# TypeScript MCP Client

## Install

```bash
npm install @modelcontextprotocol/sdk
```

---

## Connect

```typescript
import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";

const GATEWAY_URL = "https://gateway.mewcp.com/personal/mcp";
const MEWCP_API_KEY = "API_KEY";

const transport = new StreamableHTTPClientTransport(new URL(GATEWAY_URL), {
  requestInit: {
    headers: {
      Authorization: `Bearer ${MEWCP_API_KEY}`,
      Accept: "application/json, text/event-stream",
    },
  },
});

const client = new Client({
  name: "my-node-client",
  version: "1.0.0",
});

await client.connect(transport);

const tools = await client.listTools();
console.log(
  "Available tools:",
  tools.tools.map((t) => t.name),
);
// -> ["search", "get_schema", "list_accounts", "call_tool"]
```

Every app you have connected is reachable through this one endpoint. You get four tools rather than the tools of each app, and you use them to reach the rest.

---

## Find a tool

```typescript
const found = await client.callTool({
  name: "search",
  arguments: { query: "calendar events" },
});
// each hit carries the server_maskedId and tool_name you need next
```

```typescript
const schema = await client.callTool({
  name: "get_schema",
  arguments: {
    tools: [{ server_maskedId: "google-calendar", tool_name: "list_events" }],
  },
});
```

---

## Run a tool

```typescript
const result = await client.callTool({
  name: "call_tool",
  arguments: {
    server_maskedId: "google-calendar",
    tool_name: "list_events",
    args: {
      calendar_id: "primary",
      time_min: "2026-01-15T00:00:00Z",
      time_max: "2026-01-16T00:00:00Z",
    },
  },
});
console.log(result);
```

If your code already knows which tool it wants, call `call_tool` directly. `search` and `get_schema` exist for agents that have to work it out at runtime.

---

## Choosing an account

When you have connected more than one account for the same app, list them and pass the one you want as `alias`:

```typescript
const accounts = await client.callTool({
  name: "list_accounts",
  arguments: { provider: "google-gmail" },
});

const result = await client.callTool({
  name: "call_tool",
  arguments: {
    server_maskedId: "google-gmail",
    tool_name: "list_messages",
    args: { max_results: 10 },
    alias: "work",
  },
});
```

With a single connected account you can leave `alias` out.

---

## B2B: audience member credential routing

If you are managing audience member credentials via the [MewCP Auth API](/mewcp-auth), identify the end user with a header and MewCP resolves their stored credential automatically:

```typescript
const transport = new StreamableHTTPClientTransport(new URL(GATEWAY_URL), {
  requestInit: {
    headers: {
      Authorization: `Bearer ${MEWCP_API_KEY}`,
      "x-mewcp-enduser-id": currentUser.id,
    },
  },
});
```

---

## Where to find your values

| Value          | Where to get it       |
| -------------- | --------------------- |
| `API_KEY`      | Dashboard -> API Keys |
| Connected apps | Dashboard -> Servers  |