#!/usr/bin/env node
const MCP_BASE_URL = process.env.MCP_BASE_URL || "http://localhost:3000";
let sseReader = null;
let sseDecoder = null;
let sseBuffer = "";
let messageHandlers = new Map();
async function establishSession() {
const response = await fetch(`${MCP_BASE_URL}/mcp`, {
method: "GET",
headers: {
Accept: "text/event-stream",
Connection: "keep-alive"
}
});
if (!response.body) {
throw new Error("SSE stream not supported");
}
sseReader = response.body.getReader();
sseDecoder = new TextDecoder();
let sessionId = null;
while (!sessionId) {
const { value, done } = await sseReader.read();
if (done) break;
sseBuffer += sseDecoder.decode(value, { stream: true });
const lines = sseBuffer.split("\n");
sseBuffer = lines.pop() || "";
for (const line of lines) {
if (line.startsWith("data:")) {
const data = line.slice(5).trim();
// Try JSON format first
try {
const parsed = JSON.parse(data);
if (parsed && parsed.sessionId) {
sessionId = parsed.sessionId;
break;
}
} catch (error) {
// Try URL format: /messages?sessionId=xxx
const match = data.match(/sessionId=([a-f0-9-]+)/i);
if (match) {
sessionId = match[1];
break;
}
}
}
}
}
if (!sessionId) {
throw new Error("Unable to obtain sessionId from SSE stream");
}
// Start listening for messages in background
listenForMessages();
return sessionId;
}
async function listenForMessages() {
while (true) {
try {
const { value, done } = await sseReader.read();
if (done) break;
sseBuffer += sseDecoder.decode(value, { stream: true });
const lines = sseBuffer.split("\n");
sseBuffer = lines.pop() || "";
for (const line of lines) {
if (line.startsWith("data:")) {
try {
const data = JSON.parse(line.slice(5).trim());
if (data.id && messageHandlers.has(data.id)) {
const handler = messageHandlers.get(data.id);
handler(data);
messageHandlers.delete(data.id);
}
} catch (error) {
// Ignore malformed JSON
}
}
}
} catch (error) {
break;
}
}
}
async function callMcp(method, payload, sessionId) {
const id = Date.now();
// Set up promise to wait for response via SSE
const responsePromise = new Promise((resolve, reject) => {
const timeout = setTimeout(() => {
messageHandlers.delete(id);
reject(new Error("Request timeout"));
}, 30000);
messageHandlers.set(id, (data) => {
clearTimeout(timeout);
resolve(data);
});
});
const response = await fetch(
`${MCP_BASE_URL}/messages?sessionId=${sessionId}`,
{
method: "POST",
headers: {
"Content-Type": "application/json"
},
body: JSON.stringify({
jsonrpc: "2.0",
id,
method,
params: payload
})
}
);
if (!response.ok) {
const errorText = await response.text();
messageHandlers.delete(id);
throw new Error(`HTTP ${response.status}: ${errorText}`);
}
// Wait for response via SSE
return await responsePromise;
}
async function callTool(toolName, args, sessionId) {
return await callMcp(
"tools/call",
{
name: toolName,
arguments: args
},
sessionId
);
}
async function listTools(sessionId) {
return await callMcp("tools/list", {}, sessionId);
}
async function main() {
const args = process.argv.slice(2);
if (!args[0]) {
console.log("Usage: node scripts/mcp-client.js <command> [args]");
console.log("");
console.log("Commands:");
console.log(" list-tools List available tools");
console.log(" cnpj <cnpj> Run cnpj_lookup");
console.log(" cep <cep> Run cep_lookup");
console.log(" intelligence <cnpj> Run cnpj_intelligence");
console.log("");
console.log(
"Env: MCP_BASE_URL=http://localhost:3000 (override to target other hosts)"
);
console.log(
"Start server: MCP_TRANSPORT=http MCP_HTTP_PORT=3000 node build/lib/adapters/cli.js"
);
return;
}
let sessionId;
try {
sessionId = await establishSession();
} catch (error) {
console.error("Failed to establish SSE session:", error.message);
process.exit(1);
}
try {
const command = args[0];
if (command === "list-tools") {
const result = await listTools(sessionId);
console.log(JSON.stringify(result, null, 2));
} else if (command === "cnpj" && args[1]) {
const result = await callTool("cnpj_lookup", { cnpj: args[1] }, sessionId);
console.log(JSON.stringify(result, null, 2));
} else if (command === "cep" && args[1]) {
const result = await callTool("cep_lookup", { cep: args[1] }, sessionId);
console.log(JSON.stringify(result, null, 2));
} else if (command === "intelligence" && args[1]) {
const result = await callTool(
"cnpj_intelligence",
{
cnpj: args[1],
max_results_per_query: Number(process.env.MAX_RESULTS || 5),
max_queries: Number(process.env.MAX_QUERIES || 10),
},
sessionId
);
console.log(JSON.stringify(result, null, 2));
} else {
console.log("Unknown command or missing argument.");
}
} catch (error) {
console.error("Error:", error.message);
process.exit(1);
}
}
main().catch((error) => {
console.error("Unexpected error:", error);
process.exit(1);
});
