Vibecosystem user-story-generator

User story generation - INVEST criteria, acceptance criteria (BDD/Given-When-Then), story mapping, epic decomposition, edge case stories, NFR stories

install
source · Clone the upstream repo
git clone https://github.com/vibeeval/vibecosystem
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/vibeeval/vibecosystem "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/user-story-generator" ~/.claude/skills/vibeeval-vibecosystem-user-story-generator && rm -rf "$T"
manifest: skills/user-story-generator/SKILL.md
source content

User Story Generator

User Story Format

Standard Format

As a [role/persona],
I want [goal/feature],
so that [benefit/value].

Extended Format (with context)

As a [role/persona],
In the context of [situation/scenario],
I want [goal/feature],
so that [benefit/value].

Examples

As a new user,
I want to sign up with my email and password,
so that I can create an account and start using the service.

As a team admin,
In the context of onboarding a new team member,
I want to invite users via email,
so that they can join the workspace without manual account creation.

As an API consumer,
I want to authenticate with an API key,
so that I can securely access resources programmatically.

INVEST Criteria

Checklist

CriteriaQuestionExample (Iyi)Example (Kotu)
IndependentCan it be developed without other stories?"User can reset password""User can reset password (requires email service story)"
NegotiableIs implementation flexible?"User can search products""User searches with Elasticsearch 8.x using fuzzy match"
ValuableDoes it deliver user/business value?"User can export data as CSV""Refactor database schema"
EstimableCan the team estimate it?"User can upload a profile photo""Improve system performance"
SmallCan it be done in one sprint?"User can add item to cart""User can complete entire checkout flow"
TestableCan we verify it's done?"Login with wrong password shows error message""System should be user-friendly"

INVEST Validation

## Story: [story title]

### INVEST Check
- [ ] **Independent:** No hard dependency on other stories
- [ ] **Negotiable:** Multiple implementation approaches possible
- [ ] **Valuable:** Clear end-user or business value
- [ ] **Estimable:** Team can estimate within 1 story point range
- [ ] **Small:** Fits within a single sprint
- [ ] **Testable:** Clear pass/fail acceptance criteria

Acceptance Criteria (Given-When-Then / BDD)

Format

Scenario: [descriptive scenario name]
  Given [precondition / initial state]
  And [additional precondition if needed]
  When [action / trigger]
  And [additional action if needed]
  Then [expected result / assertion]
  And [additional assertion if needed]
  But [exception / negative assertion if needed]

Complete Example

Feature: Shopping Cart

  Scenario: Add item to empty cart
    Given the user is logged in
    And the cart is empty
    When the user clicks "Add to Cart" on a product
    Then the cart should contain 1 item
    And the cart badge should show "1"
    And the cart total should equal the product price

  Scenario: Add same item twice
    Given the user has 1 unit of "Widget A" in the cart
    When the user clicks "Add to Cart" on "Widget A" again
    Then the cart should show 2 units of "Widget A"
    And the cart total should be 2x the unit price
    But a duplicate line item should NOT be created

  Scenario: Add item when not logged in
    Given the user is not logged in
    When the user clicks "Add to Cart"
    Then the item should be saved to a guest cart (cookie-based)
    And the user should NOT be redirected to login
    And the guest cart should merge on login

  Scenario: Add out-of-stock item
    Given the product "Widget B" has 0 stock
    When the user views "Widget B"
    Then the "Add to Cart" button should be disabled
    And a "Notify me" option should be shown

Acceptance Criteria Anti-Patterns

Anti-PatternNeden YanlisDogru Yol
"Should work properly"TanimsizSpecify exact expected behavior
Implementation detailsCozumu kisitlar"Data persists" not "saves to PostgreSQL"
Missing error casesIncomplete specAdd scenarios for every failure mode
Too many scenarios (10+)Story too bigSplit the story
No performance criteriaNFR eksikAdd "within 2 seconds" where needed
Duplicate of another storyRedundancyReference, don't repeat

