API lookups
Store answers from API calls.
Last updated
Was this helpful?
Store answers from API calls.
Last updated
Was this helpful?
Using an API lookup, you can fetch an from a server that returns JSON responses. To make the call dynamic, the lookup can use answers collected with the flow as request headers or query parameters.
Some examples of common uses of API lookups include:
Finding the current price of an item.
Locating the closest store to a user, based on their zipcode.
Looking up an account ID based on a user's email.
The answers fetched in an API lookup behave just like any other variable: they can be used for , into other components, and are sent to your .
If an API answer has no dependencies (there are no templated answers within its URL), the API lookup will happen as soon as the flow loads.
If an API answer has dependencies, the API lookup will happen as soon as all of its inputs are defined, and will be re-run whenever those inputs change. If any of the inputs become undefined, the API answer will be cleared.
For more control over when the API lookup happens, you can set a condition for its evaluation with Fetch conditionally, or you can choose to wait with .
API-lookup http
requests come directly from the responder's browser. If your server enforces restrictions (CORS), you will need to whitelist the following in the Access-Control-Allow-Origin
response header:
<client-id>.formsort.app
studio.formsort.com
(for testing within the studio)
To configure an API lookup, in any variant go to Variables > API lookups and click Add API lookup.
Take a look at our API lookup editor settings and configurations below.
You can change the REST method of the API lookup. Currently available is GET, POST, and PUT.
Provide the URL of the endpoint you wish to hit in the API URL field.
For example, if you ask the responder for their postal code in an answer with variable name user_zip
, you can use that answer to look up store locations with a URL like
https://example.com/api/stores?zip_code={{user_zip}}
.
Optional parameters
The default template formatting function default values for an API variable's URL. If you have a lookup like
https://example.com?age={{age}}&promo={{promo | default ""}}
then the API will be dispatched whenever the age
variable is defined. Promo
does not need to be defined by the user, since it has a default value of an empty string (""
).
If your API returns a payload with a shape that isn't directly the desired variable type, you can process the result within Formsort to avoid having to change the shape of your API responses.
For the following result processing examples, consider the below JSON response payload for a list of stores:
If the answer you want to access can be accessed directly with keys and indices, you can write out the path to the desired data with the JSON accessor. Formsort opens an object upon receipt, so it is unnecessary to include the object name in the accessor function.
For example, in the object above, Result.person.locationperson.location
would return "The Shire"
. You can drill down a level as well: person.name.firstName
would return "Frodo"
.
In the array example, 0.address
would return the address of the first result, which in the above example would be "123 Main St"
.
This function has an argument, res
, which is the body of the raw JSON object returned from the server. It should return
the desired answer.
For example, if we'd like to access the address of the first open address from the response above, the mapping function would be:
... which would result in "4 Back st"
.
This needs to be set you expect the response to contain multiple answers in an array format.
As stated earlier, the API lookup will be dispatched either immediately if there are no variable dependencies templated into the Request Headers or URL query parameters, or as soon as the templated variables are all defined by the user.
To have the API lookup wait until the user proceeds from the past the step where the last variable is defined, enable calculate on submit.
If an API answer was retrieved in a previous session, and the responder returns to the flow, the default behavior is not to re-fetch the answer.
To always fetch the answer on load, enable Re-calculate on load. This is useful for situations when calculated answers are not idempotent, meaning that repeated invocations do not result in the same result, such as answers depending on an API response that changes over time.
Sometimes, you may need to extract multiple fields from a JSON response body. Imagine an endpoint like GET /userLookup?email={{email}}
. This endpoint takes the email address value from the email
query param. And, if the email address is found in the database, returns the id and name associated with that email. In many cases, you may need to extract both fields -- id
and name
-- from the response body.
To extract multiple fields from a single JSON response object, you need to create multiple API variables: one API variable per field. Of course, you likely would prefer not to have to make a separate API call for each field. So, to avoid making multiple API requests when using multiple API variables, simply give every API variable the same URL string and query params.
By creating multiple API variables with the same URL string and query params, a single request to the given URL is made. However, the response is processed by every API variable with that URL string and query params signature. So, by using different JSON accessors or Mapping Functions (see above) for each API variable, you can extract different fields. Continuing the example above, we could use the set of API variables below to successfully retrieve the id
and name
fields. Note that both API variables are the same, except for their accessors. This will result in a single API request, but allow us to retrieve both fields.
If there is a pending API answer lookup, and the user is trying to advance to a step that uses the resultant answer, a loading indicator will be displayed while they await the result of the lookup.
If an API answer request fails, or returns an invalid response, the answer will be undefined, and the answer will be marked as failed.
Additionally, if you are using to host your flows, you will need to whitelist those domains.
API lookups are created inside of are local to those variants.
You can use existing answers from the flow to template the API lookup URL with the standard syntax. The API lookup will not be dispatched unless all of the templated variables are defined, unless the variable is made optional (see below).
For more complex processing of results, you can write a mapping function using javascript. The editor here uses the same calculated answer's .
Variable type sets the expected that we are expecting from the response: string
, number
, or boolean
. This needs to be properly defined for the API lookup to return successfully.
You can create to fine-tune when the API lookup should be dispatched.
This should be enabled if you'd like to wait until the API variable has completed the network call and any API variable functions have resolved. This is especially useful if the next step requires the return of the API for conditional logic or .
You can use the condition operator on a group, step, or question to affect the logic of a flow based on a failed answer, for example to put up a custom error message, or provide the responder an alternative way forward.
In flows, credentials are passed along with every request. This allows the use of cookies to authenticate requests to your own APIs.