Merge pull request #428 from LuxVTZ/feat/gitlab-duo-auth-plus

Add GitLab Duo provider support

README.md

@@ -8,6 +8,13 @@ All third-party provider support is maintained by community contributors; CLIPro
 
 The Plus release stays in lockstep with the mainline features.
 
+GitLab Duo is supported here via OAuth or personal access token login, with model discovery and provider-native routing through the GitLab AI gateway when managed credentials are available.
+
+## Docs
+
+- GitLab Duo guide: [docs/gitlab-duo.md](docs/gitlab-duo.md)
+- 中文说明: [docs/gitlab-duo_CN.md](docs/gitlab-duo_CN.md)
+
 ## Contributing
 
 This project only accepts pull requests that relate to third-party provider support. Any pull requests unrelated to third-party provider support will be rejected.

README_CN.md

@@ -8,6 +8,13 @@
 
 该 Plus 版本的主线功能与主线功能强制同步。
 
+GitLab Duo 已在这里接入，支持 OAuth 或 personal access token 登录，并在 GitLab 提供 managed credentials 时通过 GitLab AI gateway 做 provider-native 路由。
+
+## 文档
+
+- GitLab Duo 说明：[docs/gitlab-duo_CN.md](docs/gitlab-duo_CN.md)
+- English guide: [docs/gitlab-duo.md](docs/gitlab-duo.md)
+
 ## 贡献
 
 该项目仅接受第三方供应商支持的 Pull Request。任何非第三方供应商支持的 Pull Request 都将被拒绝。
@@ -16,4 +23,4 @@
 
 ## 许可证
 
-此项目根据 MIT 许可证授权 - 有关详细信息，请参阅 [LICENSE](LICENSE) 文件。
+此项目根据 MIT 许可证授权 - 有关详细信息，请参阅 [LICENSE](LICENSE) 文件。

cmd/server/main.go

@@ -79,6 +79,8 @@ func main() {
 	var kiloLogin bool
 	var iflowLogin bool
 	var iflowCookie bool
+	var gitlabLogin bool
+	var gitlabTokenLogin bool
 	var noBrowser bool
 	var oauthCallbackPort int
 	var antigravityLogin bool
@@ -111,6 +113,8 @@ func main() {
 	flag.BoolVar(&kiloLogin, "kilo-login", false, "Login to Kilo AI using device flow")
 	flag.BoolVar(&iflowLogin, "iflow-login", false, "Login to iFlow using OAuth")
 	flag.BoolVar(&iflowCookie, "iflow-cookie", false, "Login to iFlow using Cookie")
+	flag.BoolVar(&gitlabLogin, "gitlab-login", false, "Login to GitLab Duo using OAuth")
+	flag.BoolVar(&gitlabTokenLogin, "gitlab-token-login", false, "Login to GitLab Duo using a personal access token")
 	flag.BoolVar(&noBrowser, "no-browser", false, "Don't open browser automatically for OAuth")
 	flag.IntVar(&oauthCallbackPort, "oauth-callback-port", 0, "Override OAuth callback port (defaults to provider-specific port)")
 	flag.BoolVar(&useIncognito, "incognito", false, "Open browser in incognito/private mode for OAuth (useful for multiple accounts)")
@@ -527,6 +531,10 @@ func main() {
 		cmd.DoIFlowLogin(cfg, options)
 	} else if iflowCookie {
 		cmd.DoIFlowCookieAuth(cfg, options)
+	} else if gitlabLogin {
+		cmd.DoGitLabLogin(cfg, options)
+	} else if gitlabTokenLogin {
+		cmd.DoGitLabTokenLogin(cfg, options)
 	} else if kimiLogin {
 		cmd.DoKimiLogin(cfg, options)
 	} else if kiroLogin {

docs/gitlab-duo.md

@@ -0,0 +1,115 @@
+# GitLab Duo guide
+
+CLIProxyAPI can now use GitLab Duo as a first-class provider instead of treating it as a plain text wrapper.
+
+It supports:
+
+- OAuth login
+- personal access token login
+- automatic refresh of GitLab `direct_access` metadata
+- dynamic model discovery from GitLab metadata
+- native GitLab AI gateway routing for Anthropic and OpenAI/Codex managed models
+- Claude-compatible and OpenAI-compatible downstream APIs
+
+## What this means
+
+If GitLab Duo returns an Anthropic-managed model, CLIProxyAPI routes requests through the GitLab AI gateway Anthropic proxy and uses the existing Claude executor path.
+
+If GitLab Duo returns an OpenAI-managed model, CLIProxyAPI routes requests through the GitLab AI gateway OpenAI proxy and uses the existing Codex/OpenAI executor path.
+
+That gives GitLab Duo much closer runtime behavior to the built-in `codex` provider:
+
+- Claude-compatible clients can use GitLab Duo models through `/v1/messages`
+- OpenAI-compatible clients can use GitLab Duo models through `/v1/chat/completions`
+- OpenAI Responses clients can use GitLab Duo models through `/v1/responses`
+
+The model list is not hardcoded. CLIProxyAPI reads the current model metadata from GitLab `direct_access` and registers:
+
+- a stable alias: `gitlab-duo`
+- any discovered managed model names, such as `claude-sonnet-4-5` or `gpt-5-codex`
+
+## Login
+
+OAuth login:
+
+```bash
+./CLIProxyAPI -gitlab-login
+```
+
+PAT login:
+
+```bash
+./CLIProxyAPI -gitlab-token-login
+```
+
+You can also provide inputs through environment variables:
+
+```bash
+export GITLAB_BASE_URL=https://gitlab.com
+export GITLAB_OAUTH_CLIENT_ID=your-client-id
+export GITLAB_OAUTH_CLIENT_SECRET=your-client-secret
+export GITLAB_PERSONAL_ACCESS_TOKEN=glpat-...
+```
+
+Notes:
+
+- OAuth requires a GitLab OAuth application.
+- PAT login requires a personal access token that can call the GitLab APIs used by Duo. In practice, `api` scope is the safe baseline.
+- Self-managed GitLab instances are supported through `GITLAB_BASE_URL`.
+
+## Using the models
+
+After login, start CLIProxyAPI normally and point your client at the local proxy.
+
+You can select:
+
+- `gitlab-duo` to use the current Duo-managed model for that account
+- the discovered provider model name if you want to pin it explicitly
+
+Examples:
+
+```bash
+curl http://127.0.0.1:8080/v1/models
+```
+
+```bash
+curl http://127.0.0.1:8080/v1/chat/completions \
+  -H 'Content-Type: application/json' \
+  -d '{
+    "model": "gitlab-duo",
+    "messages": [
+      {"role": "user", "content": "Write a Go HTTP middleware for request IDs."}
+    ]
+  }'
+```
+
+If the GitLab account is currently mapped to an Anthropic model, Claude-compatible clients can use the same account through the Claude handler path. If the account is currently mapped to an OpenAI/Codex model, OpenAI-compatible clients can use `/v1/chat/completions` or `/v1/responses`.
+
+## How model freshness works
+
+CLIProxyAPI does not ship a fixed GitLab Duo model catalog.
+
+Instead, it refreshes GitLab `direct_access` metadata and uses the returned `model_details` and any discovered model list entries to keep the local registry aligned with the current GitLab-managed model assignment.
+
+This matches GitLab's current public contract better than hardcoding model names.
+
+## Current scope
+
+The GitLab Duo provider now has:
+
+- OAuth and PAT auth flows
+- runtime refresh of Duo gateway credentials
+- native Anthropic gateway routing
+- native OpenAI/Codex gateway routing
+- handler-level smoke tests for Claude-compatible and OpenAI-compatible paths
+
+Still out of scope today:
+
+- websocket or session-specific parity beyond the current HTTP APIs
+- GitLab-specific IDE features that are not exposed through the public gateway contract
+
+## References
+
+- GitLab Code Suggestions API: https://docs.gitlab.com/api/code_suggestions/
+- GitLab Agent Assistant and managed credentials: https://docs.gitlab.com/user/duo_agent_platform/agent_assistant/
+- GitLab Duo model selection: https://docs.gitlab.com/user/gitlab_duo/model_selection/

