API Reference

import fs from "fs";
import FormData from "form-data";

const form = new FormData();
form.append("signer_name", "Alex Morgan");
form.append("signer_email", "alex@example.com");
form.append("attestation_type", "signature");
form.append("document", fs.createReadStream("./contract.pdf"));
form.append("reference", fs.createReadStream("./alex-photo.jpg"));

const res = await fetch("https://districtseal.com/api/transactions", {
  method: "POST",
  headers: { "X-API-Key": process.env.DISTRICTSEAL_API_KEY },
  body: form,
});

const { sign_url } = await res.json();
const full = "https://districtseal.com" + sign_url;
// → email `full` to your signer

import os, requests

r = requests.post(
    "https://districtseal.com/api/transactions",
    headers={"X-API-Key": os.environ["DISTRICTSEAL_API_KEY"]},
    files={
        "document":  open("contract.pdf", "rb"),
        "reference": open("alex-photo.jpg", "rb"),
    },
    data={
        "signer_name":      "Alex Morgan",
        "signer_email":     "alex@example.com",
        "attestation_type": "signature",
    },
)
r.raise_for_status()
sign_url = "https://districtseal.com" + r.json()["sign_url"]

$ch = curl_init("https://districtseal.com/api/transactions");
curl_setopt_array($ch, [
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_POST           => true,
  CURLOPT_HTTPHEADER     => ["X-API-Key: " . getenv("DISTRICTSEAL_API_KEY")],
  CURLOPT_POSTFIELDS     => [
    "signer_name"      => "Alex Morgan",
    "signer_email"     => "alex@example.com",
    "attestation_type" => "signature",
    "document"         => new CURLFile("contract.pdf"),
    "reference"        => new CURLFile("alex-photo.jpg"),
  ],
]);
$data     = json_decode(curl_exec($ch), true);
$sign_url = "https://districtseal.com" . $data["sign_url"];

import hmac, hashlib, json, os
from fastapi import FastAPI, Request, HTTPException

app = FastAPI()

@app.post("/hooks/districtseal")
async def hook(request: Request):
    header = request.headers.get("x-districtseal-signature", "")
    parts  = dict(p.split("=", 1) for p in header.split(","))

    raw = await request.body()
    expected = hmac.new(
        os.environ["DISTRICTSEAL_WEBHOOK_SECRET"].encode(),
        f"{parts['t']}.".encode() + raw,
        hashlib.sha256,
    ).hexdigest()

    if not hmac.compare_digest(parts["v1"], expected):
        raise HTTPException(401, "invalid signature")

    event = json.loads(raw)
    if event["event"] == "transaction.completed":
        pass  # mark contract signed
    return {"ok": True}

$raw    = file_get_contents("php://input");
$header = $_SERVER["HTTP_X_DISTRICTSEAL_SIGNATURE"] ?? "";
$parts  = [];
foreach (explode(",", $header) as $p) {
    [$k, $v] = explode("=", $p, 2);
    $parts[$k] = $v;
}

$expected = hash_hmac(
    "sha256",
    $parts["t"] . "." . $raw,
    getenv("DISTRICTSEAL_WEBHOOK_SECRET")
);

if (!hash_equals($parts["v1"], $expected)) {
    http_response_code(401); exit;
}

$event = json_decode($raw, true);
// handle $event