Story Mapping

Story Map Structure

               User Journey (left to right)
               ─────────────────────────────────────
Activities:    | Discovery  | Purchase   | Support  |
               ─────────────────────────────────────
User Tasks:    | Search     | Add to     | Contact  |
               | Browse     | Cart       | Support  |
               | Compare    | Checkout   | Return   |
               |            | Pay        | Review   |
               ─────────────────────────────────────
Release 1:     | Basic      | Cart +     | Email    |
(MVP)          | search     | Checkout   | form     |
               ─────────────────────────────────────
Release 2:     | Filters    | Saved      | Live     |
               | Sort       | cards      | chat     |
               | Compare    | Wishlist   | FAQ      |
               ─────────────────────────────────────
Release 3:     | AI search  | Subscr.    | Chatbot  |
               | Reco's     | Gift cards | Ticket   |

Story Map Template

## Story Map: [Product/Feature Name]

### Backbone (Activities - user's high-level goals)
1. [Activity 1]: [description]
2. [Activity 2]: [description]
3. [Activity 3]: [description]

### Walking Skeleton (minimum viable flow)
| Activity | Minimum Story | Priority |
|----------|--------------|----------|
| [Act 1] | [simplest version] | Must |
| [Act 2] | [simplest version] | Must |
| [Act 3] | [simplest version] | Must |

### Release Slices
| Release | Scope | Theme |
|---------|-------|-------|
| R1 (MVP) | Walking skeleton | "It works" |
| R2 | Enhanced UX | "It's pleasant" |
| R3 | Advanced features | "It's powerful" |

Epic Decomposition

Epic to Stories Workflow

EPIC: User Authentication System
├── STORY: Email/password registration
├── STORY: Email verification
├── STORY: Login with email/password
├── STORY: Password reset via email
├── STORY: Social login (Google)
├── STORY: Social login (GitHub)
├── STORY: MFA setup (TOTP)
├── STORY: MFA verification on login
├── STORY: Session management (logout, expire)
└── STORY: Account deletion

Decomposition Strategies

StrategyWhen to UseExample
By workflow stepSequential processesCheckout: cart -> address -> payment -> confirmation
By data variationMultiple input typesImport: CSV upload, API sync, manual entry
By user roleMulti-role featuresDashboard: admin view, manager view, user view
By CRUD operationData managementProducts: create, read, update, delete
By business ruleComplex logicPricing: base price, discounts, tax, shipping
By platformMulti-platformNotifications: email, push, SMS, in-app
By performanceOptimization layersSearch: basic search, filters, autocomplete, facets

Decomposition Template

## Epic: [Epic Name]

**Business Value:** [neden onemli]
**Target Persona:** [kim icin]
**Size Estimate:** [S/M/L/XL]

### Stories

| # | Story | Priority | Size | Sprint |
|---|-------|----------|------|--------|
| 1 | As a [role], I want [X], so that [Y] | Must | S | 1 |
| 2 | As a [role], I want [X], so that [Y] | Must | M | 1 |
| 3 | As a [role], I want [X], so that [Y] | Should | S | 2 |
| 4 | As a [role], I want [X], so that [Y] | Could | M | 3 |

### Dependencies
- Story 2 depends on Story 1
- Story 4 can be done in parallel with Story 3

### Definition of Done (Epic Level)
- [ ] All Must stories completed
- [ ] Integration tests passing
- [ ] Documentation updated
- [ ] Stakeholder demo completed

Decomposition Anti-Patterns

Anti-PatternNeden YanlisDogru Yol
Technical decomposition"Create DB schema" has no user valueSplit by user-facing behavior
Too small (< 1 hour)Overhead > valueCombine related micro-tasks
Too large (> 1 sprint)Unestimable, riskyDecompose further
Horizontal slicing"Build all APIs, then all UI"Vertical slice (API + UI for one feature)

Edge Case Stories

Common Edge Cases

## Edge Case Stories for [Feature]

### Empty State
As a new user,
When I have no [items/data/history],
I want to see a helpful empty state with a clear CTA,
so that I know how to get started.

