Adding a New AI Format to PRPM

Complete process for adding support for a new AI editor format (like OpenCode, Cursor, Claude, etc.) to PRPM.

Overview

This skill documents the systematic process for adding a new AI format to PRPM, based on the OpenCode integration. Follow these steps in order to ensure complete integration across all packages.

Prerequisites

• Format documentation (understand file structure, frontmatter, directory conventions)
• Example files from the format
• Understanding of format-specific features (tools, agents, commands, etc.)

Step 1: Types Package (

packages/types/

)

File:

src/package.ts

Add the format to the Format type and FORMATS array:

export type Format =
  | 'cursor'
  | 'claude'
  | 'continue'
  | 'windsurf'
  | 'copilot'
  | 'kiro'
  | 'agents.md'
  | 'gemini.md'
  | 'claude.md'
  | 'gemini'
  | 'opencode'  // Add new format here
  | 'ruler'
  | 'generic'
  | 'mcp';

export const FORMATS: readonly Format[] = [
  'cursor',
  'claude',
  // ... other formats
  'opencode',  // Add here too
  'ruler',
  'generic',
  'mcp',
] as const;

Build and verify:

npm run build --workspace=@pr-pm/types

Step 2: Converters Package - Schema (

packages/converters/schemas/

)

Create JSON schema file:

{format}.schema.json

Example structure:

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://registry.prpm.dev/api/v1/schemas/opencode.json",
  "title": "OpenCode Agent Format",
  "description": "JSON Schema for OpenCode Agents",
  "type": "object",
  "required": ["frontmatter", "content"],
  "properties": {
    "frontmatter": {
      "type": "object",
      "required": ["description"],
      "properties": {
        "description": { "type": "string" },
        // Format-specific fields
      },
      "additionalProperties": false
    },
    "content": {
      "type": "string",
      "description": "Body content as markdown"
    }
  }
}

CRITICAL Schema Requirements:

• $id

  must use new URL pattern:

  https://registry.prpm.dev/api/v1/schemas/{format}.json

  for base schemas
• For subtypes:

  https://registry.prpm.dev/api/v1/schemas/{format}/{subtype}.json

• Add

  "additionalProperties": false

  to frontmatter object to catch invalid fields
• String fields requiring slugs (like

  name

  ) should use pattern:

  "pattern": "^[a-z0-9-]+$"

If the format has subtypes (like Claude with agents/skills/commands), create separate schema files:

• {format}-agent.schema.json

• {format}-skill.schema.json

• {format}-slash-command.schema.json

• etc.

IMPORTANT: When creating subtype schemas, you MUST update the validation logic to map them.

Step 3: Converters Package - Format Documentation (

packages/converters/docs/

)

CRITICAL: Create comprehensive format documentation file:

{format}.md

This documentation serves as the source of truth for:

• Package authors creating packages in this format
• PRPM contributors implementing converters
• Users understanding format capabilities and limitations

Required sections:

# {Format Name} Format Specification

**File Locations:**
- {Type 1}: `{path}`
- {Type 2}: `{path}`

**Format:** {Markdown/JSON/etc.} with {YAML frontmatter/etc.}
**Official Docs:** {link to official documentation}

## Overview

Brief description of the format and its purpose.

## Frontmatter Fields

### Required Fields

- **`field-name`** (type): Description

### Optional Fields

- **`field-name`** (type): Description

## Content Format

Describe the body/content structure.

## Best Practices

1. Practice 1
2. Practice 2

## Conversion Notes

### From {Format} to Canonical

How the converter parses this format.

### From Canonical to {Format}

How the converter generates this format.

## Limitations

- Limitation 1
- Limitation 2

## Examples

### Example 1

```markdown
{example content}

Related Documentation

• Official Docs
• PRPM Format Guide

Changelog

• {Date}: Initial format support

**Add to README.md**:

1. **Format Matrix table**: Add row(s) with subtypes, official docs, and OpenCode docs links
2. **Available Formats table**: Add row with link to your new `.md` file
3. **Schema Validation section**: Add schema filename(s) to appropriate list
4. **Frontmatter Support table**: Add row with frontmatter requirements
5. **File Organization table**: Add row with file paths and structure

See `packages/converters/docs/README.md` for examples of how other formats are documented.

## Step 4: Converters Package - Canonical Types

**File**: `packages/converters/src/types/canonical.ts`

### 3a. Add format to CanonicalPackage.format union:

