---
sidebar_position: 2
title: "Skills System"
description: "On-demand knowledge documents — progressive disclosure, agent-managed skills, and the Skills Hub"
---

# Skills System

Skills are on-demand knowledge documents the agent can load when needed. They follow a **progressive disclosure** pattern to minimize token usage and are compatible with the [agentskills.io](https://agentskills.io/specification) open standard.

All skills live in **`~/.hermes/skills/`** — a single directory that serves as the source of truth. On fresh install, bundled skills are copied from the repo. Hub-installed and agent-created skills also go here. The agent can modify or delete any skill.

## Using Skills

Every installed skill is automatically available as a slash command:

```bash
# In the CLI or any messaging platform:
/gif-search funny cats
/axolotl help me fine-tune Llama 3 on my dataset
/github-pr-workflow create a PR for the auth refactor

# Just the skill name loads it and lets the agent ask what you need:
/excalidraw
```

You can also interact with skills through natural conversation:

```bash
hermes chat --toolsets skills -q "What skills do you have?"
hermes chat --toolsets skills -q "Show me the axolotl skill"
```

## Progressive Disclosure

Skills use a token-efficient loading pattern:

```
Level 0: skills_list()           → [{name, description, category}, ...]   (~3k tokens)
Level 1: skill_view(name)        → Full content + metadata       (varies)
Level 2: skill_view(name, path)  → Specific reference file       (varies)
```

The agent only loads the full skill content when it actually needs it.

## SKILL.md Format

```markdown
---
name: my-skill
description: Brief description of what this skill does
version: 1.0.0
platforms: [macos, linux]     # Optional — restrict to specific OS platforms
metadata:
  hermes:
    tags: [python, automation]
    category: devops
    fallback_for_toolsets: [web]    # Optional — conditional activation (see below)
    requires_toolsets: [terminal]   # Optional — conditional activation (see below)
---

# Skill Title

## When to Use
Trigger conditions for this skill.

## Procedure
1. Step one
2. Step two

## Pitfalls
- Known failure modes and fixes

## Verification
How to confirm it worked.
```

### Platform-Specific Skills

Skills can restrict themselves to specific operating systems using the `platforms` field:

| Value | Matches |
|-------|---------|
| `macos` | macOS (Darwin) |
| `linux` | Linux |
| `windows` | Windows |

```yaml
platforms: [macos]            # macOS only (e.g., iMessage, Apple Reminders, FindMy)
platforms: [macos, linux]     # macOS and Linux
```

When set, the skill is automatically hidden from the system prompt, `skills_list()`, and slash commands on incompatible platforms. If omitted, the skill loads on all platforms.

### Conditional Activation (Fallback Skills)

Skills can automatically show or hide themselves based on which tools are available in the current session. This is most useful for **fallback skills** — free or local alternatives that should only appear when a premium tool is unavailable.

```yaml
metadata:
  hermes:
    fallback_for_toolsets: [web]      # Show ONLY when these toolsets are unavailable
    requires_toolsets: [terminal]     # Show ONLY when these toolsets are available
    fallback_for_tools: [web_search]  # Show ONLY when these specific tools are unavailable
    requires_tools: [terminal]        # Show ONLY when these specific tools are available
```

| Field | Behavior |
|-------|----------|
| `fallback_for_toolsets` | Skill is **hidden** when the listed toolsets are available. Shown when they're missing. |
| `fallback_for_tools` | Same, but checks individual tools instead of toolsets. |
| `requires_toolsets` | Skill is **hidden** when the listed toolsets are unavailable. Shown when they're present. |
| `requires_tools` | Same, but checks individual tools. |

**Example:** The built-in `duckduckgo-search` skill uses `fallback_for_toolsets: [web]`. When you have `FIRECRAWL_API_KEY` set, the web toolset is available and the agent uses `web_search` — the DuckDuckGo skill stays hidden. If the API key is missing, the web toolset is unavailable and the DuckDuckGo skill automatically appears as a fallback.