docs/gitlab-duo_CN.md

@@ -0,0 +1,115 @@
+# GitLab Duo 使用说明
+
+CLIProxyAPI 现在可以把 GitLab Duo 当作一等 Provider 来使用，而不是仅仅把它当成简单的文本补全封装。
+
+当前支持：
+
+- OAuth 登录
+- personal access token 登录
+- 自动刷新 GitLab `direct_access` 元数据
+- 根据 GitLab 返回的元数据动态发现模型
+- 针对 Anthropic 和 OpenAI/Codex 托管模型的 GitLab AI gateway 原生路由
+- Claude 兼容与 OpenAI 兼容下游 API
+
+## 这意味着什么
+
+如果 GitLab Duo 返回的是 Anthropic 托管模型，CLIProxyAPI 会通过 GitLab AI gateway 的 Anthropic 代理转发，并复用现有的 Claude executor 路径。
+
+如果 GitLab Duo 返回的是 OpenAI 托管模型，CLIProxyAPI 会通过 GitLab AI gateway 的 OpenAI 代理转发，并复用现有的 Codex/OpenAI executor 路径。
+
+这让 GitLab Duo 的运行时行为更接近内置的 `codex` Provider：
+
+- Claude 兼容客户端可以通过 `/v1/messages` 使用 GitLab Duo 模型
+- OpenAI 兼容客户端可以通过 `/v1/chat/completions` 使用 GitLab Duo 模型
+- OpenAI Responses 客户端可以通过 `/v1/responses` 使用 GitLab Duo 模型
+
+模型列表不是硬编码的。CLIProxyAPI 会从 GitLab `direct_access` 中读取当前模型元数据，并注册：
+
+- 一个稳定别名：`gitlab-duo`
+- GitLab 当前发现到的托管模型名，例如 `claude-sonnet-4-5` 或 `gpt-5-codex`
+
+## 登录
+
+OAuth 登录：
+
+```bash
+./CLIProxyAPI -gitlab-login
+```
+
+PAT 登录：
+
+```bash
+./CLIProxyAPI -gitlab-token-login
+```
+
+也可以通过环境变量提供输入：
+
+```bash
+export GITLAB_BASE_URL=https://gitlab.com
+export GITLAB_OAUTH_CLIENT_ID=your-client-id
+export GITLAB_OAUTH_CLIENT_SECRET=your-client-secret
+export GITLAB_PERSONAL_ACCESS_TOKEN=glpat-...
+```
+
+说明：
+
+- OAuth 方式需要一个 GitLab OAuth application。
+- PAT 登录需要一个能够调用 GitLab Duo 相关 API 的 personal access token。实践上，`api` scope 是最稳妥的基线。
+- 自建 GitLab 实例可以通过 `GITLAB_BASE_URL` 接入。
+
+## 如何使用模型
+
+登录完成后，正常启动 CLIProxyAPI，并让客户端连接到本地代理。
+
+你可以选择：
+
+- `gitlab-duo`，始终使用该账号当前的 Duo 托管模型
+- GitLab 当前发现到的 provider 模型名，如果你想显式固定模型
+
+示例：
+
+```bash
+curl http://127.0.0.1:8080/v1/models
+```
+
+```bash
+curl http://127.0.0.1:8080/v1/chat/completions \
+  -H 'Content-Type: application/json' \
+  -d '{
+    "model": "gitlab-duo",
+    "messages": [
+      {"role": "user", "content": "Write a Go HTTP middleware for request IDs."}
+    ]
+  }'
+```
+
+如果该 GitLab 账号当前绑定的是 Anthropic 模型，Claude 兼容客户端可以通过 Claude handler 路径直接使用它。如果当前绑定的是 OpenAI/Codex 模型，OpenAI 兼容客户端可以通过 `/v1/chat/completions` 或 `/v1/responses` 使用它。
+
+## 模型如何保持最新
+
+CLIProxyAPI 不内置固定的 GitLab Duo 模型清单。
+
+它会刷新 GitLab `direct_access` 元数据，并使用返回的 `model_details` 以及可能存在的模型列表字段，让本地 registry 尽量与 GitLab 当前分配的托管模型保持一致。
+
+这比硬编码模型名更符合 GitLab 当前公开 API 的实际契约。
+
+## 当前覆盖范围
+
+GitLab Duo Provider 目前已经具备：
+
+- OAuth 和 PAT 登录流程
+- Duo gateway 凭据的运行时刷新
+- Anthropic gateway 原生路由
+- OpenAI/Codex gateway 原生路由
+- Claude 兼容和 OpenAI 兼容路径的 handler 级 smoke 测试
+
+当前仍未覆盖：
+
+- websocket 或 session 级别的完全对齐
+- GitLab 公开 gateway 契约之外的 IDE 专有能力
+
+## 参考资料
+
+- GitLab Code Suggestions API: https://docs.gitlab.com/api/code_suggestions/
+- GitLab Agent Assistant 与 managed credentials: https://docs.gitlab.com/user/duo_agent_platform/agent_assistant/
+- GitLab Duo 模型选择: https://docs.gitlab.com/user/gitlab_duo/model_selection/

