PHP - Send message to Discord via Webhook

discord.msg.send.php

<?php
/**
 * discord.msg.send.php v0.8
 * Kirill Krasin &copy; 2025
 * https://github.com/Mo45
 * 
 * For revisions and comments vist: https://gist.github.com/Mo45/cb0813cb8a6ebcd6524f6a36d4f8862c
 * 
 * Sends a message to Discord via Webhook with file support and rate limit handling
 * 
 * This function handles both simple messages and complex embeds with attachments,
 * automatically retrying on rate limits and validating file requirements.
 * 
 * Create new webhook in your Discord channel settings and copy&paste URL into $webhookUrl.
 * 
 * You can use Markdown in your message. More about formatting: https://discordapp.com/developers/docs/reference#message-formatting
 * 
 * @param string $webhookUrl Full Discord webhook URL (from channel settings)
 * @param array $payload Message data array (content, embeds, username, etc.)
 * @param string|null $filePath Absolute path to file for attachment (optional)
 * @param int $maxRetries Maximum retry attempts on rate limits (default: 3)
 * @return bool True on success, false on failure (errors logged)
 */
function sendDiscordWebhook(string $webhookUrl, array $payload, ?string $filePath = null, int $maxRetries = 3): bool
{
    // =================================================================
    // FILE VALIDATION CHECKS
    // =================================================================
    // Verify file existence before processing
    if ($filePath && !file_exists($filePath)) {
        error_log("File not found: $filePath");
        return false;
    }
    
    // Enforce Discord's file size limit (8MB standard servers, 50MB boosted)
    if ($filePath && filesize($filePath) > 8 * 1024 * 1024) {
        error_log("File size exceeds Discord limit: $filePath");
        return false;
    }

    $retryCount = 0;
    
    // =================================================================
    // RATE LIMIT RETRY LOOP
    // =================================================================
    while ($retryCount <= $maxRetries) {
        $ch = curl_init($webhookUrl);
        
        // =============================================================
        // CURL BASE CONFIGURATION
        // =============================================================
        $options = [
            CURLOPT_FOLLOWLOCATION => true,   // Follow redirects (301/302)
            CURLOPT_HEADER => true,           // Include headers in response
            CURLOPT_RETURNTRANSFER => true,   // Return transfer instead of output
            CURLOPT_TIMEOUT => 120,           // Maximum execution time (seconds)
            CURLOPT_SSL_VERIFYPEER => true,   // Verify SSL certificate
            CURLOPT_POST => true,             // Always use POST method
        ];
        
        // =============================================================
        // PAYLOAD PREPARATION: FILE ATTACHMENT MODE
        // =============================================================
        if ($filePath) {
            // Generate unique boundary for multipart separation
            $boundary = '----DiscordWebhookBoundary' . uniqid();
            
            // Encode metadata payload to JSON
            $payloadJson = json_encode($payload, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
            
            // =========================================================
            // MULTIPART REQUEST BODY CONSTRUCTION
            // =========================================================
            // Part 1: JSON metadata payload
            $body = "--$boundary\r\n";
            $body .= "Content-Disposition: form-data; name=\"payload_json\"\r\n";
            $body .= "Content-Type: application/json\r\n\r\n";
            $body .= $payloadJson . "\r\n";
            
            // Part 2: File attachment
            $body .= "--$boundary\r\n";
            $body .= "Content-Disposition: form-data; name=\"file\"; filename=\"" . basename($filePath) . "\"\r\n";
            $body .= "Content-Type: " . mime_content_type($filePath) . "\r\n\r\n";
            $body .= file_get_contents($filePath) . "\r\n";
            
            // End boundary marker
            $body .= "--$boundary--\r\n";
            
            // =========================================================
            // CURL CONFIG FOR FILE UPLOAD
            // =========================================================
            $options[CURLOPT_HTTPHEADER] = [
                "Content-Type: multipart/form-data; boundary=$boundary",
                "Content-Length: " . strlen($body)
            ];
            $options[CURLOPT_POSTFIELDS] = $body;
        } 
        // =============================================================
        // PAYLOAD PREPARATION: JSON-ONLY MODE
        // =============================================================
        else {
            // Standard JSON request configuration
            $options[CURLOPT_HTTPHEADER] = ['Content-Type: application/json'];
            $options[CURLOPT_POSTFIELDS] = json_encode($payload, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
        }
        
        // Apply all configured options
        curl_setopt_array($ch, $options);
        
        // =============================================================
        // EXECUTE CURL REQUEST
        // =============================================================
        $response = curl_exec($ch);
        
        // =============================================================
        // CURL ERROR HANDLING
        // =============================================================
        if ($response === false) {
            $error = curl_error($ch);
            $errno = curl_errno($ch);
            curl_close($ch);
            error_log("cURL error ($errno): $error");
            return false;
        }
        
