# skillbay is open: a marketplace for AI agent skills, with proof > Source: > Published: 2026-09-16 00:00:00+00:00 # skillbay is open: a marketplace for AI agent skills, with proof A curated marketplace of skills for coding agents, where every listing is reviewed by a person and shows the same prompt answered without and with the skill. I built skillbay because I kept writing my own skills for jobs I am not an expert in. I am a software engineer. When I redline a contract or build a sales deck with an agent, I do not want to teach the agent contract law from scratch. I want to buy the skill from someone who has done that job a hundred times. That is the whole idea. Skills are valuable because of the expertise in them, and most of us are generalists outside our own field. skillbay is where the specialists sell what they know and everyone else installs it. ## What a skill is [#](#what-a-skill-is) A skill is a `SKILL.md` file, sometimes with a folder of supporting files, that teaches a coding agent how to do one narrow job well. Claude Code, Codex, Cursor and most other agents load them from a skills directory. A good one changes the agent's output in a way you can see. **get new posts by email** ## What is different here [#](#what-is-different-here) - **Every listing is reviewed by a person.** Today that person is me. Nothing goes live without a human reading it. - **Every listing shows before-and-after evidence.** The same prompt, answered without the skill and with it, side by side. If the "with" answer is not clearly better, the skill does not get listed. - **Sellers keep the whole price.** There is no platform cut. Free skills are welcome too. - **You do not need an account** to browse, read the evidence, install free skills, or submit a skill for review. ## How to use it [#](#how-to-use-it) Search or browse by category on the site. On a listing, read the examples first, then the seller's specialization, then the description. Free skills install straight from the page or from the [Agent Skills index](https://skillbay.sh/.well-known/agent-skills/index.json), which `npx skills add skillbay.sh` reads. If you work inside an agent, [install the MCP server](https://skillbay.sh/mcp). One remote server, no keys. Your agent can search, read the evidence, install free skills, submit, and buy without leaving its editor. There is a JSON API at `/api/v1` and an [OpenAPI description](https://skillbay.sh/openapi.json) for everything else. ## How to sell [#](#how-to-sell) Selling is invite-only, and the invite comes from a submission. [Post a skill](https://skillbay.sh/submit) with the before-and-after evidence and a line on why you are the specialist, or use [the quick way](https://skillbay.sh/submit/quick) with just a `SKILL.md` and an email. I read every one. If it is a fit, you get an invite, set up payouts through Stripe, and list. ## If the skill you need does not exist [#](#if-the-skill-you-need-does-not-exist) Post it on the [skills wanted](https://skillbay.sh/wanted) board. Say what the agent should do and what goes wrong when you try today. Specialists who have done it reply by email. It works like the wanted section on craigslist: no account, confirm by email, the post stays up for thirty days. ## Frequently asked questions [#](#frequently-asked-questions) **Do I need to pay to use skillbay?** No. Browsing, evidence, free skills, submitting, and the wanted board are free. Only paid skills cost money, and the price is on the listing. **Who reviews the skills?** I do, with the evidence the seller supplies. The rules are written up in [what makes a skill worth paying for](https://skillbay.sh/blog/what-makes-a-skill-worth-paying-for). **Can my agent buy a skill by itself?** Yes, in two ways: through the MCP server after you sign in, or with USDC over HTTP 402. The second one is explained in [selling to AI agents over HTTP 402](https://skillbay.sh/blog/sell-to-ai-agents-over-http-402-with-stripe). Cheers, Nick, aka [@skeptrune](https://x.com/skeptrune)