gitlab-duo-codex-parity-plan.md

@@ -0,0 +1,278 @@
+# Plan: GitLab Duo Codex Parity
+
+**Generated**: 2026-03-10
+**Estimated Complexity**: High
+
+## Overview
+Bring GitLab Duo support from the current "auth + basic executor" stage to the same practical level as `codex` inside `CLIProxyAPI`: a user logs in once, points external clients such as Claude Code at `CLIProxyAPI`, selects GitLab Duo-backed models, and gets stable streaming, multi-turn behavior, tool calling compatibility, and predictable model routing without manual provider-specific workarounds.
+
+The core architectural shift is to stop treating GitLab Duo as only two REST wrappers (`/api/v4/chat/completions` and `/api/v4/code_suggestions/completions`) and instead use GitLab's `direct_access` contract as the primary runtime entrypoint wherever possible. Official GitLab docs confirm that `direct_access` returns AI gateway connection details, headers, token, and expiry; that contract is the closest path to codex-like provider behavior.
+
+## Prerequisites
+- Official GitLab Duo API references confirmed during implementation:
+  - `POST /api/v4/code_suggestions/direct_access`
+  - `POST /api/v4/code_suggestions/completions`
+  - `POST /api/v4/chat/completions`
+- Access to at least one real GitLab Duo account for manual verification.
+- One downstream client target for acceptance testing:
+  - Claude Code against Claude-compatible endpoint
+  - OpenAI-compatible client against `/v1/chat/completions` and `/v1/responses`
+- Existing PR branch as starting point:
+  - `feat/gitlab-duo-auth`
+  - PR [#2028](https://github.com/router-for-me/CLIProxyAPI/pull/2028)
+
+## Definition Of Done
+- GitLab Duo models can be used via `CLIProxyAPI` from the same client surfaces that already work for `codex`.
+- Upstream streaming is real passthrough or faithful chunked forwarding, not synthetic whole-response replay.
+- Tool/function calling survives translation layers without dropping fields or corrupting names.
+- Multi-turn and session semantics are stable across `chat/completions`, `responses`, and Claude-compatible routes.
+- Model exposure stays current from GitLab metadata or gateway discovery without hardcoded stale model tables.
+- `go test ./...` stays green and at least one real manual end-to-end client flow is documented.
+
+## Sprint 1: Contract And Gap Closure
+**Goal**: Replace assumptions with a hard compatibility contract between current `codex` behavior and what GitLab Duo can actually support.
+
+**Demo/Validation**:
+- Written matrix showing `codex` features vs current GitLab Duo behavior.
+- One checked-in developer note or test fixture for real GitLab Duo payload examples.
+
+### Task 1.1: Freeze Codex Parity Checklist
+- **Location**: [internal/runtime/executor/codex_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/codex_executor.go), [internal/runtime/executor/codex_websockets_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/codex_websockets_executor.go), [sdk/api/handlers/openai/openai_responses_handlers.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/api/handlers/openai/openai_responses_handlers.go), [sdk/api/handlers/openai/openai_responses_websocket.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/api/handlers/openai/openai_responses_websocket.go)
+- **Description**: Produce a concrete feature matrix for `codex`: HTTP execute, SSE execute, `/v1/responses`, websocket downstream path, tool calling, request IDs, session close semantics, and model registration behavior.
+- **Dependencies**: None
+- **Acceptance Criteria**:
+  - A checklist exists in repo docs or issue notes.
+  - Each capability is marked `required`, `optional`, or `not possible` for GitLab Duo.
+- **Validation**:
+  - Review against current `codex` code paths.
+
+### Task 1.2: Lock GitLab Duo Runtime Contract
+- **Location**: [internal/auth/gitlab/gitlab.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/auth/gitlab/gitlab.go), [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go)
+- **Description**: Validate the exact upstream contract we can rely on:
+  - `direct_access` fields and refresh cadence
+  - whether AI gateway path is usable directly
+  - when `chat/completions` is available vs when fallback is required
+  - what streaming shape is returned by `code_suggestions/completions?stream=true`
+- **Dependencies**: Task 1.1
+- **Acceptance Criteria**:
+  - GitLab transport decision is explicit: `gateway-first`, `REST-first`, or `hybrid`.
+  - Unknown areas are isolated behind feature flags, not spread across executor logic.
+- **Validation**:
+  - Official docs + captured real responses from a Duo account.
+
+### Task 1.3: Define Client-Facing Compatibility Targets
+- **Location**: [README.md](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/README.md), [gitlab-duo-codex-parity-plan.md](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/gitlab-duo-codex-parity-plan.md)
+- **Description**: Define exactly which external flows must work to call GitLab Duo support "like codex".
+- **Dependencies**: Task 1.2
+- **Acceptance Criteria**:
+  - Required surfaces are listed:
+    - Claude-compatible route
+    - OpenAI `chat/completions`
+    - OpenAI `responses`
+    - optional downstream websocket path
+  - Non-goals are explicit if GitLab upstream cannot support them.
+- **Validation**:
+  - Maintainer review of stated scope.
+
+## Sprint 2: Primary Transport Parity
+**Goal**: Move GitLab Duo execution onto a transport that supports codex-like runtime behavior.
+
+**Demo/Validation**:
+- A GitLab Duo model works over real streaming through `/v1/chat/completions`.
+- No synthetic "collect full body then fake stream" path remains on the primary flow.
+
+### Task 2.1: Refactor GitLab Executor Into Strategy Layers
+- **Location**: [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go)
+- **Description**: Split current executor into explicit strategies:
+  - auth refresh/direct access refresh
+  - gateway transport
+  - GitLab REST fallback transport
+  - downstream translation helpers
+- **Dependencies**: Sprint 1
+- **Acceptance Criteria**:
+  - Executor no longer mixes discovery, refresh, fallback selection, and response synthesis in one path.
+  - Transport choice is testable in isolation.
+- **Validation**:
+  - Unit tests for strategy selection and fallback boundaries.
+
+### Task 2.2: Implement Real Streaming Path
+- **Location**: [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go), [internal/runtime/executor/gitlab_executor_test.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor_test.go)
+- **Description**: Replace synthetic streaming with true upstream incremental forwarding:
+  - use gateway stream if available
+  - otherwise consume GitLab Code Suggestions streaming response and map chunks incrementally
+- **Dependencies**: Task 2.1
+- **Acceptance Criteria**:
+  - `ExecuteStream` emits chunks before upstream completion.
+  - error handling preserves status and early failure semantics.
+- **Validation**:
+  - tests with chunked upstream server
+  - manual curl check against `/v1/chat/completions` with `stream=true`
+
+### Task 2.3: Preserve Upstream Auth And Headers Correctly
+- **Location**: [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go), [internal/auth/gitlab/gitlab.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/auth/gitlab/gitlab.go)
+- **Description**: Use `direct_access` connection details as first-class transport state:
+  - gateway token
+  - expiry
+  - mandatory forwarded headers
+  - model metadata
+- **Dependencies**: Task 2.1
+- **Acceptance Criteria**:
+  - executor stops ignoring gateway headers/token when transport requires them
+  - refresh logic never over-fetches `direct_access`
+- **Validation**:
+  - tests verifying propagated headers and refresh interval behavior
+
+## Sprint 3: Request/Response Semantics Parity
+**Goal**: Make GitLab Duo behave correctly under the same request shapes that current `codex` consumers send.
+
+**Demo/Validation**:
+- OpenAI and Claude-compatible clients can do non-streaming and streaming conversations without losing structure.
+
+### Task 3.1: Normalize Multi-Turn Message Mapping
+- **Location**: [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go), [sdk/translator](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/translator)
+- **Description**: Replace the current "flatten prompt into one instruction" behavior with stable multi-turn mapping:
