lvkit 0.2.0

Understand and convert LabVIEW VIs to Python without a LabVIEW license

lvkit

Read, document, diff, and convert LabVIEW VI files — no LabVIEW license required.

lvkit parses .vi, .ctl, .lvclass, and .lvlib files directly into queryable dependency and dataflow graphs. Use it to document code, track changes in CI, feed VI structure to AI tools, or generate equivalent Python.

Contents

• Quick Start
• What you can do with it
• How it works
• AI and IDE integration
• Cleanroom approach
• Development

Quick Start

pip install lvkit
lvkit setup

For a global install: pipx install lvkit or uv tool install lvkit.

lvkit setup creates a .lvkit/ resolution store and installs AI agent skills:

• Auto-detects Claude Code (CLAUDE.md / .claude/) and Copilot (.github/copilot-instructions.md / .github/instructions/ / .github/agents.md)
• Pass claude, copilot, or all to be explicit
• Use --no-skills to create the .lvkit/ store without installing any skills

Command	Description
lvkit describe	Human-readable VI description with signature and operations
lvkit docs	Generate cross-referenced HTML documentation
lvkit diff	Compare two VI versions — terminals, operations, wiring
lvkit visualize	Mermaid flowchart or interactive dependency graph
lvkit generate	Generate Python from a VI, library, or class (experimental — see Cleanroom approach)
lvkit structure	Inspect .lvlib or .lvclass structure
lvkit setup	Install AI agent skills; create .lvkit/ resolution store
lvkit mcp	Start the MCP server for IDE integration

lvkit visualize --format interactive requires pip install lvkit[visualize]. All other commands work on a bare pip install lvkit.

What you can do with it

Describe what a VI does

Get a human-readable signature, inputs/outputs, operations, and control flow — without opening LabVIEW. Never requires primitive or vi.lib mappings.

lvkit describe <path-to.vi> [--search-path <libraries/>] [--chart]

--chart adds a Mermaid flowchart of the block diagram.

Generate documentation

Cross-referenced HTML docs for a .vi, .lvlib, or .lvclass — inputs, outputs, operations, wiring diagrams.

lvkit docs <input-path> <output-dir> [--search-path <libraries/>]

Diff two versions of a VI

See what changed between two .vi files — added/removed terminals, changed operations, rewired connections. Useful in code review and CI.

lvkit diff <vi-a> <vi-b> [--long]

--long gives a structured change report instead of a unified diff.

Generate Python

Convert a VI, library, or class to Python. Deterministic — same VI in, same Python out, every run, no LLM involved.

lvkit generate <input-path> -o <output-dir> [--search-path <libraries>] [--placeholder-on-unresolved]

--placeholder-on-unresolved lets the build succeed when mappings are missing — unresolved calls become inline raise PrimitiveResolutionNeeded(...) in the output so you can track them down at runtime.

Coverage is incremental and results will vary — see Cleanroom approach for what that means in practice.

How it works

lvkit reads VI binaries directly — no LabVIEW installation required. The pipeline has three stages:

1. Parse — the VI binary is extracted to XML (via pylabview), then parsed into a typed representation of the block diagram: nodes, wires, constants, types, and front panel terminals.

2. Graph — all loaded VIs are linked into a graph that captures two things: the dependency tree (which VIs call which) and the dataflow within each VI (how data moves between operations). This is what describe, docs, diff, and visualize query — no semantic mappings needed.

3. Generate — the graph is walked deterministically to produce Python source, HTML documentation, or flowcharts. Code generation is pure AST construction: same VI in, same output every run, no LLM.

See docs/graph-reference.md for the full graph type reference.

AI and IDE integration

The CLI works standalone from any terminal or CI script. For deeper IDE integration, lvkit ships two optional layers.

AI agent skills — install lvkit's built-in workflows into Claude Code or Copilot so your AI agent can describe VIs, convert them, and resolve unknowns without you writing prompts. All five workflows call the CLI under the hood — no MCP server required.

lvkit setup           # auto-detect from project layout
lvkit setup claude    # installs .claude/skills/lvkit-*
lvkit setup copilot   # installs .github/prompts/ + router instruction
lvkit setup all       # both

Five workflows ship: lvkit-describe, lvkit-convert, lvkit-resolve-primitive, lvkit-resolve-vilib, lvkit-idiomatic.

MCP server — for interactive IDE sessions where your AI agent needs to load a graph, walk wires, and ask follow-up questions across multiple VIs:

{
  "mcpServers": {
    "lvkit": { "command": "uvx", "args": ["--from", "lvkit", "lvkit-mcp"] }
  }
}

Tool	Description
load	Load VI into the in-memory graph
list_loaded	List loaded VIs
get_context	Full VI context: inputs, outputs, operations, wires
generate_ast_code	Generate Python from a loaded VI
describe	Human-readable VI description
get_operations	List operations in a VI
get_dataflow	Show wire connections
get_structure	Inspect a structure node (loop, case, sequence)
get_constants	List constant values
analyze	Parse and describe VI structure (stateless)
generate_documents	Generate HTML docs for VIs/libraries (stateless)
generate_python	Generate Python from a VI (stateless)

Cleanroom approach

lvkit has no access to LabVIEW source code or runtime. LabVIEW's built-in primitives and standard library VIs are semantically replaced: each operation is mapped to an equivalent Python implementation in JSON data files (src/lvkit/data/primitives.json, src/lvkit/data/vilib/). These mappings are built from published documentation and observed behavior.

Coverage is incremental. When lvkit generate encounters an unmapped primitive or vi.lib VI, it raises an error with diagnostic context so the mapping can be added. describe, docs, diff, and visualize are unaffected — they work from the graph, not the semantic mappings.

Project-local resolution store (.lvkit/)

You can supplement the bundled mappings with a .lvkit/ directory in your project root. lvkit reads .lvkit/ first and falls back to its bundled data.

Run lvkit setup --no-skills to create the store with a README that documents the file layout and JSON formats for adding primitive and vi.lib mappings manually.

When lvkit generate hits an unknown, you have two options:

1. Resolve up front — run lvkit setup to install the resolve skills and let your AI agent write the mapping into .lvkit/.
2. Defer to runtime — pass --placeholder-on-unresolved. lvkit emits an inline raise PrimitiveResolutionNeeded(...) in the generated Python with full diagnostic context. The build succeeds; runtime fails at the unresolved call.

Development

uv sync
pytest
ruff check .
python -m pyright src/

See CLAUDE.md for contributor workflow, code style, and how to add primitive or vi.lib mappings.

License

Apache-2.0. See LICENSE.

Further reading

• docs/graph-reference.md — graph type reference (nodes, VIContext, operations, wires)
• docs/vi-xml-reference.md — pylabview XML format reference
• docs/highlight-reel.md — design narrative and architecture decisions
• docs/demo-script.md — 30-minute demo script / tutorial
• pylabview — the VI binary parser lvkit builds on