Action Triggers

Action triggers allow you to automate the execution of your actions based on specific events or schedules. Besides the web interface, you can manage triggers with klein trigger (see the CLI Reference) and with the Python SDK.

Kleinkram supports three types of triggers:

Trigger Type	Description	Example Use Case
Cron Triggers	Schedule-based	Generate a report with summary statistics daily at midnight.
Webhook Triggers	Event-based	Run a verification action as soon as a new docker image version is pushed
File Pattern Triggers	Data-based	Run a post-processing action as soon as a new file is uploaded

Cron Triggers

Cron triggers allow you to schedule actions to run periodically at fixed times or intervals. This is useful for regular maintenance tasks, nightly reports, or periodic data synchronization.

To set up a cron trigger:

1. From your action's settings, go to the Triggers tab.
2. Click New Trigger and select Cron for the Trigger Type.
3. Enter a valid cron expression (e.g., 0 0 * * * for daily at midnight).
4. Click Create Trigger.

The action will now run automatically based on the scheduled cron expression.

Cron Syntax

Kleinkram uses standard cron syntax. You can use sites like crontab.guru to help generate expressions.

Webhook Triggers

Webhook triggers allow external systems to trigger Kleinkram actions via HTTP requests. This enables integration with CI/CD pipelines, external data sources, or other tools in your ecosystem.

To set up a webhook trigger:

1. From your action's settings, go to the Triggers tab.
2. Click New Trigger and select Webhook for the Trigger Type.
3. Click Create Trigger.

Kleinkram will generate a unique Webhook URL for this trigger. You can now send a POST request to this URL to trigger the action.

Triggering the Webhook

Send a POST request to the webhook URL to trigger the action. The URL points at the Kleinkram API (not the web app) and has the form <API_URL>/hooks/actions/<TRIGGER_UUID>.

curl -X POST https://<your-kleinkram-api>/hooks/actions/<TRIGGER_UUID>

The request needs no authentication: anyone who knows the URL can start the action, so treat the URL like a password. The action runs with the access rights of the user who created the trigger.

• A GET request to the same URL also starts the action.
• A POST body is optional. If you send one, it must be a JSON object of at most 100 KB. Kleinkram does not pass it on to the action container.
• POST requests are limited to 10 per minute per client IP address. Further requests are answered with 429 Too Many Requests.
• The response contains the ID of the new execution (actionUUID), the template ID (templateUUID), its state and creation time.

File Pattern Triggers

File pattern triggers allow you to automatically run an action when a file matching a specific pattern is uploaded or modified within a mission. This is perfect for processing pipelines, such as automatically converting new bag files or analyzing newly uploaded images.

To set up a file pattern trigger:

1. From your action's settings, go to the Triggers tab.
2. Click New Trigger and select File Pattern for the Trigger Type.
3. Enter a glob pattern to match files.
4. Click Create Trigger.

The action will now trigger automatically whenever a matching file is uploaded to any mission the action has access to.

Glob Pattern Examples

Kleinkram flattens all uploaded files, meaning filenames do not contain folders or slashes. Therefore, your glob patterns should only match against the filename itself.

Pattern	Description
*.bag	Matches any .bag file.
2026-*.yaml	Matches any .yaml file starting with 2026-.
*_processed.db3	Matches any .db3 file ending in _processed.
mission-10-?.mcap	Matches files like mission-10-A.mcap or mission-10-1.mcap using the ? single-character wildcard.

TIP

You can use * to match any character sequence and ? to match a single character.