feat: Add GitLab Duo Agentic Chat Provider Support (#7333)

Co-authored-by: Aiden Cline <[email protected]>
Co-authored-by: Aiden Cline <[email protected]>

6 files changed, 433 insertions, 2 deletions

diff --git a/packages/opencode/package.json b/packages/opencode/package.json
index f2c95d0b3..c0c4e79b6 100644
--- a/packages/opencode/package.json
+++ b/packages/opencode/package.json
@@ -70,6 +70,7 @@
     "@ai-sdk/vercel": "1.0.31",
     "@ai-sdk/xai": "2.0.51",
     "@clack/prompts": "1.0.0-alpha.1",
+    "@gitlab/gitlab-ai-provider": "3.1.0",
     "@hono/standard-validator": "0.1.5",
     "@hono/zod-validator": "catalog:",
     "@modelcontextprotocol/sdk": "1.25.2",
diff --git a/packages/opencode/src/plugin/index.ts b/packages/opencode/src/plugin/index.ts
index b0c9eee2c..8ce6dfd3c 100644
--- a/packages/opencode/src/plugin/index.ts
+++ b/packages/opencode/src/plugin/index.ts
@@ -14,7 +14,11 @@ import { NamedError } from "@opencode-ai/util/error"
 export namespace Plugin {
   const log = Log.create({ service: "plugin" })
 
-  const BUILTIN = ["[email protected]", "[email protected]"]
+  const BUILTIN = [
+    "[email protected]",
+    "[email protected]",
+    "@gitlab/[email protected]",
+  ]
 
   // Built-in plugins that are directly imported (not installed from npm)
   const INTERNAL_PLUGINS: PluginInstance[] = [CodexAuthPlugin]
@@ -46,6 +50,7 @@ export namespace Plugin {
     if (!Flag.OPENCODE_DISABLE_DEFAULT_PLUGINS) {
       plugins.push(...BUILTIN)
     }
+
     for (let plugin of plugins) {
       // ignore old codex plugin since it is supported first party now
       if (plugin.includes("opencode-openai-codex-auth")) continue
diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index 3b76b1e02..9bde1333e 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -1,4 +1,6 @@
 import z from "zod"
+import path from "path"
+import os from "os"
 import fuzzysort from "fuzzysort"
 import { Config } from "../config/config"
 import { mapValues, mergeDeep, omit, pickBy, sortBy } from "remeda"
@@ -35,6 +37,7 @@ import { createGateway } from "@ai-sdk/gateway"
 import { createTogetherAI } from "@ai-sdk/togetherai"
 import { createPerplexity } from "@ai-sdk/perplexity"
 import { createVercel } from "@ai-sdk/vercel"
+import { createGitLab } from "@gitlab/gitlab-ai-provider"
 import { ProviderTransform } from "./transform"
 
 export namespace Provider {
@@ -60,6 +63,7 @@ export namespace Provider {
     "@ai-sdk/togetherai": createTogetherAI,
     "@ai-sdk/perplexity": createPerplexity,
     "@ai-sdk/vercel": createVercel,
+    "@gitlab/gitlab-ai-provider": createGitLab,
     // @ts-ignore (TODO: kill this code so we dont have to maintain it)
     "@ai-sdk/github-copilot": createGitHubCopilotOpenAICompatible,
   }
@@ -390,6 +394,43 @@ export namespace Provider {
         },
       }
     },
+    async gitlab(input) {
+      const instanceUrl = Env.get("GITLAB_INSTANCE_URL") || "https://gitlab.com"
+
+      const auth = await Auth.get(input.id)
+      const apiKey = await (async () => {
+        if (auth?.type === "oauth") return auth.access
+        if (auth?.type === "api") return auth.key
+        return Env.get("GITLAB_TOKEN")
+      })()
+
+      const config = await Config.get()
+      const providerConfig = config.provider?.["gitlab"]
+
+      return {
+        autoload: !!apiKey,
+        options: {
+          instanceUrl,
+          apiKey,
+          featureFlags: {
+            duo_agent_platform_agentic_chat: true,
+            duo_agent_platform: true,
+            ...(providerConfig?.options?.featureFlags || {}),
+          },
+        },
+        async getModel(sdk: ReturnType<typeof createGitLab>, modelID: string, options?: { anthropicModel?: string }) {
+          const anthropicModel = options?.anthropicModel
+          return sdk.agenticChat(modelID, {
+            anthropicModel,
+            featureFlags: {
+              duo_agent_platform_agentic_chat: true,
+              duo_agent_platform: true,
+              ...(providerConfig?.options?.featureFlags || {}),
+            },
+          })
+        },
+      }
+    },
     "cloudflare-ai-gateway": async (input) => {
       const accountId = Env.get("CLOUDFLARE_ACCOUNT_ID")
       const gateway = Env.get("CLOUDFLARE_GATEWAY_ID")
diff --git a/packages/opencode/test/provider/amazon-bedrock.test.ts b/packages/opencode/test/provider/amazon-bedrock.test.ts
index d10e85139..05f5bd01f 100644
--- a/packages/opencode/test/provider/amazon-bedrock.test.ts
+++ b/packages/opencode/test/provider/amazon-bedrock.test.ts
@@ -9,7 +9,11 @@ import path from "path"
 
