Version: 3.0

Microsoft Fabric (OneLake) Nodes

Append rows to lakehouse Delta tables, and write, read, list and delete files and create directories in a Microsoft Fabric lakehouse, over the ADLS Gen2 endpoint.

Needs: A Microsoft Fabric (OneLake) connection
Operations: Append to Table · Write · Read · List Paths · Create Directory · Delete Path
Limits: Binary payloads need Input Format base64

Microsoft Fabric OneLake nodes let pipelines write rows into lakehouse tables and read and write files in a Fabric lakehouse over the ADLS Gen2 endpoint. Use them to stream OT data into Delta tables, land payloads and Parquet inputs, list and create directories, and clean up processed files. All six node types connect through your configured Microsoft Fabric (OneLake) connections.

Configuration Quick Reference

Field	What you choose	Details
Parameters	`Connection`, `Function`, `Function Parameters`, `Timeout Override`	Select the connection profile, function, configure function parameters with expression support, and optionally override timeout.
Settings	`Description`, `Timeout (seconds)`, `Retry on Timeout`, `Retry on Fail`, `On Error`	Node description, maximum execution time, retry behavior on timeout or failure, and error handling strategy. All execution settings default to pipeline-level values.

Table Operations

OneLake Append to Table Node

Write pipeline rows into a Delta table under Tables/. The node writes the Parquet data file and the _delta_log commit itself, so the rows are queryable from the Lakehouse, its SQL analytics endpoint and Power BI Direct Lake when the node finishes; there is no Load to Tables step. The first write creates the table.

Supported Function Types:

Function Name	Purpose	Common Use Cases
Append to Table	Append rows to a lakehouse Delta table	Streaming UNS readings into a table for Fabric AI and analytics, feeding Power BI Direct Lake reports

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Microsoft Fabric (OneLake) connection profile to use
Function	Selection	Yes	Append to Table function from the selected connection
Function Parameters	Dynamic	Varies	Auto-populated from the function schema (`table`, `data`, `columns`, `schemaName`). See your OneLake connection functions for full parameter details.
Timeout Override	Number (seconds)	No	Override the default function timeout

data takes one row (an object) or a batch (an array of objects). Bind it to the rows an upstream node produces, for example {{ $node["Buffer"].result }}.

Batch rows before the node

Every execution adds one Parquet file to the table, and readers slow down as small files pile up. Put a Buffer node in front so each write carries hundreds of rows, not one.

Output Structure

{
  "result": {
    "table": "Tables/sensor_readings",
    "committed": true,
    "version": 42,
    "created": false,
    "rowsWritten": 500,
    "parseFailures": 0,
    "bytesWritten": 18432,
    "dataFile": "Tables/sensor_readings/part-00000-3f2a9c1e-7d4b-4e8a-9b1c-2d5e6f7a8b9c-c000.zstd.parquet"
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 640, "timestamp": "2026-10-05T08:00:00Z" }
}

Field	Type	Description
`result.table`	string	The table's path in the lakehouse
`result.committed`	boolean	Whether rows were committed; `false` only when the input carried no rows
`result.version`	number	The table version this execution committed (when `committed`); on a replay, the version that already holds its rows
`result.created`	boolean	Whether this execution created the table (when `committed`)
`result.rowsWritten`	number	Rows written
`result.parseFailures`	number	Values that did not parse as their column's type and were written as null. A rising count means the upstream data changed shape. The first failure in each column of a table is also logged as a warning
`result.bytesWritten`	number	Size of the Parquet data file (when `committed`)
`result.dataFile`	string	The data file this execution added (when `committed`, and not on a replay)
`result.liveFiles`	number	Data files the table holds after this execution (when `committed`). Each execution adds one; batch rows and run Fabric's Optimize to keep it down. Past 10,000 the connector logs a warning, once per table
`result.alreadyCommitted`	boolean	Present and `true` when this execution is a replay of a write the table already holds: nothing was written
`result.ignoredFields`	array	Row fields left out because no column matches them; present only when there are some. The first time each field is left out is also logged as a warning
`result.checkpointed`	boolean	Present and `true` when this commit also wrote a checkpoint (every 10 versions by default)
`result.warning`	string	Present when a checkpoint was due but not written, with the reason. The table stays correct; readers replay more commit files until a checkpoint exists

A replayed execution lands once

When store-and-forward, Retry on Fail or a dead-letter replay sends a write again, the table already holds its rows. The connector recognises that from the write's key, recorded in the table log, and answers with alreadyCommitted: true instead of appending a second copy. The record lasts 31 days, the longest the engine resends a write with its default retention. Within one execution, a commit whose outcome is unknown (a timeout) is checked against the table log before retrying, so it is never committed twice.

