External API Client

🌐 External API Client

In this example, you’ll build a Zuno microservice that fetches data from an external API (e.g. JSONPlaceholder) and returns it to the client. This is useful for:

• Proxying third-party APIs
• Aggregating data from multiple sources
• Building microservices that depend on external systems

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📦 Requirements

This example uses a lightweight HTTP client library. You can use any C++ HTTP client you prefer (e.g. cpr, Boost.Beast, or a custom wrapper around libcurl). For simplicity, we’ll assume you’re using cpr via FetchContent.

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🧱 Project Structure

external-api-client/
├── CMakeLists.txt
└── main.cpp

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📄 CMakeLists.txt

cmake_minimum_required(VERSION 3.16)
project(external_api_client)

set(CMAKE_CXX_STANDARD 20)

include(FetchContent)

FetchContent_Declare(
zuno
GIT_REPOSITORY https://github.com/ZunoFramework/zuno.git
GIT_TAG        main
)

FetchContent_Declare(
cpr
GIT_REPOSITORY https://github.com/libcpr/cpr.git
GIT_TAG        1.10.4
)

FetchContent_MakeAvailable(zuno cpr)

add_executable(external-api main.cpp)
target_link_libraries(external-api PRIVATE zuno cpr::cpr)

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📄 main.cpp

#include <zuno/zuno.hpp>;
#include <cpr/cpr.h>;

int main() {
zuno::App app;

app.get("/posts/:id", [](auto& req, auto& res) {
  std::string id = req.params["id"];
  auto response = cpr::Get(cpr::Url{"https://jsonplaceholder.typicode.com/posts/" + id});

  if (response.status_code == 200) {
    res.status(200).send(response.text);
  } else {
    res.status(502).send("Failed to fetch external data");
  }
});

app.listen(3000);
}

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🧪 Test the Microservice

curl http://localhost:3000/posts/1

You should receive a JSON response from the external API, proxied through your Zuno server.

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🧭 What’s Next?

• Add Caching to reduce external load
• Use Error Handling for better fallback logic
• Secure the endpoint with Authentication

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Zuno makes it easy to build microservices that talk to the outside world—securely and efficiently.