: 0, createdUtc: Math.floor(Date.now() / 1000), over18: false, spoiler: false, edited: false, isSelf: isSelf, linkFlairText: "", permalink: `/r/${subreddit}/comments/${postId}/`, }; } } else { console.error(`[Post] Reddit API returned success=false:`, response.data); const errors = response.data.errors || []; const errorMsg = errors.length > 0 ? errors.join(", ") : "Unknown error"; throw new Error(`Failed to create post: ${errorMsg}`); } } catch (error: any) { console.error(`[Error] Failed to create post in r/${subreddit}:`, error); if (error.response) { console.error(`[Error] Reddit API error response:`, error.response.data); throw new Error(`Failed to create post: ${error.response.data?.message || error.message}`); } else if (error.code === 'ECONNABORTED') { console.error(`[Error] Request timeout when creating post`); throw new Error(`Post creation timed out - check Reddit manually to see if it was created`); } else { throw new Error(`Failed to create post in r/${subreddit}: ${error.message}`); } } }