 mock.module("../../src/bun/index", () => ({
   BunProc: {
-    install: async (pkg: string) => pkg,
+    install: async (pkg: string, _version?: string) => {
+      // Return package name without version for mocking
+      const lastAtIndex = pkg.lastIndexOf("@")
+      return lastAtIndex > 0 ? pkg.substring(0, lastAtIndex) : pkg
+    },
     run: async () => {
       throw new Error("BunProc.run should not be called in tests")
     },
@@ -28,6 +32,7 @@ mock.module("@aws-sdk/credential-providers", () => ({
 const mockPlugin = () => ({})
 mock.module("opencode-copilot-auth", () => ({ default: mockPlugin }))
 mock.module("opencode-anthropic-auth", () => ({ default: mockPlugin }))
+mock.module("@gitlab/opencode-gitlab-auth", () => ({ default: mockPlugin }))
 
 // Import after mocks are set up
 const { tmpdir } = await import("../fixture/fixture")
diff --git a/packages/opencode/test/provider/gitlab-duo.test.ts b/packages/opencode/test/provider/gitlab-duo.test.ts
new file mode 100644
index 000000000..4d5aa9c74
--- /dev/null
+++ b/packages/opencode/test/provider/gitlab-duo.test.ts
@@ -0,0 +1,286 @@
+import { test, expect, mock } from "bun:test"
+import path from "path"
+
+// === Mocks ===
+// These mocks prevent real package installations during tests
+
+mock.module("../../src/bun/index", () => ({
+  BunProc: {
+    install: async (pkg: string, _version?: string) => {
+      // Return package name without version for mocking
+      const lastAtIndex = pkg.lastIndexOf("@")
+      return lastAtIndex > 0 ? pkg.substring(0, lastAtIndex) : pkg
+    },
+    run: async () => {
+      throw new Error("BunProc.run should not be called in tests")
+    },
+    which: () => process.execPath,
+    InstallFailedError: class extends Error {},
+  },
+}))
+
+const mockPlugin = () => ({})
+mock.module("opencode-copilot-auth", () => ({ default: mockPlugin }))
+mock.module("opencode-anthropic-auth", () => ({ default: mockPlugin }))
+mock.module("@gitlab/opencode-gitlab-auth", () => ({ default: mockPlugin }))
+
+// Import after mocks are set up
+const { tmpdir } = await import("../fixture/fixture")
+const { Instance } = await import("../../src/project/instance")
+const { Provider } = await import("../../src/provider/provider")
+const { Env } = await import("../../src/env")
+const { Global } = await import("../../src/global")
+
+test("GitLab Duo: loads provider with API key from environment", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("GITLAB_TOKEN", "test-gitlab-token")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      expect(providers["gitlab"]).toBeDefined()
+      expect(providers["gitlab"].key).toBe("test-gitlab-token")
+    },
+  })
+})
+
+test("GitLab Duo: config instanceUrl option sets baseURL", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            gitlab: {
+              options: {
+                instanceUrl: "https://gitlab.example.com",
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("GITLAB_TOKEN", "test-token")
+      Env.set("GITLAB_INSTANCE_URL", "https://gitlab.example.com")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      expect(providers["gitlab"]).toBeDefined()
+      expect(providers["gitlab"].options?.instanceUrl).toBe("https://gitlab.example.com")
+    },
+  })
+})
+
+test("GitLab Duo: loads with OAuth token from auth.json", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+        }),
+      )
+    },
+  })
+
+  const authPath = path.join(Global.Path.data, "auth.json")
+  await Bun.write(
+    authPath,
+    JSON.stringify({
+      gitlab: {
+        type: "oauth",
+        access: "test-access-token",
+        refresh: "test-refresh-token",
+        expires: Date.now() + 3600000,
+      },
+    }),
+  )
+
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("GITLAB_TOKEN", "")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      expect(providers["gitlab"]).toBeDefined()
+    },
+  })
+})
+
+test("GitLab Duo: loads with Personal Access Token from auth.json", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+        }),
+      )
+    },
+  })
+
+  const authPath2 = path.join(Global.Path.data, "auth.json")
+  await Bun.write(
+    authPath2,
+    JSON.stringify({
+      gitlab: {
+        type: "api",
+        key: "glpat-test-pat-token",
+      },
+    }),
+  )
+
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("GITLAB_TOKEN", "")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      expect(providers["gitlab"]).toBeDefined()
+      expect(providers["gitlab"].key).toBe("glpat-test-pat-token")
+    },
+  })
+})
+
+test("GitLab Duo: supports self-hosted instance configuration", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            gitlab: {
+              options: {
+                instanceUrl: "https://gitlab.company.internal",
+                apiKey: "glpat-internal-token",
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("GITLAB_INSTANCE_URL", "https://gitlab.company.internal")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      expect(providers["gitlab"]).toBeDefined()
+      expect(providers["gitlab"].options?.instanceUrl).toBe("https://gitlab.company.internal")
+    },
+  })
+})
+
+test("GitLab Duo: config apiKey takes precedence over environment variable", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            gitlab: {
+              options: {
+                apiKey: "config-token",
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("GITLAB_TOKEN", "env-token")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      expect(providers["gitlab"]).toBeDefined()
+    },
+  })
+})
+
+test("GitLab Duo: supports feature flags configuration", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            gitlab: {
+              options: {
+                featureFlags: {
+                  duo_agent_platform_agentic_chat: true,
+                  duo_agent_platform: true,
+                },
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("GITLAB_TOKEN", "test-token")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      expect(providers["gitlab"]).toBeDefined()
+      expect(providers["gitlab"].options?.featureFlags).toBeDefined()
+      expect(providers["gitlab"].options?.featureFlags?.duo_agent_platform_agentic_chat).toBe(true)
+    },
+  })
+})
+
+test("GitLab Duo: has multiple agentic chat models available", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    init: async () => {
+      Env.set("GITLAB_TOKEN", "test-token")
+    },
+    fn: async () => {
+      const providers = await Provider.list()
+      expect(providers["gitlab"]).toBeDefined()
+      const models = Object.keys(providers["gitlab"].models)
+      expect(models.length).toBeGreaterThan(0)
+      expect(models).toContain("duo-chat-haiku-4-5")
+      expect(models).toContain("duo-chat-sonnet-4-5")
+      expect(models).toContain("duo-chat-opus-4-5")
+    },
+  })
+})
diff --git a/packages/web/src/content/docs/providers.mdx b/packages/web/src/content/docs/providers.mdx
index 80c6f89e1..7af4ab85d 100644
--- a/packages/web/src/content/docs/providers.mdx
+++ b/packages/web/src/content/docs/providers.mdx
@@ -557,6 +557,99 @@ Cloudflare AI Gateway lets you access models from OpenAI, Anthropic, Workers AI,
 
