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Async & Network Fetch

Kyna includes a built-in asynchronous runtime that enables non-blocking HTTP networking, concurrent task execution, and streaming I/O without heavy thread overhead.

1. Asynchronous Functions (async)​

Mark any function with the async keyword to designate it as asynchronous:

async fn fetchServiceHealth(endpoint: str): str {
    const url = "https://api.kyna.dev/health/" + endpoint;
    const response = await fetch(url);
    return response;
}

2. Awaiting Promises (await)​

Use await to yield control until an asynchronous operation finishes:

async fn runHealthCheck() {
    print("Initiating health check...");
    
    try {
        const result = await fetchServiceHealth("db-primary");
        const parsed = jsonParse(result);
        
        print("Status:", parsed["status"]);
        print("Latency:", parsed["latency_ms"], "ms");
    } catch (err) {
        print("Health check failed:", err);
    }
}

await runHealthCheck();

3. Parsing JSON Responses​

The standard library includes fast native JSON decoding and encoding functions:

# JSON string to typed Map / Object
const rawJson = "{\"service\": \"payment-gw\", \"active\": true, \"workers\": 4}";
const data = jsonParse(rawJson);

print("Service:", data["service"]);
print("Workers:", data["workers"]);

# Typed Map / Object to JSON string
const outboundPayload = {
    "event": "HEARTBEAT",
    "timestamp": 1725250000
};

const jsonString = jsonStringify(outboundPayload);
print("Serialized JSON:", jsonString);

4. Concurrent Requests​

Execute multiple independent network calls concurrently:

async fn checkAllClusters(): str {
    const authTask = fetchServiceHealth("auth");
    const billingTask = fetchServiceHealth("billing");
    
    # Await results concurrently
    const authStatus = await authTask;
    const billingStatus = await billingTask;
    
    return "Auth: " + authStatus + " | Billing: " + billingStatus;
}

Next Steps​