Skills

A Ren skill is a reusable, versioned capability an agent can invoke: a discrete ability like “summarize a document,” “query a CRM,” or “run a security scan.”

Ren skills vs. agent commands

A coding agent like Claude Code or opencode may have its own slash commands or skills: local shortcuts defined in a config file, with no versioning, sharing, or credential management. A Ren skill is different: it lives on the server, is versioned independently, can be shared across agents and organizations, and declares the credentials it needs. In these docs, “skill” always means the Ren primitive.

What a skill contains

Every skill bundles three things:

1. Interface: the inputs it accepts and outputs it produces, so an agent knows what to pass and what to expect.
2. Instructions: the prose or code that runs when the skill is invoked.
3. Required credentials: the secrets it needs at runtime, supplied from a vault so the skill never handles raw secrets.

The SKILL.md manifest

Every skill has a SKILL.md file at its root. Its frontmatter declares:

• name: a hyphen-case identifier, 1 to 64 characters (e.g. search-crm).
• description: a human-readable summary.
• license (optional): the license the skill is published under.
• allowed-tools (optional): tools the skill is permitted to use.

The body holds the skill’s instructions: the guidance the agent follows while the skill runs.

Versions

Skills use semver, starting at 0.0.1. Each version carries its own source files, supplied either as an uploaded archive or as a reference into a Git repository (a repo URL, optional ref, and optional sub-path).

When an agent attaches a skill, it can pin a specific version or track the latest. Pinning gives stability; tracking latest means updates apply automatically. Choose based on how sensitive the workflow is to changes.

Required credentials

A skill declares the secrets it needs as named slots (for example SALESFORCE_API_KEY), each with an optional description. These are a contract, not the secret itself. When you attach the skill to an agent, Ren checks the agent’s vault for every declared credential and fails fast with a clear message if any are missing.

Scopes and publishing

A skill has a scope: private (just you), org (your organization), or public (the registry). Publishing is one-way: a public skill can’t be unpublished, only deprecated, because other agents may depend on it.

Skills, agents, and MCPs

	Skill	Agent	MCP
Role	What the agent does	Who reasons and orchestrates	What the agent can access
Reasoning loop
System prompt
Stateful
Invoked by	An agent	A user or trigger	An agent (tool call)
Schedulable

Skill

Role

What the agent does

Reasoning loop

System prompt

Stateful

Invoked by

An agent

Schedulable

Agent

Role

Who reasons and orchestrates

Reasoning loop

System prompt

Stateful

Invoked by

A user or trigger

Schedulable

MCP

Role

What the agent can access

Reasoning loop

System prompt

Stateful

Invoked by

An agent (tool call)

Schedulable

An agent decides what to do. Skills are the actions it can take: self-contained procedures it carries and runs. MCPs are the external services it can reach. An agent might use a skill to “draft a pull request” and an MCP to “read from GitHub”: the skill provides the procedure, the MCP provides the access.

CLI commands

ren skills create ./my-skill --name "My skill"   # upload a folder containing SKILL.md
ren skills versions create <skillId> ./my-skill  # add a version from a folder
ren skills search                                # search the registry
ren skills list                                  # list skills visible to you

For the full reference, see the CLI docs. For a walkthrough, see Create a skill.