Generate project-specific rules from Product Requirements Documents.

When to Use This Skill

Use this skill when... Use alternative when...

Need to generate rules from existing PRDs Use /blueprint:rules to manually create/edit rules

Want path-scoped rules for specific file types Use /blueprint:claude-md for general project instructions

Automating rule creation from requirements Writing custom rules without PRD reference

Extracting architecture/testing patterns from PRDs Need to create one-off rules for specific contexts

Rules are generated to .claude/rules/ directory. Rules with paths frontmatter are loaded conditionally when working on matching files.

Prerequisites:

• docs/prds/ directory exists

• At least one PRD file in docs/prds/

Steps:

Find and read all PRDs:

• Use Glob to find all .md files in docs/prds/

• Read each PRD file

• If no PRDs found, report error and suggest writing PRDs first

Check for existing generated rules:

ls .claude/rules/ 2>/dev/null

• If rules exist, check manifest for content hashes

• Compare current content hash vs stored hash

• If modified, offer options: overwrite, skip, or backup

Analyze PRDs and extract (aggregated from all PRDs):

Architecture Patterns:

• Project structure and organization

• Architectural style (MVC, layered, hexagonal, etc.)

• Design patterns

• Dependency injection approach

• Error handling strategy

• Code organization conventions

• Integration patterns

Testing Strategies:

• TDD workflow requirements

• Test types (unit, integration, e2e)

• Mocking patterns

• Coverage requirements

• Test structure and organization

• Test commands

Implementation Guides:

• How to implement APIs/endpoints

• How to implement UI components (if applicable)

• Database operation patterns

• External service integration patterns

• Background job patterns (if applicable)

Quality Standards:

• Code review checklist

• Performance baselines

• Security requirements (OWASP, validation, auth)

• Code style and formatting

• Documentation requirements

• Dependency management

Generate four aggregated domain rules:

Create in .claude/rules/ :

architecture-patterns.md :

• Aggregated patterns from all PRDs

• Fill in project-specific patterns extracted from PRDs

• Include code examples where possible

• Reference specific files/directories

testing-strategies.md :

• Aggregated testing requirements from all PRDs

• Fill in TDD requirements from PRDs

• Include coverage requirements

• Include test commands for the project

• Add paths frontmatter if tests live in specific directories:

paths:

• "tests/**/*"
• "**/.{test,spec}."

implementation-guides.md :

• Aggregated implementation patterns from all PRDs

• Fill in step-by-step patterns for feature types

• Include code examples

• Scope to source paths if applicable:

paths:

• "src/**/*"
• "lib/**/*"

quality-standards.md :

• Aggregated quality requirements from all PRDs

• Fill in performance baselines from PRDs

• Fill in security requirements from PRDs

• Create project-specific checklist

Path-scoping guidance: Add paths frontmatter when a rule only applies to specific file types or directories. This reduces context noise — Claude only loads the rule when working on matching files. Use brace expansion for concise patterns: .{ts,tsx} , src/{api,routes}/**/ .

Update manifest with generation tracking:

{ "generated": { "rules": { "architecture-patterns": { "source": "docs/prds/*", "source_hash": "sha256:...", "generated_at": "[ISO timestamp]", "plugin_version": "3.0.0", "content_hash": "sha256:...", "status": "current" }, "testing-strategies": { ... }, "implementation-guides": { ... }, "quality-standards": { ... } } } }

Update task registry:

Update the task registry entry in docs/blueprint/manifest.json :

jq --arg now "$(date -u +%Y-%m-%dT%H:%M:%SZ)"
--argjson processed "${PRDS_READ:-0}"
--argjson created "${RULES_GENERATED:-0}"
'.task_registry["generate-rules"].last_completed_at = $now | .task_registry["generate-rules"].last_result = "success" | .task_registry["generate-rules"].context.source_prd_hashes = ($source_prd_hashes // {}) | .task_registry["generate-rules"].stats.runs_total = ((.task_registry["generate-rules"].stats.runs_total // 0) + 1) | .task_registry["generate-rules"].stats.items_processed = $processed | .task_registry["generate-rules"].stats.items_created = $created'
docs/blueprint/manifest.json > tmp.json && mv tmp.json docs/blueprint/manifest.json

For source_prd_hashes , compute sha256sum of each PRD file and pass as a JSON object via --argjson .

Report:

Rules generated from PRDs!

Created in .claude/rules/:

• architecture-patterns.md
• testing-strategies.md
• implementation-guides.md
• quality-standards.md

PRDs analyzed:

• docs/prds/[List PRD files]

Key patterns extracted:

• Architecture: [Brief summary]
• Testing: [Brief summary]
• Implementation: [Brief summary]
• Quality: [Brief summary]

Rules are immediately available - Claude auto-discovers them based on context!

Prompt for next action (use AskUserQuestion):

question: "Rules generated. What would you like to do next?" options:

• label: "Generate workflow commands (Recommended)" description: "Create /project:continue and /project:test-loop commands"
• label: "Update CLAUDE.md" description: "Regenerate project overview document with new rules"
• label: "Review generated rules" description: "I'll examine and refine the rules manually"
• label: "I'm done for now" description: "Exit - rules are already available"

Based on selection:

• "Generate workflow commands" -> Run /blueprint:generate-commands

• "Update CLAUDE.md" -> Run /blueprint:claude-md

• "Review generated rules" -> Show rule file locations and exit

• "I'm done for now" -> Exit

Important:

• Rules should be markdown files with clear headings

• Keep rule content specific and focused

• Include code examples to make patterns concrete

• Reference PRD sections for traceability

• Rules should be actionable, not just documentation

Error Handling:

• If no PRDs found -> Guide user to derive PRDs first (/blueprint:derive-prd )

• If PRDs incomplete -> Generate rules with TODO markers for missing sections

• If rules already exist and modified -> Offer to backup before overwriting