 ---
 
+### GitLab Duo
+
+GitLab Duo provides AI-powered agentic chat with native tool calling capabilities through GitLab's Anthropic proxy.
+
+1. Run the `/connect` command and select GitLab.
+
+   ```txt
+   /connect
+   ```
+
+2. Choose your authentication method:
+
+   ```txt
+   ┌ Select auth method
+   │
+   │ OAuth (Recommended)
+   │ Personal Access Token
+   └
+   ```
+
+   #### Using OAuth (Recommended)
+
+   Select **OAuth** and your browser will open for authorization.
+
+   #### Using Personal Access Token
+   1. Go to [GitLab User Settings > Access Tokens](https://gitlab.com/-/user_settings/personal_access_tokens)
+   2. Click **Add new token**
+   3. Name: `OpenCode`, Scopes: `api`
+   4. Copy the token (starts with `glpat-`)
+   5. Enter it in the terminal
+
+3. Run the `/models` command to see available models.
+
+   ```txt
+   /models
+   ```
+
+   Three Claude-based models are available:
+   - **duo-chat-haiku-4-5** (Default) - Fast responses for quick tasks
+   - **duo-chat-sonnet-4-5** - Balanced performance for most workflows
+   - **duo-chat-opus-4-5** - Most capable for complex analysis
+
+##### Self-Hosted GitLab
+
+For self-hosted GitLab instances:
+
+```bash
+GITLAB_INSTANCE_URL=https://gitlab.company.com GITLAB_TOKEN=glpat-xxxxxxxxxxxxxxxxxxxx opencode
+```
+
+Or add to your bash profile:
+
+```bash title="~/.bash_profile"
+export GITLAB_INSTANCE_URL=https://gitlab.company.com
+export GITLAB_TOKEN=glpat-xxxxxxxxxxxxxxxxxxxx
+```
+
+##### Configuration
+
+Customize through `opencode.json`:
+
+```json title="opencode.json"
+{
+  "$schema": "https://opencode.ai/config.json",
+  "provider": {
+    "gitlab": {
+      "options": {
+        "instanceUrl": "https://gitlab.com",
+        "featureFlags": {
+          "duo_agent_platform_agentic_chat": true,
+          "duo_agent_platform": true
+        }
+      }
+    }
+  }
+}
+```
+
+##### GitLab API Tools (Optional)
+
+To access GitLab tools (merge requests, issues, pipelines, CI/CD, etc.):
+
+```json title="opencode.json"
+{
+  "$schema": "https://opencode.ai/config.json",
+  "plugin": ["@gitlab/opencode-gitlab-plugin"]
+}
+```
+
+This plugin provides comprehensive GitLab repository management capabilities including MR reviews, issue tracking, pipeline monitoring, and more.
+
+---
+
 ### GitHub Copilot
 
 To use your GitHub Copilot subscription with opencode: