/skills - Anthropic Skills API

Feature	Supported
Cost Tracking	✅
Logging	✅
Load Balancing	✅
Supported Providers	`anthropic`

tip

LiteLLM follows the Anthropic Skills API for creating, managing, and using reusable AI capabilities.

LiteLLM Python SDK Usage

Quick Start - Create a Skill

create_skill.py
from litellm import create_skill
import zipfile
import os

# Create a SKILL.md file
skill_content = """---
name: test-skill
description: A custom skill for data analysis
---

# Test Skill

This skill helps with data analysis tasks.
"""

# Create skill directory and SKILL.md
os.makedirs("test-skill", exist_ok=True)
with open("test-skill/SKILL.md", "w") as f:
    f.write(skill_content)

# Create a zip file
with zipfile.ZipFile("test-skill.zip", "w") as zipf:
    zipf.write("test-skill/SKILL.md", "test-skill/SKILL.md")

# Create the skill
response = create_skill(
    display_title="My Custom Skill",
    files=[open("test-skill.zip", "rb")],
    custom_llm_provider="anthropic",
    api_key="sk-ant-..."
)

print(f"Skill created: {response.id}")

List Skills

list_skills.py
from litellm import list_skills

response = list_skills(
    custom_llm_provider="anthropic",
    api_key="sk-ant-...",
    limit=20
)

for skill in response.data:
    print(f"{skill.display_title}: {skill.id}")

Get Skill Details

get_skill.py
from litellm import get_skill

skill = get_skill(
    skill_id="skill_01...",
    custom_llm_provider="anthropic",
    api_key="sk-ant-..."
)

print(f"Skill: {skill.display_title}")
print(f"Description: {skill.description}")

Delete a Skill

delete_skill.py
from litellm import delete_skill

response = delete_skill(
    skill_id="skill_01...",
    custom_llm_provider="anthropic",
    api_key="sk-ant-..."
)

print(f"Deleted: {response.id}")

Async Usage

async_skills.py
from litellm import acreate_skill, alist_skills, aget_skill, adelete_skill
import asyncio

async def manage_skills():
    # Create skill
    with open("test-skill.zip", "rb") as f:
        skill = await acreate_skill(
            display_title="My Async Skill",
            files=[f],
            custom_llm_provider="anthropic",
            api_key="sk-ant-..."
        )
    
    # List skills
    skills = await alist_skills(
        custom_llm_provider="anthropic",
        api_key="sk-ant-..."
    )
    
    # Get skill
    skill_detail = await aget_skill(
        skill_id=skill.id,
        custom_llm_provider="anthropic",
        api_key="sk-ant-..."
    )
    
    # Delete skill (if no versions exist)
    # await adelete_skill(
    #     skill_id=skill.id,
    #     custom_llm_provider="anthropic",
    #     api_key="sk-ant-..."
    # )

asyncio.run(manage_skills())

LiteLLM Proxy Usage

LiteLLM provides Anthropic-compatible /skills endpoints for managing skills.

Authentication

There are two ways to authenticate Skills API requests:

Option 1: Use Default ANTHROPIC_API_KEY

Set the ANTHROPIC_API_KEY environment variable. Requests without a model parameter will use this default key.

config.yaml
# No model_list needed - uses env var
# ANTHROPIC_API_KEY=sk-ant-...

# Request will use ANTHROPIC_API_KEY from environment
curl "http://0.0.0.0:4000/v1/skills?beta=true" \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

Option 2: Specify Model for Credential Selection

Define multiple models in your config and use the model parameter to specify which credentials to use.

config.yaml
model_list:
  - model_name: claude-sonnet
    litellm_params:
      model: anthropic/claude-3-5-sonnet-20241022
      api_key: os.environ/ANTHROPIC_API_KEY

Start litellm

litellm --config /path/to/config.yaml

# RUNNING on http://0.0.0.0:4000

Basic Usage

All examples below work with either authentication option (default env key or model-based routing).

Create Skill

You can upload either a ZIP file or directly upload the SKILL.md file:

Option 1: Upload ZIP file

create_skill_zip.sh
curl "http://0.0.0.0:4000/v1/skills?beta=true" \
  -X POST \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02" \
  -F "display_title=My Skill" \
  -F "files[]=@test-skill.zip"

Option 2: Upload SKILL.md directly

create_skill_md.sh
curl "http://0.0.0.0:4000/v1/skills?beta=true" \
  -X POST \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02" \
  -F "display_title=My Skill" \
  -F "files[]=@test-skill/SKILL.md;filename=test-skill/SKILL.md"

List Skills

list_skills.sh
curl "http://0.0.0.0:4000/v1/skills?beta=true" \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

Get Skill

get_skill.sh
curl "http://0.0.0.0:4000/v1/skills/skill_01abc?beta=true" \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

Delete Skill

delete_skill.sh
curl "http://0.0.0.0:4000/v1/skills/skill_01abc?beta=true" \
  -X DELETE \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

Model-Based Routing (Multi-Account)

If you have multiple Anthropic accounts, you can use model-based routing to specify which account to use:

config.yaml
model_list:
  - model_name: claude-team-a
    litellm_params:
      model: anthropic/claude-3-5-sonnet-20241022
      api_key: os.environ/ANTHROPIC_API_KEY_TEAM_A
  
  - model_name: claude-team-b
    litellm_params:
      model: anthropic/claude-3-5-sonnet-20241022
      api_key: os.environ/ANTHROPIC_API_KEY_TEAM_B