```typescript
format: 'cursor' | 'claude' | ... | 'opencode' | 'ruler' | 'generic' | 'mcp';

3b. Add format-specific metadata (if needed):

// In CanonicalPackage.metadata
metadata?: {
  // ... existing configs
  opencode?: {
    mode?: 'subagent' | 'primary' | 'all';
    model?: string;
    temperature?: number;
    permission?: Record<string, any>;
    disable?: boolean;
  };
};

3c. Add to MetadataSection.data (if storing format-specific data):

export interface MetadataSection {
  type: 'metadata';
  data: {
    title: string;
    description: string;
    // ... existing fields
    opencode?: {
      // Same structure as above
    };
  };
}

3d. Add to formatScores and sourceFormat:

formatScores?: {
  cursor?: number;
  // ... others
  opencode?: number;
};

sourceFormat?: 'cursor' | 'claude' | ... | 'opencode' | ... | 'generic';

Step 5: Converters Package - From Converter

File:

packages/converters/src/from-{format}.ts

Create converter that parses format → canonical:

import type {
  CanonicalPackage,
  PackageMetadata,
  Section,
  MetadataSection,
  ToolsSection,
} from './types/canonical.js';
import { setTaxonomy } from './taxonomy-utils.js';
import yaml from 'js-yaml';  // If using YAML frontmatter

// Define format-specific interfaces
interface FormatFrontmatter {
  // Format-specific frontmatter structure
}

// Parse frontmatter if needed
function parseFrontmatter(content: string): {
  frontmatter: Record<string, any>;
  body: string
} {
  const match = content.match(/^---\n([\s\S]*?)\n---\n([\s\S]*)$/);
  if (!match) {
    return { frontmatter: {}, body: content };
  }

  const frontmatter = yaml.load(match[1]) as Record<string, any>;
  const body = match[2];

  return { frontmatter, body };
}

export function fromFormat(
  content: string,
  metadata: Partial<PackageMetadata> & Pick<PackageMetadata, 'id' | 'name' | 'version' | 'author'>
): CanonicalPackage {
  const { frontmatter, body } = parseFrontmatter(content);
  const fm = frontmatter as FormatFrontmatter;

  const sections: Section[] = [];

  // 1. Create metadata section
  const metadataSection: MetadataSection = {
    type: 'metadata',
    data: {
      title: metadata.name || metadata.id,
      description: fm.description || metadata.description || '',
      version: metadata.version || '1.0.0',
      author: metadata.author,
    },
  };

  // Store format-specific data for roundtrip
  if (/* has format-specific fields */) {
    metadataSection.data.formatName = {
      // Format-specific data
    };
  }

  sections.push(metadataSection);

  // 2. Extract tools (if applicable)
  if (fm.tools) {
    const enabledTools = Object.entries(fm.tools)
      .filter(([_, enabled]) => enabled === true)
      .map(([tool, _]) => {
        // Normalize tool names to canonical format
        return normalizeToolName(tool);
      });

    if (enabledTools.length > 0) {
      sections.push({
        type: 'tools',
        tools: enabledTools,
      });
    }
  }

  // 3. Add body as instructions
  if (body.trim()) {
    sections.push({
      type: 'instructions',
      title: 'Instructions',
      content: body.trim(),
    });
  }

  // 4. Build canonical package
  const canonicalContent: CanonicalPackage['content'] = {
    format: 'canonical',
    version: '1.0',
    sections
  };

  const pkg: CanonicalPackage = {
    ...metadata,
    id: metadata.id,
    name: metadata.name || metadata.id,
    version: metadata.version,
    author: metadata.author,
    description: metadata.description || fm.description || '',
    tags: metadata.tags || [],
    format: 'formatname',
    subtype: 'agent', // Or detect from content
    content: canonicalContent,
  };

  setTaxonomy(pkg, 'formatname', 'agent');
  return pkg;
}

Key points:

