Subnets/Components and Composition by kube · Pull Request #8662 · hashintel/hash

kube · 2026-04-28T10:15:54Z

This is a draft PR, just as an exploration for what subnets and composition should be in Petrinaut.

But the actual implementation will be done after Petrinaut Core Library Extraction (FE-628).

Introduces the Subnet type (isolated sub-networks within a net) across the core types, file format, import/export, mutation layer, and UI. Adds a "Nets" subview to the left sidebar listing the root net and subnets, with a button to create new subnets. Includes a Hospital Network example demonstrating the feature. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Introduces ActiveNetContext to decouple "which net is being viewed" from the full SDCPN. Display consumers (canvas, sidebar lists, properties panel, diagnostics) read from ActiveNetContext while export/simulation/LSP keep reading the full SDCPN. Mutations route through resolveNet() so edits target the active subnet. Adds "add-component" edition mode with componentSubnetId in EditorContext, a Component dropdown in the BottomBar toolbar (root net only), and a cursor-following tooltip showing what will be created on click. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

…lace Introduces the ComponentInstance entity: a subnet instantiation with parameter values, wiring (place-to-port connections), and canvas positioning. Places gain an `isPort` flag to mark them as ports exposed on component instances. Rendering: sharp-cornered rectangle node with port handles derived from the subnet's port places. Wiring rendered as a dedicated "wire" edge type (dashed, bezier) distinct from arcs. Edges array replaces the former arcs-only array to hold both arc and wire edge types. Mutations: addComponentInstance, updateComponentInstance, removeComponentInstance, plus deleteItemsByIds and commitNodePositions support. Hospital Network example updated with an ER Triage component instance wired to the root net. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Render a properties panel when a component instance node is selected, showing instance details and parameter overrides for the underlying subnet. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

vercel · 2026-04-28T10:15:59Z

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
hash	Ready	Preview, Comment	Apr 28, 2026 10:15am
petrinaut	Ready	Preview, Comment	Apr 28, 2026 10:15am

1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
hashdotdesign-tokens	Ignored		Apr 28, 2026 10:15am

cursor · 2026-04-28T10:16:01Z

PR Summary

Medium Risk
Introduces new SDCPN data structures (subnets, componentInstances, wiring) and routes most editor mutations/rendering through an ActiveNet abstraction, which can affect many core edit flows and file import/export compatibility.

Overview
Adds basic subnet-based composition to Petrinaut by extending the SDCPN schema with subnets, componentInstances, port places (Place.isPort), and wiring, plus a new hospitalNetwork example demonstrating the format.

Introduces an ActiveNetProvider to switch the editor between the root net and a selected subnet, updating sidebar lists, diagnostics, selection cleanup, parameter defaults, graph layout, and mutation helpers to operate on the active net.

Adds UI for managing/viewing nets (new Nets sidebar subview), creating component instances from the toolbar (add-component mode + cursor tooltip), rendering component instance nodes with port handles, and drawing dashed wire edges; selection/properties support is extended to componentInstance items. File import/remove-visual-info and Zod schemas are updated to handle subnets/component instances and their positions.

^{Reviewed by Cursor Bugbot for commit 01705ea. Bugbot is set up for automated code reviews on this repo. Configure here.}

augmentcode · 2026-04-28T10:19:08Z

🤖 Augment PR Summary

Summary: This draft PR explores “subnets” and component-based composition in Petrinaut by introducing a notion of an “active net” (root vs selected subnet) and rendering subnet instances as nodes with wiring.

Changes:

Extends the SDCPN type model with Subnet, ComponentInstance, Wire, and a Place.isPort flag.
Updates the file format schema and import/export helpers to include subnets/component instances and to fill/strip their visual positioning data.
Adds ActiveNetContext/ActiveNetProvider and migrates multiple UI panels/hooks to operate on the active net’s places/transitions/types/etc.
Introduces a “Nets” sidebar subview to switch between root and subnets, plus toolbar support for “add component instance” mode.
Enhances mutation helpers to target the active net (root or subnet) and adds CRUD helpers for subnets/component instances.
Adds ReactFlow rendering for component instance nodes (with port handles) and dashed “wire” edges, plus a cursor-following tooltip for add modes.
Adds a new “Hospital Network” example demonstrating a root net with an ER triage subnet and a component instance wired to ports.

