import { z } from "zod";
import fetch from "node-fetch";
import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { countTokens } from "./tokenizer.js";
import { contentCache } from "./cache.js";
import { paginateContent, getPage } from "./pagination.js";
import {
createHeaders,
handleGitHubUrl,
buildJinaHeaders
} from "./utils.js";
import { JinaReaderResponse } from "./types.js";
export function registerReaderTool(
server: McpServer,
tokensPerPage: number
): void {
server.registerTool(
"jina_reader",
{
title: "Jina Web Reader",
description: `Read and extract content from web page.`,
inputSchema: {
url: z.string().url().describe("URL of the webpage to read and extract content from"),
customTimeout: z.number().optional().describe("Override timeout in seconds for slow sites"),
page: z.number().optional().default(1).describe("Page number for paginated content (1-indexed)")
}
},
async ({ url, customTimeout, page = 1 }: {
url: string;
customTimeout?: number;
page?: number;
}) => {
try {
if (contentCache.has(url)) {
const cached = contentCache.get(url);
if (!cached) {
throw new Error("Cache error: Content not found");
}
const requestedPage = getPage(cached.pages, page);
if (!requestedPage) {
throw new Error(`Page ${page} not found. Total pages: ${cached.pages.length}`);
}
const paginationInfo = `Page ${page} of ${cached.pages.length} | ${requestedPage.tokens} tokens`;
return {
content: [{
type: "text" as const,
text: `${paginationInfo}\n${'='.repeat(60)}\n\n${requestedPage.content}`
}]
};
}
const { isGitHub, convertedUrl, originalUrl, shouldBypassJina } = handleGitHubUrl(url);
const actualUrl = convertedUrl;
let content: string;
if (shouldBypassJina) {
const directResponse = await fetch(actualUrl);
if (!directResponse.ok) {
throw new Error(`GitHub API error (${directResponse.status}): ${directResponse.statusText}`);
}
content = await directResponse.text();
} else {
const jinaHeaders = buildJinaHeaders(isGitHub);
if (customTimeout) {
jinaHeaders["X-Timeout"] = customTimeout.toString();
}
const headers = createHeaders(jinaHeaders);
const response = await fetch("https://r.jina.ai/", {
method: "POST",
headers,
body: JSON.stringify({ url: actualUrl })
});
if (!response.ok) {
const errorText = await response.text();
throw new Error(`Jina Reader API error (${response.status}): ${errorText}`);
}
const data = await response.json() as JinaReaderResponse;
const responseData = data.data || {};
content = responseData.content || "No content extracted";
}
const pages = paginateContent(content, tokensPerPage);
contentCache.set(url, {
url,
content,
totalTokens: countTokens(content),
pages
});
const requestedPage = getPage(pages, page);
if (!requestedPage) {
throw new Error(`Page ${page} not found. Total pages: ${pages.length}`);
}
const paginationInfo = `Page ${page} of ${pages.length} | ${requestedPage.tokens} tokens`;
return {
content: [{
type: "text" as const,
text: `${paginationInfo}\n${'='.repeat(60)}\n\n${requestedPage.content}`
}]
};
} catch (error) {
const errorMessage = error instanceof Error ? error.message : String(error);
return {
content: [{
type: "text" as const,
text: errorMessage
}],
isError: true
};
}
}
);
}