• Import yaml if format uses YAML frontmatter
• Extract all format-specific metadata for roundtrip conversion
• Normalize tool names to canonical format (Write, Edit, Bash, etc.)
• Always include

  format: 'canonical'

  and

  version: '1.0'

  in content
• InstructionsSection requires

  title

  field
• Call

  setTaxonomy()

  before returning

Step 6: Converters Package - To Converter

File:

packages/converters/src/to-{format}.ts

Create converter that converts canonical → format:

import type {
  CanonicalPackage,
  ConversionResult,
} from './types/canonical.js';
import yaml from 'js-yaml';

export function toFormat(pkg: CanonicalPackage): ConversionResult {
  const warnings: string[] = [];
  let qualityScore = 100;

  try {
    const content = convertContent(pkg, warnings);

    const lossyConversion = warnings.some(w =>
      w.includes('not supported') || w.includes('skipped')
    );

    if (lossyConversion) {
      qualityScore -= 10;
    }

    return {
      content,
      format: 'formatname',
      warnings: warnings.length > 0 ? warnings : undefined,
      lossyConversion,
      qualityScore,
    };
  } catch (error) {
    warnings.push(`Conversion error: ${error instanceof Error ? error.message : String(error)}`);
    return {
      content: '',
      format: 'formatname',
      warnings,
      lossyConversion: true,
      qualityScore: 0,
    };
  }
}

function convertContent(pkg: CanonicalPackage, warnings: string[]): string {
  const lines: string[] = [];

  // Extract sections
  const metadata = pkg.content.sections.find(s => s.type === 'metadata');
  const tools = pkg.content.sections.find(s => s.type === 'tools');
  const instructions = pkg.content.sections.find(s => s.type === 'instructions');

  // Build frontmatter
  const frontmatter: Record<string, any> = {};

  if (metadata?.type === 'metadata') {
    frontmatter.description = metadata.data.description;
  }

  // Restore format-specific metadata (for roundtrip)
  const formatData = metadata?.type === 'metadata' ? metadata.data.formatName : undefined;
  if (formatData) {
    Object.assign(frontmatter, formatData);
  }

  // Convert tools
  if (tools?.type === 'tools' && tools.tools.length > 0) {
    frontmatter.tools = convertToolsToFormatStructure(tools.tools);
  }

  // Generate YAML frontmatter (if applicable)
  lines.push('---');
  lines.push(yaml.dump(frontmatter, { indent: 2, lineWidth: -1 }).trim());
  lines.push('---');
  lines.push('');

  // Add body content
  if (instructions?.type === 'instructions') {
    lines.push(instructions.content);
  }

  return lines.join('\n').trim() + '\n';
}

Section type handling:

• PersonaSection:

  section.data.role

  (NOT

  section.content

  )
• RulesSection:

  section.items

  (NOT

  section.rules

  ), each item has

  rule.content

• InstructionsSection:

  section.content

  and

  section.title

• ExamplesSection:

  section.examples

  array with

  description

  and

  code

Step 7: Converters Package - Exports and Validation

File:

packages/converters/src/index.ts

Add to exports:

// From converters
export { fromFormat } from './from-format.js';

// To converters
export { toFormat } from './to-format.js';

File:

packages/converters/src/validation.ts

7a. Add to FormatType:

export type FormatType =
  | 'cursor'
  | 'claude'
  // ... others
  | 'opencode'
  | 'canonical';

7b. Add to base schema map:

const schemaMap: Record<FormatType, string> = {
  'cursor': 'cursor.schema.json',
  // ... others
  'opencode': 'opencode.schema.json',
  'canonical': 'canonical.schema.json',
};

7c. CRITICAL: Add subtype schemas to subtypeSchemaMap:

const subtypeSchemaMap: Record<string, string> = {
  'claude:agent': 'claude-agent.schema.json',
  'claude:skill': 'claude-skill.schema.json',
  'claude:slash-command': 'claude-slash-command.schema.json',
  'claude:hook': 'claude-hook.schema.json',
  'cursor:slash-command': 'cursor-command.schema.json',
  'kiro:hook': 'kiro-hooks.schema.json',
  'kiro:agent': 'kiro-agent.schema.json',
  'droid:skill': 'droid-skill.schema.json',
  'droid:slash-command': 'droid-slash-command.schema.json',
  'droid:hook': 'droid-hook.schema.json',
  'opencode:slash-command': 'opencode-slash-command.schema.json',  // Add your subtypes here
};

Why this matters: Without adding subtypes to

subtypeSchemaMap

, validation will fall back to the base format schema and won't validate subtype-specific fields. This causes validation to fail or pass incorrectly.

