@upstash/context7-mcp
Version:
MCP server for Context7
151 lines (150 loc) • 5.95 kB
JavaScript
import { generateHeaders } from "./encryption.js";
import { Agent, ProxyAgent, setGlobalDispatcher } from "undici";
import { CONTEXT7_API_BASE_URL } from "./constants.js";
import { readFileSync } from "fs";
import tls from "tls";
/**
* Parses error response from the Context7 API
* Extracts the server's error message, falling back to status-based messages if parsing fails
* @param response The fetch Response object
* @param apiKey Optional API key (used for fallback messages)
* @returns Error message string
*/
async function parseErrorResponse(response, apiKey) {
try {
const json = (await response.json());
if (json.message) {
return json.message;
}
}
catch {
// JSON parsing failed, fall through to default
}
const status = response.status;
if (status === 429) {
return apiKey
? "Rate limited or quota exceeded. Upgrade your plan at https://context7.com/plans for higher limits."
: "Rate limited or quota exceeded. Create a free API key at https://context7.com/dashboard for higher limits.";
}
if (status === 404) {
return "The library you are trying to access does not exist. Please try with a different library ID.";
}
if (status === 401) {
return "Invalid API key. Please check your API key. API keys should start with 'ctx7sk' prefix.";
}
return `Request failed with status ${status}. Please try again later.`;
}
const PROXY_URL = process.env.HTTPS_PROXY ??
process.env.https_proxy ??
process.env.HTTP_PROXY ??
process.env.http_proxy ??
null;
const CUSTOM_CA_CERTS = process.env.NODE_EXTRA_CA_CERTS;
export function getDefaultCACertificates() {
if (typeof tls.getCACertificates === "function") {
return tls.getCACertificates("default");
}
return [...tls.rootCertificates];
}
export function loadCustomCACerts(customCACertsPath = CUSTOM_CA_CERTS) {
if (!customCACertsPath)
return undefined;
try {
const customCa = readFileSync(customCACertsPath, "utf-8");
return [...getDefaultCACertificates(), customCa];
}
catch (error) {
console.error(`[Context7] Failed to load custom CA certificates from ${customCACertsPath}:`, error);
return undefined;
}
}
if (PROXY_URL && !PROXY_URL.startsWith("$") && /^(http|https):\/\//i.test(PROXY_URL)) {
try {
const ca = loadCustomCACerts();
setGlobalDispatcher(new ProxyAgent({
uri: PROXY_URL,
...(ca ? { requestTls: { ca }, proxyTls: { ca } } : {}),
}));
}
catch (error) {
console.error(`[Context7] Failed to configure proxy agent for provided proxy URL: ${PROXY_URL}:`, error);
}
}
else if (CUSTOM_CA_CERTS) {
const ca = loadCustomCACerts();
if (ca) {
try {
setGlobalDispatcher(new Agent({ connect: { ca } }));
}
catch (error) {
console.error(`[Context7] Failed to configure custom CA certificates:`, error);
}
}
}
function readPromptSignal(response, context) {
if (response.headers.get("X-Context7-Auth-Prompt") === "1") {
context.shouldPrompt = true;
}
}
/**
* Searches for libraries matching the given query
* @param query The user's question or task (used for LLM relevance ranking)
* @param libraryName The library name to search for in the database
* @param context Client context including IP, API key, and client info
* @returns Search results or error
*/
export async function searchLibraries(query, libraryName, context = {}) {
try {
const url = new URL(`${CONTEXT7_API_BASE_URL}/v2/libs/search`);
url.searchParams.set("query", query);
url.searchParams.set("libraryName", libraryName);
const headers = generateHeaders(context);
const response = await fetch(url, { headers });
readPromptSignal(response, context);
if (!response.ok) {
const errorMessage = await parseErrorResponse(response, context.apiKey);
console.error(errorMessage);
return { results: [], error: errorMessage };
}
const searchData = await response.json();
return searchData;
}
catch (error) {
const errorMessage = `Error searching libraries: ${error}`;
console.error(errorMessage);
return { results: [], error: errorMessage };
}
}
/**
* Fetches intelligent, reranked context for a natural language query
* @param request The context request parameters (query, libraryId)
* @param context Client context including IP, API key, and client info
* @returns Context response with data
*/
export async function fetchLibraryContext(request, context = {}) {
try {
const url = new URL(`${CONTEXT7_API_BASE_URL}/v2/context`);
url.searchParams.set("query", request.query);
url.searchParams.set("libraryId", request.libraryId);
const headers = generateHeaders(context);
const response = await fetch(url, { headers });
readPromptSignal(response, context);
if (!response.ok) {
const errorMessage = await parseErrorResponse(response, context.apiKey);
console.error(errorMessage);
return { data: errorMessage };
}
const text = await response.text();
if (!text) {
return {
data: "Documentation not found or not finalized for this library. This might have happened because you used an invalid Context7-compatible library ID. To get a valid Context7-compatible library ID, use the 'resolve-library-id' with the package name you wish to retrieve documentation for.",
};
}
return { data: text };
}
catch (error) {
const errorMessage = `Error fetching library context. Please try again later. ${error}`;
console.error(errorMessage);
return { data: errorMessage };
}
}