C++ SDK

Official SDKs

C++ SDK

C++17 static library. The external dependencies are libcurl and OpenSSL — no JSON library required. JSON fields are extracted using targeted string search so the dependency tree stays minimal. Built with CMake 3.14+.

Download C++ SDK (ZIP)

Building — Linux / macOS

Bash

# Ubuntu / Debian
sudo apt-get install libcurl4-openssl-dev libssl-dev

# macOS (Homebrew)
brew install curl openssl

cd SDKs/cpp
cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

Building — Windows (vcpkg + Visual Studio)

PowerShell

vcpkg install curl:x64-windows openssl:x64-windows
cmake -B build `
    -DCMAKE_TOOLCHAIN_FILE=C:/vcpkg/scripts/buildsystems/vcpkg.cmake
cmake --build build --config Release

Integrating into your CMake project

CMakeLists.txt

add_subdirectory(SDKs/cpp)
target_link_libraries(your_target PRIVATE permitcore)

Quick start

C++

#include <permitcore/permit_client.hpp>
#include <iostream>

int main() {
    permitcore::PermitClient client("https://api.permitcore.dev");

    auto result = client.validate("PERMIT-XXXX-XXXX-XXXX-XXXX");
    if (result.is_valid) {
        std::cout << "License OK — product: " << result.product_name << "\n";
        if (result.is_offline) std::cout << "Running on a cached result — server was unreachable.\n";
    } else {
        std::cerr << "License rejected: " << result.message << "\n";
    }
}

validate() and activate() never throw for a network failure — they fall back to the local offline-grace cache automatically and, failing that, return is_valid: false with is_offline: true. Only meter() throws PermitException.

Validate with version check

C++

auto result = client.validate("PERMIT-XXXX-XXXX-XXXX-XXXX", "2.3.1");
if (!result.is_valid && !result.min_version.empty())
    show_error("Upgrade required: minimum version is " + result.min_version);

Activation

C++

permitcore::ActivateOptions opts;
opts.device_id   = "sha256-of-mac-plus-board-serial";
opts.device_name = "My-Linux-Server";
opts.version     = "2.3.1";

auto result = client.activate("PERMIT-XXXX-XXXX-XXXX-XXXX", opts);
if (result.is_valid) {
    std::cout << "Activated successfully.\n";
} else {
    std::cerr << "Activation failed: " << result.message << "\n";
}

Metered billing

C++

auto m = client.meter("PERMIT-XXXX-XXXX-XXXX-XXXX", "export", 1);
if (m.recorded) std::cout << "Usage recorded.\n";

// Batch — 5 API calls at once
auto m2 = client.meter("PERMIT-XXXX-XXXX-XXXX-XXXX", "api_call", 5);

ValidateResult struct fields

Field	Type	Description
`is_valid`	bool	true if the license is active and all checks pass
`product_name`	std::string	Product name
`remaining_activations`	int	Remaining activation seats (0 = at limit)
`expires_at`	std::string	ISO 8601 expiry timestamp; empty if perpetual
`message`	std::string	Status message from the server
`vendor_warning`	std::string	Non-empty if the vendor's PermitCore plan is lapsing
`features`	std::vector<std::string>	Enabled feature flags
`custom_fields`	std::map<std::string, std::string>	Vendor-defined metadata
`is_trial`	bool	true if this is a trial license
`trial_days_remaining`	int	Days remaining in the trial
`node_locked`	bool	true if HWID node-locking is enabled
`offline_grace_days`	int	Days the software may run without a server check
`min_version`	std::string	Minimum required software version; empty if unrestricted
`max_version`	std::string	Maximum allowed software version; empty if unrestricted
`is_offline`	bool	true when this result was served from the local offline-grace cache (server unreachable)

ActivateOptions struct

Field	Description
`device_id`	Hardware fingerprint — SHA-256 of MAC address, motherboard serial, or similar stable identifier
`device_name`	Human-readable label shown in the admin activation history
`version`	Current software version string, e.g. "2.3.1"

Offline grace period (built in)

When offline_grace_days is set on the license, validate()/activate() cache every successful result to the OS temp directory (%TEMP% on Windows, $TMPDIR//tmp on POSIX). If a later call can't reach the server, the cached result is returned automatically — check is_offline to detect it. Disable via the third constructor argument: permitcore::PermitClient client(base_url, 10, false);.

Implementation notes

No JSON library. Fields extracted from responses (including the cache file) using std::string::find — the client also links OpenSSL for signature verification.
Thread safety. Each method call creates and destroys its own curl easy handle. Safe to call from multiple threads on a shared PermitClient instance.
Custom timeout. Default is 10 seconds. Pass a second argument: permitcore::PermitClient client("https://...", 5); for 5 seconds.
HTTPS on Windows. Build against the WinSSL backend (CURL_USE_SCHANNEL) for zero-config HTTPS without deploying a CA bundle.

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