Embed & Integrate

"""Generate a sequence diagram via the WebSequenceDiagrams API.""" import json import urllib.parse import urllib.request def get_sequence_diagram(text, output_file, style="default", fmt="png", api_key=None): """Fetch a diagram image and save it to output_file.""" params = { "message": text, "style": style, "apiVersion": "1", "format": fmt, } if api_key: params["apikey"] = api_key data = urllib.parse.urlencode(params).encode("utf-8") url = "https://www.websequencediagrams.com/index.php" with urllib.request.urlopen(url, data) as resp: body = json.loads(resp.read().decode("utf-8")) if "img" not in body: raise RuntimeError(f"Server error: {body}") img_url = "https://www.websequencediagrams.com/" + body["img"] urllib.request.urlretrieve(img_url, output_file) return output_file if __name__ == "__main__": diagram = "Alice->Bob: Authentication Request\nBob-->Alice: Response" get_sequence_diagram(diagram, "out.png", style="modern-blue") print("Saved to out.png")

/** * Generate a sequence diagram via the WebSequenceDiagrams API. * Works with Node.js 18+ (built-in fetch). */ const fs = require("fs"); async function getSequenceDiagram(text, outputFile, style = "modern-blue", format = "png") { const params = new URLSearchParams({ message: text, style: style, apiVersion: "1", format: format, // apikey: "YOUR_PREMIUM_KEY", // uncomment for premium features }); // Step 1: request the diagram const res = await fetch("https://www.websequencediagrams.com/index.php", { method: "POST", headers: { "Content-Type": "application/x-www-form-urlencoded" }, body: params.toString(), }); const json = await res.json(); if (!json.img) { throw new Error("Server error: " + JSON.stringify(json)); } // Step 2: download the image const imgRes = await fetch("https://www.websequencediagrams.com/" + json.img); const buffer = Buffer.from(await imgRes.arrayBuffer()); fs.writeFileSync(outputFile, buffer); return outputFile; } // Usage getSequenceDiagram( "Alice->Bob: Hello\nBob-->Alice: Hi there", "diagram.png" ).then((f) => console.log("Saved to", f));

/** * Fetch a diagram image URL from the browser using the REST API. * Returns a blob URL you can assign to an <img> src. */ interface WsdResponse { img: string; errors: string[]; } async function getDiagramBlobUrl( message: string, style: string = "modern-blue", format: string = "png" ): Promise<string> { const params = new URLSearchParams({ message, style, apiVersion: "1", format, }); const res = await fetch("https://www.websequencediagrams.com/index.php", { method: "POST", headers: { "Content-Type": "application/x-www-form-urlencoded" }, body: params.toString(), }); const json: WsdResponse = await res.json(); if (!json.img) { throw new Error(`Server error: ${JSON.stringify(json)}`); } const imgRes = await fetch( `https://www.websequencediagrams.com/${json.img}` ); const blob = await imgRes.blob(); return URL.createObjectURL(blob); } // Example usage getDiagramBlobUrl("Alice->Bob: Hello").then((url) => { const img = document.createElement("img"); img.src = url; document.body.appendChild(img); });

<?php /** * Generate a sequence diagram via the WebSequenceDiagrams API. */ function getSequenceDiagram(array $params): string { $postFields = http_build_query($params); $ch = curl_init("https://www.websequencediagrams.com/index.php"); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_POSTFIELDS, $postFields); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); $response = curl_exec($ch); curl_close($ch); $json = json_decode($response, true); if (empty($json['img'])) { throw new RuntimeException("Server error: " . $response); } return "https://www.websequencediagrams.com/" . $json['img']; } // Usage $imageUrl = getSequenceDiagram([ "apiVersion" => "1", "message" => "Alice->Bob: Hello\nBob-->Alice: Hi", "style" => "modern-blue", "format" => "png", // "apikey" => "YOUR_PREMIUM_KEY", ]); // Download the image to a local file file_put_contents("diagram.png", file_get_contents($imageUrl)); echo "Saved to diagram.png\n";

# frozen_string_literal: true # Generate a sequence diagram via the WebSequenceDiagrams API. require "net/http" require "json" require "uri" def get_sequence_diagram(text, output_file, style: "modern-blue", format: "png", api_key: nil) uri = URI("https://www.websequencediagrams.com/index.php") params = { "message" => text, "style" => style, "apiVersion" => "1", "format" => format } params["apikey"] = api_key if api_key response = Net::HTTP.post_form(uri, params) unless response.is_a?(Net::HTTPSuccess) raise "HTTP error: #{response.code} #{response.message}" end body = JSON.parse(response.body) raise "Server error: #{body}" unless body["img"] img_url = URI("https://www.websequencediagrams.com/#{body['img']}") img_data = Net::HTTP.get(img_url) File.binwrite(output_file, img_data) output_file end # Usage diagram = "Alice->Bob: Authentication Request\nBob-->Alice: Response" get_sequence_diagram(diagram, "diagram.png") puts "Saved to diagram.png"