        // =============================================================
        // RESPONSE PROCESSING
        // =============================================================
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $headerSize = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
        $responseHeaders = substr($response, 0, $headerSize);
        $responseBody = substr($response, $headerSize);
        
        curl_close($ch);
        
        // =============================================================
        // SUCCESSFUL DELIVERY (2xx STATUS)
        // =============================================================
        if ($httpCode >= 200 && $httpCode < 300) {
            return true;
        }
        
        // =============================================================
        // RATE LIMIT HANDLING (429 TOO MANY REQUESTS)
        // =============================================================
        if ($httpCode === 429) {
            $retryAfter = 1;  // Default cooldown (in seconds)
            
            // Parse Retry-After header (seconds to wait)
            if (preg_match('/retry-after: (\d+)/i', $responseHeaders, $matches)) {
                $retryAfter = (int)$matches[1];
            } 
            // Fallback to Discord's rate-limit header
            elseif (preg_match('/x-ratelimit-reset-after: (\d+\.?\d*)/i', $responseHeaders, $matches)) {
                $retryAfter = (float)$matches[1];
            }
            
            error_log("Rate limit hit. Retrying after {$retryAfter} seconds");
            sleep(ceil($retryAfter) + 1);  // Add safety buffer
            $retryCount++;
            continue;
        }
        
        // =============================================================
        // ERROR LOGGING AND ANALYSIS
        // =============================================================
        $errorInfo = [
            'http_code' => $httpCode,
            'response' => $responseBody,
            'headers' => $responseHeaders,
            'file' => $filePath ? basename($filePath) : 'none'
        ];
        
        error_log("Discord API error: " . print_r($errorInfo, true));
        
        // =============================================================
        // FATAL ERROR HANDLING (4xx CLIENT ERRORS)
        // =============================================================
        // Don't retry on permanent client errors (except 429)
        if ($httpCode >= 400 && $httpCode < 500 && $httpCode !== 429) {
            return false;
        }
        
        $retryCount++;
    }
    
    // =================================================================
    // FINAL FAILURE AFTER RETRIES
    // =================================================================
    error_log("Failed after $maxRetries attempts");
    return false;
}

// =====================================================================
// PASTE YOUR WEBHOOK URL HERE
// =====================================================================
$webhookUrl = "YOUR_WEBHOOK_URL";

// =====================================================================
// MESSAGE CONFIGURATION
// =====================================================================
// Base message parameters
$message = [
	// Text content
    'content' => "This is message with mention, use userID <@12341234123412341>",
    // Custom username
    'username' => "php-msg-bot",
    // Text-to-speech
    'tts' => false,
    // Mention permissions
    'allowed_mentions' => [
        'parse' => ['users'] // Allow @user mentions
    ]
];

// =====================================================================
// EMBED CONSTRUCTION
// =====================================================================
$embed = [
    'title' => "Annotated Discord Webhook",               // Embed title
    'type' => "rich",                                     // Embed type
    'description' => "Embed with detailed documentation", // Main text
    'url' => "https://gist.github.com/Mo45/cb0813cb8a6ebcd6524f6a36d4f8862c", //URL of title link
    'timestamp' => date(DATE_ATOM),                       // ISO 8601 timestamp
    'color' => hexdec("3366ff"),                          // Left border color
    'footer' => [                                         // Footer section
        'text' => "GitHub.com/Mo45",
        'icon_url' => "https://avatars.githubusercontent.com/u/4648775"
    ],
    'author' => [                                         // Author section
        'name' => "Mo45",
        'url' => "https://github.com/Mo45"
    ],
    'fields' => [                                         // Data fields
        [
            'name' => "New Feature",
            'value' => "File upload",
            'inline' => true
        ],
        [
            'name' => "Status",
            'value' => "Completed",
            'inline' => true
        ]
    ]
];

// Attach embed to message
$message['embeds'] = [$embed];

// =====================================================================
// FILE ATTACHMENT (OPTIONAL)
// =====================================================================
// Uncomment to enable file upload:
// $filePath = __DIR__ . '/test.jpg';

// =====================================================================
// EXECUTION
// =====================================================================
$result = sendDiscordWebhook(
    webhookUrl: $webhookUrl,
    payload: $message,
    filePath: $filePath ?? null,  // Pass null if no file
    maxRetries: 5
);

if ($result) {
    echo "Message delivered successfully!";
} else {
    echo "Delivery failed. Check error logs for details.";
}

@debug420, your code is wrong. Learn how to execute and debug. Also Discord docs. Here is fully working code.

Stop being negative in the comments thank you!

Updated code. Key features in this version (v0.8):

• File Validation
  • Checks file existence before processing & enforces Discord's 8MB file size limit
• Rate Limit Handling
  • Automatic retry loop with configurable attempts & Discord's Retry-After header parsing
• Multipart Request
  • Proper CRLF line endings (RFC-compliant)
  • Combines JSON metadata + binary file
• And other cool stuff like SSL verification, error handling, ISO 8601 timestamp

Find this code useful? Feel free to donate.