Document Fetcher

Your responsibility is to fetch documents by codex:// URI reference, delegating to the cli-helper skill which invokes the fractary codex fetch CLI command.

Architecture (v4.0):

document-fetcher skill
  ↓ (delegates to)
cli-helper skill
  ↓ (invokes)
fractary codex fetch <uri>
  ↓ (uses)
@fractary/codex SDK (CodexClient)

This provides cache-first retrieval, permission checking, and multi-source support via the TypeScript SDK.

Step 1: Validate URI Format

Check that reference is a valid codex:// URI:

• Must start with codex://
• Must have format: codex://{org}/{project}/{path}
• Path must not contain directory traversal (../)

If invalid: Return error with format explanation:

{
  "status": "failure",
  "message": "Invalid URI format",
  "expected": "codex://{org}/{project}/{path}",
  "example": "codex://fractary/auth-service/docs/oauth.md"
}

STOP

Step 2: Delegate to CLI Helper

USE SKILL: cli-helper Operation: invoke-cli Parameters:

{
  "command": "fetch",
  "args": [
    "{reference}",
    "--bypass-cache" (if bypass_cache == true),
    "--ttl", "{ttl}" (if ttl provided)
  ],
  "parse_output": true
}

The cli-helper will:

1. Validate CLI installation
2. Execute: fractary codex fetch {reference} [--bypass-cache] [--ttl {seconds}] --json
3. Parse JSON output
4. Return results

Step 3: Process CLI Response

The CLI returns JSON like:

{
  "status": "success",
  "uri": "codex://fractary/auth-service/docs/oauth.md",
  "content": "# OAuth Implementation\n...",
  "metadata": {
    "fromCache": true,
    "fetchedAt": "2025-12-14T12:00:00Z",
    "expiresAt": "2025-12-21T12:00:00Z",
    "contentLength": 12543,
    "contentHash": "abc123..."
  }
}

IF status == "success":

• Extract content from CLI response
• Extract metadata
• Return to calling agent/command
• DONE ✅

IF status == "failure":

• Extract error message from CLI
• Pass through CLI's suggested_fixes if present
• Return error to calling agent/command
• DONE (with error)

Step 4: Return Results

Return structured response to caller:

Success:

{
  "status": "success",
  "operation": "fetch",
  "uri": "codex://fractary/auth-service/docs/oauth.md",
  "content": "...",
  "metadata": {
    "fromCache": true,
    "source": "CLI",
    "fetchedAt": "2025-12-14T12:00:00Z",
    "expiresAt": "2025-12-21T12:00:00Z",
    "contentLength": 12543
  }
}

Failure:

{
  "status": "failure",
  "operation": "fetch",
  "uri": "codex://fractary/auth-service/docs/oauth.md",
  "error": "Document not found",
  "suggested_fixes": [
    "Check URI format",
    "Verify document exists in repository",
    "Check permissions in frontmatter"
  ]
}

✅ For successful fetch:

• URI validated
• cli-helper invoked successfully
• Content retrieved from CLI
• Metadata extracted
• Results returned to caller

✅ For failed fetch:

• Error captured from CLI
• Error message clear and actionable
• Suggested fixes included (if available)
• Results returned to caller

✅ In all cases:

• No direct bash script execution
• No custom retrieval logic
• CLI handles all operations
• Structured response returned

Success Response

{
  "status": "success",
  "operation": "fetch",
  "uri": "codex://fractary/auth-service/docs/oauth.md",
  "content": "# OAuth Implementation\n\n...",
  "metadata": {
    "fromCache": true,
    "fetchedAt": "2025-12-14T12:00:00Z",
    "expiresAt": "2025-12-21T12:00:00Z",
    "contentLength": 12543,
    "source": "CLI"
  }
}

Failure Response: Invalid URI

{
  "status": "failure",
  "operation": "fetch",
  "error": "Invalid URI format",
  "provided": "invalid-uri",
  "expected": "codex://{org}/{project}/{path}",
  "example": "codex://fractary/auth-service/docs/oauth.md"
}

Failure Response: CLI Error

{
  "status": "failure",
  "operation": "fetch",
  "uri": "codex://fractary/missing/file.md",
  "error": "Document not found",
  "cli_error": {
    "message": "Document not found: codex://fractary/missing/file.md",
    "suggested_fixes": [
      "Verify document exists in repository",
      "Check permissions in frontmatter"
    ]
  }
}

Failure Response: CLI Not Available

{
  "status": "failure",
  "operation": "fetch",
  "error": "CLI not available",
  "suggested_fixes": [
    "Install globally: npm install -g @fractary/cli",
    "Or ensure npx is available"
  ]
}

Invalid URI

When URI format is invalid:

1. Return clear error message
2. Show expected format
3. Provide example
4. Don't attempt to fetch

CLI Not Available

When cli-helper reports CLI unavailable:

1. Pass through installation instructions
2. Don't attempt workarounds
3. Return clear error to caller

CLI Command Failed

When CLI returns error:

1. Preserve exact error message from CLI
2. Include suggested fixes if CLI provides them
3. Add context about what was being fetched
4. Return structured error

Permission Denied

When CLI reports permission denied:

1. Show permission error from CLI
2. Suggest checking frontmatter
3. Provide document path for reference

Migration from v3.0

v3.0 (bash scripts):

document-fetcher
  ├─ resolve-reference.sh
  ├─ cache-lookup.sh
  ├─ github-fetch.sh
  └─ cache-store.sh

v4.0 (CLI delegation):

document-fetcher
  └─ delegates to cli-helper
      └─ invokes: fractary codex fetch

Benefits:

• ~95% code reduction in this skill
• TypeScript type safety from SDK
• Better error messages
• Automatic cache management
• Permission checking built-in

Performance

• Cache hit: < 100ms (same as v3.0)
• Cache miss: < 2s (same as v3.0)
• CLI overhead: ~50-100ms (negligible)

Backward Compatibility

This skill no longer supports:

• @codex/ prefix (use codex:// instead)
• Direct script invocation
• Custom cache management

Use CLI migration tools to convert references:

fractary codex check --fix

CLI Command Used

This skill delegates to:

fractary codex fetch <uri> [--bypass-cache] [--ttl <seconds>] --json

SDK Features Leveraged

Via the CLI, this skill benefits from:

• CodexClient.fetch() - Main fetch logic
• CacheManager - Cache hit/miss logic
• StorageManager - Multi-provider support (GitHub, HTTP, S3)
• PermissionManager - Frontmatter-based permissions
• Built-in validation and error handling

Testing

To test this skill:

# Ensure CLI installed
npm install -g @fractary/cli

# Initialize config
fractary codex init --org fractary

# Test fetch
USE SKILL: document-fetcher
Parameters: {
  "reference": "codex://fractary/codex/README.md"
}

Troubleshooting

If fetch fails:

1. Check CLI installation: fractary --version
2. Check config: .fractary/codex.yaml
3. Test CLI directly: fractary codex fetch <uri>
4. Check cache: fractary codex cache list
5. Run health check: fractary codex health