Currently supported: gemini, openai, codestral, ollama.

Adding a new provider requires changes in 7 areas. The examples below use anthropic.

Reference implementations: Before starting, read an existing service — src/services/openaiService.ts is the best reference for HTTP-based providers. For providers that expose a model listing API (like Gemini), also look at src/services/geminiService.ts and the IModelService interface in src/models/types.ts.

Create a new service file. Use an existing service as a reference (e.g., openaiService.ts for HTTP-based APIs).

Your service must implement the IAIService interface from src/models/types.ts:

import { CommitMessage, ProgressReporter } from '../models/types';
import { BaseAIService } from './baseAIService';
import { ConfigService } from '../utils/configService';

export class AnthropicService {
    static async generateCommitMessage(
        prompt: string,
        progress: ProgressReporter,
        attempt: number = 0
    ): Promise<CommitMessage> {
        // 1. Get config values (model, API key, etc.)
        // 2. Make API request
        // 3. Use BaseAIService.extractAndValidateMessage() to validate response
        // 4. Use BaseAIService.handleHttpError() for error handling
        // 5. Return { message, model }
    }
}

Key patterns to follow:

• Use BaseAIService.handleHttpError() for consistent HTTP error handling
• Use BaseAIService.extractAndValidateMessage() to validate AI responses
• Report progress via progress.report()
• Support retry logic via the attempt parameter
• Respect ConfigService.getApiRequestTimeout() for request timeouts

If your provider supports fetching the list of available models dynamically (like Gemini), implement IModelService in addition to the service class:

import { IModelService } from '../models/types';

export class AnthropicService implements IModelService {
    static async getAvailableModels(): Promise<string[]> {
        // fetch and return model names from the provider API
    }
    // ...rest of the service
}

This enables the auto model selection mode for your provider.

Import the service and add it to the factory:

import { AnthropicService } from './anthropicService';

export enum AIServiceType {
    // ...existing types...
    ANTHROPIC = 'anthropic'
}

export class AIServiceFactory {
    private static readonly services: Record<AIServiceType, AIServiceClass> = {
        // ...existing services...
        [AIServiceType.ANTHROPIC]: AnthropicService
    };
}

Add the provider to the type union and add provider-specific config:

export interface ProjectConfig {
    provider?: {
        type?: 'gemini' | 'codestral' | 'openai' | 'ollama' | 'anthropic';
    };
    // ...existing providers...
    anthropic?: {
        model?: string;
    };
}

Add getter methods for the new provider's settings:

static getAnthropicModel(): string {
    return this.getConfig<string>('anthropic', 'model', 'claude-sonnet-4-6');
}

Also add the provider to the validation list in getProvider():

if (!['gemini', 'openai', 'codestral', 'ollama', 'anthropic'].includes(provider)) {

Add commands for setting and removing the API key:

• Create or extend files in src/commands/setApiKeys.ts
• Register new commands in src/commands/index.ts

Add in three places:

a) Provider enum:

"commitSage.provider.type": {
    "enum": ["gemini", "openai", "codestral", "ollama", "anthropic"]
}

b) Provider settings section:

"commitSage.anthropic.model": {
    "type": "string",
    "default": "claude-sonnet-4-6",
    "description": "Anthropic model to use"
}

c) Commands (for API key management):

{
    "command": "commitsage.setAnthropicApiKey",
    "title": "Commit Sage: Set Anthropic API Key"
},
{
    "command": "commitsage.removeAnthropicApiKey",
    "title": "Commit Sage: Remove Anthropic API Key"
}

Add the new provider to:

• The provider list at the top
• AI Provider Settings section
• Requirements section (if the provider has specific requirements)

After making all changes:

1. npm run compile — ensure no TypeScript errors.
2. Open VS Code Settings → CommitSage → confirm the new provider appears in the dropdown.
3. Set the API key via Command Palette.
4. Select the new provider and generate a commit message.
5. Test error handling: use an invalid API key and verify the error message is clear.