gitlab-ai-provider

v5.2.0

Published

a day ago

GitLab Duo provider for Vercel AI SDK

GitLab AI Provider

A comprehensive TypeScript provider for integrating GitLab Duo AI capabilities with the Vercel AI SDK. This package enables seamless access to GitLab's AI-powered features including chat, agentic workflows, and tool calling through a unified interface.

🌟 Features

🤖 Multi-Provider Agentic Chat: Native tool calling support via GitLab's AI Gateway (Anthropic & OpenAI)
🔄 Duo Workflow Service: Server-side agentic loop with WebSocket streaming and dynamic model discovery
🔐 Multiple Authentication: Support for OAuth, Personal Access Tokens, and OpenCode auth
🌐 Self-Hosted Support: Works with both GitLab.com and self-hosted instances
🔧 Tool Support: Native tool calling via Vercel AI SDK and MCP tools for workflows
🔍 Project Detection: Automatic GitLab project detection from git remotes
💾 Smart Caching: Project, token, and model discovery caching for optimal performance
🎯 Type-Safe: Complete TypeScript definitions with Zod validation

📦 Installation

npm install gitlab-ai-provider

Peer Dependencies

npm install @ai-sdk/provider @ai-sdk/provider-utils

🚀 Quick Start

Basic Chat

import { createGitLab } from 'gitlab-ai-provider';
import { generateText } from 'ai';

const gitlab = createGitLab({
  apiKey: process.env.GITLAB_TOKEN,
  instanceUrl: 'https://gitlab.com', // optional, defaults to gitlab.com
});

// All equivalent ways to create a chat model:
const model = gitlab('duo-chat'); // callable provider
const model2 = gitlab.chat('duo-chat'); // .chat() alias (recommended)
const model3 = gitlab.languageModel('duo-chat'); // explicit method

const { text } = await generateText({
  model: gitlab.chat('duo-chat'),
  prompt: 'Explain how to create a merge request in GitLab',
});

console.log(text);

Agentic Chat with Tool Calling

import { createGitLab } from 'gitlab-ai-provider';
import { generateText } from 'ai';

const gitlab = createGitLab({
  apiKey: process.env.GITLAB_TOKEN,
});

// Use agentic model for native tool calling support
const model = gitlab.agenticChat('duo-chat', {
  anthropicModel: 'claude-sonnet-4-20250514',
  maxTokens: 8192,
});

const { text } = await generateText({
  model,
  prompt: 'List all open merge requests in my project',
  tools: {
    // Your custom tools here
  },
});

Model Variants

The provider automatically maps specific model IDs to their corresponding provider models (Anthropic or OpenAI) and routes requests to the appropriate AI Gateway proxy:

import { createGitLab } from 'gitlab-ai-provider';
import { generateText } from 'ai';

const gitlab = createGitLab({
  apiKey: process.env.GITLAB_TOKEN,
});

// Anthropic Models (Claude)
const opusModel = gitlab.agenticChat('duo-chat-opus-4-5');
// Automatically uses: claude-opus-4-5-20251101

const sonnetModel = gitlab.agenticChat('duo-chat-sonnet-4-5');
// Automatically uses: claude-sonnet-4-5-20250929

const haikuModel = gitlab.agenticChat('duo-chat-haiku-4-5');
// Automatically uses: claude-haiku-4-5-20251001

// OpenAI Models (GPT-5)
const gpt5Model = gitlab.agenticChat('duo-chat-gpt-5-1');
// Automatically uses: gpt-5.1-2025-11-13

const gpt5MiniModel = gitlab.agenticChat('duo-chat-gpt-5-mini');
// Automatically uses: gpt-5-mini-2025-08-07

const codexModel = gitlab.agenticChat('duo-chat-gpt-5-codex');
// Automatically uses: gpt-5-codex

// You can still override with explicit providerModel option
const customModel = gitlab.agenticChat('duo-chat-opus-4-5', {
  providerModel: 'claude-sonnet-4-5-20250929', // Override mapping
});

