import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import {
search,
getSubredditInfo,
getSubredditPosts,
getPostComments,
searchSubreddit,
} from "./reddit.ts";
import { formatPosts, formatSubredditInfo, formatPostWithComments } from "./format.ts";
import { version } from "../package.json";
export function createServer(): McpServer {
const server = new McpServer({
name: "reddit-mcp",
version,
});
const formatSchema = z.enum(["md", "json"]).default("md").describe("Output format: md (markdown) or json");
const sortSchema = z.enum(["relevance", "hot", "top", "new"]).default("relevance");
const postSortSchema = z.enum(["hot", "new", "top", "rising"]).default("hot");
const timeSchema = z.enum(["hour", "day", "week", "month", "year", "all"]).default("all");
server.registerTool(
"search",
{
title: "Search Reddit",
description: "Search Reddit globally for posts matching a query",
inputSchema: {
query: z.string().describe("Search query"),
limit: z.number().min(1).max(25).default(5).describe("Number of results (max 25)"),
sort: sortSchema.describe("Sort order"),
time: timeSchema.describe("Time filter for results"),
after: z.string().optional().describe("Pagination cursor from previous response"),
format: formatSchema,
},
},
async ({ query, limit, sort, time, after, format }) => {
const result = await search(query, limit, sort, time, after);
const text = formatPosts(result.items, format, result.after);
return { content: [{ type: "text", text }] };
}
);
server.registerTool(
"subreddit_info",
{
title: "Get Subreddit Info",
description: "Get information about a subreddit",
inputSchema: {
subreddit: z.string().describe("Subreddit name (without r/)"),
format: formatSchema,
},
},
async ({ subreddit, format }) => {
const info = await getSubredditInfo(subreddit);
const text = formatSubredditInfo(info, format);
return { content: [{ type: "text", text }] };
}
);
server.registerTool(
"subreddit_posts",
{
title: "Get Subreddit Posts",
description: "Get posts from a subreddit",
inputSchema: {
subreddit: z.string().describe("Subreddit name (without r/)"),
limit: z.number().min(1).max(25).default(5).describe("Number of posts (max 25)"),
sort: postSortSchema.describe("Sort order"),
time: timeSchema.describe("Time filter (only applies to top)"),
after: z.string().optional().describe("Pagination cursor from previous response"),
format: formatSchema,
},
},
async ({ subreddit, limit, sort, time, after, format }) => {
const result = await getSubredditPosts(subreddit, limit, sort, time, after);
const text = formatPosts(result.items, format, result.after);
return { content: [{ type: "text", text }] };
}
);
server.registerTool(
"post_comments",
{
title: "Get Post Comments",
description: "Get a post and its comments",
inputSchema: {
subreddit: z.string().describe("Subreddit name (without r/)"),
post_id: z.string().describe("Post ID (the base36 ID from the URL)"),
limit: z.number().min(1).max(50).default(10).describe("Number of top-level comments (max 50)"),
format: formatSchema,
},
},
async ({ subreddit, post_id, limit, format }) => {
const { post, comments } = await getPostComments(subreddit, post_id, limit);
const text = formatPostWithComments(post, comments, format);
return { content: [{ type: "text", text }] };
}
);
server.registerTool(
"subreddit_search",
{
title: "Search Subreddit",
description: "Search within a specific subreddit",
inputSchema: {
subreddit: z.string().describe("Subreddit name (without r/)"),
query: z.string().describe("Search query"),
limit: z.number().min(1).max(25).default(5).describe("Number of results (max 25)"),
sort: sortSchema.describe("Sort order"),
time: timeSchema.describe("Time filter for results"),
after: z.string().optional().describe("Pagination cursor from previous response"),
format: formatSchema,
},
},
async ({ subreddit, query, limit, sort, time, after, format }) => {
const result = await searchSubreddit(subreddit, query, limit, sort, time, after);
const text = formatPosts(result.items, format, result.after);
return { content: [{ type: "text", text }] };
}
);
return server;
}