+  - preserve system context
+  - preserve user/assistant ordering
+  - maintain bounded context truncation
+- **Dependencies**: Sprint 2
+- **Acceptance Criteria**:
+  - multi-turn requests are not collapsed into a lossy single string unless fallback mode explicitly requires it
+  - truncation policy is deterministic and tested
+- **Validation**:
+  - golden tests for request mapping
+
+### Task 3.2: Tool Calling Compatibility Layer
+- **Location**: [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go), [sdk/api/handlers/openai/openai_responses_handlers.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/api/handlers/openai/openai_responses_handlers.go)
+- **Description**: Decide and implement one of two paths:
+  - native pass-through if GitLab gateway supports tool/function structures
+  - strict downgrade path with explicit unsupported errors instead of silent field loss
+- **Dependencies**: Task 3.1
+- **Acceptance Criteria**:
+  - tool-related fields are either preserved correctly or rejected explicitly
+  - no silent corruption of tool names, tool calls, or tool results
+- **Validation**:
+  - table-driven tests for tool payloads
+  - one manual client scenario using tools
+
+### Task 3.3: Token Counting And Usage Reporting Fidelity
+- **Location**: [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go), [internal/runtime/executor/usage_helpers.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/usage_helpers.go)
+- **Description**: Improve token/usage reporting so GitLab models behave like first-class providers in logs and scheduling.
+- **Dependencies**: Sprint 2
+- **Acceptance Criteria**:
+  - `CountTokens` uses the closest supported estimation path
+  - usage logging distinguishes prompt vs completion when possible
+- **Validation**:
+  - unit tests for token estimation outputs
+
+## Sprint 4: Responses And Session Parity
+**Goal**: Reach codex-level support for OpenAI Responses clients and long-lived sessions where GitLab upstream permits it.
+
+**Demo/Validation**:
+- `/v1/responses` works with GitLab Duo in a realistic client flow.
+- If websocket parity is not possible, the code explicitly declines it and keeps HTTP paths stable.
+
+### Task 4.1: Make GitLab Compatible With `/v1/responses`
+- **Location**: [sdk/api/handlers/openai/openai_responses_handlers.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/api/handlers/openai/openai_responses_handlers.go), [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go)
+- **Description**: Ensure GitLab transport can safely back the Responses API path, including compact responses if applicable.
+- **Dependencies**: Sprint 3
+- **Acceptance Criteria**:
+  - GitLab Duo can be selected behind `/v1/responses`
+  - response IDs and follow-up semantics are defined
+- **Validation**:
+  - handler tests analogous to codex/openai responses tests
+
+### Task 4.2: Evaluate Downstream Websocket Parity
+- **Location**: [sdk/api/handlers/openai/openai_responses_websocket.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/api/handlers/openai/openai_responses_websocket.go), [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go)
+- **Description**: Decide whether GitLab Duo can support downstream websocket sessions like codex:
+  - if yes, add session-aware execution path
+  - if no, mark GitLab auth as websocket-ineligible and keep HTTP routes first-class
+- **Dependencies**: Task 4.1
+- **Acceptance Criteria**:
+  - websocket behavior is explicit, not accidental
+  - no route claims websocket support when the upstream cannot honor it
+- **Validation**:
+  - websocket handler tests or explicit capability tests
+
+### Task 4.3: Add Session Cleanup And Failure Recovery Semantics
+- **Location**: [internal/runtime/executor/gitlab_executor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor.go), [sdk/cliproxy/auth/conductor.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/cliproxy/auth/conductor.go)
+- **Description**: Add codex-like session cleanup, retry boundaries, and model suspension/resume behavior for GitLab failures and quota events.
+- **Dependencies**: Sprint 2
+- **Acceptance Criteria**:
+  - auth/model cooldown behavior is predictable on GitLab 4xx/5xx/quota responses
+  - executor cleans up per-session resources if any are introduced
+- **Validation**:
+  - tests for quota and retry behavior
+
+## Sprint 5: Client UX, Model UX, And Manual E2E
+**Goal**: Make GitLab Duo feel like a normal built-in provider to operators and downstream clients.
+
+**Demo/Validation**:
+- A documented setup exists for "login once, point Claude Code at CLIProxyAPI, use GitLab Duo-backed model".
+
+### Task 5.1: Model Alias And Provider UX Cleanup
+- **Location**: [sdk/cliproxy/service.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/cliproxy/service.go), [README.md](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/README.md)
+- **Description**: Normalize what users see:
+  - stable alias such as `gitlab-duo`
+  - discovered upstream model names
+  - optional prefix behavior
+  - account labels that clearly distinguish OAuth vs PAT
+- **Dependencies**: Sprint 3
+- **Acceptance Criteria**:
+  - users can select a stable GitLab alias even when upstream model changes
+  - dynamic model discovery does not cause confusing model churn
+- **Validation**:
+  - registry tests and manual `/v1/models` inspection
+
+### Task 5.2: Add Real End-To-End Acceptance Tests
+- **Location**: [internal/runtime/executor/gitlab_executor_test.go](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/internal/runtime/executor/gitlab_executor_test.go), [sdk/api/handlers/openai](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/sdk/api/handlers/openai)
+- **Description**: Add higher-level tests covering the actual proxy surfaces:
+  - OpenAI `chat/completions`
+  - OpenAI `responses`
+  - Claude-compatible request path if GitLab is routed there
+- **Dependencies**: Sprint 4
+- **Acceptance Criteria**:
+  - tests fail if streaming regresses into synthetic buffering again
+  - tests cover at least one tool-related request and one multi-turn request
+- **Validation**:
+  - `go test ./...`
+
+### Task 5.3: Publish Operator Documentation
+- **Location**: [README.md](/home/luxvtz/projects/cliproxyapi/CLIProxyAPI/README.md)
+- **Description**: Document:
+  - OAuth setup requirements
+  - PAT requirements
+  - current capability matrix
+  - known limitations if websocket/tool parity is partial
+- **Dependencies**: Sprint 5.1
+- **Acceptance Criteria**:
+  - setup instructions are enough for a new user to reproduce the GitLab Duo flow
+  - limitations are explicit
+- **Validation**:
+  - dry-run docs review from a clean environment
+
+## Testing Strategy
+- Keep `go test ./...` green after every committable task.
+- Add table-driven tests first for request mapping, refresh behavior, and dynamic model registration.
+- Add transport tests with `httptest.Server` for:
+  - real chunked streaming
+  - header propagation from `direct_access`
+  - upstream fallback rules
+- Add at least one manual acceptance checklist:
+  - login via OAuth
+  - login via PAT
+  - list models
+  - run one streaming prompt via OpenAI route
+  - run one prompt from the target downstream client
+
+## Potential Risks & Gotchas
+- GitLab public docs expose `direct_access`, but do not fully document every possible AI gateway path. We should isolate any empirically discovered gateway assumptions behind one transport layer and feature flags.
+- `chat/completions` availability differs by GitLab offering and version. The executor must not assume it always exists.
+- Code Suggestions is completion-oriented; lossy mapping from rich chat/tool payloads will make GitLab Duo feel worse than codex unless explicitly handled.
+- Synthetic streaming is not good enough for codex parity and will cause regressions in interactive clients.
+- Dynamic model discovery can create unstable UX if the stable alias and discovered model IDs are not separated cleanly.
+- PAT auth may validate successfully while still lacking effective Duo permissions. Error reporting must surface this explicitly.
+
+## Rollback Plan
+- Keep the current basic GitLab executor behind a fallback mode until the new transport path is stable.
+- If parity work destabilizes existing providers, revert only GitLab-specific executor changes and leave auth support intact.
+- Preserve the stable `gitlab-duo` alias so rollback does not break client configuration.

