Source type

Custom Webhook Source

Use a custom webhook source when the producer is an internal service, a provider FastHook does not have a preset for yet, or a test client that can send ordinary HTTP requests.

WEBHOOKPOST, PUT, PATCH, DELETEOptional Basic Auth, API key, or HMAC fieldsCustom
FastHook Sources docsAll source types
FastHook sends webhook traffic to a FastHook source, FastHook validates the provider contract, records the request, and routes accepted events through connections to destinations.FastHookProviderPOST, PUT, PATCH, DELETESignedFastHookSource URLWEBHOOKProvider credentialsignatureVerify 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.
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 WEBHOOK source type when FastHook 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 Custom Webhook, keep Authenticate enabled when verification is required, and fill the fields below.

Source Type

WEBHOOK

Allowed methods

POST, PUT, PATCH, DELETE

Authentication

Optional source auth

Optional Basic Auth, API key, or HMAC fields

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

{
  "type": "WEBHOOK",
  "config": {
    "auth_type": "HMAC",
    "auth": {
      "signature_header": "x-signature",
      "secret": "shared-secret"
    },
    "allowed_http_methods": ["POST","PUT","PATCH","DELETE"]
  }
}

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.

POSTPUTPATCHDELETE

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.

Authorization

Used when Basic Auth is enabled.

Configured API key header

Used when API key auth is enabled.

Configured signature header

Used when generic HMAC auth is enabled.

FastHook can verify a generic HMAC-SHA256 signature over the raw request body, or use Basic Auth/API key checks before queueing.

Provider setup checklist

  1. Create a source, copy the generated Source URL, and point your sender at that URL.
  2. Keep the default methods for service-to-service traffic, or narrow them to the exact methods your sender uses.
  3. Choose Basic Auth, API key, or HMAC when the sender can attach a stable credential.
  4. Open FastHook Sources docs 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 POST, PUT, PATCH, DELETE. 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