Available Model Mappings:

| Model ID | Provider | Backend Model | | ------------------------ | --------- | ---------------------------- | | duo-chat-opus-4-5 | Anthropic | claude-opus-4-5-20251101 | | duo-chat-sonnet-4-5 | Anthropic | claude-sonnet-4-5-20250929 | | duo-chat-haiku-4-5 | Anthropic | claude-haiku-4-5-20251001 | | duo-chat-gpt-5-1 | OpenAI | gpt-5.1-2025-11-13 | | duo-chat-gpt-5-mini | OpenAI | gpt-5-mini-2025-08-07 | | duo-chat-gpt-5-codex | OpenAI | gpt-5-codex | | duo-chat-gpt-5-2-codex | OpenAI | gpt-5.2-codex |

For unmapped Anthropic model IDs, the provider defaults to claude-sonnet-4-5-20250929.

OpenAI Models (GPT-5)

The provider supports OpenAI GPT-5 models through GitLab's AI Gateway proxy. OpenAI models are automatically detected based on the model ID and routed to the appropriate proxy endpoint.

import { createGitLab } from 'gitlab-ai-provider';
import { generateText } from 'ai';

const gitlab = createGitLab({
  apiKey: process.env.GITLAB_TOKEN,
});

// GPT-5.1 - Most capable model
const { text } = await generateText({
  model: gitlab.agenticChat('duo-chat-gpt-5-1'),
  prompt: 'Explain GitLab CI/CD pipelines',
});

// GPT-5 Mini - Fast and efficient
const { text: quickResponse } = await generateText({
  model: gitlab.agenticChat('duo-chat-gpt-5-mini'),
  prompt: 'Summarize this code',
});

// GPT-5 Codex - Optimized for code
const { text: codeExplanation } = await generateText({
  model: gitlab.agenticChat('duo-chat-gpt-5-codex'),
  prompt: 'Refactor this function for better performance',
});

OpenAI Models with Tool Calling:

import { createGitLab } from 'gitlab-ai-provider';
import { generateText, tool } from 'ai';
import { z } from 'zod';

const gitlab = createGitLab({
  apiKey: process.env.GITLAB_TOKEN,
});

const { text, toolCalls } = await generateText({
  model: gitlab.agenticChat('duo-chat-gpt-5-1', {
    maxTokens: 4096,
  }),
  prompt: 'What is the weather in San Francisco?',
  tools: {
    getWeather: tool({
      description: 'Get the weather for a location',
      parameters: z.object({
        location: z.string().describe('The city name'),
      }),
      execute: async ({ location }) => {
        return { temperature: 72, condition: 'sunny', location };
      },
    }),
  },
});

Agentic Chat with Feature Flags

You can pass feature flags to enable experimental features in GitLab's AI Gateway proxy:

import { createGitLab } from 'gitlab-ai-provider';

// Option 1: Set feature flags globally for all agentic chat models
const gitlab = createGitLab({
  apiKey: process.env.GITLAB_TOKEN,
  featureFlags: {
    duo_agent_platform_agentic_chat: true,
    duo_agent_platform: true,
  },
});

const model = gitlab.agenticChat('duo-chat');

// Option 2: Set feature flags per model (overrides global flags)
const modelWithFlags = gitlab.agenticChat('duo-chat', {
  featureFlags: {
    duo_agent_platform_agentic_chat: true,
    duo_agent_platform: true,
    custom_feature_flag: false,
  },
});

// Option 3: Merge both (model-level flags take precedence)
const gitlab2 = createGitLab({
  featureFlags: {
    duo_agent_platform: true, // will be overridden
  },
});

const mergedModel = gitlab2.agenticChat('duo-chat', {
  featureFlags: {
    duo_agent_platform: false, // overrides provider-level
    duo_agent_platform_agentic_chat: true, // adds new flag
  },
});

Duo Workflow Service (Server-Side Agentic)

The Duo Workflow Service provides a server-side agentic loop where GitLab drives the LLM and streams tool execution requests to the client via WebSocket. This enables powerful agentic workflows with dynamic model discovery and MCP tool integration.

