generated: '2026-07-24'
method: searched
source: >-
  https://haloconnect.io/blog/webhooks-now-live ,
  https://docs.haloconnect.io/release-notes/2026/
spec_type: Webhooks
summary: >-
  Halo Connect webhooks are notification-only callbacks that fire when an async query
  completes or a registered query detects a data change, removing the need to poll for
  results. Payloads carry metadata only (never practice data). There are no predefined
  event subscriptions: any SQL a partner can express as a registered query becomes a
  listenable event. Delivery is HMAC-SHA256 signed with a per-integrator secret and is
  retried on failure.
registration:
  method: Integrator registers a single webhook URL (or URL template) with Halo, linked to their Halo Cloud subscription; contact support to configure.
  url_template_variables: ['{siteId}', '{queryId}', '{source}']
security:
  signature: HMAC-SHA256
  secret: unique per integrator
  signed_payload_format: '<message_body>.<timestamp_iso8601>'
  headers:
  - name: X-Halo-Signature-256
    description: HMAC-SHA256 signature over '<message_body>.<timestamp_iso8601>'.
  - name: X-Halo-Timestamp
    description: ISO 8601 timestamp of the delivery, used for replay prevention.
  - name: X-Halo-Id
    description: Unique webhook delivery identifier.
delivery:
  retries: true
  note: Webhook retry behaviour improved in release 25.1211 (Jan 2026).
events:
- name: query.completed
  trigger: An async query finishes and results are available.
  payload_fields: [siteId (Halo GUID), queryId, webhookSource]
  webhookSource: async
- name: registered_query.data_changed
  trigger: A registered (recurring) query detects new/changed data at the practice.
  payload_fields: [siteId (Halo GUID), queryId, webhookSource]
  webhookSource: registered
payload:
  contains_practice_data: false
  note: Payload is a notification that something happened; the partner then fetches results via the query result endpoints.
  fields:
    siteId: Halo GUID of the practice that was queried.
    queryId: ID of the async/registered query that triggered the webhook.
    webhookSource: One of 'async' | 'registered'.