internal/auth/gitlab/gitlab.go

@@ -0,0 +1,492 @@
+package gitlab
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	DefaultBaseURL      = "https://gitlab.com"
+	DefaultCallbackPort = 17171
+	defaultOAuthScope   = "api read_user"
+)
+
+type PKCECodes struct {
+	CodeVerifier  string
+	CodeChallenge string
+}
+
+type OAuthResult struct {
+	Code  string
+	State string
+	Error string
+}
+
+type OAuthServer struct {
+	server     *http.Server
+	port       int
+	resultChan chan *OAuthResult
+	errorChan  chan error
+	mu         sync.Mutex
+	running    bool
+}
+
+type TokenResponse struct {
+	AccessToken  string `json:"access_token"`
+	TokenType    string `json:"token_type"`
+	RefreshToken string `json:"refresh_token"`
+	Scope        string `json:"scope"`
+	CreatedAt    int64  `json:"created_at"`
+	ExpiresIn    int    `json:"expires_in"`
+}
+
+type User struct {
+	ID          int64  `json:"id"`
+	Username    string `json:"username"`
+	Name        string `json:"name"`
+	Email       string `json:"email"`
+	PublicEmail string `json:"public_email"`
+}
+
+type PersonalAccessTokenSelf struct {
+	ID     int64    `json:"id"`
+	Name   string   `json:"name"`
+	Scopes []string `json:"scopes"`
+	UserID int64    `json:"user_id"`
+}
+
+type ModelDetails struct {
+	ModelProvider string `json:"model_provider"`
+	ModelName     string `json:"model_name"`
+}
+
+type DirectAccessResponse struct {
+	BaseURL      string            `json:"base_url"`
+	Token        string            `json:"token"`
+	ExpiresAt    int64             `json:"expires_at"`
+	Headers      map[string]string `json:"headers"`
+	ModelDetails *ModelDetails     `json:"model_details,omitempty"`
+}
+
+type DiscoveredModel struct {
+	ModelProvider string
+	ModelName     string
+}
+
+type AuthClient struct {
+	httpClient *http.Client
+}
+
+func NewAuthClient(cfg *config.Config) *AuthClient {
+	client := &http.Client{}
+	if cfg != nil {
+		client = util.SetProxy(&cfg.SDKConfig, client)
+	}
+	return &AuthClient{httpClient: client}
+}
+
+func NormalizeBaseURL(raw string) string {
+	value := strings.TrimSpace(raw)
+	if value == "" {
+		return DefaultBaseURL
+	}
+	if !strings.Contains(value, "://") {
+		value = "https://" + value
+	}
+	value = strings.TrimRight(value, "/")
+	return value
+}
+
+func TokenExpiry(now time.Time, token *TokenResponse) time.Time {
+	if token == nil {
+		return time.Time{}
+	}
+	if token.CreatedAt > 0 && token.ExpiresIn > 0 {
+		return time.Unix(token.CreatedAt+int64(token.ExpiresIn), 0).UTC()
+	}
+	if token.ExpiresIn > 0 {
+		return now.UTC().Add(time.Duration(token.ExpiresIn) * time.Second)
+	}
+	return time.Time{}
+}
+
+func GeneratePKCECodes() (*PKCECodes, error) {
+	verifierBytes := make([]byte, 32)
+	if _, err := rand.Read(verifierBytes); err != nil {
+		return nil, fmt.Errorf("gitlab pkce generation failed: %w", err)
+	}
+	verifier := base64.RawURLEncoding.EncodeToString(verifierBytes)
+	sum := sha256.Sum256([]byte(verifier))
+	challenge := base64.RawURLEncoding.EncodeToString(sum[:])
+	return &PKCECodes{
+		CodeVerifier:  verifier,
+		CodeChallenge: challenge,
+	}, nil
+}
+
+func NewOAuthServer(port int) *OAuthServer {
+	return &OAuthServer{
+		port:       port,
+		resultChan: make(chan *OAuthResult, 1),
+		errorChan:  make(chan error, 1),
+	}
+}
+
+func (s *OAuthServer) Start() error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.running {
+		return fmt.Errorf("gitlab oauth server already running")
+	}
+	if !s.isPortAvailable() {
+		return fmt.Errorf("port %d is already in use", s.port)
+	}
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/auth/callback", s.handleCallback)
+
+	s.server = &http.Server{
+		Addr:         fmt.Sprintf(":%d", s.port),
+		Handler:      mux,
+		ReadTimeout:  10 * time.Second,
+		WriteTimeout: 10 * time.Second,
+	}
+	s.running = true
+
+	go func() {
+		if err := s.server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			s.errorChan <- err
+		}
+	}()
+
+	time.Sleep(100 * time.Millisecond)
+	return nil
+}
+
+func (s *OAuthServer) Stop(ctx context.Context) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if !s.running || s.server == nil {
+		return nil
+	}
+	defer func() {
+		s.running = false
+		s.server = nil
+	}()
+	return s.server.Shutdown(ctx)
+}
+
+func (s *OAuthServer) WaitForCallback(timeout time.Duration) (*OAuthResult, error) {
+	select {
+	case result := <-s.resultChan:
+		return result, nil
+	case err := <-s.errorChan:
+		return nil, err
+	case <-time.After(timeout):
+		return nil, fmt.Errorf("timeout waiting for OAuth callback")
+	}
+}
+
+func (s *OAuthServer) handleCallback(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+	query := r.URL.Query()
+	if errParam := strings.TrimSpace(query.Get("error")); errParam != "" {
+		s.sendResult(&OAuthResult{Error: errParam})
+		http.Error(w, errParam, http.StatusBadRequest)
+		return
+	}
+	code := strings.TrimSpace(query.Get("code"))
+	state := strings.TrimSpace(query.Get("state"))
+	if code == "" || state == "" {
+		s.sendResult(&OAuthResult{Error: "missing_code_or_state"})
+		http.Error(w, "missing code or state", http.StatusBadRequest)
+		return
+	}
+	s.sendResult(&OAuthResult{Code: code, State: state})
+	_, _ = w.Write([]byte("GitLab authentication received. You can close this tab."))
+}
+
+func (s *OAuthServer) sendResult(result *OAuthResult) {
+	select {
+	case s.resultChan <- result:
+	default:
+		log.Debug("gitlab oauth result channel full, dropping callback result")
+	}
+}
+
+func (s *OAuthServer) isPortAvailable() bool {
+	listener, err := net.Listen("tcp", fmt.Sprintf(":%d", s.port))
+	if err != nil {
+		return false
+	}
+	_ = listener.Close()
+	return true
+}
+
+func RedirectURL(port int) string {
+	return fmt.Sprintf("http://localhost:%d/auth/callback", port)
+}
+
+func (c *AuthClient) GenerateAuthURL(baseURL, clientID, redirectURI, state string, pkce *PKCECodes) (string, error) {
+	if pkce == nil {
+		return "", fmt.Errorf("gitlab auth URL generation failed: PKCE codes are required")
+	}
+	if strings.TrimSpace(clientID) == "" {
+		return "", fmt.Errorf("gitlab auth URL generation failed: client ID is required")
+	}
+	baseURL = NormalizeBaseURL(baseURL)
+	params := url.Values{
+		"client_id":             {strings.TrimSpace(clientID)},
+		"response_type":         {"code"},
+		"redirect_uri":          {strings.TrimSpace(redirectURI)},
+		"scope":                 {defaultOAuthScope},
+		"state":                 {strings.TrimSpace(state)},
+		"code_challenge":        {pkce.CodeChallenge},
+		"code_challenge_method": {"S256"},
+	}
+	return fmt.Sprintf("%s/oauth/authorize?%s", baseURL, params.Encode()), nil
+}
+
+func (c *AuthClient) ExchangeCodeForTokens(ctx context.Context, baseURL, clientID, clientSecret, redirectURI, code, codeVerifier string) (*TokenResponse, error) {
+	form := url.Values{
+		"grant_type":    {"authorization_code"},
+		"client_id":     {strings.TrimSpace(clientID)},
+		"code":          {strings.TrimSpace(code)},
+		"redirect_uri":  {strings.TrimSpace(redirectURI)},
+		"code_verifier": {strings.TrimSpace(codeVerifier)},
+	}
+	if secret := strings.TrimSpace(clientSecret); secret != "" {
+		form.Set("client_secret", secret)
+	}
+	return c.postToken(ctx, NormalizeBaseURL(baseURL)+"/oauth/token", form)
+}
+
+func (c *AuthClient) RefreshTokens(ctx context.Context, baseURL, clientID, clientSecret, refreshToken string) (*TokenResponse, error) {
+	form := url.Values{
+		"grant_type":    {"refresh_token"},
+		"refresh_token": {strings.TrimSpace(refreshToken)},
+	}
+	if clientID = strings.TrimSpace(clientID); clientID != "" {
+		form.Set("client_id", clientID)
+	}
+	if secret := strings.TrimSpace(clientSecret); secret != "" {
+		form.Set("client_secret", secret)
+	}
+	return c.postToken(ctx, NormalizeBaseURL(baseURL)+"/oauth/token", form)
+}
+
+func (c *AuthClient) postToken(ctx context.Context, tokenURL string, form url.Values) (*TokenResponse, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, tokenURL, strings.NewReader(form.Encode()))
+	if err != nil {
+		return nil, fmt.Errorf("gitlab token request failed: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab token request failed: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab token response read failed: %w", err)
+	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, fmt.Errorf("gitlab token request failed with status %d: %s", resp.StatusCode, strings.TrimSpace(string(body)))
+	}
+	var token TokenResponse
+	if err := json.Unmarshal(body, &token); err != nil {
+		return nil, fmt.Errorf("gitlab token response decode failed: %w", err)
+	}
+	return &token, nil
+}
+
+func (c *AuthClient) GetCurrentUser(ctx context.Context, baseURL, token string) (*User, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, NormalizeBaseURL(baseURL)+"/api/v4/user", nil)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab user request failed: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+strings.TrimSpace(token))
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab user request failed: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab user response read failed: %w", err)
+	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, fmt.Errorf("gitlab user request failed with status %d: %s", resp.StatusCode, strings.TrimSpace(string(body)))
+	}
+
+	var user User
+	if err := json.Unmarshal(body, &user); err != nil {
+		return nil, fmt.Errorf("gitlab user response decode failed: %w", err)
+	}
+	return &user, nil
+}
+
+func (c *AuthClient) GetPersonalAccessTokenSelf(ctx context.Context, baseURL, token string) (*PersonalAccessTokenSelf, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, NormalizeBaseURL(baseURL)+"/api/v4/personal_access_tokens/self", nil)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab PAT self request failed: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+strings.TrimSpace(token))
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab PAT self request failed: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab PAT self response read failed: %w", err)
+	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, fmt.Errorf("gitlab PAT self request failed with status %d: %s", resp.StatusCode, strings.TrimSpace(string(body)))
+	}
+
+	var pat PersonalAccessTokenSelf
+	if err := json.Unmarshal(body, &pat); err != nil {
+		return nil, fmt.Errorf("gitlab PAT self response decode failed: %w", err)
+	}
+	return &pat, nil
+}
+
+func (c *AuthClient) FetchDirectAccess(ctx context.Context, baseURL, token string) (*DirectAccessResponse, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, NormalizeBaseURL(baseURL)+"/api/v4/code_suggestions/direct_access", nil)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab direct access request failed: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+strings.TrimSpace(token))
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab direct access request failed: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("gitlab direct access response read failed: %w", err)
+	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, fmt.Errorf("gitlab direct access request failed with status %d: %s", resp.StatusCode, strings.TrimSpace(string(body)))
+	}
+
+	var direct DirectAccessResponse
+	if err := json.Unmarshal(body, &direct); err != nil {
+		return nil, fmt.Errorf("gitlab direct access response decode failed: %w", err)
+	}
+	if direct.Headers == nil {
+		direct.Headers = make(map[string]string)
+	}
+	return &direct, nil
+}
+
+func ExtractDiscoveredModels(metadata map[string]any) []DiscoveredModel {
+	if len(metadata) == 0 {
+		return nil
+	}
+
+	models := make([]DiscoveredModel, 0, 4)
+	seen := make(map[string]struct{})
+	appendModel := func(provider, name string) {
+		provider = strings.TrimSpace(provider)
+		name = strings.TrimSpace(name)
+		if name == "" {
+			return
+		}
+		key := strings.ToLower(name)
+		if _, ok := seen[key]; ok {
+			return
+		}
+		seen[key] = struct{}{}
+		models = append(models, DiscoveredModel{
+			ModelProvider: provider,
+			ModelName:     name,
+		})
+	}
+
+	if raw, ok := metadata["model_details"]; ok {
+		appendDiscoveredModels(raw, appendModel)
+	}
+	appendModel(stringValue(metadata["model_provider"]), stringValue(metadata["model_name"]))
+
+	for _, key := range []string{"models", "supported_models", "discovered_models"} {
+		if raw, ok := metadata[key]; ok {
+			appendDiscoveredModels(raw, appendModel)
+		}
+	}
+
+	return models
+}
+
+func appendDiscoveredModels(raw any, appendModel func(provider, name string)) {
+	switch typed := raw.(type) {
+	case map[string]any:
+		appendModel(stringValue(typed["model_provider"]), stringValue(typed["model_name"]))
+		appendModel(stringValue(typed["provider"]), stringValue(typed["name"]))
+		if nested, ok := typed["models"]; ok {
+			appendDiscoveredModels(nested, appendModel)
+		}
+	case []any:
+		for _, item := range typed {
+			appendDiscoveredModels(item, appendModel)
+		}
+	case []string:
+		for _, item := range typed {
+			appendModel("", item)
+		}
+	case string:
+		appendModel("", typed)
+	}
+}
+
+func stringValue(raw any) string {
+	switch typed := raw.(type) {
+	case string:
+		return strings.TrimSpace(typed)
+	case fmt.Stringer:
+		return strings.TrimSpace(typed.String())
+	case json.Number:
+		return typed.String()
+	case int:
+		return strconv.Itoa(typed)
+	case int64:
+		return strconv.FormatInt(typed, 10)
+	case float64:
+		return strconv.FormatInt(int64(typed), 10)
+	default:
+		return ""
+	}
+}

