How to install sim-cli skills for Codex and Claude Code

One-sentence answer

Run sim plugin sync-skills --target .agents/skills --copy for Codex (or any harness that reads .agents/skills), or --target .claude/skills --copy for Claude Code, and every installed plugin’s bundled skill lands in the right place for the agent to discover.

What is a skill

Each sim-plugin-<solver> package ships a bundled agent skill — a small on-disk doc (typically SKILL.md plus references) that tells a coding agent how to drive that solver through sim-cli. The skill is solver-specific: sim-comsol, sim-abaqus, sim-ansys-workbench, sim-openfoam, sim-ltspice, sim-fluent, sim-matlab, and so on.

Skills live on disk where the coding-agent harness already looks for them:

.agents/skills/ — Codex CLI and other coding-agent harnesses that follow the generic agent-skill convention.
.claude/skills/ — Claude Code.

Same skill content, different target directory.

Install skills for Codex

After installing the plugin (or plugins) you want:

uv add sim-cli-core sim-plugin-comsol sim-plugin-abaqus
uv run sim plugin sync-skills --target .agents/skills --copy

sync-skills walks every installed plugin and copies its bundled skill into .agents/skills/<solver>/. Re-running is safe; it overwrites in place.

Install skills for Claude Code

uv add sim-cli-core sim-plugin-comsol sim-plugin-abaqus
uv run sim plugin sync-skills --target .claude/skills --copy

Same idea — only the target directory differs.

When to re-sync

Re-run sim plugin sync-skills after:

Installing a new plugin
Upgrading sim-cli-core or any sim-plugin-<solver>
Switching agent harnesses (e.g., adding Claude Code on a project that was previously Codex-only — point --target at .claude/skills as well)

After syncing

Verify that the agent can actually reach the solver before the first real run:

uv run sim check <solver>
uv run sim plugin doctor <solver> --deep

Then drive the solver through the standard bounded loop:

check readiness → attach to live session → inspect model state
→ run one bounded CAE step → verify result/state → save checkpoint/artifacts