Bkmark Webhooks — Real-Time Event Notifications API

Webhooks let your application react to changes in a user’s Bkmark account the moment they happen — no polling required. When an event occurs (a bookmark is created, a tag is renamed, a group is deleted), Bkmark sends an HTTP POST request containing a JSON payload to the URL you registered. You verify the request came from Bkmark using an HMAC-SHA256 signature, then process the event however your application needs.

Creating a Subscription

Send a POST request to /api/v1/webhooks with the endpoint URL you want to receive events and the list of events you want to subscribe to.

curl -X POST https://api.bkmark.it/api/v1/webhooks \
  -H "Authorization: Bearer ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "url": "https://yourapp.com/webhooks/bkmark",
    "events": ["bookmark.created", "bookmark.deleted", "tag.created"]
  }'

The secret field is returned only once — at creation time. Store it immediately in a secure secrets manager (such as AWS Secrets Manager, HashiCorp Vault, or an environment variable). You cannot retrieve it again. If you lose it, delete the subscription and create a new one.

Response 201 Created:

{
  "id": "wh_01hq8p2z3kxv7m4n9rbt5c6d",
  "url": "https://yourapp.com/webhooks/bkmark",
  "secret": "whsec_a3f8c2d1e94b76052718af3c0d9e1b47",
  "events": ["bookmark.created", "bookmark.deleted", "tag.created"],
  "active": true,
  "createdAt": "2025-06-01T09:00:00.000Z"
}

string

Unique identifier for this webhook subscription. Use it to update, delete, or query deliveries.

string

The HTTPS endpoint Bkmark will POST events to.

string

HMAC-SHA256 signing secret. Shown once only. Use this to verify the X-Bkmark-Signature header on every incoming request.

array

The event types this subscription will receive.

boolean

Whether the subscription is currently enabled.

Request Body Parameters

string

required

The HTTPS endpoint Bkmark will deliver events to. Must be publicly accessible.

array of strings

required

One or more event type strings. Subscribe to all events with ["*"], or list individual events. See Available Events below.

Available Events

Bkmark emits events across three resource types: bookmarks, groups, and tags.

Event	Trigger
`bookmark.created`	A new bookmark is saved
`bookmark.updated`	A bookmark’s title, description, or other fields change
`bookmark.deleted`	A bookmark is permanently deleted
`bookmark.favorited`	A bookmark is marked as a favorite (transition only)
`bookmark.unfavorited`	A bookmark’s favorite status is removed (transition only)
`bookmark.archived`	A bookmark is archived (transition only)
`bookmark.unarchived`	A bookmark is unarchived (transition only)
`bookmark.restored`	A soft-deleted bookmark is restored from trash
`group.created`	A new group is created
`group.updated`	A group’s name or color changes
`group.deleted`	A group is deleted
`tag.created`	A new tag is created
`tag.updated`	A tag’s name or color changes
`tag.deleted`	A tag is deleted

Transition events (bookmark.favorited, bookmark.unfavorited, bookmark.archived, bookmark.unarchived) fire only when the boolean state actually changes. For example, PATCHing isArchived: true on a bookmark that is already archived does not fire bookmark.archived. No-op updates to tags and groups also do not fire tag.updated or group.updated.

Payload Format

Every webhook delivery is a POST request with Content-Type: application/json. The top-level structure is consistent across all events:

{
  "event": "bookmark.created",
  "timestamp": "2025-06-01T14:32:10.000Z",
  "data": { }
}

string

The event type string, e.g. bookmark.created.

string (ISO 8601)

UTC timestamp of when the event occurred. Use this along with the entity id for idempotency checks.

object

The event payload. Shape varies by event type — see the examples below.

Payload Examples

Show bookmark.created

{
  "event": "bookmark.created",
  "timestamp": "2025-06-01T14:32:10.000Z",
  "data": {
    "bookmark": {
      "id": "bk_01hq8p2z3kxv7m4n9rbt5c6d",
      "url": "https://example.com/article",
      "title": "Understanding OAuth2 PKCE",
      "description": "A practical guide to the PKCE extension for OAuth2.",
      "isFavorite": false,
      "isArchived": false,
      "tags": [
        { "id": "tag_01abc", "name": "security" }
      ],
      "groups": [
        { "id": "grp_01xyz", "name": "Reading List" }
      ],
      "createdAt": "2025-06-01T14:32:10.000Z",
      "updatedAt": "2025-06-01T14:32:10.000Z"
    }
  }
}

Show bookmark.updated — includes a changes array

The data object includes a changes array listing every field that changed in this update.

