Simulink-agentic-toolkit building-simulink-models

Builds and edits Simulink, System Composer, Stateflow, and Simscape models. Use when modifying model structure, parameters, ports, connections, or Stateflow chart internals.

install

source · Clone the upstream repo

git clone https://github.com/matlab/simulink-agentic-toolkit

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/matlab/simulink-agentic-toolkit "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills-catalog/model-based-design-core/building-simulink-models" ~/.claude/skills/matlab-simulink-agentic-toolkit-building-simulink-models && rm -rf "$T"

manifest: skills-catalog/model-based-design-core/building-simulink-models/SKILL.md

source content

Building Models

Use

model_edit

for Simulink, System Composer, and Simscape models (structural changes and parameter configuration). For Stateflow chart internals, use

evaluate_matlab_code

with the Stateflow API (see below).

When to Use

Adding, connecting, deleting, or replacing blocks in a model
Configuring block parameters, signal properties, or model settings
Creating or editing Stateflow chart internals (states, transitions, junctions)
Building System Composer architecture models
Wiring Simscape physical connections

When NOT to Use

Querying parameter values → use
```
model_query_params
```
Resolving variable references to numeric values → use
```
model_resolve_params
```

Workflow

Read first: Use
```
model_read
```
on the target scope to get block IDs and understand existing topology.
Plan the data flow: For complex edits, sketch inputs → operations → outputs, then map to blocks.
Edit: Use
```
model_edit
```
with operations scoped to one subsystem level at a time.
Verify: Use
```
model_read
```
on the scope to confirm the structure matches your intent.

CRITICAL: If

model_edit

returns

status: partial

, run

model_read

immediately to determine if corrective action is needed.

Operation Chaining with

ref

Use

ref

to name a block and

#ref

to reference it in later operations within the same call:

[{"op": "add_block", "type": "Gain", "name": "MyGain", "ref": "g1"},
 {"op": "connect", "target": "blk_5.y1 -> #g1.u1"}]

The response

created

map shows

ref → blk_id

. In subsequent calls, use the

blk_id

(e.g.,

blk_42

) —

#ref

only works within a single call.

Guardrails

Do not call
```
Simulink.BlockDiagram.arrangeSystem
```
or use
```
set_param
```
for block positioning unless the user explicitly requests it.
```
model_edit
```
has a built-in autolayout engine that runs automatically after each call.
Use meaningfully named variables (e.g.,
```
Kp_SpeedController
```
) instead of hardcoded numeric values. Define variables in model workspace or a
```
.m
```
init script.
Don't use
```
evaluate_matlab_code
```
with
```
set_param
```
/
```
add_block
```
to bypass
```
model_edit
```
— it skips autolayout, undo tracking, and error recovery
Use
```
open_system
```
rather than
```
load_system
```
to open models that are not already open, or when creating new models, unless the user explicitly asks otherwise or the model is a library. This ensures the user can see live edits as they happen.

Naming Conventions

Prefer code-generation-safe names for blocks, signals, and variables:

Use only:
```
a-z
```
,
```
A-Z
```
,
```
0-9
```
, underscore (
```
_
```
)
Don't start with a number
Don't use leading/trailing or consecutive underscores
Prefer names under 32 characters (required for some code generation targets)

Block Types

Use the block's display name in the

type

field. Do not construct or guess library paths.

Built-in Simulink blocks: Use the BlockType directly:
```
Gain
```
,
```
Sum
```
,
```
Constant
```
,
```
Integrator
```
,
```
SubSystem
```
,
```
Scope
```
Library blocks (Simscape, Aerospace, DSP, Communications, etc.): Use the display name as it appears in the Simulink Library Browser:
```
Voltage Source
```
,
```
Resistor
```
,
```
DC Motor
```
,
```
Solver Configuration
```
,
```
6DOF (Euler Angles)
```
If
model_edit
returns
INVALID_TYPE
: Fall back to the full library path from MATLAB documentation (e.g.,
```
ee_lib/Sources/Voltage Source
```
)

[{"op": "add_block", "type": "Voltage Source", "name": "V1", "ref": "v1"},
 {"op": "add_block", "type": "Resistor", "name": "R1", "ref": "r1"},
 {"op": "add_block", "type": "Electrical Reference", "name": "Gnd", "ref": "gnd"},
 {"op": "add_block", "type": "Solver Configuration", "name": "Solver", "ref": "sc"}]

Domain-Specific Rules

When working with these domains, read the corresponding reference file before editing:

Stateflow charts ->
```
reference/stateflow.md
```
—
```
model_edit
```
can add Chart blocks but cannot edit chart internals. Use
```
evaluate_matlab_code
```
with the Stateflow API for states, transitions, junctions, and data. The reference covers API gotchas, subcharts, lint checks, and layout.
System Composer architecture models ->
```
reference/system-composer.md
```
— Create models with
```
systemcomposer.createModel
```
, then use
```
model_edit
```
. Components use
```
type: "SubSystem"
```
, ports use Bus Element blocks. The reference covers component creation, port wiring, and behavior model generation.
Simscape physical models ->
```
reference/simscape.md
```
— Physical connections use bidirectional
```
<->
```
syntax. The reference covers connection semantics, port patterns, and initial target variables.