internal/auth/gitlab/gitlab_test.go

@@ -0,0 +1,138 @@
+package gitlab
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+)
+
+func TestAuthClientGenerateAuthURLIncludesPKCE(t *testing.T) {
+	client := NewAuthClient(nil)
+	pkce, err := GeneratePKCECodes()
+	if err != nil {
+		t.Fatalf("GeneratePKCECodes() error = %v", err)
+	}
+
+	rawURL, err := client.GenerateAuthURL("https://gitlab.example.com", "client-id", RedirectURL(17171), "state-123", pkce)
+	if err != nil {
+		t.Fatalf("GenerateAuthURL() error = %v", err)
+	}
+
+	parsed, err := url.Parse(rawURL)
+	if err != nil {
+		t.Fatalf("Parse(authURL) error = %v", err)
+	}
+	if got := parsed.Path; got != "/oauth/authorize" {
+		t.Fatalf("expected /oauth/authorize path, got %q", got)
+	}
+	query := parsed.Query()
+	if got := query.Get("client_id"); got != "client-id" {
+		t.Fatalf("expected client_id, got %q", got)
+	}
+	if got := query.Get("scope"); got != defaultOAuthScope {
+		t.Fatalf("expected scope %q, got %q", defaultOAuthScope, got)
+	}
+	if got := query.Get("code_challenge_method"); got != "S256" {
+		t.Fatalf("expected PKCE method S256, got %q", got)
+	}
+	if got := query.Get("code_challenge"); got == "" {
+		t.Fatal("expected non-empty code_challenge")
+	}
+}
+
+func TestAuthClientExchangeCodeForTokens(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/oauth/token" {
+			t.Fatalf("unexpected path %q", r.URL.Path)
+		}
+		if err := r.ParseForm(); err != nil {
+			t.Fatalf("ParseForm() error = %v", err)
+		}
+		if got := r.Form.Get("grant_type"); got != "authorization_code" {
+			t.Fatalf("expected authorization_code grant, got %q", got)
+		}
+		if got := r.Form.Get("code_verifier"); got != "verifier-123" {
+			t.Fatalf("expected code_verifier, got %q", got)
+		}
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"access_token":  "oauth-access",
+			"refresh_token": "oauth-refresh",
+			"token_type":    "Bearer",
+			"scope":         "api read_user",
+			"created_at":    1710000000,
+			"expires_in":    3600,
+		})
+	}))
+	defer srv.Close()
+
+	client := NewAuthClient(nil)
+	token, err := client.ExchangeCodeForTokens(context.Background(), srv.URL, "client-id", "client-secret", RedirectURL(17171), "auth-code", "verifier-123")
+	if err != nil {
+		t.Fatalf("ExchangeCodeForTokens() error = %v", err)
+	}
+	if token.AccessToken != "oauth-access" {
+		t.Fatalf("expected access token, got %q", token.AccessToken)
+	}
+	if token.RefreshToken != "oauth-refresh" {
+		t.Fatalf("expected refresh token, got %q", token.RefreshToken)
+	}
+}
+
+func TestExtractDiscoveredModels(t *testing.T) {
+	models := ExtractDiscoveredModels(map[string]any{
+		"model_details": map[string]any{
+			"model_provider": "anthropic",
+			"model_name":     "claude-sonnet-4-5",
+		},
+		"supported_models": []any{
+			map[string]any{"model_provider": "openai", "model_name": "gpt-4.1"},
+			"claude-sonnet-4-5",
+		},
+	})
+	if len(models) != 2 {
+		t.Fatalf("expected 2 unique models, got %d", len(models))
+	}
+	if models[0].ModelName != "claude-sonnet-4-5" {
+		t.Fatalf("unexpected first model %q", models[0].ModelName)
+	}
+	if models[1].ModelName != "gpt-4.1" {
+		t.Fatalf("unexpected second model %q", models[1].ModelName)
+	}
+}
+
+func TestFetchDirectAccessDecodesModelDetails(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v4/code_suggestions/direct_access" {
+			t.Fatalf("unexpected path %q", r.URL.Path)
+		}
+		if got := r.Header.Get("Authorization"); !strings.Contains(got, "token-123") {
+			t.Fatalf("expected bearer token, got %q", got)
+		}
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"base_url":   "https://cloud.gitlab.example.com",
+			"token":      "gateway-token",
+			"expires_at": 1710003600,
+			"headers": map[string]string{
+				"X-Gitlab-Realm": "saas",
+			},
+			"model_details": map[string]any{
+				"model_provider": "anthropic",
+				"model_name":     "claude-sonnet-4-5",
+			},
+		})
+	}))
+	defer srv.Close()
+
+	client := NewAuthClient(nil)
+	direct, err := client.FetchDirectAccess(context.Background(), srv.URL, "token-123")
+	if err != nil {
+		t.Fatalf("FetchDirectAccess() error = %v", err)
+	}
+	if direct.ModelDetails == nil || direct.ModelDetails.ModelName != "claude-sonnet-4-5" {
+		t.Fatalf("expected model details, got %+v", direct.ModelDetails)
+	}
+}