File:

packages/converters/src/taxonomy-utils.ts

Add to Format type:

export type Format = 'cursor' | 'claude' | ... | 'opencode' | ... | 'mcp';

Add to normalizeFormat:

export function normalizeFormat(sourceFormat: string): Format {
  const normalized = sourceFormat.toLowerCase();

  if (normalized.includes('cursor')) return 'cursor';
  // ... others
  if (normalized.includes('opencode')) return 'opencode';

  return 'generic';
}

Build converters:

npm run build --workspace=@pr-pm/converters

Step 8: CLI Package - Filesystem

File:

packages/cli/src/core/filesystem.ts

7a. Add to getDestinationDir:

export function getDestinationDir(format: Format, subtype: Subtype, name?: string): string {
  const packageName = stripAuthorNamespace(name);

  switch (format) {
    // ... existing cases

    case 'opencode':
      // OpenCode supports agents, slash commands, and custom tools
      // Agents: .opencode/agent/*.md
      // Commands: .opencode/command/*.md
      // Tools: .opencode/tool/*.ts or *.js
      if (subtype === 'agent') return '.opencode/agent';
      if (subtype === 'slash-command') return '.opencode/command';
      if (subtype === 'tool') return '.opencode/tool';
      return '.opencode/agent';  // Default

    // ... rest
  }
}

7b. Add to autoDetectFormat:

const formatDirs: Array<{ format: Format; dir: string }> = [
  { format: 'cursor', dir: '.cursor' },
  // ... others
  { format: 'opencode', dir: '.opencode' },
  { format: 'agents.md', dir: '.agents' },
];

Step 9: CLI Package - Format Mappings

Files:

packages/cli/src/commands/search.ts

and

packages/cli/src/commands/install.ts

Add to both files:

8a. formatIcons:

const formatIcons: Record<Format, string> = {
  'claude': '🤖',
  'cursor': '📋',
  // ... others
  'opencode': '⚡',  // Choose appropriate emoji
  'gemini.md': '✨',  // Don't forget format aliases
  'claude.md': '🤖',
  'ruler': '📏',
  'generic': '📦',
};

8b. formatLabels:

const formatLabels: Record<Format, string> = {
  'claude': 'Claude',
  'cursor': 'Cursor',
  // ... others
  'opencode': 'OpenCode',
  'gemini.md': 'Gemini',  // Format aliases
  'claude.md': 'Claude',
  'ruler': 'Ruler',
  'generic': '',
};

Step 10: Webapp - Format Subtypes and Filter Dropdown

File:

packages/webapp/src/app/(app)/search/SearchClient.tsx

9a. Add to FORMAT_SUBTYPES:

const FORMAT_SUBTYPES: Record<Format, Subtype[]> = {
  'cursor': ['rule', 'agent', 'slash-command', 'tool'],
  'claude': ['skill', 'agent', 'slash-command', 'tool', 'hook'],
  'claude.md': ['agent'],  // Format aliases
  'gemini.md': ['slash-command'],
  // ... others
  'opencode': ['agent', 'slash-command', 'tool'],  // List all supported subtypes
  'ruler': ['rule', 'agent', 'tool'],
  'generic': ['rule', 'agent', 'skill', 'slash-command', 'tool', 'chatmode', 'hook'],
};

9b. Add to format filter dropdown (around line 1195):

<select
  value={selectedFormat}
  onChange={(e) => setSelectedFormat(e.target.value as Format | '')}
  className="w-full px-3 py-2 bg-prpm-dark border border-prpm-border rounded text-white focus:outline-none focus:border-prpm-accent"
>
  <option value="">All Formats</option>
  <option value="cursor">Cursor</option>
  <option value="claude">Claude</option>
  <option value="continue">Continue</option>
  <option value="windsurf">Windsurf</option>
  <option value="copilot">GitHub Copilot</option>
  <option value="kiro">Kiro</option>
  <option value="gemini">Gemini CLI</option>
  <option value="droid">Droid</option>
  <option value="opencode">OpenCode</option>  {/* Add your format here */}
  <option value="mcp">MCP</option>
  <option value="agents.md">Agents.md</option>
  <option value="generic">Generic</option>
</select>

9c. Add compatibility info section (after the dropdown):

{selectedFormat === 'opencode' && (
  <div className="mt-3 p-3 bg-gray-500/10 border border-gray-500/30 rounded-lg">
    <p className="text-xs text-gray-400">
      Tool-specific format for <strong>OpenCode AI</strong>
    </p>
  </div>
)}

Step 11: Registry - Fastify Route Schemas

CRITICAL: Add the format to all Fastify route validation schemas to prevent 400 errors.

