Errors & Registry

Errors

class SimpleWebMCPError extends Error { code: string; cause?: unknown; toJSON(); }
class NotSupportedError extends SimpleWebMCPError // code 'NOT_SUPPORTED'
class NotAllowedError extends SimpleWebMCPError    // code 'NOT_ALLOWED' — Permissions Policy
class RegistrationError extends SimpleWebMCPError   // code 'REGISTRATION_ERROR'
class ValidationError extends SimpleWebMCPError     // code 'VALIDATION_ERROR'
class ConfigurationError extends SimpleWebMCPError  // code 'CONFIGURATION_ERROR' — e.g. strict inference

See Browser Support for NotSupportedError / NotAllowedError handling and Schema for strict validation.

Registry

import { registry, getRegistry } from 'simple-webmcp';
registry.list(); // [{name, status}]
registry.clear();
registry.isRegistered(name);
registry.getStatus(name);

Async register(contract, {signal, execute}) → ()=>void unregister. Deduped; NotAllowedError on NotAllowedError/Permissions Policy message.

See also

• Guide — Browser Support — feature detection + polyfill
• Guide — Hooks — error hooks are observational
• Analytics — Sentry — reporting via error hooks
• Schema & Inference — strict and validation
• External: Chrome WebMCP API