Skills without any conditional fields behave exactly as before — they're always shown.

## Secure Setup on Load

Skills can declare required environment variables without disappearing from discovery:

```yaml
required_environment_variables:
  - name: TENOR_API_KEY
    prompt: Tenor API key
    help: Get a key from https://developers.google.com/tenor
    required_for: full functionality
```

When a missing value is encountered, Hermes asks for it securely only when the skill is actually loaded in the local CLI. You can skip setup and keep using the skill. Messaging surfaces never ask for secrets in chat — they tell you to use `hermes setup` or `~/.hermes/.env` locally instead.

## Skill Directory Structure

```
~/.hermes/skills/                  # Single source of truth
├── mlops/                         # Category directory
│   ├── axolotl/
│   │   ├── SKILL.md               # Main instructions (required)
│   │   ├── references/            # Additional docs
│   │   ├── templates/             # Output formats
│   │   └── assets/                # Supplementary files
│   └── vllm/
│       └── SKILL.md
├── devops/
│   └── deploy-k8s/                # Agent-created skill
│       ├── SKILL.md
│       └── references/
├── .hub/                          # Skills Hub state
│   ├── lock.json
│   ├── quarantine/
│   └── audit.log
└── .bundled_manifest              # Tracks seeded bundled skills
```

## Agent-Managed Skills (skill_manage tool)

The agent can create, update, and delete its own skills via the `skill_manage` tool. This is the agent's **procedural memory** — when it figures out a non-trivial workflow, it saves the approach as a skill for future reuse.

### When the Agent Creates Skills

- After completing a complex task (5+ tool calls) successfully
- When it hit errors or dead ends and found the working path
- When the user corrected its approach
- When it discovered a non-trivial workflow

### Actions

| Action | Use for | Key params |
|--------|---------|------------|
| `create` | New skill from scratch | `name`, `content` (full SKILL.md), optional `category` |
| `patch` | Targeted fixes (preferred) | `name`, `old_string`, `new_string` |
| `edit` | Major structural rewrites | `name`, `content` (full SKILL.md replacement) |
| `delete` | Remove a skill entirely | `name` |
| `write_file` | Add/update supporting files | `name`, `file_path`, `file_content` |
| `remove_file` | Remove a supporting file | `name`, `file_path` |

:::tip
The `patch` action is preferred for updates — it's more token-efficient than `edit` because only the changed text appears in the tool call.
:::

## Skills Hub

Browse, search, install, and manage skills from online registries and official optional skills:

```bash
hermes skills browse                     # Browse all hub skills (official first)
hermes skills browse --source official   # Browse only official optional skills
hermes skills search kubernetes          # Search all sources
hermes skills install openai/skills/k8s  # Install with security scan
hermes skills inspect openai/skills/k8s  # Preview before installing
hermes skills list --source hub          # List hub-installed skills
hermes skills audit                      # Re-scan all hub skills
hermes skills uninstall k8s              # Remove a hub skill
hermes skills publish skills/my-skill --to github --repo owner/repo
hermes skills snapshot export setup.json # Export skill config
hermes skills tap add myorg/skills-repo  # Add a custom source
```

All hub-installed skills go through a **security scanner** that checks for data exfiltration, prompt injection, destructive commands, and other threats.

### Trust Levels

| Level | Source | Policy |
|-------|--------|--------|
| `builtin` | Ships with Hermes | Always trusted |
| `official` | `optional-skills/` in the repo | Builtin trust, no third-party warning |
| `trusted` | openai/skills, anthropics/skills | Trusted sources |
| `community` | Everything else | Any findings = blocked unless `--force` |

### Slash Commands (Inside Chat)

All the same commands work with `/skills` prefix:

```
/skills browse
/skills search kubernetes
/skills install openai/skills/skill-creator
/skills list
```