10a. File:

packages/registry/src/routes/download.ts

Add to format enum in schema (2-3 places):

// Download route schema (line ~46)
format: {
  type: 'string',
  enum: ['cursor', 'claude', 'continue', 'windsurf', 'copilot', 'kiro', 'ruler', 'agents.md', 'gemini', 'droid', 'opencode', 'generic'],
  description: 'Target format for conversion (optional)',
},

// Compatibility check route schema (lines ~201, 205)
from: {
  type: 'string',
  enum: ['cursor', 'claude', 'continue', 'windsurf', 'copilot', 'kiro', 'ruler', 'agents.md', 'gemini', 'droid', 'opencode', 'generic'],
},
to: {
  type: 'string',
  enum: ['cursor', 'claude', 'continue', 'windsurf', 'copilot', 'kiro', 'ruler', 'agents.md', 'gemini', 'droid', 'opencode', 'generic'],
},

10b. File:

packages/registry/src/routes/search.ts

Add to FORMAT_ENUM constant (line ~12):

const FORMAT_ENUM = ['cursor', 'claude', 'continue', 'windsurf', 'copilot', 'kiro', 'agents.md', 'gemini', 'ruler', 'droid', 'opencode', 'generic', 'mcp'] as const;

10c. File:

packages/registry/src/routes/analytics.ts

Add to both Zod schema and Fastify schema:

// Zod schema (line ~15)
const TrackDownloadSchema = z.object({
  packageId: z.string(),
  version: z.string().optional(),
  format: z.enum(['cursor', 'claude', 'continue', 'windsurf', 'copilot', 'kiro', 'agents.md', 'gemini', 'ruler', 'droid', 'opencode', 'generic', 'mcp']).optional(),
  client: z.enum(['cli', 'web', 'api']).optional(),
});

// Fastify schema (line ~45)
format: {
  type: 'string',
  enum: ['cursor', 'claude', 'continue', 'windsurf', 'copilot', 'kiro', 'agents.md', 'gemini', 'ruler', 'droid', 'opencode', 'generic', 'mcp'],
  description: 'Download format'
},

Why this matters: Without these additions, the registry will reject API requests with 400 validation errors when users try to download or filter by the new format.

Step 12: Testing and Validation

11a. Build types package first:

npm run build --workspace=@pr-pm/types

This is critical because other packages depend on the updated Format type.

11b. Build registry and webapp:

npm run build --workspace=@pr-pm/registry
npm run build --workspace=@pr-pm/webapp

11c. Run typecheck:

npm run typecheck

Fix any TypeScript errors:

• Missing format in type unions
• Format aliases ('gemini.md', 'claude.md')
• Section structure (use correct field names)

11d. Build all packages:

npm run build

11e. Run converter tests:

npm test --workspace=@pr-pm/converters

11f. Create test fixtures (recommended):

// packages/converters/src/__tests__/to-opencode.test.ts
import { describe, it, expect } from 'vitest';
import { toOpencode } from '../to-opencode.js';
import { validateMarkdown } from '../validation.js';
import type { CanonicalPackage } from '../types/canonical.js';

describe('OpenCode Format', () => {
  it('should convert from OpenCode to canonical', () => {
    const opencodeContent = `---
description: Test agent
mode: subagent
---
Test instructions`;

    const result = fromOpencode(opencodeContent, {
      id: 'test',
      name: 'test',
      version: '1.0.0',
      author: 'test',
    });

    expect(result.format).toBe('opencode');
    expect(result.subtype).toBe('agent');
  });

  it('should convert canonical to OpenCode', () => {
    const canonical: CanonicalPackage = {
      // ... build test package
    };

    const result = toOpencode(canonical);
    expect(result.format).toBe('opencode');
    expect(result.content).toContain('---');
  });

  // CRITICAL: Add schema validation tests!
  describe('JSON Schema Validation', () => {
    it('should generate schema-compliant agent output', () => {
      const agentPackage: CanonicalPackage = {
        // ... build agent test package with subtype: 'agent'
      };

      const result = toOpencode(agentPackage);
      const validation = validateMarkdown('opencode', result.content, 'agent');

      if (!validation.valid) {
        console.error('Validation errors:', validation.errors);
      }

      expect(validation.valid).toBe(true);
      expect(validation.errors).toHaveLength(0);
    });
  });
});

