Sections & Field Groups

Sections and field groups are the two halves of mcp-rune’s prompt structure. Sections define the user-facing workflow — how an LLM walks the user through a creation or update flow. Field groups define validation — which fields belong together and what rules apply. They live side by side in every prompt class, and the framework derives field tables, flow diagrams, and per-section docs from both.

This guide is the reference for how the two work together. For the strategy that consumes them (stateless / hybrid / stateful), see the Prompt Creation guide.

Why sections?

Separation of concerns — display structure (sections) vs validation structure (fieldGroups)
Scalability — add new fieldGroups to existing sections without changing the user-facing workflow
Flexibility — multiple fieldGroups can be grouped under one section
Single source of truth — section titles and descriptions defined once

Sections vs FieldGroups

Aspect	Sections	FieldGroups
Purpose	User-facing workflow	Validation & technical organization
Contains	`title`, `description`, `required`, `groups[]`	`fields[]`, `required`, `conditional`, `validateSection`
Used by	`generateFlowDiagramFromConfig()`, `getSections()`	`validateSection()`, `getProgress()`
Granularity	Coarse (user journey)	Fine (field validation)

Defining sections

static sections = {
  basics: {
    title: 'Basic Information',
    description: 'Title and description for the activity',
    required: true,
    groups: ['basics'],
    content: {
      intro: 'The title and description that identify the activity.'
    }
  },
  classification: {
    title: 'Classification',
    description: 'Theme and category for organizing the activity',
    required: true,
    groups: ['classification'],
    content: {
      notes: [
        'Use `find_records(model: "theme")` to find the theme',
        'Use `find_records(model: "category")` to find the category'
      ]
    }
  },
  timing: {
    title: 'Timing',
    description: 'When the activity occurred and how long it lasted',
    required: false,
    groups: ['timing'],
    content: {
      intro: 'When the activity occurred and how long it lasted.'
    }
  }
}

Section content enrichment

Sections support a content property with intro and notes that are automatically rendered in the generated section documentation. Use these to add domain-specific context without writing custom section generator methods.

Property	Type	Description
`content.intro`	`string`	Introductory text rendered at the top of the section, before the field table. Supports full markdown.
`content.notes`	`string[]`	Array of notes rendered as a bullet list after the field table and enum tables.
`askPrompt`	`string`	Custom prompt shown as “Ask the user: …” at the end of the section.

How it works: When allSections() or generateSectionDocumentation() renders a section, it automatically:

Adds content.intro before the field table
Generates the field table from fieldDefinitions
Generates enum tables for any field with enumDescriptions
Adds content.notes as a bullet list
Adds the askPrompt prompt

Key principle: Prefer content.intro and content.notes over custom generateSectionXDocumentation() methods. This keeps domain content in configuration and lets the framework auto-generate field tables and enum tables alongside it.

Per-group content (multi-group sections)

When a section contains multiple groups (groups: ['group_a', 'group_b']), each group can have its own context (display name) and content: { intro, notes } defined in fieldGroups. The generator renders each group as a ### sub-section with its own field table.

Key behaviors:

context defaults to title-cased group name if absent (snake_case_name → “Snake Case Name”)
Groups without content render just a heading and field table (no intro/notes)
Single-group sections are completely unchanged — they read from section.content as before
context and content on fieldGroups are ignored by StatefulStrategy (no breaking changes to validation)

Defining fieldGroups (simplified)

With sections as first-class citizens, fieldGroups focus on validation:

static fieldGroups = {
  basics: {
    fields: ['title', 'description'],
    context: 'Basic Information',
    required: true,
    description: 'Title and description for the activity'
  },
  classification: {
    fields: ['theme_id', 'category_id'],
    context: 'Classification',
    required: true,
    description: 'Theme and category for organizing the activity'
  }
}

Section helper methods

BasePrompt provides helper methods for working with sections:

Method	Description
`getSectionFields(sectionName)`	Get all field definitions for a section (across all its groups)
`getSectionFieldNames(sectionName)`	Get all field names for a section
`getSectionForGroup(groupName)`	Reverse lookup: find which section a group belongs to
`getSectionNumber(sectionName)`	Get 1-based section number for display

Flow diagram generation

The generateFlowDiagramFromConfig() method uses sections to create a compact flow overview:

// Auto-generated from sections config
**Flow:** (● required, ○ optional)
● 1. BASIC INFORMATION - title, description
● 2. CLASSIFICATION - theme_id, category_id
○ 3. TIMING - started_at, ended_at, duration_minutes
○ 4. RESOURCES - book_ids, notes_generated
● 5. SUMMARY