{
  "event": "bookmark.updated",
  "timestamp": "2025-06-02T09:15:00.000Z",
  "data": {
    "bookmark": {
      "id": "bk_01hq8p2z3kxv7m4n9rbt5c6d",
      "url": "https://example.com/article",
      "title": "Understanding OAuth2 PKCE — Updated",
      "description": "Revised and expanded.",
      "isFavorite": false,
      "isArchived": false,
      "tags": [
        { "id": "tag_01abc", "name": "security" }
      ],
      "groups": [
        { "id": "grp_01xyz", "name": "Reading List" }
      ],
      "createdAt": "2025-06-01T14:32:10.000Z",
      "updatedAt": "2025-06-02T09:15:00.000Z"
    },
    "changes": ["title", "description"]
  }
}

Show bookmark.deleted

Deleted bookmark payloads include the ID, URL, and title so you can identify the resource even though it no longer exists.

{
  "event": "bookmark.deleted",
  "timestamp": "2025-06-03T11:00:00.000Z",
  "data": {
    "bookmarkId": "bk_01hq8p2z3kxv7m4n9rbt5c6d",
    "url": "https://example.com/article",
    "title": "Understanding OAuth2 PKCE — Updated",
    "deletedAt": "2025-06-03T11:00:00.000Z"
  }
}

Show bookmark.restored

Fires when a soft-deleted bookmark is recovered from trash.

{
  "event": "bookmark.restored",
  "timestamp": "2025-06-04T08:44:00.000Z",
  "data": {
    "id": "bk_01hq8p2z3kxv7m4n9rbt5c6d",
    "url": "https://example.com/article",
    "title": "Understanding OAuth2 PKCE — Updated",
    "isArchived": false
  }
}

Show tag.updated — includes previous object

tag.updated and group.updated both include a previous object inside data with the prior values of every field that changed. Useful for “if name changed from X to Y” workflows.

{
  "event": "tag.updated",
  "timestamp": "2025-06-02T10:00:00.000Z",
  "data": {
    "id": "tag_01abc",
    "name": "reading-list",
    "color": "blue",
    "previous": {
      "name": "todo",
      "color": "gray"
    }
  }
}

Show group.updated — includes previous object

{
  "event": "group.updated",
  "timestamp": "2025-06-02T10:05:00.000Z",
  "data": {
    "id": "grp_01xyz",
    "name": "Articles",
    "color": "blue",
    "previous": {
      "name": "Reading",
      "color": "gray"
    }
  }
}

Show test event (from POST /webhooks/:id/test)

{
  "event": "test",
  "timestamp": "2025-06-01T09:00:01.000Z",
  "data": {
    "message": "This is a test webhook delivery from bkmark.it"
  }
}

Signature Verification

Every delivery includes an X-Bkmark-Signature header containing the HMAC-SHA256 hex digest of the raw request body, computed using your webhook secret.

Always verify the signature before processing any webhook. Skip this step and an attacker can send forged events to your endpoint. Use a timing-safe comparison function — standard string equality is vulnerable to timing attacks.

The verification algorithm is:

Read the raw request body as bytes (do not parse JSON first).
Compute HMAC-SHA256(secret, rawBody) and encode as a hex string.
Compare the result with the value in X-Bkmark-Signature using a timing-safe equality function.
Reject any request where the values do not match.

Node.js

import { createHmac, timingSafeEqual } from 'node:crypto';
import express from 'express';

const app = express();

// Use express.raw() so you get the unmodified body buffer
app.post('/webhooks/bkmark', express.raw({ type: 'application/json' }), (req, res) => {
  const signature = req.headers['x-bkmark-signature'];
  const secret = process.env.BKMARK_WEBHOOK_SECRET;

  if (!signature) {
    return res.status(401).json({ error: 'Missing signature' });
  }

  const expected = createHmac('sha256', secret)
    .update(req.body) // req.body is a Buffer when using express.raw()
    .digest('hex');

  const sigBuffer = Buffer.from(signature);
  const expBuffer = Buffer.from(expected);

  // Reject if lengths differ (timingSafeEqual requires equal-length buffers)
  if (sigBuffer.length !== expBuffer.length) {
    return res.status(401).json({ error: 'Invalid signature' });
  }

  if (!timingSafeEqual(sigBuffer, expBuffer)) {
    return res.status(401).json({ error: 'Invalid signature' });
  }

  // Signature is valid — parse and process the event
  const { event, timestamp, data } = JSON.parse(req.body.toString());

  switch (event) {
    case 'bookmark.created':
      // e.g. sync to your own database
      console.log('New bookmark:', data.bookmark.url);
      break;
    case 'bookmark.deleted':
      console.log('Deleted bookmark ID:', data.bookmarkId);
      break;
    // Handle other events...
  }