Path Operations

OneLake Write File Node

Upload data to a file under the configured workspace and lakehouse, creating it or overwriting an existing file.

Supported Function Types:

Function Name	Purpose	Common Use Cases
Write File	Upload data to a lakehouse file path	Landing OT snapshots, staging Parquet for a Fabric table load, archiving pipeline output

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Microsoft Fabric (OneLake) connection profile to use
Function	Selection	Yes	Write function from the selected connection
Function Parameters	Dynamic	Varies	Auto-populated from the function schema (e.g. `path`, `data`). See your OneLake connection functions for full parameter details.
Timeout Override	Number (seconds)	No	Override the default function timeout

All function parameters support expression syntax ({{ expression }}) for dynamic values from the pipeline context.

Binary payloads need Input Format = base64

The data parameter is a string. A Convert to File node emits Parquet and Excel base64-encoded, so the write function's Input Format must be set to base64 for those payloads; otherwise the base64 characters are uploaded as the file contents and the result is unreadable. CSV and JSON are text and need no change.

Output Structure

{
  "result": {
    "path": "Files/snapshots/2026-06-03.json",
    "bytesWritten": 2048,
    "contentType": "application/json"
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 120, "timestamp": "2026-06-03T08:00:00Z" }
}

Field	Type	Description
`result.path`	string	Resolved lakehouse path the file was written to
`result.bytesWritten`	number	Number of bytes written
`result.contentType`	string	MIME content type applied (auto-detected when not supplied)

Store-and-forward eligible

The Write File node is a durable sink with keyed idempotency: the path is the idempotency handle, so retries converge to the same end state.

OneLake Read File Node

Download the full content of a file from the lakehouse and return it as node output.

Supported Function Types:

Function Name	Purpose	Common Use Cases
Read File	Download a lakehouse file's content	Reading reference files, configuration blobs, archived payloads

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Microsoft Fabric (OneLake) connection profile to use
Function	Selection	Yes	Read function from the selected connection
Function Parameters	Dynamic	Varies	Auto-populated from the function schema (e.g. `path`). See your OneLake connection functions for full parameter details.
Timeout Override	Number (seconds)	No	Override the default function timeout

Output Structure

{
  "result": {
    "data": "id,value\n1,42\n",
    "metadata": {
      "path": "Files/reference/lookup.csv",
      "fileName": "lookup.csv",
      "sizeBytes": 15,
      "encoding": "text"
    }
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 120, "timestamp": "2026-06-03T08:00:00Z" }
}

Field	Type	Description
`result.data`	string	File content: text, or base64 for binary content types
`result.metadata.path`	string	Resolved lakehouse path read
`result.metadata.fileName`	string	File name extracted from the path
`result.metadata.sizeBytes`	number	File size in bytes
`result.metadata.encoding`	string	`text` or `base64`: how `data` is encoded
`result.metadata.contentType`	string	MIME content type (when the service reports it)
`result.metadata.contentLength`	number	Content length as reported by the service (when present)
`result.metadata.etag`	string	File ETag (when present)
`result.metadata.lastModified`	string	Last modification timestamp, RFC 3339 UTC (when present)

OneLake List Paths Node

Enumerate paths under a directory, optionally recursively, with pagination.

Supported Function Types:

Function Name	Purpose	Common Use Cases
List Paths	Enumerate files and directories under a path	Discovering files, building inventories, driving fan-out

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Microsoft Fabric (OneLake) connection profile to use
Function	Selection	Yes	List function from the selected connection
Function Parameters	Dynamic	Varies	Auto-populated from the function schema (e.g. `path`, `recursive`, `maxResults`). See your OneLake connection functions for full parameter details.
Timeout Override	Number (seconds)	No	Override the default function timeout

Output Structure

{
  "result": {
    "path": "Tables/sensor_readings",
    "paths": [
      {
        "name": "Tables/sensor_readings/data.parquet",
        "isDirectory": false,
        "contentLength": 20480,
        "lastModified": "2026-06-03T08:00:00Z",
        "etag": "0x8D..."
      }
    ],
    "count": 1,
    "hasMore": true,
    "continuationToken": "..."
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 120, "timestamp": "2026-06-03T08:00:00Z" }
}

