Revit 2026 API Reference

Query Process

Step 0: Requirement Pre-research (Mandatory for Ambiguous Questions)

IUpdater

DocumentChanged

FilteredElementCollector

1. Parse Business Intent: Break down the user's ambiguous requirements into specific technical concepts.
   • Example: "Implement DMU" → Dynamic Model Update mechanism → Requires

     IUpdater

     interface,

     UpdaterRegistry

     class
   • Example: "Link update phase" → Loading/update events of Revit linked documents → Requires

     LinkedFileStatus

     ,

     RevitLinkType

     ,

     TransmissionData

2. Web Search Verification: Use WebSearch to search for

   Revit API + <technical concept>

   to confirm the core classes and namespaces involved.

   Search Example: "Revit API Dynamic Model Update IUpdater"
   Search Example: "Revit API linked file update phase event"

3. Extract Keyword List: Extract 2-5 specific class names/interface names/method names from the search results as input for subsequent queries.
4. Proceed to Step 1: Continue with explicit API identifiers.

Important: It is forbidden to skip pre-research and answer ambiguous questions directly based on experience. Even if you think you know the answer, you must confirm it through pre-research and then verify it with this knowledge base.

Step 1: Determine Question Type

Step 2: Execute Corresponding Path

Path A: Search for Specific APIs (Most Commonly Used)

1. First search and locate:

python scripts/search_api.py search "keyword"

1. View member overview of the class:

python scripts/search_api.py class "Autodesk.Revit.DB.ClassName"

1. When complete documentation is needed (signature, Remarks, inheritance chain):

python scripts/extract_page.py --type "Autodesk.Revit.DB.ClassName"

1. View member-level details (property/method signatures):

python scripts/extract_page.py --id "P:Autodesk.Revit.DB.Wall.Flipped"
python scripts/extract_page.py --id "M:Autodesk.Revit.DB.Wall.Flip"

Path B: Browse Namespace

1. List all namespaces:

python scripts/search_api.py namespaces

1. View the type list of a specific namespace:

python scripts/search_api.py namespace "Autodesk.Revit.DB"

1. Or directly read references/namespace-overview.md for complete navigation.

Path C: Find Member Attribution

1. Cross-class search for member names:

python scripts/search_api.py member "GetParameters"

1. After locating the target class from the results, follow steps 2-4 of Path A to get details.

Path D: Quick Reference for Development Patterns

1. Directly read references/core-patterns.md, which includes C# code examples for 11 core patterns.
2. If further details about the APIs involved in the patterns are needed, continue with Path A.

Step 3: Organize the Answer

1. Prioritize displaying API signatures and usage directly related to the user's question.
2. Attach brief code examples (refer to patterns in core-patterns.md).
3. If there are related classes or methods, add supplementary hints.

Quick Reference for Core Classes

Document

Element

ElementId

FilteredElementCollector

Transaction

Wall

Floor

FamilyInstance

FamilySymbol

Parameter

XYZ

Line

Arc

CurveLoop

Solid

Face

Edge

Level

View

ViewPlan

View3D

UIApplication

UIDocument

ExternalCommandData

TaskDialog

Selection

Namespace Navigation

• Autodesk.Revit.DB

  — Database core: elements, geometry, parameters, transactions

• Autodesk.Revit.UI

  — User interface: Ribbon, dialog boxes, selection

• Autodesk.Revit.ApplicationServices

  — Application services: Application, ControlledApplication

• Autodesk.Revit.Creation

  — Factory methods: create documents, geometric objects

• Autodesk.Revit.Attributes

  — Attribute markers: Transaction, Regeneration

• DB.Architecture

  — Architecture: rooms, stairs, railings

• DB.Structure

  — Structure: beams, columns, foundations

• DB.Mechanical

  — HVAC: ducts, equipment

• DB.Electrical

  — Electrical: circuits, switchboards

• DB.Plumbing

  — Plumbing: pipes, sanitary ware

• DB.ExtensibleStorage

  — Custom data storage

• DB.ExternalService

  — External service framework

• DB.Events

  /

  UI.Events

  — Event system

• DB.DirectContext3D

  — Custom 3D rendering

• DB.Visual

  — Materials and rendering appearance

• Autodesk.Revit.Exceptions

  — Exception types

Prohibited Items

• It is forbidden to skip Step 0 pre-research for ambiguous questions and directly answer API details from memory
• It is forbidden to guess API names or signatures without search verification; confirmation must be done through pre-research + script queries
• It is forbidden to directly edit JSON data files in the

  data/

  directory
• It is forbidden to provide API usage not documented in the knowledge base; if the documentation is insufficient, it should be clearly stated
• It is forbidden to confuse APIs of different Revit versions; this documentation only covers Revit 2026 (v26.0.4.0)

Notes

• All scripts are based on Python standard libraries, no additional dependencies are required
• Script paths are relative to this skill directory, use the

  scripts/

  prefix
• Data has been pre-extracted into namespace-based JSON files (

  data/pages/*.json

  ), no original HTML is needed
• The index file

  data/api_index.json

  is generated by

  build_index.py

• extract_page.py

  supports the

  --id

  parameter to directly query member-level documentation (prefixes: T=type, P=property, M=method, E=event)