Imported from majiayu000/claude-skill-registry (skills/api/alps/SKILL.md). Install upstream with npx skills add majiayu000/claude-skill-registry --skill alps. Copyright stays with the author.

ALPS Profile Assistant

Generate, validate, and improve ALPS profiles for RESTful API design.

Ideal ALPS Profile

Goal: An ALPS that someone unfamiliar with the app can read and understand.

What Makes a Good ALPS

1. States = What the user sees

   • ProductList - viewing a list of products
   • ProductDetail - viewing one product
   • Cart - viewing cart contents

2. Transitions = What the user does

   • goProductDetail - select a product
   • doAddToCart - add to cart

3. Self-documenting

   • title explains the purpose
   • doc describes behavior and side effects
   • No need to read code to understand

4. No unreachable states

   • Every state has an entry point
   • Orphan states indicate design mistakes

5. Necessary and sufficient

   • No over-abstraction
   • Describes semantics, not implementation
   • No HTTP methods or URLs

What to Avoid

• Mechanical CRUD listings without meaning
• Implementation details leaking in
• States without transitions (can't draw a diagram)
• Excessive documentation nobody reads

How to Use

This skill responds to natural language requests:

Generate ALPS from Natural Language

• "Create an ALPS profile for a blog application"
• "Generate ALPS for an e-commerce cart system"
• "Design an ALPS profile for user authentication"

Validate Existing Profile

• "Validate this ALPS profile" (with file path or content)
• "Check my ALPS file for issues"
• "Review the ALPS profile at docs/api.json"

Get Improvement Suggestions

• "Improve this ALPS profile"
• "Suggest enhancements for my ALPS"
• "How can I make this ALPS better?"

ALPS Structure Reference

Three Layers of ALPS

1. Ontology - Semantic descriptors (data elements)

   • Atomic data fields with type="semantic" (default)
   • Should have id, title, and optionally doc and def (schema.org link)

2. Taxonomy - State descriptors (screens/pages)

   • Composite descriptors containing semantic fields and transitions
   • Represents application states (e.g., HomePage, ProductDetail, Cart)

3. Choreography - Transition descriptors (actions)

   • type="safe" - Read operations (GET)
   • type="unsafe" - Create operations (POST) - not idempotent
   • type="idempotent" - Update/Delete operations (PUT/DELETE)
   • Must have rt (return type) pointing to target state

Naming Conventions

Safe Transition Naming Rule

IMPORTANT: Safe transitions (go*) MUST include the target state name in their id.

• rt="#ProductList" → id must be goProductList (or goToProductList)
• rt="#UserProfile" → id must be goUserProfile (or goToUserProfile)

Invalid examples:

• goStart with rt="#ProductList" - Wrong! Should be goProductList
• goNext with rt="#Checkout" - Wrong! Should be goCheckout

This rule ensures consistency and makes the diagram self-documenting. When a transition has no source state (entry point), it will be displayed as originating from UnknownState in the diagram.

Determining idempotent: PUT vs DELETE

Context clues for AI inference:

PUT (Update) indicators:

• update, edit, modify, change, set, replace
• Example: doUpdateProfile, doEditComment, doSetQuantity

DELETE indicators:

• delete, remove, cancel, clear, destroy
• Example: doDeleteUser, doRemoveFromCart, doCancelOrder

Generation Guidelines

When Creating ALPS from Natural Language

IMPORTANT: Structure the ALPS file in three blocks in this order:

1. Identify Entities (Ontology - Semantic definitions)

   • Extract nouns: user, product, order, cart, etc.
   • Define atomic fields for each entity
   • Add def links to schema.org where applicable
   • Add doc for validation rules, formats, constraints

2. Identify States (Taxonomy - Inclusion relationships)

   • Map user journey: login -> home -> browse -> cart -> checkout
   • Each state contains relevant fields and available transitions
   • Use PascalCase for state names
   • Add doc explaining what user sees and available actions

3. Identify Transitions (Choreography - State transitions)

   • Safe: navigation, viewing, searching (prefix: go)
   • Unsafe: creating new resources (prefix: do)
   • Idempotent: updating or deleting resources (prefix: do)
   • Add doc explaining behavior, side effects, preconditions