Why Schema Validation Tests Matter:

• Catch mismatches between converter implementation and schema
• Ensure converters generate compliant output
• Reveal missing required fields or incorrect field names
• Example: We discovered Claude agent schema was missing required

  mode

  field via validation tests

Step 13: Additional Documentation

Beyond the format documentation created in Step 3:

• User-facing: Add to Mintlify docs if the format needs special installation instructions
• Internal: Add notes to

  docs/development/

  if there are special considerations
• Decision logs: Document any architectural decisions in

  docs/decisions/

Common Pitfalls

1. Missing Format Aliases

Formats like 'gemini.md' and 'claude.md' are aliases that MUST be included in all format mappings.

2. Incorrect Section Structure

• PersonaSection uses

  data.role

  , not

  content

• RulesSection uses

  items

  , not

  rules

• InstructionsSection requires

  title

  field
• Each Rule has

  content

  , not

  description

3. CanonicalContent Requirements

Must always include:

{
  format: 'canonical',
  version: '1.0',
  sections: [...]
}

4. setTaxonomy Signature

setTaxonomy(pkg, 'formatname', 'subtype');  // Returns void
return pkg;  // Return the package separately

5. Tool Name Normalization

Map format-specific tool names to canonical:

• write

  →

  Write

• edit

  →

  Edit

• bash

  →

  Bash

6. YAML Import

If using YAML frontmatter:

import yaml from 'js-yaml';  // Top-level import
// NOT: const yaml = await import('js-yaml');

Checklist

Before submitting:

Types Package:

• Added format to types/src/package.ts (Format type and FORMATS array)
• Built types package

Converters Package:

• Created schema file(s) in converters/schemas/
• If format has subtypes, created separate schema files for each subtype (e.g., {format}-agent.schema.json, {format}-slash-command.schema.json)
• Created format documentation in converters/docs/{format}.md
• Updated converters/docs/README.md (Format Matrix, Available Formats, Schema Validation, Frontmatter Support, File Organization tables)
• Updated converters/src/types/canonical.ts (all 4 places: format union, metadata, MetadataSection.data, formatScores, sourceFormat)
• Created from-{format}.ts converter
• Created to-{format}.ts converter
• Updated converters/src/index.ts exports
• Updated converters/src/validation.ts (FormatType, schemaMap, and CRITICAL: subtypeSchemaMap for each subtype)
• Updated converters/src/taxonomy-utils.ts (Format type and normalizeFormat)
• Copied all schemas to packages/cli/dist/schemas/ for runtime use

CLI Package:

• Updated cli/src/core/filesystem.ts (getDestinationDir and autoDetectFormat)
• Updated cli/src/commands/search.ts (formatIcons and formatLabels, including aliases)
• Updated cli/src/commands/install.ts (formatIcons and formatLabels, including aliases)

Webapp Package:

• Updated webapp SearchClient.tsx (FORMAT_SUBTYPES, including aliases)
• Added to format filter dropdown
• Added compatibility info section

Registry Package:

• Updated registry/src/routes/download.ts (format enum in 2-3 places)
• Updated registry/src/routes/search.ts (FORMAT_ENUM constant)
• Updated registry/src/routes/analytics.ts (Zod schema and Fastify schema)
• Built registry package

Testing:

• Ran typecheck successfully
• Built all packages successfully
• Wrote tests for converters
• Documented the integration

Example: OpenCode Integration

See the following files for reference:

• packages/converters/src/from-opencode.ts

• packages/converters/src/to-opencode.ts

• packages/converters/schemas/opencode.schema.json

• Git commit history for the OpenCode integration PR

Summary

Adding a new format requires changes across 6 packages:

1. types - Add to Format type (build first!)
2. converters - Schema, from/to converters, canonical types, validation, taxonomy
3. cli - Filesystem and format mappings
4. webapp - Format subtypes, filter dropdown, compatibility info
5. registry - Fastify route schemas (download, search, analytics)
6. tests - Verify everything works

Build order matters: types → converters → cli → webapp → registry

Follow the steps systematically, use existing format implementations as reference, and always run typecheck and tests before submitting.