eyaltoledano/claude-task-master · error

Provider must implement BaseAIProvider interface

Error message

Provider must implement BaseAIProvider interface

What it means

registerProvider() enforces the BaseAIProvider contract: any registered provider must implement generateText, streamText, and generateObject as functions. This duck-typing check runs at registration time so that lookup failures surface early instead of when a consumer first calls the provider. Passing a plain object, a partial implementation, or a misnamed method triggers this error.

Source

Thrown at src/provider-registry/index.js:70

	 * @param {object} options - Additional options for registration
	 * @returns {ProviderRegistry} The singleton instance for chaining
	 */
	registerProvider(providerName, provider, options = {}) {
		if (!providerName || typeof providerName !== 'string') {
			throw new Error('Provider name must be a non-empty string');
		}

		if (!provider) {
			throw new Error('Provider instance is required');
		}

		// Validate that provider implements the required interface
		if (
			typeof provider.generateText !== 'function' ||
			typeof provider.streamText !== 'function' ||
			typeof provider.generateObject !== 'function'
		) {
			throw new Error('Provider must implement BaseAIProvider interface');
		}

		// Add provider to the registry
		this._providers.set(providerName, {
			instance: provider,
			options,
			registeredAt: new Date()
		});

		return this;
	}

	/**
	 * Check if a provider exists in the registry
	 * @param {string} providerName - The name of the provider
	 * @returns {boolean} True if the provider exists
	 */
	hasProvider(providerName) {

View on GitHub (pinned to c0c98d367c)

Solutions

1. Extend BaseAIProvider (or implement all three methods: generateText, streamText, generateObject) before registering.
2. console.log(typeof p.generateText, typeof p.streamText, typeof p.generateObject) to see which method is missing.
3. If you meant to pass a class, instantiate it: new MyProvider() so prototype methods exist on the instance.
4. Update your stub/mock to implement the full interface when testing.
5. Check for version drift between your provider package and the registry's expected interface.

Example fix

// before
registry.registerProvider('custom', {
  generateText: async (p) => 'hi'
});
// after
class CustomProvider extends BaseAIProvider {
  async generateText(prompt) { return 'hi'; }
  async streamText(prompt, cb) { cb('hi'); }
  async generateObject(prompt, schema) { return {}; }
}
registry.registerProvider('custom', new CustomProvider());

function assertImplementsBaseAIProvider(p) {
  const required = ['generateText', 'streamText', 'generateObject'];
  const missing = required.filter((m) => typeof p?.[m] !== 'function');
  if (missing.length) {
    throw new TypeError(`Provider missing BaseAIProvider methods: ${missing.join(', ')}`);
  }
}
assertImplementsBaseAIProvider(myProvider);
registry.registerProvider('custom', myProvider);

const implementsBaseAIProvider = (p) =>
  p != null &&
  typeof p.generateText === 'function' &&
  typeof p.streamText === 'function' &&
  typeof p.generateObject === 'function';

try {
  registry.registerProvider('custom', provider);
} catch (err) {
  if (err.message.includes('BaseAIProvider interface')) {
    console.error('Provider', provider?.constructor?.name, 'must implement generateText, streamText, generateObject');
    provider = new BaseAIProviderAdapter(provider); // wrap/adapt
    registry.registerProvider('custom', provider);
    return;
  }
  throw err;
}

When it happens

Trigger: registerProvider('custom', { generateText: fn }) missing streamText/generateObject; registering a class reference instead of an instance (methods not bound/instance methods not on the object); a v2 provider with renamed methods registered into a registry expecting the BaseAIProvider interface.

Common situations: Writing a custom provider from docs and only implementing one or two methods; refactoring method names (e.g. generate → generateText) without updating all interface methods; mocking providers in tests with incomplete stubs; registering objects that proxy methods via getters, which typeof checks at registration may miss if lazily defined.

Related errors

• Provider name must be a non-empty string
• Provider instance is required
• MFA_VERIFICATION_FAILED
• Failed to initialize services: ${(error as Error).message}
• Invalid format: ${options.format}. Valid formats are: text,

AI-assisted analysis of eyaltoledano/claude-task-master@c0c98d367c (2026-08-29). Data as JSON: /api/errors/c1286c86c1b1002e. Report an issue: GitHub.