4. Add Documentation

   • Every descriptor MUST have a meaningful title
   • Add doc when title alone cannot fully explain the descriptor:
     • Semantic fields: Validation rules, format requirements, constraints, examples
       • Example: {"id": "title", "title": "Title", "doc": {"value": "Article title. Maximum 100 characters."}}
     • States: What user sees, available actions, when this state is shown
       • Example: {"id": "BlogPost", "doc": {"value": "User-created article. Visible to all users after publication."}}
     • Transitions: Behavior, side effects, preconditions, error cases
       • Example: {"id": "doPublishBlogPost", "doc": {"value": "Publish article. Sets publishedAt to current time."}}
   • Use def to link to schema.org definitions for standard concepts
   • Rule of thumb: If someone unfamiliar with the app would ask "what does this do?" or "what format?", add doc

5. Add Tags for Organization

   • Functional area tags: Group by feature domain (e.g., search, product, cart, checkout, order, account, review)
   • Flow tags: Group by user journey with flow- prefix (e.g., flow-purchase, flow-register, flow-return)
   • States and transitions should have both types where applicable
   • Tags are space-separated strings, not arrays
   • Example: A cart-related transition might have "tag": "cart flow-purchase"

6. Add Semantic Descriptors to Transitions

   • Every transition (go/do) should specify its required input parameters as nested descriptors
   • These define what data is needed to perform the action
   • Example:

     {"id": "goProductDetail", "type": "safe", "rt": "#ProductDetail", "tag": "product", "descriptor": [
       {"href": "#productId"}
     ]},
     {"id": "doAddToCart", "type": "unsafe", "rt": "#Cart", "tag": "cart flow-purchase", "descriptor": [
       {"href": "#productId"},
       {"href": "#quantity"},
       {"href": "#selectedVariant"}
     ]}

7. MANDATORY: Validate After Generation

   • After generating ALPS JSON, save it to a temporary file
   • Run asd --validate <file> to validate (outputs JSON per validation-result.json schema)
   • Parse the JSON result and report issues to the user
   • If errors exist, fix them before presenting the final output

Output Format

Generate XML format by default. Use JSON only if explicitly requested.

XML Format (default):

• Use XML comments to mark blocks: <!-- Ontology -->, <!-- Taxonomy -->, <!-- Choreography -->
• One descriptor per line for simple elements
• Multi-line for nested structures
• Clear hierarchical structure makes maintenance easy

<?xml version="1.0" encoding="UTF-8"?>
<alps version="1.0"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:noNamespaceSchemaLocation="https://alps-io.github.io/schemas/alps.xsd">
  <title>Application Title</title>
  <doc>Description of the application</doc>

  <!-- Ontology -->
  <descriptor id="fieldName" title="Human Title">
    <doc>Description</doc>
  </descriptor>
  <descriptor id="otherField" title="Other Field"/>

  <!-- Taxonomy -->
  <descriptor id="StateName" title="State Title">
    <descriptor href="#fieldName"/>
    <descriptor href="#transitionName"/>
  </descriptor>

  <!-- Choreography -->
  <descriptor id="goTargetState" type="safe" rt="#TargetState" title="Go to Target State"/>
  <descriptor id="doAction" type="unsafe" rt="#ResultState" title="Perform Action">
    <descriptor href="#requiredField"/>
  </descriptor>
</alps>

JSON Format (when explicitly requested):

• Simple descriptors (few attributes, no nesting): Write on a single line
• Complex descriptors (with nesting or long doc): Use multiple lines with "descriptor": [ at end of first line
• Block separation: Add ONE blank line between Ontology/Taxonomy/Choreography blocks
• No other blank lines: Keep descriptors within the same block compact

{
  "$schema": "https://alps-io.github.io/schemas/alps.json",
  "alps": {
    "title": "Application Title",
    "doc": {"value": "Description of the application"},
    "descriptor": [
      {"id": "fieldName", "title": "Human Title", "doc": {"value": "Description"}},
      {"id": "otherField", "title": "Other Field"},

      {"id": "StateName", "title": "State Title", "descriptor": [
        {"href": "#fieldName"},
        {"href": "#transitionName"}
      ]},

      {"id": "goTargetState", "type": "safe", "rt": "#TargetState", "title": "Go to Target State"},
      {"id": "doAction", "type": "unsafe", "rt": "#ResultState", "title": "Perform Action", "descriptor": [
        {"href": "#requiredField"}
      ]}
    ]
  }
}

Validation

Use asd --validate <file> to validate ALPS profiles. Output conforms to the validation-result.json schema.

