feat: Add GitLab Duo Agentic Chat Provider Support

[vglafirov]

Add GitLab Duo Provider Support

Problem

In-line with GitLab's open-core strategy, we want to officially integrate GitLab Duo with OpenCode as a supported provider, operable with both GitLab.com and self-hosted GitLab instances. To streamline our users' journey across tools and enable access to GitLab's AI capabilities including agentic chat with native tool calling, GitLab is upstreaming the required provider packages to this repository.

Solution

This PR adds GitLab as a supported provider with three agentic chat model variants (Haiku, Sonnet, Opus), enabling seamless integration with GitLab.com and self-hosted instances.

Changes

Dependencies Added

• @gitlab/gitlab-ai-provider@3.0.9 - Provider implementation
• @gitlab/opencode-gitlab-auth@1.2.1 - OAuth/PAT authentication
• @gitlab/opencode-gitlab-plugin@1.0.6 - GitLab API tools

Provider Implementation

• Added GitLab to bundled providers in provider.ts
• Implemented custom loader with multi-source auth (env, config, OAuth, PAT)
• Registered three Claude-based models: haiku-4-5, sonnet-4-5, opus-4-5
• OAuth token refresh support
• Self-hosted GitLab instance support via GITLAB_INSTANCE_URL

Plugin Auto-Loading

• GitLab auth/tools plugins load automatically when GitLab is configured
• Checks environment variables, config, and auth.json
• Respects OPENCODE_DISABLE_DEFAULT_PLUGINS flag

Tests

• Added 8 provider-specific tests covering auth methods, config options, and model availability
• All 619 existing tests pass

Files Changed

• packages/opencode/package.json - Added 3 GitLab dependencies
• packages/opencode/src/provider/provider.ts - GitLab provider implementation
• packages/opencode/src/plugin/index.ts - Auto-loading logic
• packages/opencode/test/provider/gitlab-duo.test.ts - New tests (8 tests)
• packages/docs/essentials/gitlab-duo.mdx - Documentation

Usage

Basic setup with environment variable:

export GITLAB_TOKEN="glpat-xxxxxxxxxxxx"

Then use in config:

{
  "model": "gitlab/duo-chat-sonnet-4-5"
}

Self-hosted GitLab:

export GITLAB_INSTANCE_URL="https://gitlab.company.internal"
export GITLAB_TOKEN="glpat-xxxxxxxxxxxx"

Testing

• All 619 existing tests pass
• Added 8 provider-specific tests
• Tested with GitLab.com and environment variable auth

Closes #7455

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

No duplicate PRs found

[vglafirov]

Related PR to models.dev registry: anomalyco/models.dev#616

[rekram1-node]

/review

[vglafirov]

/review

[vglafirov]

Closes #7455

[vglafirov]

I am not sure why PR Standards check is failing. I've created an issue and linked it to this PR.

[rekram1-node]

@vglafirov apologies for delay I had this open on my computer but forgot to look at it

[vglafirov]

@rekram1-node You recently merged Gitlab Duo PR on models.dev, but deployment pipeline is failing. If we get models deployed on models.dev, I can remove models from https://github.com/anomalyco/opencode/pull/7333/changes#diff-b0155a9e5561043f50ba86bc54d5fd59aa528c7af7c92b2f37585d80e792cd9aR740

PR to fix deployment issues: anomalyco/models.dev#631

[rekram1-node]

@vglafirov I merged pr thx for callout

[rekram1-node]

why are these 2 added as deps if they arent imported?

[vglafirov]

The @gitlab/opencode-gitlab-auth and @gitlab/opencode-gitlab-plugin packages are imported, but dynamically in the auto-loading logic at packages/opencode/src/plugin/index.ts. They're loaded conditionally when GitLab is configured:

if (shouldLoadGitLabPlugins && !Flag.OPENCODE_DISABLE_DEFAULT_PLUGINS) {
    log.info("auto-loading GitLab plugins")
    plugins.push("@gitlab/opencode-gitlab-auth@latest")
    plugins.push("@gitlab/opencode-gitlab-plugin@latest")
}

Since they're dynamically imported rather than statically at the top of the file, they need to be in dependencies (not devDependencies) for runtime availability

[rekram1-node]

Can you link me to these packages you are adding? for some reason they aren't popping up when I try to search for them but that is likely me being an idiot

[rekram1-node]

Just address these and I will merge tmr morn! Once again sorry for delays our issue and pr volume has exploded

Feel free to DM or email me if needed

[vglafirov]

Can you link me to these packages you are adding? for some reason they aren't popping up when I try to search for them but that is likely me being an idiot

You are not an idiot. I have no idea why, but they are not popping up in a search, for some reason 😞 Here they are:

1. Gitlab AI Provider
2. Gitlab Auth Plugin
3. Gitlab Plugin for OpenCode

[kamilchm]

@vglafirov this is awesome — thanks for building it!
I have a self-hosted GitLab in my organization and would love to test the integration.
Is there any doc I should follow, or a quick minimal setup guide (env vars + callback URL/redirect URI + required scopes) to get it working?