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a2ui-create-feature-blueprint

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Provides instructions on how to create a new language-agnostic A2UI Feature Blueprint, ensuring consistency and ease of cross-language implementation.

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How to use this skill

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Source SKILL.md: https://github.com/a2ui-project/a2ui/blob/HEAD/blueprints/skills/a2ui-create-feature-blueprint/SKILL.md

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Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

A2UI Create Feature Blueprint Skill

This skill provides step-by-step instructions on how to design, format, and check in a new A2UI Feature Blueprint inside blueprints/features/ to specify behavioral or protocol changes before implementation.

1. Design Principles for Feature Blueprints

  • Language Agnosticism: Keep the blueprint completely free of language-specific or framework-specific terminology.
  • Generic Protocol Alignment: Reference specific messages, schemas, or JSON pointers as the primary mechanism for interaction.
  • Portability: Design the feature so that it can be implemented cleanly across targeted SDK languages.

2. Step-by-Step Creation Recipe

Step 1: File Naming & Location

  • Target Path: blueprints/features/<feature_name>.blueprint.md
    • <feature_name> must be in snake_case (e.g. dynamic_theming.blueprint.md).
    • Do NOT prefix filenames with a date.
  • Initial Status: All newly created feature blueprints in blueprints/features/ start as optional (unmerged).

Step 2: Define YAML Frontmatter

Every feature blueprint must start with a YAML block containing:

---
feature_name: feature_name # Must match the filename's snake_case name exactly
module_blueprints:
  - a2ui_core # One or more valid module blueprint names affected
dependencies: [] # Optional list of prerequisite feature names
date_added: 2026-07-07 # Date initially authored (YYYY-MM-DD)
---

Step 3: Structure Content

Implement canonical Markdown sections:

  1. # **[Feature Name] Feature Blueprint**
  2. ## **Requirements**
  3. ## **Detailed Description of Changes**
  4. ## **Links**
  5. ## **Test Cases & Conformance**
  6. ## **Implementation Steps**

Step 4: Validate Blueprint

Run the blueprint validator script:

python3 blueprints/validate_blueprints.py