Hi all,
I have been using Claude Code with SysIDE in VSCode with a decent amount of success. I wanted to share what is working for me so far, and see if anyone else has lessons learned to share.
The biggest help so far has been making a custom MCP to connect Claude with SysIDE’s CLI model validation tools, which live in the vscode extensions directory. Thank you to the SysIDE team for making these transparent, by the way! With this connection Claude can easily review models to make sure the code has no errors. It looks to me that the SysML v2 LSP is a wrapper for these CLI tools, so I just access them directly rather than going through the LSP. Claude can help you construct this MCP pretty easily, but I can share my code if people are interested.
Another useful thing is a sysml-patterns.md rule where common modeling patterns are kept. Examples:
## Abstract Part with Multiplicity Pattern
Use when a component contains N sub-parts that must each be individually addressable:
```sysml
abstract part <slots> slotName : PartType [N];
part <s1> name1 :> slotName;
part <s2> name2 :> slotName;
// ... N total named specializations
```
- The `abstract part` declares the typed slot with multiplicity `[N]`
- Each named part specializes it with `:>`
- Short aliases in `< >` are optional but useful for cross-referencing
## ISQ Attributes with SI Default Values
For attributes with known fixed values, assign them inline using SI units.
**Operator choice — `:>` vs `:`**:
- Prefer `:>` (subsetting) when the ISQ name is a **Feature** (attribute instance). This is the common case for physical quantities like `ISQ::voltage`, `ISQ::frequency`, `ISQ::electricCurrent`, `ISQ::mass`, `ISQ::temperature`.
- Use `:` (typing) when the ISQ name is only an **AttributeDefinition** (no instance exists to subset). Example: `ISQ::TemperatureValue` is a definition — there is no feature named `TemperatureValue` to redefine. When in doubt, try `:>` first; if validation fails with "cannot subset a definition", switch to `:`.
```sysml
// ISQ Features — use :> (subsetting)
attribute inputVoltage :> ISQ::voltage = 28 [SI::V];
attribute inputCurrentMax :> ISQ::electricCurrent = 1.8 [SI::A];
attribute frequencyStepSize :> ISQ::frequency = 500000 [SI::Hz]; // 0.5 MHz
attribute dataRateMax :> ISQ::frequency = 28000000 [SI::Hz]; // 28 MHz
// Temperature min/max — no dedicated ISQ feature; use : with TemperatureValue
attribute operatingTempMin : ISQ::TemperatureValue; // e.g. -40 °C — assign value separately
attribute operatingTempMax : ISQ::TemperatureValue; // e.g. +85 °C
// Single temperature — use :> with the ISQ::temperature feature (preferred)
attribute temperature :> ISQ::temperature;
```
