JITX Skills

JITX hardware design automation skills for both Claude Code and Codex/GPT. The repo uses one shared skills/ tree and platform-specific plugin manifests for each agent runtime.

Installation

Claude Code

Install from the Claude marketplace:

/plugin marketplace add JITx-Inc/jitx-skills
/plugin install jitx-skills@jitx

For local development without installing from a marketplace:

claude --plugin-dir /absolute/path/to/jitx-skills

Claude plugin skills are namespaced. For example, invoke the base workflow with /jitx-skills:jitx.

Codex / GPT

Codex uses .codex-plugin/plugin.json and the shared skills/ directory. The repo ships its Codex marketplace at .agents/plugins/marketplace.json, so the repo itself is a marketplace named jitx.

This GitHub marketplace layout requires Codex CLI 0.142.0 or newer.

Install from GitHub:

codex plugin marketplace add JITx-Inc/jitx-skills
codex plugin add jitx-skills@jitx

For local development, point the marketplace at a checkout instead:

codex plugin marketplace add /absolute/path/to/jitx-skills
codex plugin add jitx-skills@jitx

Codex skills can be invoked explicitly with $jitx, $jitx-component-modeler, and the other skill names, or selected implicitly from the user request.

Updating

Claude Code:

/plugin marketplace update jitx
claude plugin update jitx-skills@jitx

Restart Claude Code or run /reload-plugins after local plugin edits. If you previously added this marketplace under the old jitx-skills name, migrate it with:

/plugin marketplace remove jitx-skills
/plugin marketplace add JITx-Inc/jitx-skills
/plugin install jitx-skills@jitx

Codex/GPT:

codex plugin marketplace upgrade jitx
codex plugin add jitx-skills@jitx

For local-path marketplaces, update the checkout instead of running marketplace upgrade (it only refreshes Git snapshots). Then start a new thread so Codex reloads the skill list and manifest metadata.

Skills

jitx

Base workflow skill for JITX projects. Triggers on JITX-related tasks and provides environment setup, build commands, project structure guidance, and navigation to specialized skills.

Example triggers:

• “Build my JITX design”
• “Set up JITX environment”
• “Create a full JITX project”

jitx-component-modeler

Generate JITX Python component code from datasheets, KiCad footprints, or user specifications.

Example triggers:

• “Create a JITX component from this datasheet”
• “Model the RP2040 for my project”
• “Add an LDO component from the TI datasheet”

jitx-circuit-builder

Build JITX circuits with wiring, passives, power connections, application circuits, placement, and basic copper geometry.

Example triggers:

• “Wire up a buck converter circuit”
• “Connect the MCU to sensors over I2C”
• “Add decoupling caps to all power pins”

jitx-substrate-modeler

Model JITX substrates: stackups, materials, vias, routing structures, fabrication constraints, and design rules.

Example triggers:

• “Create a 4-layer JLCPCB substrate”
• “Define a 14-layer RF stackup with via fencing”
• “Set up 100-ohm differential routing structure”

jitx-physical-layout

Author PCB physical layout from code: copper, custom shapes, pad features, explicit placement, vias, code-based routes, and layout-intent tags.

Example triggers:

• “Draw an IFA antenna from code”
• “Create a net tie between AGND and DGND”
• “Route the BGA escape lanes from code”

jitx-interconnect-constraints

Apply signal-integrity constraints to JITX designs: topologies, insertion loss, timing, differential pairs, bus matching, pin models, and protocol constraints.

Example triggers:

• “Constrain this differential pair with 5ps skew”
• “Add insertion loss limits to the data bus”
• “Set up PCIe Gen4 constraints”

jitx-pin-assignment

Model flexible pin mapping with provide/require patterns, pin muxing, P/N swap, lane ordering, byte/bit swapping, and topology constraints on assigned ports.

Example triggers:

• “Let the tool pick which UART maps to these pins”
• “Allow P/N swap on the LVDS pairs”
• “Set up DDR4 byte swapping”

jitx-code-review

Same-model self-critique pass on JITX Python code just written in the current workspace. Catches architectural failure modes that grep gates and static linters miss.

Example triggers:

• “Review my JITX code”
• “Check this for string-hacking”
• “Audit before merge”

jitx-mechanical

Mechanical CAD interface for JITX designs: inspect/import DXF, EMN, IDF, IDX, and BDF data; export DXF; attach STEP models; export a full board STEP via the JITX UI (no CLI in py-jitx 4.2.x).

Example triggers:

• “Import this EMN as the board outline”
• “Export my board to DXF for the ME team”
• “Attach a STEP model to this connector”

Project Structure

jitx-skills/
├── .agents/
│   └── plugins/
│       └── marketplace.json     # Codex marketplace listing
├── .claude-plugin/
│   ├── plugin.json              # Claude Code plugin manifest
│   └── marketplace.json         # Claude marketplace listing
├── .codex-plugin/
│   └── plugin.json              # Codex plugin manifest
├── skills/
│   ├── jitx/
│   │   ├── SKILL.md
│   │   ├── agents/openai.yaml   # Codex UI metadata
│   │   ├── references/
│   │   │   ├── domain-checklists.md  # Checklist index
│   │   │   ├── domains/              # Focused checklist files
│   │   │   └── net-classes.md        # Cross-domain net taxonomy
│   │   └── scripts/
│   ├── jitx-component-modeler/
│   ├── jitx-circuit-builder/
│   ├── jitx-substrate-modeler/
│   ├── jitx-physical-layout/
│   ├── jitx-interconnect-constraints/
│   ├── jitx-pin-assignment/
│   ├── jitx-code-review/
│   └── jitx-mechanical/
├── scripts/
│   └── validate_dual_plugin.py
└── sample-project.md

Requirements

• A JITX Python project with pyproject.toml containing a JITX dependency
• Python 3.12+
• For datasheet processing: pip install pymupdf

Usage Examples

Generate a Component from Datasheet

User: Create a JITX component for the NE555 timer from this datasheet
Agent: uses the jitx-component-modeler skill to generate component code

Build a Design

User: Build my power supply design
Agent: uses the jitx skill to set up the environment and run the build

Extract Datasheet Pages

The extract_pages.py script helps extract relevant pages from large datasheets:

python skills/jitx-component-modeler/scripts/extract_pages.py datasheet.pdf --find "pinout" "dimension" "package"
python skills/jitx-component-modeler/scripts/extract_pages.py datasheet.pdf --pages 10 11 12 -o extract.pdf

Supported Package Generators

Validation

Run the repo-local dual validation:

python scripts/validate_dual_plugin.py .

Run Codex manifest validation with the Codex plugin-creator validator:

python /path/to/plugin-creator/scripts/validate_plugin.py .

Run Claude validation when Claude Code is installed:

claude plugin validate .

Contributing

Keep the shared instructions in skills//SKILL.md. Use platform-specific metadata only where each runtime expects it:

• Claude Code: .claude-plugin/plugin.json and .claude-plugin/marketplace.json
• Codex/GPT: .codex-plugin/plugin.json, .agents/plugins/marketplace.json, and skills//agents/openai.yaml
• Shared skill content: skills//SKILL.md, references/, scripts/, and assets/