Requirements:

GitLab Ultimate with Duo Enterprise add-on
GitLab 18.4+ (18.5+ for pinned model support)

import { createGitLab } from 'gitlab-ai-provider';
import { streamText } from 'ai';

const gitlab = createGitLab({
  apiKey: process.env.GITLAB_TOKEN,
  instanceUrl: 'https://gitlab.com', // or your self-hosted instance
});

// Use the duo-workflow model for server-side agentic workflows
const model = gitlab.workflowChat('duo-workflow', {
  // Optional: Specify root namespace for model discovery
  rootNamespaceId: 'gid://gitlab/Group/12345',

  // Optional: Provide MCP tools for the workflow
  mcpTools: [
    {
      name: 'searchCode',
      description: 'Search for code in the repository',
      inputSchema: JSON.stringify({
        type: 'object',
        properties: {
          query: { type: 'string' },
        },
        required: ['query'],
      }),
    },
  ],

  // Optional: Pre-approve tools for automatic execution
  preapprovedTools: ['read_file', 'write_file'],
});

// Stream the workflow execution
const result = await streamText({
  model,
  prompt: 'Refactor the authentication module to use JWT tokens',
});

for await (const chunk of result.textStream) {
  process.stdout.write(chunk);
}

Dynamic Model Discovery:

The workflow service automatically discovers available models for your namespace and respects admin-pinned models:

const model = gitlab.workflowChat('duo-workflow', {
  rootNamespaceId: 'gid://gitlab/Group/12345',

  // Optional: Callback for interactive model selection
  onSelectModel: async (models) => {
    // Present model picker to user
    console.log('Available models:', models);
    // Return selected model ref or null for default
    return models[0].ref;
  },
});

Model Selection Priority:

Admin-pinned model (always used if set)
User-selected model (via onSelectModel callback)
Namespace default model

Built-in Tool Support:

The workflow service automatically maps DWS built-in tools to consumer tool names:

| DWS Tool | Consumer Tool | Description | | ----------------- | ------------- | ----------------------------- | | runReadFile | read | Read file contents | | runWriteFile | write | Write file contents | | runEditFile | edit | Edit file with old/new string | | runShellCommand | bash | Execute shell command | | runCommand | bash | Execute structured command | | runGitCommand | bash | Execute git command | | listDirectory | read | List directory contents | | findFiles | glob | Find files by pattern | | grep | grep | Search file contents | | mkdir | bash | Create directory | | runHTTPRequest | bash | Execute HTTP request |

Workflow Options:

interface GitLabWorkflowOptions {
  // Root namespace ID for model discovery and token scoping
  rootNamespaceId?: string;

  // GitLab project ID (numeric or path)
  projectId?: string;

  // GitLab namespace ID
  namespaceId?: string;

  // MCP tool definitions to expose to the workflow
  mcpTools?: McpToolDefinition[];

  // Client capabilities to advertise
  clientCapabilities?: string[]; // Default: ['shell_command']

  // Tool names pre-approved for execution without confirmation
  preapprovedTools?: string[];

  // Additional context items for conversation history
  additionalContext?: AdditionalContext[];

  // Feature flags for the workflow
  featureFlags?: Record<string, boolean>;

  // Working directory for project auto-detection
  workingDirectory?: string; // Default: process.cwd()

  // Flow configuration for agent behavior
  flowConfig?: unknown;

  // Flow configuration schema version
  flowConfigSchemaVersion?: string;

  // Callback for interactive model selection
  onSelectModel?: (models: AiModel[]) => Promise<string | null | undefined>;
}

Environment Variables:

| Variable | Description | Default | | --------------------- | ------------------------------------------- | -------------------- | | GITLAB_INSTANCE_URL | GitLab instance URL | https://gitlab.com | | GITLAB_TOKEN | GitLab Personal Access Token or OAuth token | - |

Model Cache:

The workflow service caches model discovery results and user selections in ~/.cache/opencode/gitlab-workflow-model-cache.json (or $XDG_CACHE_HOME/opencode/...). The cache is keyed by workspace directory and instance URL, with a 10-minute TTL for discovery data.

