Variable substitution

A variable is a {{name}} placeholder that Nouto replaces with a value when you send a request. This page explains where placeholders work, the order in which Nouto looks up a name, and the placeholders that read from responses, cookies, and scripts. To create environments and global variables, see Environments and global variables.

Placeholder types

Every placeholder uses double braces. The text inside determines where the value comes from:

Placeholder	Value source
{{name}}	The active environment, collection or folder variables, global variables, or a linked .env file. See Resolution order.
{{$namespace.method}}	A generated value such as a UUID, timestamp, or hash. See Dynamic variables.
{{$prompt.name}}	A value you type in a dialog when you send. See Dynamic variables.
{{$file.read, path}}	The content of a file. See Dynamic variables.
{{$response.path}}	The most recent response. See Response values.
{{RequestName.$response.path}}	The response of a specific request. See Response values from a named request.
{{$cookie.name}}	A cookie in the active cookie jar. See Cookie values.

If Nouto can’t resolve a placeholder, it sends the placeholder text unchanged, braces included.

Fields that support variables

Nouto substitutes variables in these parts of an HTTP request:

• The URL, including path parameter values
• Query parameter names and values
• Header names and values, including headers inherited from the collection or folder
• The body, including form fields and GraphQL variables
• On the Auth tab: the username, password, token, API key name, and API key value

For WebSocket and Server-Sent Events connections, Nouto substitutes variables in the URL and headers. For gRPC, it substitutes variables in the address, metadata, and message body.

Resolution order

When the same name is defined in more than one place, Nouto uses the value from the source highest in this list:

1. The active environment
2. Variables on the request’s folder, then its parent folders, then the collection. A child folder’s value overrides its parent’s.
3. Global variables
4. The linked .env file

For example, if the global variables define baseUrl as https://api.example.com and the active environment defines it as http://localhost:3000, requests go to http://localhost:3000.

Nouto skips variables whose checkbox is cleared. Collection and folder variables apply only to requests saved in that collection. See Collections to define them.

Variable names

Use letters, digits, and underscores in variable names, for example base_url or apiKey2. The variable editor accepts names with dots and hyphens, such as api-key, but Nouto doesn’t substitute placeholders with those names. Names are case-sensitive: {{Token}} and {{token}} are different variables.

Variables inside variable values

A variable’s value can contain other placeholders. For example, define host as api.example.com and baseUrl as https://{{host}}/v2. A request to {{baseUrl}}/users then goes to https://api.example.com/v2/users.

Nouto resolves up to five levels of nested references. A value can also contain a dynamic variable, such as {{$uuid.v4}}, which generates a new value on each send.

Response values

Use {{$response.path}} to insert a value from the most recent response, for example a token returned by a login request:

Placeholder	Value
{{$response.body}}	The entire response body. A JSON body is inserted as JSON text.
{{$response.body.token}}	The token field of a JSON body
{{$response.body.data[0].id}}	A nested field, using dot notation and array indexes
{{$response.headers.content-type}}	A response header. Write the header name in lowercase.
{{$response.status}}	The status code, for example 200
{{$response.statusText}}	The status text, for example OK
{{$response.duration}}	The response time in milliseconds
{{$response.size}}	The response size in bytes

Which response counts as most recent depends on where you send from:

• In the VS Code extension, each request opens in its own editor tab. $response reads the last response received in the same tab.
• In the desktop app, $response reads the last response received in any tab.
• In the Collection Runner, $response reads the response of the previous request in the run. The runner supports the body, status, and headers paths.

To pass a value from one request to another reliably, save it to a variable in a post-response script with nt.setVar(). See Variables set by scripts.

Response values from a named request

Prefix $response with a request name to read the response of that request:

{{Login.$response.body.token}}
{{Login.$response.status}}
{{CreateUser.$response.body.id}}

The name must match the saved request’s name exactly, including case. Named references support the body, headers, status, and statusText paths. If the named request hasn’t run yet, Nouto sends the placeholder unchanged.

Named references are built for the Collection Runner, where every request in the run is available. Outside the runner, Nouto finds the named request only if it was sent earlier in the same session. In the VS Code extension, it must also have been sent from the same editor tab.

Cookie values

Use {{$cookie.name}} to insert the value of a cookie from the active cookie jar:

X-CSRF-Token: {{$cookie.csrftoken}}

Nouto uses the first cookie with that name in the jar. It doesn’t match the cookie’s domain or path against the request URL, so use distinct cookie names or a separate jar per API. The Collection Runner doesn’t resolve $cookie placeholders.

Variables set by scripts

Scripts save values with nt.setVar(). By default the value goes to the active environment. Pass 'global' as the third argument to save a global variable instead:

// Post-response script: save the token for later requests
nt.setVar('authToken', nt.response.json().token);

// Save a global variable
nt.setVar('tenantId', nt.response.json().tenant, 'global');

If no environment is active, Nouto discards values saved without the 'global' argument.

When the value takes effect depends on how you send the request:

• When you send a single request, Nouto substitutes its variables before the pre-request script runs. A value set in the pre-request script applies from the next send. To change the current request from a pre-request script, modify nt.request instead. See the script API.
• In the Collection Runner, a value set in a pre-request script applies to the same request.
• A value set in a post-response script applies to every request sent after it.

Pass a login token to another request

A post-response script on the login request saves the token, and every other request reads it with a variable. This works across editor tabs in VS Code, unlike {{$response.body.token}}.

Before you start, activate an environment. nt.setVar() saves to the active environment, and Nouto discards the value when no environment is active. See Activate an environment.

1. Open the login request, select the Scripts tab, and select Post-response Script.

2. Enter this script, replacing token with the name of the field your API returns:

   nt.setVar('authToken', nt.response.json().token);

3. Send the login request. Nouto saves the token as authToken in the active environment.

4. Open the request that needs the token, select the Auth tab, and select Bearer Token from the Type dropdown.

5. Enter {{authToken}} in the Token field and send the request.

Nouto sends Authorization: Bearer followed by the saved token. When the token expires, send the login request again. Every request that uses {{authToken}} picks up the new token on its next send.

For a quick test without a script, enter {{$response.body.token}} in the Token field instead. It reads the most recent response, which in VS Code is the last response received in the same editor tab. See Response values.