Error Codes (E)

• E001: Missing id or href
• E002: Missing rt on transition
• E003: Invalid type
• E004: Broken reference
• E005: Duplicate id
• E006: Invalid href
• E007: Invalid rt format
• E008: Missing alps property in document
• E009: Descriptor must be an array
• E010: Invalid XML character in descriptor title
• E011: Tag must be a string (space-separated), not an array

Warning Codes (W)

• W001: Missing title
• W002: Safe transition naming (should start with 'go')
• W003: Unsafe/idempotent naming (should start with 'do')
• W004: Orphan descriptor
• W005: Safe transition id does not match rt target (e.g., goStart with rt="#ProductList" should be goProductList)
• W006: Tag contains comma - may be confused with space-separated format

Suggestion Codes (S)

• S001: Missing doc on transition
• S002: Missing ALPS title
• S003: Missing ALPS doc

Example: Blog Application

Input: "Create an ALPS for a simple blog with posts and comments"

Output (XML - default):

<?xml version="1.0" encoding="UTF-8"?>
<alps version="1.0"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:noNamespaceSchemaLocation="https://alps-io.github.io/schemas/alps.xsd">
  <title>Simple Blog</title>
  <doc>ALPS profile for a blog application with posts and comments</doc>

  <!-- Ontology -->
  <descriptor id="postId" title="Post ID" def="https://schema.org/identifier">
    <doc>Unique identifier for blog post</doc>
  </descriptor>
  <descriptor id="title" title="Post Title" def="https://schema.org/headline">
    <doc>Article title. Maximum 100 characters.</doc>
  </descriptor>
  <descriptor id="body" title="Post Body" def="https://schema.org/articleBody">
    <doc>Article content. Markdown format supported.</doc>
  </descriptor>
  <descriptor id="authorName" title="Author Name" def="https://schema.org/author"/>
  <descriptor id="createdAt" title="Created Date" def="https://schema.org/dateCreated">
    <doc>Publication date and time. ISO 8601 format.</doc>
  </descriptor>
  <descriptor id="commentId" title="Comment ID">
    <doc>Unique identifier for comment</doc>
  </descriptor>
  <descriptor id="commentBody" title="Comment Text">
    <doc>Comment content. Maximum 500 characters.</doc>
  </descriptor>

  <!-- Taxonomy -->
  <descriptor id="Home" title="Home Page">
    <doc>Blog home page. Shows navigation to post list.</doc>
    <descriptor href="#goPostList"/>
  </descriptor>
  <descriptor id="PostList" title="Post List">
    <doc>List of blog posts. Shows latest 10 posts with title and author.</doc>
    <descriptor href="#postId"/>
    <descriptor href="#title"/>
    <descriptor href="#authorName"/>
    <descriptor href="#goPostDetail"/>
    <descriptor href="#goHome"/>
  </descriptor>
  <descriptor id="PostDetail" title="Post Detail">
    <doc>Single post view. Shows full content and comments. Allows adding new comments.</doc>
    <descriptor href="#postId"/>
    <descriptor href="#title"/>
    <descriptor href="#body"/>
    <descriptor href="#authorName"/>
    <descriptor href="#createdAt"/>
    <descriptor href="#Comment"/>
    <descriptor href="#goPostList"/>
    <descriptor href="#doCreateComment"/>
  </descriptor>
  <descriptor id="Comment" title="Comment">
    <doc>User comment on a post. Can be deleted by comment author or post author.</doc>
    <descriptor href="#commentId"/>
    <descriptor href="#commentBody"/>
    <descriptor href="#authorName"/>
    <descriptor href="#createdAt"/>
    <descriptor href="#doDeleteComment"/>
  </descriptor>