🔑 Authentication

Personal Access Token

const gitlab = createGitLab({
  apiKey: 'glpat-xxxxxxxxxxxxxxxxxxxx',
});

Environment Variable

export GITLAB_TOKEN=glpat-xxxxxxxxxxxxxxxxxxxx

const gitlab = createGitLab(); // Automatically uses GITLAB_TOKEN

OAuth (OpenCode Auth)

The provider automatically detects and uses OpenCode authentication if available:

const gitlab = createGitLab({
  instanceUrl: 'https://gitlab.com',
  // OAuth tokens are loaded from ~/.opencode/auth.json
});

Custom Headers

const gitlab = createGitLab({
  apiKey: 'your-token',
  headers: {
    'X-Custom-Header': 'value',
  },
});

AI Gateway Headers

Custom headers can be sent to GitLab's AI Gateway (Anthropic/OpenAI proxy) for traffic identification and routing. By default, the provider sends User-Agent: gitlab-ai-provider/{version}.

// Provider-level headers (apply to all agentic models)
const gitlab = createGitLab({
  apiKey: process.env.GITLAB_TOKEN,
  aiGatewayHeaders: {
    'X-Custom-Routing': 'premium-tier',
  },
});

// Model-level headers (override provider-level)
const model = gitlab.agenticChat('duo-chat-opus-4-5', {
  aiGatewayHeaders: {
    'X-Request-Priority': 'high',
  },
});

Header Precedence (lowest to highest):

Default headers (User-Agent: gitlab-ai-provider/{version})
Provider-level aiGatewayHeaders
Model-level aiGatewayHeaders

🏗️ Architecture

Core Components

1. GitLabProvider

Main provider factory that creates language models with different capabilities.

interface GitLabProvider {
  (modelId: string): LanguageModelV2;
  languageModel(modelId: string): LanguageModelV2;
  agenticChat(modelId: string, options?: GitLabAgenticOptions): GitLabAgenticLanguageModel;
  workflowChat(modelId: string, options?: GitLabWorkflowOptions): GitLabWorkflowLanguageModel;
}

2. GitLabAnthropicLanguageModel

Provides native tool calling through GitLab's Anthropic proxy.

Uses Claude models via https://cloud.gitlab.com/ai/v1/proxy/anthropic/
Automatic token refresh and retry logic
Direct access token management
Supports all Anthropic tool calling features

3. GitLabOpenAILanguageModel

Provides native tool calling through GitLab's OpenAI proxy.

Uses GPT-5 models via https://cloud.gitlab.com/ai/v1/proxy/openai/
Automatic token refresh and retry logic
Direct access token management
Supports all OpenAI tool calling features including parallel tool calls

4. GitLabWorkflowLanguageModel

Provides server-side agentic execution through GitLab Duo Workflow Service.

WebSocket-based bidirectional communication with DWS
Dynamic model discovery via GraphQL (aiChatAvailableModels)
Automatic model selection (pinned → user-selected → default)
Built-in tool mapping and MCP tool support
Per-stream state isolation for concurrent requests
Dual heartbeat (WebSocket ping + JSON heartbeat)

Supporting Utilities

GitLabProjectDetector

Automatically detects GitLab projects from git remotes.

const detector = new GitLabProjectDetector({
  instanceUrl: 'https://gitlab.com',
  getHeaders: () => ({ Authorization: `Bearer ${token}` }),
});

const project = await detector.detectProject(process.cwd());
// Returns: { id: 12345, path: 'group/project', namespaceId: 67890 }

GitLabProjectCache

Caches project information with TTL.

const cache = new GitLabProjectCache(5 * 60 * 1000); // 5 minutes
cache.set('key', project);
const cached = cache.get('key');

