Dynamo Onboarding

Dynamo Onboarding

When to use

• Learning the Dynamo codebase for the first time.
• Answering "where do I start?" for a Jira ticket in Dynamo.
• Understanding how Dynamo's architecture fits together.
• Producing an architecture briefing for a teammate.

When not to use

• Writing or reviewing C# code -- use dynamo-dotnet-expert.
• Architecture / onboarding for DynamoMCP -- that lives in the DynamoMCP repo.

Inputs expected

A question like "how does X work?", a Jira ticket number, or a request for an architecture brief.

Output format

A structured briefing following the sections below. Skip sections that don't apply.

Briefing Structure

1. System purpose (1 sentence)
2. Tech stack (3-6 bullets)
3. Core components (component -> responsibility)
4. Repo map (key folders and what lives in each)
5. Flow (5-9 ordered steps from input to output)
6. Data contracts (input/output models, key payload shapes)
7. Start here (top 5-8 files to read first)
8. Pitfalls (up to 5 common mistakes)
9. Confidence and unknowns (what is confirmed vs what needs verification)

How to build the brief

• Start from entry points (DynamoModel, DynamoSandbox, extension loader, test harness).
• Trace one real execution path end-to-end (user action -> node evaluation -> engine -> result).
• Name interfaces and concrete classes involved.
• Explicitly list assumptions when code evidence is partial.
• Prefer concise, concrete wording over broad theory.

Project Description

Dynamo is a visual programming tool accessible to non-programmers and programmers alike. Users can visually script behavior, define custom logic, and script using textual programming languages. C# + WPF, .NET 10. Core engine (DynamoCore.sln) is cross-platform; full UI (Dynamo.All.sln) is Windows-only.

Build:

# Full (Windows)
dotnet restore src/Dynamo.All.sln --runtime=win-x64 -p:Configuration=Release -p:DotNet=net10.0
msbuild src/Dynamo.All.sln /p:Configuration=Release

# Core only (cross-platform)
dotnet build src/DynamoCore.sln -c Release

Test: NUnit. dotnet test or Visual Studio Test Explorer.

Key areas:

Architecture Overview

Core Model

DynamoModel is the central class -- it owns the workspace, manages state transitions, and coordinates node evaluation. Key states: NotStarted, StartedUI, StartedUIless.

Workspace

WorkspaceModel holds the graph: nodes, connectors, groups, notes. HomeWorkspaceModel extends it with execution (run) support. CustomNodeWorkspaceModel represents reusable sub-graphs.

Nodes

NodeModel is the base class for all nodes. Built-in nodes live in src/Libraries/. Custom nodes can be created via Zero-Touch (annotated C# methods) or NodeModel subclassing.

Engine

The DesignScript engine (src/Engine/) compiles and evaluates the visual graph. ProtoCore handles AST construction, ProtoScript runs the execution.

Extensions

Dynamo supports view extensions (IViewExtension) and extensions (IExtension). View extensions can add UI panels and interact with the workspace. Examples: GraphNodeManager, PackageDetails, DocumentationBrowser.

Related Projects

Debugging Approaches

Build failing

1. Check global.json SDK version: .NET 10 SDK required.
2. Windows full build needs msbuild (Visual Studio 2022).
3. Cross-platform build uses dotnet build with DynamoCore.sln only.
4. Check NuGet feeds: some packages come from internal feeds.

Test failing

1. Check the test project matches the source project (e.g., DynamoCoreTests tests DynamoCore).
2. Tests use NUnit -- look for [Test], [TestCase], [SetUp] attributes.
3. Some tests need Dynamo running (DynamoModelTestBase sets up a headless instance).
4. Check for test data files in test/core/ that tests may depend on.

Node not appearing in library

1. Check for [IsVisibleInDynamoLibrary(true)] attribute on the method.
2. Verify the assembly is referenced and loaded by Dynamo.
3. Check node naming: does the namespace and method name match expected layout?

PublicAPI analyzer errors (RS0016/RS0017)

1. RS0016: add the new public API signature to PublicAPI.Unshipped.txt.
2. RS0017: the member was removed from the shipped surface -- restore or follow the breaking change process.

"Start Here" Files

For Dynamo newcomers:

1. src/DynamoCore/Models/DynamoModel.cs -- central model, state machine
2. src/DynamoCore/Graph/Workspaces/WorkspaceModel.cs -- workspace operations
3. src/DynamoCore/Graph/Nodes/NodeModel.cs -- node base class
4. src/Libraries/CoreNodes/ -- built-in node implementations
5. src/DynamoCoreWpf/ -- UI components
6. src/Engine/ProtoCore/ -- DesignScript engine core
7. .github/copilot-instructions.md -- build/test/style quick reference

Example 1: "I got ticket DYN-5678 to add a new node for string interpolation"

Briefing output:

• String operations live in src/Libraries/CoreNodes/.
• Look at existing string nodes for the pattern (e.g., String.cs).
• New node needs [IsVisibleInDynamoLibrary(true)] and XML documentation.
• Add help files: .dyn sample, .md docs, .jpg preview in doc/distrib/NodeHelpFiles/.
• Tests go in test/Libraries/CoreNodesTests/.

Example 2: "Where does node evaluation happen?"

Briefing output:

• HomeWorkspaceModel.Run() triggers evaluation.
• The graph is compiled to DesignScript AST via the engine in src/Engine/.
• ProtoCore handles AST construction and type resolution.
• Each node's BuildAst() method generates its AST contribution.
• Results flow back through NodeModel.CachedValue.