Connecting a client

The Enterspeed Query MCP Server speaks plain MCP Streamable HTTP, so any MCP-capable client can use it. This page covers the four most common integrations; the pattern (MCP URL + x-api-key header) is identical for every other MCP client — see Other MCP clients at the bottom. Prerequisites are the same in every case:

A scoped environment client key (Query API + MCP Server at minimum). See the Overview.
The production endpoint https://mcp.query.enterspeed.com.

Pick your client

VS Code (GitHub Copilot)
Claude Code CLI
Claude Desktop
Anthropic Messages API (C#)

VS Code’s GitHub Copilot reads MCP servers from an mcp.json file. For a single workspace, put the config at .vscode/mcp.json; for every workspace, use the MCP: Open User Configuration command from the command palette.

{
  "servers": {
    "enterspeedQuery": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://mcp.query.enterspeed.com/",
        "--header",
        "x-api-key:environment-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
      ]
    }
  }
}

Reload the window (Developer: Reload Window from the command palette) and open the Copilot chat pane. The Enterspeed tools appear in the tool picker once Copilot connects.

Never commit .vscode/mcp.json with a real key. Use ${input:enterspeed-key} with a matching inputs entry so VS Code prompts for the key on first use, or put the config in your user profile instead of the workspace.

claude mcp add enterspeedQuery \
  --transport sse \
  https://mcp.query.enterspeed.com/ \
  -H "x-api-key: environment-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"

Then start a session and ask Claude to list your indices:

claude
> List the Enterspeed indices I have access to.

The CLI stores the server configuration under ~/.claude.json. Edit that file if you need to tweak the header or URL afterwards.

Open your Claude Desktop config file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

Add the mcpServers entry:

{
  "mcpServers": {
    "enterspeedQuery": {
      "type": "sse",
      "url": "https://mcp.query.enterspeed.com/",
      "headers": {
        "x-api-key": "environment-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
      }
    }
  }
}

Fully quit and relaunch Claude Desktop. The Enterspeed tools now appear in the tool picker.

If Claude Desktop shows “no tools discovered”, the key is almost certainly missing the MCP Server scope. Create a new key using the AI Assistant preset.

This is the production path: a C# service opens an MCP session to the Enterspeed server, discovers the available tools, and runs a tool-use loop with Claude. The x-api-key header is set once on the MCP transport.

Why not the inline mcp_servers feature? Anthropic’s inline remote-MCP connector forwards an Authorization: Bearer <token> header to the upstream MCP server and does not let you override the header name. The Enterspeed MCP server reads x-api-key. Driving the tool-use loop yourself (as below) works today and gives you full control over retries, logging, and cost.

Project setup

The loop uses two NuGet packages: Anthropic.SDK for the Messages API and ModelContextProtocol for the MCP session.

dotnet new console -n EnterspeedClaudeClient
cd EnterspeedClaudeClient
dotnet add package Anthropic.SDK
dotnet add package ModelContextProtocol
dotnet user-secrets init
dotnet user-secrets set "ANTHROPIC_API_KEY"   "sk-ant-..."
dotnet user-secrets set "ENTERSPEED_MCP_KEY"  "environment-xxxxxxxx-..."

Program.cs

using Anthropic.SDK;
using Anthropic.SDK.Messaging;
using Microsoft.Extensions.Configuration;
using ModelContextProtocol.Client;
using ModelContextProtocol.Protocol.Transport;
using System.Text.Json;

var config = new ConfigurationBuilder()
    .AddUserSecrets<Program>()
    .AddEnvironmentVariables()
    .Build();

var anthropicKey  = config["ANTHROPIC_API_KEY"]!;
var enterspeedKey = config["ENTERSPEED_MCP_KEY"]!;

// 1. Open an MCP session against the Enterspeed server
var transport = new SseClientTransport(new SseClientTransportOptions
{
    Endpoint = new Uri("https://mcp.query.enterspeed.com/"),
    AdditionalHeaders = new Dictionary<string, string>
    {
        ["x-api-key"] = enterspeedKey
    }
});

await using var mcp = await McpClientFactory.CreateAsync(transport);

// 2. Discover the tools this key is allowed to use
var mcpTools = await mcp.ListToolsAsync();

// 3. Hand the tool schemas to Claude as Messages API tools
var claude = new AnthropicClient(new APIAuthentication(anthropicKey));

var tools = mcpTools
    .Select(t => new Tool
    {
        Name        = t.Name,
        Description = t.Description ?? string.Empty,
        InputSchema = t.InputSchema
    })
    .ToList();

var messages = new List<Message>
{
    new(RoleType.User,
        "Find the three most recent published blog posts and summarise " +
        "them in one sentence each.")
};