  // Respond quickly — queue heavy work for a background job
  res.status(200).send('OK');
});

Python

import hmac
import hashlib
import os
from flask import Flask, request, abort

app = Flask(__name__)
WEBHOOK_SECRET = os.environ["BKMARK_WEBHOOK_SECRET"]


def verify_signature(raw_body: bytes, signature: str) -> bool:
    expected = hmac.new(
        WEBHOOK_SECRET.encode(),
        raw_body,
        hashlib.sha256
    ).hexdigest()
    # hmac.compare_digest is timing-safe
    return hmac.compare_digest(signature, expected)


@app.post("/webhooks/bkmark")
def handle_webhook():
    signature = request.headers.get("X-Bkmark-Signature", "")
    raw_body = request.get_data()  # raw bytes, before any JSON parsing

    if not verify_signature(raw_body, signature):
        abort(401, "Invalid signature")

    payload = request.get_json()
    event = payload["event"]

    if event == "bookmark.created":
        bookmark = payload["data"]["bookmark"]
        print(f"New bookmark: {bookmark['url']}")
    elif event == "bookmark.deleted":
        print(f"Deleted bookmark ID: {payload['data']['bookmarkId']}")
    # Handle other events...

    return "", 200

Managing Subscriptions

Use the following endpoints to list, update, delete, and test your webhook subscriptions.

Method	Path	Description
`GET`	`/api/v1/webhooks`	List all subscriptions for the authenticated user
`PATCH`	`/api/v1/webhooks/:id`	Update a subscription’s URL, event list, or active status
`DELETE`	`/api/v1/webhooks/:id`	Permanently delete a subscription
`POST`	`/api/v1/webhooks/:id/test`	Send a test event to verify your endpoint is reachable
`GET`	`/api/v1/webhooks/:id/deliveries`	View the last 50 delivery attempts and their HTTP response codes

Example — disable a subscription without deleting it:

curl -X PATCH https://api.bkmark.it/api/v1/webhooks/wh_01hq8p2z3kxv7m4n9rbt5c6d \
  -H "Authorization: Bearer ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{ "active": false }'

Delivery and Retries

Bkmark dispatches webhook requests asynchronously from a background job queue. The following guarantees and constraints apply:

Your endpoint must return a 2xx status code within 10 seconds. Any non-2xx response or a timeout is treated as a failure.
Failed deliveries are retried 3 times using exponential backoff.
You can inspect every attempt — including the HTTP response code your server returned — via GET /api/v1/webhooks/:id/deliveries.

Respond with 200 OK immediately and offload any heavy processing to a background worker or task queue. This prevents timeouts caused by slow database writes or third-party API calls inside your handler.

Because deliveries can be retried, your handler should be idempotent. Use the timestamp field and the entity id inside data together as a deduplication key — if you’ve already processed an event with that combination, skip it.

Polling Helpers

If you need to backfill events or reconcile state without webhooks, you can poll the bookmarks list endpoint with time-based filters.

Parameter	Description
`?since=<ISO 8601>`	Return bookmarks with `createdAt` after the given timestamp
`?updatedSince=<ISO 8601>`	Return bookmarks with `updatedAt` after the given timestamp

Both filters are strictly greater-than — a bookmark whose timestamp exactly matches the boundary is excluded. Combine with sortField=updatedAt&sortDir=desc for efficient incremental sync.

# Fetch all bookmarks created after June 1st
curl "https://api.bkmark.it/api/v1/bookmarks?since=2025-06-01T00:00:00.000Z&sortField=createdAt&sortDir=desc" \
  -H "Authorization: Bearer ACCESS_TOKEN"

# Fetch all bookmarks updated in the last 15 minutes
curl "https://api.bkmark.it/api/v1/bookmarks?updatedSince=2025-06-01T14:15:00.000Z&sortField=updatedAt&sortDir=desc" \
  -H "Authorization: Bearer ACCESS_TOKEN"

Overview

Endpoints

OAuth2

Bkmark Webhooks — Real-Time Event Notifications API

Creating a Subscription

Request Body Parameters

Available Events

Payload Format

Payload Examples

Signature Verification

Node.js

Python

Managing Subscriptions

Delivery and Retries

Polling Helpers

​Creating a Subscription

​Request Body Parameters

​Available Events

​Payload Format

​Payload Examples

​Signature Verification

​Node.js

​Python

​Managing Subscriptions

​Delivery and Retries

​Polling Helpers

Creating a Subscription

Request Body Parameters

Available Events

Payload Format

Payload Examples

Signature Verification

Node.js

Python

Managing Subscriptions

Delivery and Retries

Polling Helpers