Unit 9 · Connect to external tools and data

Connect to an MCP server

You connect one MCP client over the transport that fits your deployment. Streamable HTTP is the normal remote choice and supports both stateful and stateless servers.

AxMCPClient8 focused minutesNot started

Unit example (nearest native match)

See the idea in context

auto transport = std::make_shared<axllm::AxMCPStreamableHTTPTransport>(endpoint);
auto mcp = std::make_shared<axllm::AxMCPClient>(transport, axllm::object({{"namespace", "inventory"}}));
axllm::AxExecutionContext context({mcp});
auto program = axllm::ax("request:string -> answer:string");
context.attach(program);
axllm::OpenAICompatibleClient llm(axllm::object({
  {"api_key", key}, {"model", "gpt-5.4-mini"},
}));
auto catalog = mcp->inspect_catalog();
std::cout << "MCP catalog: " << axllm::Core::iter(catalog.tools).size()
          << " tools, " << axllm::Core::iter(catalog.resources).size()
          << " resources\n";
std::cout << axllm::stringify(program.forward(
  llm, axllm::object({{"request", "Reindex inventory."}})
)) << "\n";
mcp->close();

Create the transport
Streamable HTTP connects the client to the remote URL.
Create one client
AxMCPClient owns era classification and the protocol lifecycle.
Use a namespace
orders keeps discovered names clear when several servers are attached.

Run itIn your own project

cmake_minimum_required(VERSION 3.20)
project(ax_quick_start LANGUAGES CXX)
set(CMAKE_CXX_STANDARD 17)

include(FetchContent)
FetchContent_Declare(axllm GIT_REPOSITORY https://github.com/ax-llm/ax GIT_TAG main SOURCE_SUBDIR packages/cpp)
FetchContent_MakeAvailable(axllm)

add_executable(quick_start quick_start.cpp)
target_link_libraries(quick_start PRIVATE axllm::axllm)

#include <axllm/axllm.hpp>
#include <cstdlib>
#include <iostream>

int main() {
  auto llm = axllm::ai("openai", axllm::object({{"apiKey", std::getenv("OPENAI_API_KEY")}}));
  auto classify = axllm::ax("review:string -> sentiment:class \"positive, negative, neutral\"");
  auto result = classify.forward(*llm, axllm::object({
    {"review", "Useful and boring in the best way."}
  }));

  auto sentiment = axllm::Core::get(result, "sentiment");
  std::cout << "sentiment: " << std::get<std::string>(sentiment.data) << "\n";
}

Set OPENAI_APIKEY in your environment before running provider-backed code.

In the ax repo

From a clone of the ax repo:

npm run example -- cpp src/examples/cpp/mcp/native_mcp_tools.cpp

Active practice

Show that you can use it

Answer 2 in a row to learn this · attempt 1

Keep exploring

See the idea in context

Show that you can use it

Source-backed follow-up