Workflow webhooks

Reply: success

{
  "request_id": "8f2c41d7",
  "status": "SUCCESS",
  "balance": 240.78,
  "arrears": 36.0,
  "nextpaymentdate": "2026-11-28"
}

Reply: failure

{
  "request_id": "8f2c41d7",
  "status": "FAILURE",
  "statusMessage": "Account not found"
}

Python

"""Answer Workflow Remote Query calls: custom lookups, inbound SMS and delivery receipts.

pip install fastapi uvicorn
Run with:  uvicorn remote_query:app --host 0.0.0.0 --port 8000
"""
import os
import secrets

from fastapi import Body, Depends, FastAPI, HTTPException
from fastapi.security import HTTPBasic, HTTPBasicCredentials

app = FastAPI()
basic = HTTPBasic()

# The key and secret entered in the Workflow connection settings.
KEY = os.environ["EM_RQ_KEY"].encode()
SECRET = os.environ["EM_RQ_SECRET"].encode()


def check(creds: HTTPBasicCredentials = Depends(basic)) -> None:
    ok_key = secrets.compare_digest(creds.username.encode(), KEY)
    ok_secret = secrets.compare_digest(creds.password.encode(), SECRET)
    if not (ok_key and ok_secret):
        raise HTTPException(status_code=401, headers={"WWW-Authenticate": "Basic"})


@app.post("/remote.query/{method}", dependencies=[Depends(check)])
def remote_query(method: str, body: dict = Body(...)):
    # Always echo request_id so Workflow can match the reply to its request.
    reply = {"request_id": body.get("request_id")}

    match method.lower():
        case "custom.query":  # the "Query name" set in the Remote Query action
            if body.get("query_type") == "BALANCE":
                reference = body.get("reference")
                # Look the customer up here. Each value below maps to a journey variable.
                reply |= {"status": "SUCCESS", "balance": 240.78, "arrears": 36.00,
                          "nextpaymentdate": "2026-11-28"}
            else:
                reply |= {"status": "FAILURE", "statusMessage": "Unknown query type"}
        case "sms.inbox":
            print(f"SMS {body.get('messageid')} from {body.get('from')} "
                  f"to {body.get('to')}: {body.get('body')}")
            reply["status"] = "SUCCESS"
        case "sms.delivery":
            print(f"Message {body.get('messageid')}: status {body.get('status')}, "
                  f"code {body.get('code')}")
            reply["status"] = "SUCCESS"
        case _:
            raise HTTPException(status_code=404)

    return reply

Node.js

// Answer Workflow Remote Query calls: custom lookups, inbound SMS and delivery receipts
// (Node.js 18 or later, no packages needed). Run with:  node remote_query.js
const http = require("node:http");
const crypto = require("node:crypto");

// The key and secret entered in the Workflow connection settings.
const expected = Buffer.from(`${process.env.EM_RQ_KEY}:${process.env.EM_RQ_SECRET}`);

function authorized(req) {
  const [scheme, token] = (req.headers.authorization || "").split(" ");
  if (scheme !== "Basic" || !token) return false;
  const supplied = Buffer.from(token, "base64");
  return supplied.length === expected.length && crypto.timingSafeEqual(supplied, expected);
}

http.createServer(async (req, res) => {
  const match = req.url.match(/^\/remote\.query\/([^/?]+)/);
  if (req.method !== "POST" || !match) return res.writeHead(404).end();
  if (!authorized(req)) return res.writeHead(401).end();

  let body;
  try {
    const chunks = [];
    for await (const chunk of req) chunks.push(chunk);
    body = JSON.parse(Buffer.concat(chunks).toString("utf8"));
  } catch {
    return res.writeHead(400).end();
  }

  // Always echo request_id so Workflow can match the reply to its request.
  const reply = { request_id: body.request_id };

  switch (match[1].toLowerCase()) {
    case "custom.query": // the "Query name" set in the Remote Query action
      if (body.query_type === "BALANCE") {
        // Look the customer up here (body.reference). Each value maps to a journey variable.
        Object.assign(reply, { status: "SUCCESS", balance: 240.78, arrears: 36.0, nextpaymentdate: "2026-11-28" });
      } else {
        Object.assign(reply, { status: "FAILURE", statusMessage: "Unknown query type" });
      }
      break;
    case "sms.inbox":
      console.log(`SMS ${body.messageid} from ${body.from} to ${body.to}: ${body.body}`);
      reply.status = "SUCCESS";
      break;
    case "sms.delivery":
      console.log(`Message ${body.messageid}: status ${body.status}, code ${body.code}`);
      reply.status = "SUCCESS";
      break;
    default:
      return res.writeHead(404).end();
  }

  res.writeHead(200, { "Content-Type": "application/json" }).end(JSON.stringify(reply));
}).listen(process.env.PORT || 8881);