BIM Collaboration Format (BCF) is a standard by buildingSMART to manage and exchange coordination topics between disciplines collaborating on a project. For example, when there is an issue during the design, engineering, or construction of a project, a topic may be created, assigned, prioritised, commented, or linked to objects in a BIM model or camera location.

There are two implementations of BCF:

  1. BCF-XML: an XML file-based exchange of collaboration topics. This is useful for mass imports, exports, data migration across CDEs, or fully offline implementations.

  2. BCF-API: an online RESTful API-based management of collaboration topics. When topics are managed by a CDE, if the CDE follows the OpenCDE specification by buildingSMART, their topics may be accessed and manipulated using BCF.

The upstream documentation by buildingSMART for BCF is available here:

  1. BCF-XML 2.1 upstream documentation.

  2. BCF-XML 3.0 upstream documentation.

  3. BCF-API 3.0 upstream documentation.

The IfcOpenShell BCF library supports BCF-XML version 2.1 and 3.0, and BCF-API 3.0.


The bcfxml.load function lets you read a BCF-XML file.

It takes care of using the right version based on the “bcf.version” file contained in the BCF package.

The BCF files are extracted and parsed on-demand, and edits are stored in memory until you call the save method.

from bcf.bcfxml import load

# Load a project
with load("/path/to/file.bcf") as bcfxml:
    project = bcfxml.project

    # To edit a project, just modify the object directly
    bcfxml.project.name = "New name"

    # Get a dictionary of topics
    topics = bcfxml.topics

    for topic_guid, topic_handler in bcfxml.topics.items():
        topic = topic_handler.topic
        print("Topic guid is", topic.guid)
        print("Topic title is", topic.title)

        # Fetch extra data about a topic
        header = topic_handler.header
        comments = topic_handler.comments
        viewpoints = topic_handler.viewpoints

        for comment in comments:

    # Get a particular topic
    topic = bcfxml.get_topic(guid)

    # Modify a topic
    topic.title = "New title"



The bcfapi module lets you interact with the BCF-API standard.

from bcf.v3.bcfapi import FoundationClient, BcfClient

foundation_client = FoundationClient("YOUR_CLIENT_ID", "YOUR_CLIENT_SECRET", "OPENCDE_BASEURL")
auth_methods = foundation_client.get_auth_methods()

# Our library currently only implements the authorization_code flow
if "authorization_code" in auth_methods:

bcf_client = BcfClient(foundation_client)

versions = foundation_client.get_versions()
for version in versions:
if "3.0" in versions:
    if version["api_id"] == "bcf" and version["version_id"] == "3.0":

data = bcf_client.get_projects()
project_id = data[0]["project_id"]
data = bcf_client.get_project(project_id)
data = bcf_client.get_extensions(project_id)