Technical Notes: Graph layout and selection cleanup now operate on the active net; getItemType was broadened to search both root and all subnets for IDs.

_{🤖 Was this summary useful? React with 👍 or 👎}

augmentcode

Review completed. 4 suggestions posted.

Comment augment review to trigger a new review at any time.

augmentcode · 2026-04-28T10:19:10Z

@@ -75,12 +89,13 @@ export const MutationProvider: React.FC<MutationProviderProps> = ({
    },
    removePlace(placeId) {


libs/@hashintel/petrinaut/src/state/mutation-provider.tsx:L90 — When a place is removed from a net, any componentInstances[].wiring entries that reference it (as externalPlaceId, or indirectly via a port ID) aren’t cleaned up, which can leave dangling wire edges/handles in the ReactFlow view. This same issue can also occur when places are deleted via deleteItemsByIds (wires aren’t considered there either).

Severity: medium

Other Locations

libs/@hashintel/petrinaut/src/state/mutation-provider.tsx:403

_{🤖 Was this useful? React with 👍 or 👎, or 🚀 if it prevented an incident/outage.}

augmentcode · 2026-04-28T10:19:10Z

+        sdcpn.subnets = subnets;
+      });
+    },
+    removeSubnet(subnetId) {


libs/@hashintel/petrinaut/src/state/mutation-provider.tsx:L389 — removeSubnet removes the subnet definition but doesn’t address any componentInstances (in the root net or other nets) that reference that subnetId, which can leave instances/wires pointing at non-existent ports. Consider either preventing subnet deletion while referenced or cleaning up dependent instances/wiring to avoid inconsistent state.

Severity: medium

_{🤖 Was this useful? React with 👍 or 👎, or 🚀 if it prevented an incident/outage.}

augmentcode · 2026-04-28T10:19:10Z

+  );
+  const rafRef = useRef(0);
+
+  useEffect(() => {


libs/@hashintel/petrinaut/src/views/SDCPN/components/cursor-tooltip.tsx:L40 — This useEffect attaches a global mousemove listener and calls setPosition(...) on every mouse move even when not in an add mode (when the tooltip returns null). That can cause unnecessary re-renders across long sessions; consider only subscribing/updating while label is non-null (i.e., when the tooltip would actually render).

Severity: medium

_{🤖 Was this useful? React with 👍 or 👎, or 🚀 if it prevented an incident/outage.}

augmentcode · 2026-04-28T10:19:10Z

      };
 };

+/**


libs/@hashintel/petrinaut/src/core/types/sdcpn.ts:L117 — The JSDoc for “An instance of a subnet…” currently sits above Wire, so it looks like it’s documenting the wrong type (and the Wire docblock follows immediately after). Consider moving that first docblock onto ComponentInstance to avoid misleading generated docs/tooltips.

Severity: low

_{🤖 Was this useful? React with 👍 or 👎, or 🚀 if it prevented an incident/outage.}

cursor

Cursor Bugbot has reviewed your changes and found 3 potential issues.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 01705ea. Configure here.}

cursor · 2026-04-28T10:22:00Z

+          type === "place" ||
+          type === "transition" ||
+          type === "componentInstance"
+        ) {


Component instances treated as non-canvas items in selection

Medium Severity

The hasNonCanvasItems check (around line 86) only considers place, transition, and arc as canvas item types. Since this PR adds componentInstance as a new canvas node type, any selected component instance is incorrectly treated as a "non-canvas" item. This causes the selection base to be cleared when a component instance is in the selection and the user interacts with canvas selection, breaking multi-select behavior for component instances.

^{Reviewed by Cursor Bugbot for commit 01705ea. Configure here.}

cursor · 2026-04-28T10:22:00Z

    },
    commitNodePositions(commits) {
      guardedMutate((sdcpn) => {
+        const net = resolveNet(sdcpn);


Paste always targets root net, ignoring active subnet

Medium Severity

pasteEntities calls pasteFromClipboard(mutatePetriNetDefinition) which directly mutates the root SDCPN's places, transitions, etc. arrays. Unlike all other mutation functions in this provider, it does not use resolveNet to target the active net. When a user is viewing a subnet and pastes, entities are incorrectly added to the root net instead of the active subnet.

