Trello Source Configuration

Trello configuration

Create a Trello source, keep HEAD and POST enabled, and provide the configured Application Secret values for provider signature. FastHook uses these settings to validate each Trello delivery before it enters the routing workflow.

{
  "type": "TRELLO",
  "config": {
    "auth_type": "PROVIDER_SIGNATURE",
    "auth": {
      "provider": "TRELLO",
      "webhook_signing_secret": "provider-secret"
    },
    "allowed_http_methods": ["HEAD","POST"]
  }
}

HEAD validation before event POST

1. Trello validates callbackURL with a HEAD request before it sends events.
2. FastHook answers that HEAD request with an empty 200 OK response.
3. After validation succeeds, Trello sends signed POST webhooks to the same Source URL.

Trello request contract

FastHook answers HEAD validation with 200 and verifies x-trello-webhook as HMAC-SHA1 base64 over raw body + callback URL.

Special response: HEAD validation returns HTTP 200 with an empty body.

Trello headers

Preserve x-trello-webhook when sending Trello test deliveries. FastHook evaluates this request context before accepting the payload, so missing or modified values remain visible as rejected requests instead of routed events.

Trello setup

1. Create a Trello webhook with the generated FastHook Source URL as callbackURL.
2. Paste the Trello application secret into FastHook.
3. If the callback URL Trello signs differs from the incoming URL, set callback_url through the API so the signature input is exact.

Trello routing hints

• Trello webhook traffic usually routes by action type, board id, list id, card id, or member id.
• The HEAD callback validation must succeed before normal POST event delivery starts.

Continue with Trello

• Trello webhooks documentation
• Source operations and troubleshooting