Skiller

Declarative, human-in-the-loop workflow runner for VS Code chat.

Write branching YAML playbooks that orchestrate your language model and MCP tools — with review and input steps — and run them from the @skiller chat participant.

Skiller in action — a skill running with its live execution graph

📖 Full documentation → https://tivaliy.github.io/skiller/

What is Skiller?

Skiller runs skills — declarative, multi-step workflows defined in YAML and Markdown. Each skill is a playbook: a sequence of steps that call a language model, invoke your MCP tools, and pause for your input or approval exactly where you tell them to.

It is deliberately not a free-form agent and not an "Agent Skills" auto-loader:

	Free-form agent	Skiller
Control flow	Model decides what to do next	You define the steps; the model fills them in
Side effects	Can act on its own	Runs only the steps you wrote, pausing for confirmation where you ask
Reproducibility	Varies run to run	Same playbook, same shape every time
Branching	Implicit	Explicit `confirmation` steps with `goto` jumps

If you want predictable, reviewable automation that still leverages an LLM — not an autonomous agent — Skiller is for you. As a skill runs, you can watch it as a live execution graph, with branches and loops lighting up as they fire.

Requirements

VS Code 1.93+
A chat language model provider (e.g. GitHub Copilot, or any provider exposing VS Code's Language Model API)
MCP servers configured in VS Code (optional — only needed for tool integrations)

Quick start

Install

From the Marketplace:

ext install tivaliy.skiller

From source:

npm install
npm run package
code --install-extension skiller-*.vsix

Run your first skill

Open the Chat view and talk to @skiller:

@skiller /help            Show available commands
@skiller /skills          List discovered skills
@skiller /skill greeter   Run the built-in "greeter" example skill

A message that is not a slash command and not a skill gets a short hint — Skiller does not do free-form chat.

See the Getting Started tutorial to install, run a skill, and author your own.

Learn more

The docs are the single source of truth. Jump to what you need:

Run a built-in skill and Write your first skill — guided tutorials.
Guides — how-to for tool/MCP skills, branching & looping, debugging, and models.
Skills & discovery, Step types & state, Templating with Liquid, and The execution graph — how it all works.
skill.yaml manifest and step-file frontmatter — every field.
Commands — all @skiller slash commands.
Settings — every skiller.* setting and its default.
Built-in tools — skiller_createFile and skiller_replaceInFile.

Contributing

Issues and pull requests are welcome. See Contributing & development for build, test, and PR guidelines, and for running the Extension Development Host.

License

Licensed under the MIT License.