// 4. Tool-use loop — repeat until Claude produces a final answer
while (true)
{
    var response = await claude.Messages.GetClaudeMessageAsync(new MessageParameters
    {
        Model     = AnthropicModels.Claude4Sonnet,
        MaxTokens = 4096,
        Messages  = messages,
        Tools     = tools
    });

    // Record Claude's turn
    messages.Add(new Message(response));

    if (response.StopReason != "tool_use")
    {
        Console.WriteLine(response.Message);
        break;
    }

    // Execute every tool_use block via the MCP client and feed results back
    foreach (var block in response.Content.OfType<ToolUseContent>())
    {
        var args = block.Input.Deserialize<Dictionary<string, object?>>()
                   ?? new();
        var mcpResult = await mcp.CallToolAsync(block.Name, args);

        messages.Add(new Message
        {
            Role    = RoleType.User,
            Content = new List<ContentBase>
            {
                new ToolResultContent
                {
                    ToolUseId = block.Id,
                    Content   = mcpResult.Content.FirstOrDefault()?.Text ?? string.Empty
                }
            }
        });
    }
}

Run it:

dotnet run

Expected output includes a short summary of three blog posts, and the loop’s intermediate turns show Claude calling query_blog (or the equivalent per-index tool for whatever index the key is scoped to).

SDK property names. The exact property names on ToolUseContent, ToolResultContent, and the Message / Tool shapes evolve with the Anthropic.SDK package. If a symbol above does not resolve, check the current release notes for the corresponding type name — the orchestration pattern (list tools once, loop until StopReason != "tool_use") stays the same.

Keeping costs under control

Cache the tool list. Call ListToolsAsync() once per session, not per request. The MCP server also caches per API key for 5 minutes, so repeat calls are cheap even if you do list more often.
Narrow the tool set with an Index Scope. Fewer indices means fewer query_* tools surfaced to Claude, which means fewer input tokens.
Use prompt caching on the tool list. When you pass tools to the Messages API, mark the list with cache_control: { type: "ephemeral" } via CacheControl-style helpers in Anthropic.SDK — see the package README for the current property name.

Other MCP clients

The four clients above are the ones we test against regularly, but the MCP server is client-agnostic. Any MCP-capable client follows the same pattern — point it at https://mcp.query.enterspeed.com/ with SSE transport and set an x-api-key header. Some known-good examples:

Cursor — .cursor/mcp.json with the same servers schema as VS Code.
Windsurf — settings → Cascade → MCP Servers, using the SSE + header form.
Continue — ~/.continue/config.json under experimental.modelContextProtocolServers.
Zed — settings under "context_servers" with type: "sse".

If your client does not support custom headers, pass the key as an ?apiKey= query-string parameter on the MCP URL instead. Avoid that in production — the key ends up in request logs.

Troubleshooting

Symptom	Likely cause	Fix
Client responds “I don’t have any tools”	MCP server entry missing, or the URL is wrong	Confirm the config was reloaded by the client; hit `/health` on the MCP endpoint.
Every tool call returns “forbidden”	`x-api-key` forwarded correctly but scope missing	Add `Query API` to the environment client.
`mcp add` / config reload fails with “failed to establish connection”	Local proxy, VPN, or corporate firewall stripping SSE headers	Bypass the proxy (`NO_PROXY=mcp.query.enterspeed.com`) or try a different network.
Tools list is empty after reload	Client caches tool lists per session	Fully quit and relaunch the client (on macOS, Cmd-Q in Claude Desktop; Developer: Reload Window in VS Code).
`401` on every request	Wrong key type — Management API token instead of environment-client key	Create an environment client key, not a Management API token.

Next steps

Overview — sample prompts and scope reference.
Connecting an agent — Azure AI Foundry and custom-agent wiring.

Overview

Schema reference

API

Integrations

Tutorials

Best practices

CLI

MCP server

Pick your client

Project setup

Program.cs

Keeping costs under control

Other MCP clients

Troubleshooting

Next steps

​Pick your client

​Project setup

​Program.cs

​Keeping costs under control

​Other MCP clients

​Troubleshooting

​Next steps

Pick your client

Project setup

Program.cs

Keeping costs under control

Other MCP clients

Troubleshooting

Next steps