Expressions

Expressions is how you reference and manipulate data inline in action inputs, run-if conditions, and loop expressions. Tracecat supports the following expression contexts:

Prefix	Expression syntax	Description
`ACTIONS`	`ACTIONS.<action_slug>.result.<jsonpath>`	Reference the result of an action
`TRIGGER`	`TRIGGER.<jsonpath>`	Reference data passed via webhook or UI
`SECRETS`	`SECRETS.<name>.<key>`	Reference a secret
`FN`	`FN.<fn_name>(<arg1>, <arg2>, ...)`	Call an inline function

To use an expression, you must use the ${{ <context>.<expression> }} syntax:

${{ <context>.<expression> }}

Expressions are evaluated into values at the start of each action run.

`ACTIONS` context

Tracecat uses JSONPath and dot notation to select outputs from previous actions.

For example, ACTIONS.my_action.result.data.items selects the items field from a nested JSON object returned by the my_action action.

You can reference outputs from a previous action in the same workflow using the ACTIONS context. Actions are referenced by a sluggified version of their name.

Rename action

For example, let’s assume you renamed the core.http_request action in Your first workflow from HTTP Request to Get weather. You can rename the action under the General section in the action inputs panel.

Reference action output

You can then reference the Get weather action’s output in the next action by using the ACTIONS.get_weather.result expression. For example, you can use the core.transform.reshape action as a pass-through action to extract and organize the weather data.

value:
  temp: ${{ ACTIONS.get_weather.result.data.current.temperature_2m }}
  rain: ${{ ACTIONS.get_weather.result.data.current.precipitation_probability }}

You can then reference the temp and rain outputs in downstream actions in the workflow using:

${{ ACTIONS.reshape.result.temp }}
${{ ACTIONS.reshape.result.rain }}

`TRIGGER` context

Check out the workflow triggers tutorial for a detailed guide setting up webhooks for workflows.

Workflows can be triggered via webhook, manual UI trigger, or the Execute Child Workflow action. Use the TRIGGER context to reference the data from the trigger as a JSON object.

Send webhook

For example, if you send a POST request to the workflow’s webhook URL with the following payload:

{"lat": 40, "long": 70}

Reference webhook payload

You can reference the lat and long values in an action’s inputs using the TRIGGER context.

url: https://api.open-meteo.com/v1/forecast
method: GET
params:
  latitude: ${{ TRIGGER.lat }}
  longitude: ${{ TRIGGER.long }}
      current: temperature_2m,precipitation_probability

Given a workflow with a live webhook, the following curl command will send the JSON payload {"data": {"name": "John", "age": 30}} and trigger the workflow:

export WEBHOOK_URL=https://tracecat.com/api/webhooks/<webhook_id>/<secret>
curl -X POST $WEBHOOK_URL \
    -H "Content-Type: application/json" \
    -d '{"data": {"name": "John", "age": 30}}'

The following expression will return the string John:

${{ TRIGGER.data.name }}

`SECRETS` context

Tracecat comes with a built-in secrets manager. This allows you to store and retrieve sensitive data scoped to a workspace without exposing the value in plaintext. Secrets are encrypted at rest and stored in the database.

Secrets stored in the secrets manager can be accessed using the SECRETS prefix:

${{ SECRETS.<name>.<key> }}

Tracecat will automatically replace the expression with the secret value at runtime. Retrieved secrets are deleted from memory after the workflow run completes.

`FN` context

Check out the full list of supported functions in the functions cheatsheet.

Tracecat supports inline functions in the FN context. For example, you can use the FN.deserialize_json function to decode a JSON string into a JSON object.

${{ FN.deserialize_json(ACTIONS.get_weather.result.data) }}

Check out the docs on Data manipulation to learn more about the different data types and how to manipulate them.

Get Started

Tutorials

Self Host

Data Manipulation

`ACTIONS` context

`TRIGGER` context

`SECRETS` context

`FN` context

Get Started

Tutorials

Self Host

Data Manipulation

​ACTIONS context

​TRIGGER context

​SECRETS context

​FN context

`ACTIONS` context

`TRIGGER` context

`SECRETS` context

`FN` context