Template Functions#

Beyond the request variables, templates can call functions — either built-in request helpers or random generators.

Request Helpers#

Function	Description
`{{Header "X-Key"}}`	Value of a request header (empty string if absent).
`{{Query "param"}}`	Value of a query parameter (empty string if absent).

Random Helpers#

Function	Description
`{{RandomInt 1 100}}`	Random integer in the inclusive range.
`{{RandomHex 8}}`	Random hex string of the given length.

The full set of realistic random data generators — {{Name}}, {{Email}}, {{Company}}, etc. — is on the Faker Generators page.

Example#

id: greeting
method: POST
path: /webhooks/greeting
response:
  status_code: 200
  template: true
  body: '{"greeting":"Hello {{Header \"X-Caller\"}}","source":"{{Query \"channel\"}}","luck":"{{RandomInt 1 100}}","token":"{{RandomHex 8}}"}'

Send a request:

curl -X POST "http://localhost:8080/webhooks/greeting?channel=web" \
  -H "X-Caller: Ada" \
  -d '{}'

Response:

{
  "greeting": "Hello Ada",
  "source": "web",
  "luck": "42",
  "token": "3f9a1c0b"
}

Notes#

{{Header}} / {{Query}} return the first value of the header / query parameter.
Header names are case-insensitive (HTTP semantics); query parameter names are exact.
Functions compose with variables: {{Header "X-User"}} and {{.Body}} can appear in the same template.