import java.io.*; import java.net.URI; import java.net.URLEncoder; import java.net.http.HttpClient; import java.net.http.HttpRequest; import java.net.http.HttpResponse; import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.nio.file.Path; public class WsdExample { public static Path getSequenceDiagram(String text, String outFile, String style, String format) throws Exception { String body = "apiVersion=1" + "&style=" + URLEncoder.encode(style, StandardCharsets.UTF_8) + "&format=" + URLEncoder.encode(format, StandardCharsets.UTF_8) + "&message=" + URLEncoder.encode(text, StandardCharsets.UTF_8); // + "&apikey=" + URLEncoder.encode("YOUR_KEY", StandardCharsets.UTF_8); HttpClient client = HttpClient.newHttpClient(); // Step 1: request the diagram HttpRequest req = HttpRequest.newBuilder() .uri(URI.create("https://www.websequencediagrams.com/index.php")) .header("Content-Type", "application/x-www-form-urlencoded") .POST(HttpRequest.BodyPublishers.ofString(body)) .build(); HttpResponse<String> res = client.send(req, HttpResponse.BodyHandlers.ofString()); // Simple JSON parsing (use a library for production code) String json = res.body(); int start = json.indexOf("\"img\""); int valStart = json.indexOf("\"", start + 5) + 1; int valEnd = json.indexOf("\"", valStart); String imgPath = json.substring(valStart, valEnd); // Step 2: download the image HttpRequest imgReq = HttpRequest.newBuilder() .uri(URI.create("https://www.websequencediagrams.com/" + imgPath)) .GET().build(); HttpResponse<byte[]> imgRes = client.send(imgReq, HttpResponse.BodyHandlers.ofByteArray()); Path target = Path.of(outFile); Files.write(target, imgRes.body()); return target; } public static void main(String[] args) throws Exception { getSequenceDiagram( "Alice->Bob: Hello\nBob-->Alice: Hi", "diagram.png", "modern-blue", "png" ); System.out.println("Saved to diagram.png"); } }

using System.Text.Json; /// <summary> /// Generate a sequence diagram via the WebSequenceDiagrams API. /// </summary> class WsdExample { static async Task<string> GetSequenceDiagramAsync( string message, string outputFile, string style = "modern-blue", string format = "png", string? apiKey = null) { using var http = new HttpClient(); var form = new Dictionary<string, string> { ["apiVersion"] = "1", ["message"] = message, ["style"] = style, ["format"] = format, }; if (apiKey is not null) form["apikey"] = apiKey; // Step 1: request the diagram var res = await http.PostAsync( "https://www.websequencediagrams.com/index.php", new FormUrlEncodedContent(form)); res.EnsureSuccessStatusCode(); var json = await res.Content.ReadAsStringAsync(); var doc = JsonDocument.Parse(json); var img = doc.RootElement.GetProperty("img").GetString() ?? throw new Exception("No img in response: " + json); // Step 2: download the image var imgBytes = await http.GetByteArrayAsync( "https://www.websequencediagrams.com/" + img); await File.WriteAllBytesAsync(outputFile, imgBytes); return outputFile; } static async Task Main() { await GetSequenceDiagramAsync( "Alice->Bob: Hello\nBob-->Alice: Hi", "diagram.png"); Console.WriteLine("Saved to diagram.png"); } }

package main import ( "encoding/json" "fmt" "io" "net/http" "net/url" "os" ) // getSequenceDiagram calls the WebSequenceDiagrams API and saves the image. func getSequenceDiagram(message, outputFile, style, format string) error { // Step 1: request the diagram resp, err := http.PostForm( "https://www.websequencediagrams.com/index.php", url.Values{ "apiVersion": {"1"}, "message": {message}, "style": {style}, "format": {format}, // "apikey": {"YOUR_PREMIUM_KEY"}, }, ) if err != nil { return fmt.Errorf("POST failed: %w", err) } defer resp.Body.Close() var result struct { Img string `json:"img"` Errors []string `json:"errors"` } if err := json.NewDecoder(resp.Body).Decode(&result); err != nil { return fmt.Errorf("JSON decode failed: %w", err) } if result.Img == "" { return fmt.Errorf("server error: %v", result.Errors) } // Step 2: download the image imgResp, err := http.Get("https://www.websequencediagrams.com/" + result.Img) if err != nil { return fmt.Errorf("image download failed: %w", err) } defer imgResp.Body.Close() f, err := os.Create(outputFile) if err != nil { return err } defer f.Close() _, err = io.Copy(f, imgResp.Body) return err } func main() { err := getSequenceDiagram( "Alice->Bob: Hello\nBob-->Alice: Hi", "diagram.png", "modern-blue", "png", ) if err != nil { fmt.Fprintf(os.Stderr, "Error: %v\n", err) os.Exit(1) } fmt.Println("Saved to diagram.png") }