internal/cmd/auth_manager.go

@@ -23,6 +23,7 @@ func newAuthManager() *sdkAuth.Manager {
 		sdkAuth.NewKiroAuthenticator(),
 		sdkAuth.NewGitHubCopilotAuthenticator(),
 		sdkAuth.NewKiloAuthenticator(),
+		sdkAuth.NewGitLabAuthenticator(),
 	)
 	return manager
 }

internal/cmd/gitlab_login.go

@@ -0,0 +1,69 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	sdkAuth "github.com/router-for-me/CLIProxyAPI/v6/sdk/auth"
+)
+
+func DoGitLabLogin(cfg *config.Config, options *LoginOptions) {
+	if options == nil {
+		options = &LoginOptions{}
+	}
+
+	promptFn := options.Prompt
+	if promptFn == nil {
+		promptFn = defaultProjectPrompt()
+	}
+
+	manager := newAuthManager()
+	authOpts := &sdkAuth.LoginOptions{
+		NoBrowser:    options.NoBrowser,
+		CallbackPort: options.CallbackPort,
+		Metadata: map[string]string{
+			"login_mode": "oauth",
+		},
+		Prompt: promptFn,
+	}
+
+	_, savedPath, err := manager.Login(context.Background(), "gitlab", cfg, authOpts)
+	if err != nil {
+		fmt.Printf("GitLab Duo authentication failed: %v\n", err)
+		return
+	}
+	if savedPath != "" {
+		fmt.Printf("Authentication saved to %s\n", savedPath)
+	}
+	fmt.Println("GitLab Duo authentication successful!")
+}
+
+func DoGitLabTokenLogin(cfg *config.Config, options *LoginOptions) {
+	if options == nil {
+		options = &LoginOptions{}
+	}
+
+	promptFn := options.Prompt
+	if promptFn == nil {
+		promptFn = defaultProjectPrompt()
+	}
+
+	manager := newAuthManager()
+	authOpts := &sdkAuth.LoginOptions{
+		Metadata: map[string]string{
+			"login_mode": "pat",
+		},
+		Prompt: promptFn,
+	}
+
+	_, savedPath, err := manager.Login(context.Background(), "gitlab", cfg, authOpts)
+	if err != nil {
+		fmt.Printf("GitLab Duo PAT authentication failed: %v\n", err)
+		return
+	}
+	if savedPath != "" {
+		fmt.Printf("Authentication saved to %s\n", savedPath)
+	}
+	fmt.Println("GitLab Duo PAT authentication successful!")
+}

