n8n Integration — self-hosted audio automation

{
  "name": "DeepScript: Upload and Process",
  "nodes": [
    {
      "name": "Manual Trigger",
      "type": "n8n-nodes-base.manualTrigger",
      "typeVersion": 1,
      "position": [240, 300],
      "parameters": {}
    },
    {
      "name": "Read Audio File",
      "type": "n8n-nodes-base.readBinaryFile",
      "typeVersion": 1,
      "position": [440, 300],
      "parameters": { "filePath": "/data/audio/meeting.mp3" }
    },
    {
      "name": "Upload to DeepScript",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4,
      "position": [640, 300],
      "parameters": {
        "method": "POST",
        "url": "https://api.deepscript.com/v1/transcriptions",
        "sendHeaders": true,
        "headerParameters": {
          "parameters": [
            { "name": "X-API-KEY", "value": "={{ $env.DEEPSCRIPT_API_KEY }}" }
          ]
        },
        "sendBody": true,
        "contentType": "multipart-form-data",
        "bodyParameters": {
          "parameters": [
            { "name": "file", "value": "={{ $binary.data }}", "parameterType": "formBinaryData" },
            { "name": "model", "value": "premium" },
            { "name": "language", "value": "de" }
          ]
        }
      }
    },
    {
      "name": "Webhook (transcription.completed)",
      "type": "n8n-nodes-base.webhook",
      "typeVersion": 1,
      "position": [840, 300],
      "parameters": {
        "path": "deepscript-completed",
        "responseMode": "responseNode"
      }
    },
    {
      "name": "Get Transcript",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4,
      "position": [1040, 300],
      "parameters": {
        "method": "GET",
        "url": "=https://api.deepscript.com/v1/transcriptions/{{ $json.data.transcriptionId }}",
        "sendHeaders": true,
        "headerParameters": {
          "parameters": [
            { "name": "X-API-KEY", "value": "={{ $env.DEEPSCRIPT_API_KEY }}" }
          ]
        }
      }
    }
  ],
  "connections": {
    "Manual Trigger": { "main": [[{ "node": "Read Audio File", "type": "main", "index": 0 }]] },
    "Read Audio File": { "main": [[{ "node": "Upload to DeepScript", "type": "main", "index": 0 }]] },
    "Webhook (transcription.completed)": { "main": [[{ "node": "Get Transcript", "type": "main", "index": 0 }]] }
  }
}

// In an n8n Code node placed right after the Webhook node.
// Verifies the X-DeepScript-Signature header against the raw body.
const crypto = require("crypto");

const SIGNING_SECRET = $env.DEEPSCRIPT_WEBHOOK_SECRET; // "whsec_xxx"
const header = $input.first().json.headers["x-deepscript-signature"];
const rawBody = $input.first().json.body;

const parts = Object.fromEntries(header.split(",").map((p) => p.split("=")));
const { t: timestamp, v1: signature } = parts;

if (Math.abs(Date.now() / 1000 - Number(timestamp)) > 300) {
  throw new Error("Webhook timestamp out of tolerance (>5min)");
}

const signedPayload = `${timestamp}.${JSON.stringify(rawBody)}`;
const expected = crypto
  .createHmac("sha256", SIGNING_SECRET)
  .update(signedPayload)
  .digest("hex");

const valid = crypto.timingSafeEqual(
  Buffer.from(signature, "hex"),
  Buffer.from(expected, "hex")
);
if (!valid) throw new Error("Invalid webhook signature");

return [{ json: { verified: true, event: rawBody } }];