GitLabOAuthManager

Manages OAuth token lifecycle.

const oauthManager = new GitLabOAuthManager();

// Exchange authorization code
const tokens = await oauthManager.exchangeAuthorizationCode({
  instanceUrl: 'https://gitlab.com',
  code: 'auth-code',
  codeVerifier: 'verifier',
});

// Refresh tokens
const refreshed = await oauthManager.refreshIfNeeded(tokens);

GitLabDirectAccessClient

Manages direct access tokens for Anthropic proxy.

const client = new GitLabDirectAccessClient({
  instanceUrl: 'https://gitlab.com',
  getHeaders: () => ({ Authorization: `Bearer ${token}` }),
});

const directToken = await client.getDirectAccessToken();
// Returns: { token: 'xxx', headers: {...}, expiresAt: 123456 }

GitLabModelDiscovery

Discovers available workflow models via GraphQL.

const discovery = new GitLabModelDiscovery({
  instanceUrl: 'https://gitlab.com',
  getHeaders: () => ({ Authorization: `Bearer ${token}` }),
});

const models = await discovery.discover('gid://gitlab/Group/12345');
// Returns: { defaultModel, selectableModels, pinnedModel, modelSwitchingEnabled }

const effectiveRef = await discovery.getEffectiveModelRef(
  'gid://gitlab/Group/12345',
  'claude_sonnet_4_6'
);

GitLabModelCache

Persists model discovery results and user selections.

const cache = new GitLabModelCache('/workspace/path', 'https://gitlab.com');

cache.saveDiscovery(discoveredModels);
cache.saveSelection('claude_sonnet_4_6', 'Claude Sonnet 4.6');

const selectedRef = cache.getSelectedModelRef();
const discovery = cache.getDiscovery();

GitLabWorkflowClient

Low-level WebSocket client for DWS communication.

const client = new GitLabWorkflowClient();

await client.connect(
  {
    instanceUrl: 'https://gitlab.com',
    modelRef: 'claude_sonnet_4_6',
    headers: { Authorization: `Bearer ${token}` },
    projectId: 'my-group/my-project',
  },
  (event) => {
    if (event.type === 'checkpoint') {
      console.log('Checkpoint:', event.data);
    } else if (event.type === 'tool-request') {
      console.log('Tool request:', event.data);
    }
  }
);

client.sendStartRequest({ workflowID: '123', goal: 'Refactor code', ... });
client.sendActionResponse('request-id', 'tool result');
client.stop();

GitLabWorkflowTokenClient

Manages DWS token lifecycle and workflow creation.

const tokenClient = new GitLabWorkflowTokenClient({
  instanceUrl: 'https://gitlab.com',
  getHeaders: () => ({ Authorization: `Bearer ${token}` }),
});

const token = await tokenClient.getToken('chat', 'gid://gitlab/Group/12345');
const workflowId = await tokenClient.createWorkflow('Refactor authentication', {
  projectId: 'my-group/my-project',
});

📚 API Reference

Provider Configuration

interface GitLabProviderSettings {
  instanceUrl?: string; // Default: 'https://gitlab.com'
  apiKey?: string; // PAT or OAuth access token
  refreshToken?: string; // OAuth refresh token
  name?: string; // Provider name prefix
  headers?: Record<string, string>; // Custom headers for GitLab API
  aiGatewayHeaders?: Record<string, string>; // Custom headers for AI Gateway proxy
  fetch?: typeof fetch; // Custom fetch implementation
  aiGatewayUrl?: string; // AI Gateway URL (default: 'https://cloud.gitlab.com')
}

Environment Variables

| Variable | Description | Default | | ----------------------- | ------------------------------------------- | -------------------------- | | GITLAB_TOKEN | GitLab Personal Access Token or OAuth token | - | | GITLAB_INSTANCE_URL | GitLab instance URL | https://gitlab.com | | GITLAB_AI_GATEWAY_URL | AI Gateway URL for Anthropic proxy | https://cloud.gitlab.com |

