import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";
// Simple helper to print section headers
function header(title) {
console.log(`\n=== ${title} ===`);
}
async function main() {
const client = new Client({ name: "local-test", version: "0.1.0" });
const transport = new StdioClientTransport({
command: "node",
args: ["build/index.js"],
cwd: process.cwd(),
stderr: "pipe",
});
// Pipe server stderr to our stderr for visibility
const stderr = transport.stderr;
if (stderr) {
stderr.on("data", (chunk) => {
process.stderr.write(`[server] ${chunk}`);
});
}
header("Connecting to MCP server");
await client.connect(transport);
header("Listing tools");
const tools = await client.listTools({});
console.log(tools.tools.map((t) => t.name).join(", "));
// Helper to call a tool and pretty print results
async function callTool(name, params) {
header(`tools/call: ${name}`);
const res = await client.callTool({ name, arguments: params });
if (res.isError) {
console.error("Error:", res.content?.[0]?.text ?? res);
} else {
for (const item of res.content ?? []) {
if (item.type === "text") console.log(item.text);
else console.log(JSON.stringify(item, null, 2));
}
}
return res;
}
// 1) Assert some facts and a simple rule
await callTool("knowledge_base_assert_many", {
facts: [
"parent(john, mary)",
"parent(mary, alice)",
"parent(john, bob)",
"male(john)",
"female(mary)",
"female(alice)",
// Important: rules must be parenthesized when passed to assert/1
"(grandparent(X,Z) :- parent(X,Y), parent(Y,Z))"
],
});
// 2) List predicates to verify dynamic DB changed
await callTool("symbols_list", {});
// 3) Query with call_nth/2 mode and iterate with next
await callTool("query_start", { query: "grandparent(X, Z)" });
let more = true;
while (more) {
const next = await callTool("query_next", {});
const text = next.content?.[0]?.text ?? "";
if (text.includes("No more solutions")) more = false;
// stop after a few iterations to be safe
if (text.includes("Error") || text.includes("no_more_solutions")) more = false;
}
await callTool("query_close", {});
// 4) Engine mode: query_startEngine/query_next/query_close (unified)
await callTool("query_startEngine", { query: "parent(john, C)" });
for (let i = 0; i < 5; i++) {
const r = await callTool("query_next", {});
const text = r.content?.[0]?.text ?? "";
if (text.includes("No more solutions") || text.includes("Error")) break;
}
await callTool("query_close", {});
// 5) Retract one fact and verify effect
await callTool("knowledge_base_retract", { fact: "parent(john, bob)" });
await callTool("query_start", { query: "parent(john, C)" });
// Expect only mary now
for (let i = 0; i < 3; i++) {
const r = await callTool("query_next", {});
const text = r.content?.[0]?.text ?? "";
if (text.includes("No more solutions")) break;
}
await callTool("query_close", {});
header("Done");
await client.close();
}
main().catch((err) => {
console.error("Demo failed:", err);
process.exit(1);
});