Then route to specific accounts using the model parameter:

Create Skill with Routing

create_with_routing.sh
# Route to Team A - using ZIP file
curl "http://0.0.0.0:4000/v1/skills?beta=true" \
  -X POST \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02" \
  -F "model=claude-team-a" \
  -F "display_title=Team A Skill" \
  -F "files[]=@test-skill.zip"

# Route to Team B - using direct SKILL.md upload
curl "http://0.0.0.0:4000/v1/skills?beta=true" \
  -X POST \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02" \
  -F "model=claude-team-b" \
  -F "display_title=Team B Skill" \
  -F "files[]=@test-skill/SKILL.md;filename=test-skill/SKILL.md"

List Skills with Routing

list_with_routing.sh
# List Team A skills
curl "http://0.0.0.0:4000/v1/skills?beta=true&model=claude-team-a" \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

# List Team B skills
curl "http://0.0.0.0:4000/v1/skills?beta=true&model=claude-team-b" \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

Get Skill with Routing

get_with_routing.sh
# Get skill from Team A
curl "http://0.0.0.0:4000/v1/skills/skill_01abc?beta=true&model=claude-team-a" \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

# Get skill from Team B
curl "http://0.0.0.0:4000/v1/skills/skill_01xyz?beta=true&model=claude-team-b" \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

Delete Skill with Routing

delete_with_routing.sh
# Delete skill from Team A
curl "http://0.0.0.0:4000/v1/skills/skill_01abc?beta=true&model=claude-team-a" \
  -X DELETE \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

# Delete skill from Team B
curl "http://0.0.0.0:4000/v1/skills/skill_01xyz?beta=true&model=claude-team-b" \
  -X DELETE \
  -H "X-Api-Key: sk-1234" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: skills-2025-10-02"

SKILL.md Format

Skills require a SKILL.md file with YAML frontmatter:

SKILL.md
---
name: test-skill
description: A brief description of what this skill does
license: MIT
allowed-tools:
  - computer_20250124
  - text_editor_20250124
---

# Test Skill

Detailed instructions for Claude on how to use this skill.

## Usage

Examples and best practices...

YAML Frontmatter Requirements

Field	Required	Description
`name`	Yes	Skill identifier (lowercase, numbers, hyphens only). Must match the directory name.
`description`	Yes	Brief description of the skill
`license`	No	License type (e.g., MIT, Apache-2.0)
`allowed-tools`	No	List of Claude tools this skill can use
`metadata`	No	Additional custom metadata

Important: The name field must exactly match your skill directory name. For example, if your directory is test-skill, the frontmatter must have name: test-skill.

File Structure

Option 1: ZIP file structure

Skills must be packaged with a top-level directory matching the skill name:

test-skill.zip
└── test-skill/         # Top-level folder (name must match skill name in SKILL.md)
    └── SKILL.md        # Required skill definition file

All files must be in the same top-level directory, and SKILL.md must be at the root of that directory.

Option 2: Direct SKILL.md upload

When uploading SKILL.md directly (without creating a ZIP), you must include the skill directory path in the filename parameter to preserve the required structure:

# The filename parameter must include the skill directory path
-F "files[]=@test-skill/SKILL.md;filename=test-skill/SKILL.md"

This tells the API that SKILL.md belongs to the test-skill directory.

Important Requirements:

The folder name (in ZIP or filename path) must exactly match the name field in SKILL.md frontmatter
SKILL.md must be in the root of the skill directory (not in a subdirectory)
All additional files must be in the same skill directory

Response Format

Skill Object

{
  "id": "skill_01abc123",
  "type": "skill",
  "name": "my-skill",
  "display_title": "My Custom Skill",
  "description": "A brief description",
  "created_at": "2025-01-15T10:30:00.000Z",
  "updated_at": "2025-01-15T10:30:00.000Z",
  "latest_version_id": "skillver_01xyz789"
}

List Skills Response

{
  "data": [
    {
      "id": "skill_01abc",
      "type": "skill",
      "name": "skill-one",
      "display_title": "Skill One",
      "description": "First skill"
    },
    {
      "id": "skill_02def",
      "type": "skill",
      "name": "skill-two",
      "display_title": "Skill Two",
      "description": "Second skill"
    }
  ],
  "has_more": false,
  "first_id": "skill_01abc",
  "last_id": "skill_02def"
}

Supported Providers

Provider	Link to Usage
Anthropic	Usage

LiteLLM Python SDK Usage​

Quick Start - Create a Skill​

List Skills​

Get Skill Details​

Delete a Skill​

Async Usage​

LiteLLM Proxy Usage​

Authentication​

Basic Usage​

Create Skill​

List Skills​

Get Skill​

Delete Skill​

Model-Based Routing (Multi-Account)​

SKILL.md Format​

YAML Frontmatter Requirements​

File Structure​

Response Format​

Skill Object​

List Skills Response​

Supported Providers​

LiteLLM Python SDK Usage

Quick Start - Create a Skill

List Skills

Get Skill Details

Delete a Skill

Async Usage

LiteLLM Proxy Usage

Authentication

Basic Usage

Create Skill

List Skills

Get Skill

Delete Skill

Model-Based Routing (Multi-Account)

SKILL.md Format

YAML Frontmatter Requirements

File Structure

Response Format

Skill Object

List Skills Response

Supported Providers