Source type

Trello Source

Trello sources receive board, card, list, member, and action webhooks, answer Trello's callback URL HEAD validation, and verify webhook signatures.

TRELLOHEAD, POSTApplication SecretProductivity
Trello webhooks documentationAll source types
Trello sends webhook traffic to a FastHook source, FastHook validates the provider contract, records the request, and routes accepted events through connections to destinations.TrelloProviderHEAD, POSTChallengeFastHookSource URLTRELLOProvider credentialHEAD validationVerify before queue401 on auth failure405 on wrong methodAcceptedRequestverified: trueConnections route the accepted request to destinationsFilters, transformations, retries, replay, and destination signatures stay downstream from source verification.Provider setupSpecial responseHEAD validation
FastHook keeps the provider-facing contract on the source. Accepted requests are stored before routing, while rejected requests keep enough evidence to debug signature, method, and challenge failures.

When to use this source type

Choose the TRELLO source type when Trello is the system sending webhook requests into FastHook. The source type keeps sender-specific setup close to the source: accepted methods, verification headers, challenge handling, and the exact credential fields are documented together so operators do not need to translate a generic HMAC form into a provider-specific contract.

FastHook verifies the source before accepted traffic is queued. A valid request is stored with verified: true, then connections route it to destinations. A bad signature, wrong token, or missing provider header is rejected as SOURCE_AUTH_FAILED. A method outside the allowed set is rejected as SOURCE_METHOD_NOT_ALLOWED.

FastHook configuration

In the dashboard, create a source, set Source Type to Trello, keep Authenticate enabled when verification is required, and fill the fields below.

Source Type

TRELLO

Allowed methods

HEAD, POST

Authentication

Provider signature

Application Secret

Copy this value from Trello and store it on the FastHook source.

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

HTTP methods

This source accepts only the methods listed below. Keep the set narrow so provider mistakes and accidental test calls are visible as rejected requests instead of being silently accepted.

HEADPOST

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

Headers and verification

FastHook verifies the provider-specific values below before the request is accepted. The comparison is done against the raw inbound request body or the exact provider-specific signing input described here.

x-trello-webhook

Base64 HMAC-SHA1 signature over raw body + callback URL.

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

Provider setup checklist

  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.
  4. Open Trello webhooks documentation when you need the provider's event list, dashboard steps, or retry policy.

Troubleshooting

  • No request appears: the provider is not calling the generated FastHook Source URL, the source URL was copied before saving, or the provider has not completed its setup validation.
  • 405 method rejected: the provider sent a method outside HEAD, POST. Edit the source only if the provider documentation says that method is expected.
  • 401 source auth failed: check the configured FastHook field, the provider signing secret, and the header names listed on this page.
  • Signature mismatch: make sure the provider signs the same public Source URL it calls and that no proxy, parser, or manual resend changed the raw request body before FastHook received it.

Related docs