  <!-- Choreography -->
  <descriptor id="goHome" type="safe" rt="#Home" title="Go to Home">
    <doc>Navigate to blog home page.</doc>
  </descriptor>
  <descriptor id="goPostList" type="safe" rt="#PostList" title="Go to Post List">
    <doc>Display list of blog posts. Shows latest 10 posts.</doc>
  </descriptor>
  <descriptor id="goPostDetail" type="safe" rt="#PostDetail" title="Go to Post Detail">
    <doc>Display full post content with comments.</doc>
    <descriptor href="#postId"/>
  </descriptor>
  <descriptor id="doCreatePost" type="unsafe" rt="#PostDetail" title="Create Post">
    <doc>Create new blog post. Post is immediately published.</doc>
    <descriptor href="#title"/>
    <descriptor href="#body"/>
  </descriptor>
  <descriptor id="doUpdatePost" type="idempotent" rt="#PostDetail" title="Update Post">
    <doc>Update existing post content. Only post author can update.</doc>
    <descriptor href="#postId"/>
    <descriptor href="#title"/>
    <descriptor href="#body"/>
  </descriptor>
  <descriptor id="doDeletePost" type="idempotent" rt="#PostList" title="Delete Post">
    <doc>Delete post and all associated comments. Only post author can delete.</doc>
    <descriptor href="#postId"/>
  </descriptor>
  <descriptor id="doCreateComment" type="unsafe" rt="#PostDetail" title="Add Comment">
    <doc>Add comment to post. Comment is immediately visible.</doc>
    <descriptor href="#postId"/>
    <descriptor href="#commentBody"/>
  </descriptor>
  <descriptor id="doDeleteComment" type="idempotent" rt="#PostDetail" title="Delete Comment">
    <doc>Delete comment. Comment author or post author can delete.</doc>
    <descriptor href="#commentId"/>
  </descriptor>
</alps>

Integration with app-state-diagram

Generated ALPS profiles can be visualized using app-state-diagram:

# Generate HTML diagram
asd profile.json

# Generate with watch mode
asd --watch profile.json

# Generate markdown documentation
asd --mode=markdown profile.json

Advanced Features

Structured Documentation with HTML

For simple descriptions, use plain text in doc.value. When you need structured content (lists, definitions, tables), use HTML format:

{"id": "doCheckout", "type": "unsafe", "rt": "#OrderConfirmation",
 "title": "Complete Checkout",
 "doc": {
   "format": "html",
   "value": "<dl><dt>Behavior</dt><dd>Processes payment, reserves inventory, sends confirmation email</dd><dt>Preconditions</dt><dd>Valid cart with items, payment method configured</dd><dt>Errors</dt><dd>Returns 400 if payment fails or items out of stock</dd></dl>"
 }
}

Format support levels (per ALPS spec):

• text: Required (default if not specified)
• html: Recommended
• markdown: Optional
• asciidoc: Optional

Links to Related Resources

Use link elements to reference external documentation, schemas, or related resources:

{"id": "BlogPost", "def": "https://schema.org/BlogPosting",
 "title": "Blog Post",
 "doc": {"value": "User-created article visible to all after publication"},
 "link": [
   {"rel": "help", "href": "https://example.com/docs/blog-api.html", "title": "Blog API Documentation"},
   {"rel": "related", "href": "https://example.com/schemas/post.json", "title": "JSON Schema"}
 ]
}

Link attributes:

• rel (required): Relationship type - use IANA Link Relations (help, related, profile, etc.)
• href (required): URL to the related resource
• title (optional): Human-readable description of the link
• tag (optional): Classification tags

Tips for Better ALPS

1. Start with user journeys - Map the happy path first, then add alternatives
2. Be consistent - Use the same naming pattern throughout
3. Document transitions - Explain what each action does and when it's available
4. Use schema.org - Link to standard definitions for interoperability
5. Think about errors - Add error states and recovery transitions
6. Consider pagination - List states should support pagination
7. Tag descriptors - Use tag attribute to group related descriptors

References

• ALPS Specification
• Schema.org
• app-state-diagram