Processing Linked Models with the Revit Automation API: A Step-by-Step Guide

What you’ll learn in this guide

One issue you may encounter when connecting a Revit model to a cloud-based automation job is downloading a ZIP package instead of the expected single RVT file. This doesn’t always mean the download failed: according to Autodesk’s guide, if the linked files in a Revit Cloud Worksharing model aren’t in the same latest published state as the main model, the download package may contain both the main RVT and the linked RVT files.

In this guide, you’ll learn how to determine whether a model is a Revit Cloud Worksharing file, whether it’s marked as a composite design, and which automation method to use. We’ll also cover the workflow differences between files published before 7 February 2025 and those published on or after that date.

Autodesk says the Revit API can be used to automate repetitive tasks and extend Revit functionality. The Revit Automation API enables cloud-based applications and services to create, inspect, and modify Revit data. Here, the focus is on passing the Revit file to an automation work item correctly.

Requirements and preparation

For this workflow, you’ll need an application that can work with Autodesk Platform Services (APS) APIs, a way to query file and version information, and the model files to pass to the work item. Autodesk’s API page lists developer guides, SDKs, code samples, and community support resources. The Revit Automation API supports building cloud-based applications that can access the Revit DB API without requiring a Revit desktop installation.

An older Automation API announcement in the source materials mentions a valid Forge subscription or trial account. This information doesn’t confirm current pricing or access conditions; check APS’s current resources for pricing and account requirements before getting started. The documentation doesn’t specify a particular Revit version for this operation, either.

Before you begin, have the following ready:

• The APS file or version record for the Revit Cloud Worksharing model you’ll process.

• The access credentials required for authenticated API calls.

• A way to check the publication date and attributes associated with the file version.

• Record information showing when the model was published and the main file’s name.

Step by step: determine the model type and transfer method

1. Check whether the file is identified as a Revit Cloud Worksharing model. Autodesk’s guide recommends checking the attributes.extension.type field in API calls that return the contents of a project folder, an item record, or version information. If the value is versions:autodesk.bim360:C4RModel, the file is identified as a Revit Cloud Worksharing model. Check the version data rather than deciding based only on the file extension.

2. Read the composite design status. The attributes.data.isCompositeDesign field in the same version record indicates whether the model is composite. If the value is true, the file is a composite Revit design; the downloaded content may be a ZIP containing the main model and linked RVTs. If the value is false, Autodesk says the main file and its links have been published in their latest versions, so the download can be a single RVT.

3. Identify the main model’s filename. For a composite model, the attributes.data.compositeParentFile field gives the name of the main Revit file. This is needed to specify which file in the ZIP should be used as the main model, especially with the older workflow. Don’t guess the filename; use the value in the version record.

4. Choose a method based on the publication date. If the file was published before 7 February 2025, you can use Autodesk’s older method: set zip to true for the input file in the work item, and set pathInZip to the main model’s filename. This passes the ZIP package to the automation job while specifying the path to the main file Revit should open.

5. Use the new method for models published on or after 7 February 2025. For a file published on or after this date, Autodesk recommends using the GET linked Revit files call to retrieve the main model and any unpublished linked RVT files. Pass the main model and the linked file information returned by the call to the work item. Use the method specified for this date range rather than applying the older ZIP approach directly.

6. Verify the work item’s inputs. If you chose the older method, make sure the ZIP setting and pathInZip value are correct. With the new method, confirm that the linked files returned by the call are passed along with the main model. Autodesk’s example uses signed URLs for these files; don’t copy URLs from sample text—use the current values returned by your own API call.

Common mistakes

• Assuming a ZIP means the file is corrupt: A ZIP download may be expected if the linked models haven’t been published in their latest versions.

• Confusing the model type with its composite status: C4RModel identifies the file as a Cloud Worksharing model; isCompositeDesign indicates whether the design is composite. Check both.

• Guessing which RVT is the main file: Get the correct filename from the compositeParentFile field.

• Overlooking the date cutoff: The guide describes different transfer methods for files published before and after 7 February 2025.

• Using temporary access links from the example: The signed URLs in the source are part of a sample response. Use the links returned by your own call.

Implications for architecture and visualization workflows

This approach matters for teams connecting recurring model review, data extraction, reporting, or automated documentation tasks to Revit-based cloud workflows. Autodesk lists inspecting and analyzing Revit data, exporting data, creating custom Revit families, and automatically generating documentation among the possible use cases. Architecture firms, interior design teams, and BIM managers can reduce the risk of incorrect or incomplete inputs by checking the version status of linked models before running automation.

For visualization teams, transferring the main file and its links together helps ensure the automation works with the expected project data. However, this guide doesn’t provide information about render performance, hardware requirements, or compatibility with specific visualization software. Before implementation, verify API access conditions, licensing, and compatibility between your workflow and Revit data.

Next steps

Run your first test on a non-critical model. Record the file’s version attributes, confirm the publication date, and choose the method that matches the date. Check the automation output to confirm that the expected main RVT was processed. Then refer to Autodesk’s Revit API guides, getting-started tutorials, and code samples to adapt the workflow to your data extraction or reporting needs.

Sources and licensing

This guide has been adapted into Turkish based on Autodesk’s Revit Automation API and Revit API pages, as well as a developer article explaining how to pass composite Revit designs to automation work items. All sources are official Autodesk developer content and are provided under an open license.