### Error Recovery
As a user,
When an operation fails (network error, timeout, server error),
I want to see a clear error message with a retry option,
so that I can recover without losing my work.

### Boundary Values
As a user,
When I enter the maximum allowed value (e.g., 10,000 characters in a text field),
I want to see a character counter and graceful truncation,
so that I know my limits before submitting.

### Concurrent Access
As a user,
When another user edits the same resource simultaneously,
I want to be notified of the conflict,
so that I don't accidentally overwrite their changes.

### Offline / Slow Connection
As a mobile user,
When I lose network connectivity,
I want my pending actions to be queued and synced when back online,
so that I don't lose my work.

### Permission Denied
As a user without admin privileges,
When I try to access an admin-only feature,
I want to see a clear message explaining why access is denied,
so that I can request access if needed.

### Data Migration
As an existing user,
When the system migrates to a new version,
I want my existing data to be preserved and correctly mapped,
so that I don't lose any information.

Edge Case Discovery Checklist

  • What if the input is empty?
  • What if the input is at maximum length?
  • What if the input contains special characters / unicode?
  • What if the user double-clicks / double-submits?
  • What if the network fails mid-operation?
  • What if the user has no permission?
  • What if the data doesn't exist (404)?
  • What if there are concurrent modifications?
  • What if the browser is resized / mobile view?
  • What if the user navigates away mid-process?
  • What if the session expires during an action?
  • What if the third-party service is down?

Non-Functional Requirement Stories

Performance

As a user,
I want the dashboard to load within 2 seconds,
so that I can quickly access my data without frustration.

Acceptance Criteria:
- Given normal network conditions (4G+)
- When the user navigates to the dashboard
- Then the page is fully interactive within 2 seconds
- And the Largest Contentful Paint (LCP) is < 2.5s
- And the First Input Delay (FID) is < 100ms

Security

As a security-conscious user,
I want my session to expire after 30 minutes of inactivity,
so that my account is protected if I forget to log out.

Acceptance Criteria:
- Given the user has been inactive for 30 minutes
- When the user tries to perform an action
- Then the user is redirected to the login page
- And a "Session expired" message is shown
- And no sensitive data remains in the browser

Accessibility

As a user with visual impairment,
I want all form fields to have proper labels and error announcements,
so that I can use the application with a screen reader.

Acceptance Criteria:
- Given all form fields have associated labels (aria-label or <label>)
- When a validation error occurs
- Then the error is announced by the screen reader (aria-live)
- And focus moves to the first invalid field
- And color is not the only indicator of error state

Scalability

As a system,
I need to handle 10,000 concurrent users without degradation,
so that the service remains reliable during peak usage.

Acceptance Criteria:
- Given 10,000 concurrent users
- When performing standard operations
- Then response time remains < 500ms (p95)
- And error rate stays < 0.1%
- And CPU usage stays < 80%

Reliability

As a user,
I want my data changes to be saved even if the server crashes,
so that I never lose my work.

Acceptance Criteria:
- Given the user submits a form
- When the server acknowledges the request
- Then the data is persisted to durable storage
- And a power failure does not result in data loss
- And transactions are ACID-compliant

Story Quality Checklist

Before Sprint Planning

  • Story follows "As a... I want... so that..." format
  • INVEST criteria all met
  • Acceptance criteria written in Given-When-Then
  • Happy path + at least 2 error scenarios covered
  • Size is estimable (team agrees on story points)
  • No technical jargon (understandable by non-devs)
  • Dependencies identified and resolved
  • Design/wireframe attached if UI story
  • Edge cases identified
  • NFR implications noted

Common Story Smells

SmellSymptomFix
Too vague"As a user, I want a better experience"Be specific about what "better" means
Too technical"As a developer, I want to refactor the DB"Reframe as user value
Too largeTeam can't estimate confidentlyDecompose into smaller stories
No value"Create config file"Attach to a user-facing story
Hidden dependency"Requires API not built yet"Make dependency explicit, plan accordingly
Gold plating15 acceptance criteriaSplit into multiple stories