Agentic Chat Options

interface GitLabAgenticOptions {
  providerModel?: string; // Override the backend model (e.g., 'claude-sonnet-4-5-20250929' or 'gpt-5.1-2025-11-13')
  maxTokens?: number; // Default: 8192
  featureFlags?: Record<string, boolean>; // GitLab feature flags
  aiGatewayHeaders?: Record<string, string>; // Custom headers for AI Gateway proxy (per-model)
}

Note: The providerModel option allows you to override the automatically mapped model. The provider will validate that the override is compatible with the model ID's provider (e.g., you cannot use an OpenAI model with a duo-chat-opus-* model ID).

Error Handling

import { GitLabError } from 'gitlab-ai-provider';

try {
  const result = await generateText({ model, prompt });
} catch (error) {
  if (error instanceof GitLabError) {
    if (error.isAuthError()) {
      console.error('Authentication failed');
    } else if (error.isRateLimitError()) {
      console.error('Rate limit exceeded');
    } else if (error.isServerError()) {
      console.error('Server error:', error.statusCode);
    }
  }
}

🔧 Development

Build

npm run build          # Build once
npm run build:watch    # Build in watch mode

Testing

npm test              # Run all tests
npm run test:watch    # Run tests in watch mode

Code Quality

npm run lint          # Lint code
npm run lint:fix      # Lint and auto-fix
npm run format        # Format code
npm run format:check  # Check formatting
npm run type-check    # TypeScript type checking

Project Structure

gitlab-ai-provider/
├── src/
│   ├── index.ts                            # Main exports
│   ├── gitlab-provider.ts                  # Provider factory
│   ├── gitlab-anthropic-language-model.ts  # Anthropic/Claude model
│   ├── gitlab-openai-language-model.ts     # OpenAI/GPT model
│   ├── gitlab-workflow-language-model.ts   # Workflow/DWS model
│   ├── gitlab-workflow-client.ts           # WebSocket client for DWS
│   ├── gitlab-workflow-token-client.ts     # DWS token management
│   ├── gitlab-workflow-builtins.ts         # Built-in tool mapping
│   ├── gitlab-workflow-types.ts            # DWS protocol types
│   ├── gitlab-model-discovery.ts           # GraphQL model discovery
│   ├── gitlab-model-cache.ts               # Model selection cache
│   ├── model-mappings.ts                   # Model ID mappings
│   ├── gitlab-direct-access.ts             # Direct access tokens
│   ├── gitlab-oauth-manager.ts             # OAuth management
│   ├── gitlab-oauth-types.ts               # OAuth types
│   ├── gitlab-project-detector.ts          # Project detection
│   ├── gitlab-project-cache.ts             # Project caching
│   ├── gitlab-api-types.ts                 # API types
│   └── gitlab-error.ts                     # Error handling
├── tests/                                  # Test files (300 tests)
├── dist/                                   # Build output
├── package.json
├── tsconfig.json
├── tsup.config.ts
└── vitest.config.ts

📝 Code Style

Imports: Named imports, organized by external → internal → types
Formatting: Single quotes, semicolons, 100 char line width, 2 space indent
Types: Interfaces for public APIs, Zod schemas for runtime validation
Naming: camelCase (variables/functions), PascalCase (classes/types), kebab-case (files)
Exports: Named exports only (no default exports)
Comments: JSDoc for public APIs with @param/@returns

Assistant

🤝 Contributing

Contributions are welcome! Please see our Contributing Guide for detailed guidelines on:

Code style and conventions
Development workflow
Testing requirements
Submitting merge requests
Developer Certificate of Origin and License

Quick Start for Contributors:

Commit Messages: Use conventional commits format


feat(scope): add new feature
fix(scope): fix bug
docs(scope): update documentation

Code Quality: Ensure all checks pass

npm run lint
npm run type-check
npm test

Testing: Add tests for new features

🔗 Links

🙏 Acknowledgments

This project is built on top of:

Made with ❤️ for the OpenCode community