Field	Type	Description
`result.path`	string	Directory that was listed
`result.paths`	array	Path entries (see below)
`result.count`	number	Number of entries returned
`result.hasMore`	boolean	`true` when the service has another page
`result.continuationToken`	string	Present only when `hasMore` is `true`; pass it back as `continuationToken` for the next page

Path Entry Fields: each item of result.paths:

Field	Type	Description
`name`	string	Full path of the entry
`isDirectory`	boolean	`true` if the entry is a directory
`contentLength`	number	Size in bytes (files)
`lastModified`	string	Last modification timestamp, RFC 3339 UTC (when the service reports it)
`etag`	string	Entry ETag

OneLake Create Directory Node

Create a directory in the lakehouse. Idempotent: succeeds if it already exists.

Supported Function Types:

Function Name	Purpose	Common Use Cases
Create Directory	Create a lakehouse directory	Laying out partitioned paths, pre-provisioning folders

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Microsoft Fabric (OneLake) connection profile to use
Function	Selection	Yes	Create Directory function from the selected connection
Function Parameters	Dynamic	Varies	Auto-populated from the function schema (e.g. `path`). See your OneLake connection functions for full parameter details.
Timeout Override	Number (seconds)	No	Override the default function timeout

Output Structure

{
  "result": {
    "path": "Files/daily/2026-06-03"
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 120, "timestamp": "2026-06-03T08:00:00Z" }
}

Field	Type	Description
`result.path`	string	Resolved directory path

OneLake Delete Path Node

Permanently remove a file or directory from the lakehouse, optionally recursively.

Supported Function Types:

Function Name	Purpose	Common Use Cases
Delete Path	Delete a file or directory	Retention cleanup, undo-on-failure, removing processed inputs

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Microsoft Fabric (OneLake) connection profile to use
Function	Selection	Yes	Delete function from the selected connection
Function Parameters	Dynamic	Varies	Auto-populated from the function schema (e.g. `path`, `recursive`). See your OneLake connection functions for full parameter details.
Timeout Override	Number (seconds)	No	Override the default function timeout

Output Structure

{
  "result": {
    "path": "Files/staging/processed.json",
    "kind": "file"
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 120, "timestamp": "2026-06-03T08:00:00Z" }
}

Field	Type	Description
`result.path`	string	Resolved path that was deleted
`result.kind`	string	`file` or `directory`

Destructive Operation

Deletion is permanent and cannot be undone. Enable Recursive only when you intend to remove a directory and all of its contents; use a Condition node to verify before deleting.

Settings Tab

All Microsoft Fabric (OneLake) node types share the same Settings tab:

Setting	Type	Default	Description
Description	Text	-	Optional description displayed on the node
Timeout (seconds)	Number	Pipeline default	Maximum time the node may run before timing out
Retry on Timeout	Toggle	Pipeline default	Automatically retry the node if it times out
Retry on Fail	Toggle	Pipeline default	Automatically retry the node if it fails
On Error	Selection	Pipeline default	Error strategy: Pipeline Default (the pipeline's Error Handling setting), Stop Pipeline or Continue Execution

When left at their defaults, these settings inherit from the pipeline-level execution configuration.

Configuration Quick Reference​

Table Operations​

OneLake Append to Table Node​

Node Configuration​

Output Structure​

Path Operations​

OneLake Write File Node​

Node Configuration​

Output Structure​

OneLake Read File Node​

Node Configuration​

Output Structure​

OneLake List Paths Node​

Node Configuration​

Output Structure​

OneLake Create Directory Node​

Node Configuration​

Output Structure​

OneLake Delete Path Node​

Node Configuration​

Output Structure​

Settings Tab​

Configuration Quick Reference

Table Operations

OneLake Append to Table Node

Node Configuration

Output Structure

Path Operations

OneLake Write File Node

Node Configuration

Output Structure

OneLake Read File Node

Node Configuration

Output Structure

OneLake List Paths Node

Node Configuration

Output Structure

OneLake Create Directory Node

Node Configuration

Output Structure

OneLake Delete Path Node

Node Configuration

Output Structure

Settings Tab