About AI skills
What is an AI skill?
An AI skill is a reference document — a SKILL.md file — an assistant or agent loads into context to do a specific job. Skills do not run on their own; they are tools a model picks up when needed.
Sigrix skills follow the open agentskills.io specification, so the same file works in Claude Code, Codex CLI, claude.ai, and the Claude API — buy once, use everywhere.
Compare skills by the job they add, the platforms they have been tested on, and price — a good skill listing bundles the file plus a worked example so you see what 'good' looks like.
People searching for AI skills usually want a portable capability they can drop into an assistant or agent without rebuilding it from scratch.
Popular searches: agent skills marketplace, ai skills marketplace, claude code skills, agent skills, skill.md, claude skills, ai agent capabilities.
Related: ai assistants, ai agents, prompts, agentskills.io, tools.
01
A SKILL.md file
The skill is a reference document the model loads into context — instructions, procedures, and examples for one specific job.
02
Open, portable spec
Built on agentskills.io, so the same file works across Claude Code, Codex CLI, claude.ai, and the API without rewriting.
03
Loaded on demand
An assistant or agent picks the skill up only when it is relevant, so it adds capability without bloating every conversation.
04
Worked example included
Good skill listings bundle a sample run, so you can see the capability in action before you buy.
A skill is one of several AI building blocks on Sigrix. Here is how it differs from the others:
Prompt
A single instruction you send once. A skill is a reusable capability a model loads whenever the job comes up.
Persona
A kind of prompt that shapes how a model sounds. A skill adds what a model can do.
Assistant
A chat experience that loads skills when relevant — the skill is the tool, the assistant is the worker.
Agent
An autonomous tool that calls skills as it runs its steps.