# Operations Operations are the individual steps inside a flow. CairnCMS ships with a built-in set of operations covering data work, branching, communication, scripting, and HTTP. Custom operations can be added through the extension system. Every operation appends a value to the [data chain](/docs/guides/flows/#the-data-chain) under its own key. Operations that do not produce data still append `null` so that downstream operations can reference them predictably. ## Condition Routes execution to the success or failure path based on a filter rule. - **Condition Rules** — a filter rule evaluated against the data chain Use this when a flow needs to branch on data the trigger or earlier operations produced. The condition does not generate data of its own; it appends `null` regardless of which path is taken. If the filter rule itself is misconfigured, the operation appends a debug array describing the misconfiguration. When used at the end of a flow on a Filter (blocking) Event hook trigger, a failure-path Condition cancels the original database transaction. ## Run Script Runs custom JavaScript inside an isolated V8 sandbox. The sandbox is fully isolated from the host: no file system access, network access, or `require()` of built-in or external modules. The script receives the data chain as its argument and returns a JSON-serializable value, which is appended under the operation key. A `console` shim is available and routes to the platform logger. The script's `process.env` is populated from the operator-allow-listed environment variables (governed separately by `FLOWS_ENV_ALLOW_LIST`). Throwing inside a script ends the flow. On a Filter (blocking) Event hook trigger, throwing also cancels the original event transaction. The isolate has a configurable memory and time budget, set via `FLOWS_RUN_SCRIPT_MAX_MEMORY` (default 32, MB) and `FLOWS_RUN_SCRIPT_TIMEOUT` (default 10000, ms). Scripts that exceed either limit are aborted. ## Create Data Creates one or more items in a collection. - **Collection** — the target collection - **Permissions** — the role whose permissions the operation runs under - **Emit Events** — whether to fire event hooks for this create - **Payload** — the data to insert Appends an array of created item IDs. ## Read Data Reads items from a collection by ID or query. - **Collection** — the source collection - **IDs** — specific item IDs to fetch - **Query** — a filter rule for selecting items - **Permissions** — the role whose permissions the operation runs under - **Emit Events** — whether to fire event hooks Appends the result of the read. With a single ID, this is a single item; with multiple IDs or a query, this is an array of items. ## Update Data Updates one or more items in a collection by ID or query. - **Collection** — the target collection - **IDs** — specific item IDs to update - **Query** — a filter rule for selecting items to update - **Payload** — the partial update to apply - **Permissions** — the role whose permissions the operation runs under - **Emit Events** — whether to fire event hooks Appends the updated key(s). With a single ID, this is a single primary key; with multiple IDs or a query, this is an array of primary keys. ## Delete Data Deletes items from a collection by ID or query. - **Collection** — the target collection - **IDs** — specific item IDs to delete - **Query** — a filter rule for selecting items to delete - **Permissions** — the role whose permissions the operation runs under - **Emit Events** — whether to fire event hooks Appends the deleted key(s). With a single ID, this is a single primary key; with multiple IDs or a query, this is an array of primary keys. For all four data operations, **Emit Events** controls whether the operation fires its own event hooks. Turn it off when this operation might trip the same flow that contains it, to prevent infinite loops. ## Send Email Sends one or more emails through the configured email provider. - **To** — one or more email addresses - **Subject** — the email subject - **Type** — `markdown`, `wysiwyg`, or `template` - **Body** — the email body (when Type is `markdown` or `wysiwyg`) - **Template** — the name of an installed email template (when Type is `template`; defaults to `base`) - **Data** — variables to pass into the template (when Type is `template`) Appends `null`. ## Send Notification Sends an in-app notification to one or more users. - **Users** — one or more user UUIDs - **Title** — the notification title - **Message** — the notification body - **Permissions** — the role whose permissions the operation runs under Appends an array of notification IDs. ## Webhook / Request URL Sends an HTTP request to an arbitrary URL. - **Method** — GET, POST, PATCH, DELETE, or others - **URL** — the target URL - **Headers** — request headers - **Request Body** — the body to send Appends the response under the operation key. For richer outgoing webhook patterns, see the [Webhooks](/docs/guides/flows/webhooks/) page. ## Trigger Flow Runs another flow and optionally passes data to it. The other flow must use the **Another flow** trigger. - **Flow** — the UUID of the flow to trigger - **Payload** — the JSON to pass to the other flow's `$trigger` - **Iteration Mode** — when the payload is an array: `parallel` (default; runs all in parallel), `serial` (runs one after another), or `batch` (runs in batches) - **Batch Size** — the batch size when Iteration Mode is `batch` (defaults to 10) Appends the other flow's response, when one is configured. If the other flow has no Response Body, this operation appends `null`. If the payload is an array, the other flow runs once per array item using the configured iteration mode. ## Sleep Pauses the flow for a configured number of milliseconds. - **Milliseconds** — how long to sleep Appends `null`. Use sparingly; long sleeps tie up flow workers. ## Transform Payload Builds a custom JSON object that subsequent operations can reference. - **JSON** — the object to build, with [data chain variables](/docs/guides/flows/#data-chain-variables) for dynamic values Appends the resulting object. This operation is useful for stitching together values from earlier operations into a single shape, such as preparing the body of a webhook request or the payload for a Create Data operation. ## Log to Console Writes a message to the server-side console and to the flow's logs. - **Message** — the message to log Appends `null`. The message itself is visible only in the flow's logs and in the server output, not in the data chain. This is the primary debugging tool for flows.