^{Reviewed by Cursor Bugbot for commit 01705ea. Configure here.}

cursor · 2026-04-28T10:22:00Z

+            break;
+          }
+        }
+      });


Removing subnet leaves dangling component instance references

Medium Severity

removeSubnet splices the subnet from the array but does not clean up componentInstances in the root net (or other subnets) whose subnetId references the deleted subnet. Other removal functions like removeType and removeDifferentialEquation follow a pattern of clearing dangling references, but removeSubnet does not, leaving orphaned component instances pointing to a non-existent subnet.

^{Reviewed by Cursor Bugbot for commit 01705ea. Configure here.}

kube and others added 4 commits April 23, 2026 11:31

FE-522: Add ComponentInstance properties panel

01705ea

Render a properties panel when a component instance node is selected, showing instance details and parameter overrides for the underlying subnet. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

graphite-app Bot assigned kube Apr 28, 2026

github-actions Bot added area/libs Relates to first-party libraries/crates/packages (area) type/eng > frontend Owned by the @frontend team labels Apr 28, 2026

kube marked this pull request as draft April 28, 2026 10:16

kube changed the title ~~Cf/fe 522 basic support for subnets component based net composition~~ Subnets/Components and Composition Apr 28, 2026

augmentcode Bot reviewed Apr 28, 2026

View reviewed changes

cursor Bot reviewed Apr 28, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Subnets/Components and Composition#8662

Subnets/Components and Composition#8662
kube wants to merge 4 commits intomainfrom
cf/fe-522-basic-support-for-subnets-component-based-net-composition

kube commented Apr 28, 2026

Uh oh!

vercel Bot commented Apr 28, 2026

Uh oh!

cursor Bot commented Apr 28, 2026 •

edited

Loading

Uh oh!

augmentcode Bot commented Apr 28, 2026

Uh oh!

augmentcode Bot left a comment

Uh oh!

augmentcode Bot Apr 28, 2026 •

edited

Loading

Uh oh!

augmentcode Bot Apr 28, 2026 •

edited

Loading

Uh oh!

augmentcode Bot Apr 28, 2026 •

edited

Loading

Uh oh!

augmentcode Bot Apr 28, 2026 •

edited

Loading

Uh oh!

cursor Bot left a comment

Uh oh!

cursor Bot Apr 28, 2026

Uh oh!

cursor Bot Apr 28, 2026

Uh oh!

cursor Bot Apr 28, 2026

Uh oh!

Reviewers

Assignees

Labels

Milestone

Development

Uh oh!

1 participant

		@@ -75,12 +89,13 @@ export const MutationProvider: React.FC<MutationProviderProps> = ({
		},
		removePlace(placeId) {

                     };
               };
+              /**

Conversation

kube commented Apr 28, 2026

Uh oh!

vercel Bot commented Apr 28, 2026

Uh oh!

cursor Bot commented Apr 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

PR Summary

Uh oh!

augmentcode Bot commented Apr 28, 2026

Uh oh!

augmentcode Bot left a comment

Choose a reason for hiding this comment

Uh oh!

augmentcode Bot Apr 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

augmentcode Bot Apr 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

augmentcode Bot Apr 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

augmentcode Bot Apr 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

cursor Bot left a comment

Choose a reason for hiding this comment

Uh oh!

cursor Bot Apr 28, 2026

Choose a reason for hiding this comment

Component instances treated as non-canvas items in selection

Uh oh!

cursor Bot Apr 28, 2026

Choose a reason for hiding this comment

Paste always targets root net, ignoring active subnet

Uh oh!

cursor Bot Apr 28, 2026

Choose a reason for hiding this comment

Removing subnet leaves dangling component instance references

Uh oh!

Reviewers

Assignees

Labels

Milestone

Development

Uh oh!

1 participant

cursor Bot commented Apr 28, 2026 •

edited

Loading

augmentcode Bot Apr 28, 2026 •

edited

Loading

augmentcode Bot Apr 28, 2026 •

edited

Loading

augmentcode Bot Apr 28, 2026 •

edited

Loading

augmentcode Bot Apr 28, 2026 •

edited

Loading