Trigger Fields#

Note: This guide is for Zapier's legacy web builder. For new integrations, use Zapier Visual Builder and its new Trigger documentation.


Trigger Fields answer the question: How can a user filter Triggers? Almost exclusively these are dynamic dropdowns, but some real world examples are:

  • Search Term (EG: Twitter Tweet Search)
  • Label (EG: Gmail Inbox)
  • Parent Object (span relationships via dynamic dropdowns)
  • Repo for an Issue (EG: Github)
  • Notebook for a Note (EG: Evernote)

Imagine an endpoint like - that would require no trigger fields at all. However an endpoint like - that would require at least a trigger field to select the list ID (and it would be a dynamic dropdown at that!).

What a user sees:

What a developer sees:

When you attempt to add a trigger field, you'll be prompted to provide some options which are outlined below.

Use the Scripting API to modify the request to your Polling URL or Subscribe URL to include these fields or use them in the post poll or catch hook methods to filter the response from your API.

Trigger Field Options#


A key for your internal use. It is available for variable syntax in the Trigger URL field (as well as in scripting). Needs to be at least two characters long, start with an alpha, and only contain a-z, A-Z, 0-9 or _.

project or search_term


A human readable Label shown in the UI as a user builds a Zap.

Room or Title

label help default

Help Text#

Human readable description of a trigger field, useful for describing some detail you couldn't list in the Label.

Choose which project to watch for new messages. or Define a search term for finding Tweets.


A default value for a field. The behavior varies between required and optional fields. For required fields, the default will be set once when the user first creates the Trigger, but it is not guaranteed after that (we raise an error on missing/null values instead). For optional fields, it is set on initial creation and used in place of missing or null values every time the Zap runs.


The type we will try to coerce to. Falls back to unicode (text) if coercion fails.


If checked a user will not be able to continue without entering some value.

Dynamic Dropdown#

Use an existing Trigger to load in values for selection, using the machine readable value your API consumes (like id or hash) while showing a human readable version to the user (like name or itemName).

In our experience, most trigger fields are dynamic dropdowns.

Refer to our dynamic dropdown docs for a more in depth explanation.

Example: or TRIGGERKEY.hash.itemName

dynamic dropdown

Static Dropdown#

A comma separated string that will be turned into a select field for limiting the choices a user can provide to a trigger field.

choice_a,choice_b,choice_c or Yesterday, Today, Tomorrow

simple static dropdown

If you would like to provide a label for the raw value of each choice, you can also use the raw|label,raw|label syntax instead.

1|Option 1,2|Option 2

simple static dropdown as key-value pairs


Indicates if this field can hold multiple values. For example, this could be useful if you want to allow users to only trigger on new contacts with one or more tags applied. List fields gain the +/- icons to the side.

list field example

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