user skills

Skills

A skill is a Markdown instruction file that gives the agent a workflow for a specific job, such as planning a feature or reviewing a branch. Skills are extra context: they do not override your instructions, tool policy, or project files.

Bundled skills

Skill	What it does	When to use it
configure	Inspects and edits Steiner YAML configuration with minimal changes, secret handling, and validation.	You want to understand or change Steiner config.
plan	Writes a planning bundle (overview.md, plan.yaml) under .steiner/plans/YYYY-MM-DD_FEATURE_NAME/. Plans only; never edits code.	Before implementing a feature, refactor, or migration.
implement	Executes an approved plan folder step by step, delegating work to isolated sub-agents.	Planning is complete and approved.
review	Reviews changes against the approved plan, runs approved fix passes, then offers planning-doc cleanup and PR creation.	Implementation is complete.
simplify	Runs four parallel explore sub-agents (reuse, simplification, efficiency, altitude) over the branch's changes against a base branch (default main), then offers a fix and review loop. Does not hunt for bugs.	A code-quality pass on any branch; after /review when using the plan, implement, review flow.
pull-request	Detects the Git host, picks a target branch, writes a title and body from the branch commits, and opens a pull or merge request.	The branch is ready to publish.
security-audit	Static, read-only security audit of a diff or the repository. See Security audit.	Before shipping a change, or when assessing unfamiliar code.
fast-iteration	Trial-and-error mode: edits directly, without delegation or routine confirmation, and skips tests and docs; periodically reminds you that you can say "done", then offers a button-up pass (cleanup, tests, docs, full checks) or a discard of your changes.	You want to try small changes quickly and clean up once the direction works.

The workflows in plan, implement, review, simplify, and security-audit dispatch sub-agents, so they work best with delegation enabled. fast-iteration is the exception: it edits directly and does not need delegation. See Sub-agent delegation.

Using skills

Every skill starts disabled in a new interactive session.

Command	Effect
/<skill> [args]	Enables the skill and submits /<skill> [args] as your message. Also switches execution mode: /plan switches to plan, /security-audit keeps the current mode, and every other skill switches to build. See Execution modes.
/skill <name> or /skill +<name>	Enables a skill without sending a message.
/skill -<name>	Disables a skill.
/skills	Lists available skills.
steiner skills	Lists available skills from the command line.

Examples:

/plan add retry support to the HTTP client
/implement .steiner/plans/2026-11-01_http-retry
/simplify develop
/security-audit diff

Selecting /implement or /review from the slash menu, or typing either followed by a space, opens a picker of folders under .steiner/plans/, newest first. Choosing one appends its path to the composer.

A skill change takes effect with your next message. An enabled skill survives compaction; a disabled skill is dropped at the next compaction. See Context management.

Custom skills

A custom skill is a directory containing a SKILL.md file. The directory name is the skill name. Steiner looks in these roots, highest precedence first:

1. <project>/.steiner/skills/<name>/SKILL.md
2. ~/.config/steiner/skills/<name>/SKILL.md
3. ~/.agents/skills/<name>/SKILL.md

When the same name exists in more than one root, the first match wins. Bundled skill names always win: a custom skill with a bundled name is skipped and a warning is logged.

Optional YAML frontmatter supplies the description shown in the slash menu:

---
name: release-notes
description: Draft release notes from merged changes since the last tag.
---

# Release notes

Instructions for the agent...

Without a description, Steiner uses the first line of prose in the file. The skill name always comes from the directory name, not the frontmatter name.

A skill larger than 106496 bytes is truncated with a marker, and Steiner warns with the original size and the cap.