internal/runtime/executor/gitlab_executor_test.go

@@ -0,0 +1,469 @@
+package executor
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	_ "github.com/router-for-me/CLIProxyAPI/v6/internal/translator"
+	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
+	cliproxyexecutor "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/executor"
+	sdktranslator "github.com/router-for-me/CLIProxyAPI/v6/sdk/translator"
+	"github.com/tidwall/gjson"
+)
+
+func TestGitLabExecutorExecuteUsesChatEndpoint(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != gitLabChatEndpoint {
+			t.Fatalf("unexpected path %q", r.URL.Path)
+		}
+		_, _ = w.Write([]byte(`"chat response"`))
+	}))
+	defer srv.Close()
+
+	exec := NewGitLabExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{
+		Provider: "gitlab",
+		Metadata: map[string]any{
+			"base_url":     srv.URL,
+			"access_token": "oauth-access",
+			"model_name":   "claude-sonnet-4-5",
+		},
+	}
+	req := cliproxyexecutor.Request{
+		Model:   "gitlab-duo",
+		Payload: []byte(`{"model":"gitlab-duo","messages":[{"role":"user","content":"hello"}]}`),
+	}
+
+	resp, err := exec.Execute(context.Background(), auth, req, cliproxyexecutor.Options{
+		SourceFormat: sdktranslator.FromString("openai"),
+	})
+	if err != nil {
+		t.Fatalf("Execute() error = %v", err)
+	}
+	if got := gjson.GetBytes(resp.Payload, "choices.0.message.content").String(); got != "chat response" {
+		t.Fatalf("expected chat response, got %q", got)
+	}
+	if got := gjson.GetBytes(resp.Payload, "model").String(); got != "claude-sonnet-4-5" {
+		t.Fatalf("expected resolved model, got %q", got)
+	}
+}
+
+func TestGitLabExecutorExecuteFallsBackToCodeSuggestions(t *testing.T) {
+	chatCalls := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case gitLabChatEndpoint:
+			chatCalls++
+			http.Error(w, "feature unavailable", http.StatusForbidden)
+		case gitLabCodeSuggestionsEndpoint:
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"choices": []map[string]any{{
+					"text": "fallback response",
+				}},
+			})
+		default:
+			t.Fatalf("unexpected path %q", r.URL.Path)
+		}
+	}))
+	defer srv.Close()
+
+	exec := NewGitLabExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{
+		Provider: "gitlab",
+		Metadata: map[string]any{
+			"base_url":              srv.URL,
+			"personal_access_token": "glpat-token",
+			"auth_method":           "pat",
+		},
+	}
+	req := cliproxyexecutor.Request{
+		Model:   "gitlab-duo",
+		Payload: []byte(`{"model":"gitlab-duo","messages":[{"role":"user","content":"write code"}]}`),
+	}
+
+	resp, err := exec.Execute(context.Background(), auth, req, cliproxyexecutor.Options{
+		SourceFormat: sdktranslator.FromString("openai"),
+	})
+	if err != nil {
+		t.Fatalf("Execute() error = %v", err)
+	}
+	if chatCalls != 1 {
+		t.Fatalf("expected chat endpoint to be tried once, got %d", chatCalls)
+	}
+	if got := gjson.GetBytes(resp.Payload, "choices.0.message.content").String(); got != "fallback response" {
+		t.Fatalf("expected fallback response, got %q", got)
+	}
+}
+
+func TestGitLabExecutorExecuteUsesAnthropicGateway(t *testing.T) {
+	var gotAuthHeader, gotRealmHeader string
+	var gotPath string
+	var gotModel string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		gotAuthHeader = r.Header.Get("Authorization")
+		gotRealmHeader = r.Header.Get("X-Gitlab-Realm")
+		gotModel = gjson.GetBytes(readBody(t, r), "model").String()
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"id":"msg_1","type":"message","role":"assistant","model":"claude-sonnet-4-5","content":[{"type":"tool_use","id":"toolu_1","name":"Bash","input":{"cmd":"ls"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":11,"output_tokens":4}}`))
+	}))
+	defer srv.Close()
+
+	exec := NewGitLabExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{
+		Provider: "gitlab",
+		Metadata: map[string]any{
+			"duo_gateway_base_url": srv.URL,
+			"duo_gateway_token":    "gateway-token",
+			"duo_gateway_headers":  map[string]string{"X-Gitlab-Realm": "saas"},
+			"model_provider":       "anthropic",
+			"model_name":           "claude-sonnet-4-5",
+		},
+	}
+	req := cliproxyexecutor.Request{
+		Model: "gitlab-duo",
+		Payload: []byte(`{
+			"model":"gitlab-duo",
+			"messages":[{"role":"user","content":[{"type":"text","text":"list files"}]}],
+			"tools":[{"name":"Bash","description":"run bash","input_schema":{"type":"object","properties":{"cmd":{"type":"string"}},"required":["cmd"]}}],
+			"max_tokens":128
+		}`),
+	}
+
+	resp, err := exec.Execute(context.Background(), auth, req, cliproxyexecutor.Options{
+		SourceFormat: sdktranslator.FromString("claude"),
+	})
+	if err != nil {
+		t.Fatalf("Execute() error = %v", err)
+	}
+	if gotPath != "/v1/proxy/anthropic/v1/messages" {
+		t.Fatalf("Path = %q, want %q", gotPath, "/v1/proxy/anthropic/v1/messages")
+	}
+	if gotAuthHeader != "Bearer gateway-token" {
+		t.Fatalf("Authorization = %q, want Bearer gateway-token", gotAuthHeader)
+	}
+	if gotRealmHeader != "saas" {
+		t.Fatalf("X-Gitlab-Realm = %q, want saas", gotRealmHeader)
+	}
+	if gotModel != "claude-sonnet-4-5" {
+		t.Fatalf("model = %q, want claude-sonnet-4-5", gotModel)
+	}
+	if got := gjson.GetBytes(resp.Payload, "content.0.type").String(); got != "tool_use" {
+		t.Fatalf("expected tool_use response, got %q", got)
+	}
+	if got := gjson.GetBytes(resp.Payload, "content.0.name").String(); got != "Bash" {
+		t.Fatalf("expected tool name Bash, got %q", got)
+	}
+}
+
+func TestGitLabExecutorExecuteUsesOpenAIGateway(t *testing.T) {
+	var gotAuthHeader, gotRealmHeader string
+	var gotPath string
+	var gotModel string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		gotAuthHeader = r.Header.Get("Authorization")
+		gotRealmHeader = r.Header.Get("X-Gitlab-Realm")
+		gotModel = gjson.GetBytes(readBody(t, r), "model").String()
+		w.Header().Set("Content-Type", "text/event-stream")
+		_, _ = w.Write([]byte("data: {\"type\":\"response.created\",\"response\":{\"id\":\"resp_1\",\"created_at\":1710000000,\"model\":\"gpt-5-codex\"}}\n\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"response.output_text.delta\",\"delta\":\"hello from openai gateway\"}\n\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_1\",\"created_at\":1710000000,\"model\":\"gpt-5-codex\",\"output\":[{\"type\":\"message\",\"id\":\"msg_1\",\"role\":\"assistant\",\"content\":[{\"type\":\"output_text\",\"text\":\"hello from openai gateway\"}]}],\"usage\":{\"input_tokens\":11,\"output_tokens\":4,\"total_tokens\":15}}}\n\n"))
+	}))
+	defer srv.Close()
+
+	exec := NewGitLabExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{
+		Provider: "gitlab",
+		Metadata: map[string]any{
+			"duo_gateway_base_url": srv.URL,
+			"duo_gateway_token":    "gateway-token",
+			"duo_gateway_headers":  map[string]string{"X-Gitlab-Realm": "saas"},
+			"model_provider":       "openai",
+			"model_name":           "gpt-5-codex",
+		},
+	}
+	req := cliproxyexecutor.Request{
+		Model:   "gitlab-duo",
+		Payload: []byte(`{"model":"gitlab-duo","messages":[{"role":"user","content":"hello"}]}`),
+	}
+
+	resp, err := exec.Execute(context.Background(), auth, req, cliproxyexecutor.Options{
+		SourceFormat: sdktranslator.FromString("openai"),
+	})
+	if err != nil {
+		t.Fatalf("Execute() error = %v", err)
+	}
+	if gotPath != "/v1/proxy/openai/v1/responses" {
+		t.Fatalf("Path = %q, want %q", gotPath, "/v1/proxy/openai/v1/responses")
+	}
+	if gotAuthHeader != "Bearer gateway-token" {
+		t.Fatalf("Authorization = %q, want Bearer gateway-token", gotAuthHeader)
+	}
+	if gotRealmHeader != "saas" {
+		t.Fatalf("X-Gitlab-Realm = %q, want saas", gotRealmHeader)
+	}
+	if gotModel != "gpt-5-codex" {
+		t.Fatalf("model = %q, want gpt-5-codex", gotModel)
+	}
+	if got := gjson.GetBytes(resp.Payload, "choices.0.message.content").String(); got != "hello from openai gateway" {
+		t.Fatalf("expected openai gateway response, got %q payload=%s", got, string(resp.Payload))
+	}
+}
+
+func TestGitLabExecutorRefreshUpdatesMetadata(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/oauth/token":
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"access_token":  "oauth-refreshed",
+				"refresh_token": "oauth-refresh",
+				"token_type":    "Bearer",
+				"scope":         "api read_user",
+				"created_at":    1710000000,
+				"expires_in":    3600,
+			})
+		case "/api/v4/code_suggestions/direct_access":
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"base_url":   "https://cloud.gitlab.example.com",
+				"token":      "gateway-token",
+				"expires_at": 1710003600,
+				"headers":    map[string]string{"X-Gitlab-Realm": "saas"},
+				"model_details": map[string]any{
+					"model_provider": "anthropic",
+					"model_name":     "claude-sonnet-4-5",
+				},
+			})
+		default:
+			t.Fatalf("unexpected path %q", r.URL.Path)
+		}
+	}))
+	defer srv.Close()
+
+	exec := NewGitLabExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{
+		ID:       "gitlab-auth.json",
+		Provider: "gitlab",
+		Metadata: map[string]any{
+			"base_url":            srv.URL,
+			"access_token":        "oauth-access",
+			"refresh_token":       "oauth-refresh",
+			"oauth_client_id":     "client-id",
+			"oauth_client_secret": "client-secret",
+			"auth_method":         "oauth",
+			"oauth_expires_at":    "2000-01-01T00:00:00Z",
+		},
+	}
+
+	updated, err := exec.Refresh(context.Background(), auth)
+	if err != nil {
+		t.Fatalf("Refresh() error = %v", err)
+	}
+	if got := updated.Metadata["access_token"]; got != "oauth-refreshed" {
+		t.Fatalf("expected refreshed access token, got %#v", got)
+	}
+	if got := updated.Metadata["model_name"]; got != "claude-sonnet-4-5" {
+		t.Fatalf("expected refreshed model metadata, got %#v", got)
+	}
+}
+
+func TestGitLabExecutorExecuteStreamUsesCodeSuggestionsSSE(t *testing.T) {
+	var gotAccept, gotStreamingHeader, gotEncoding string
+	var gotStreamFlag bool
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != gitLabCodeSuggestionsEndpoint {
+			t.Fatalf("unexpected path %q", r.URL.Path)
+		}
+		gotAccept = r.Header.Get("Accept")
+		gotStreamingHeader = r.Header.Get(gitLabSSEStreamingHeader)
+		gotEncoding = r.Header.Get("Accept-Encoding")
+		gotStreamFlag = gjson.GetBytes(readBody(t, r), "stream").Bool()
+
+		w.Header().Set("Content-Type", "text/event-stream")
+		_, _ = w.Write([]byte("event: stream_start\n"))
+		_, _ = w.Write([]byte("data: {\"model\":{\"name\":\"claude-sonnet-4-5\"}}\n\n"))
+		_, _ = w.Write([]byte("event: content_chunk\n"))
+		_, _ = w.Write([]byte("data: {\"content\":\"hello\"}\n\n"))
+		_, _ = w.Write([]byte("event: content_chunk\n"))
+		_, _ = w.Write([]byte("data: {\"content\":\" world\"}\n\n"))
+		_, _ = w.Write([]byte("event: stream_end\n"))
+		_, _ = w.Write([]byte("data: {}\n\n"))
+	}))
+	defer srv.Close()
+
+	exec := NewGitLabExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{
+		Provider: "gitlab",
+		Metadata: map[string]any{
+			"base_url":     srv.URL,
+			"access_token": "oauth-access",
+			"model_name":   "claude-sonnet-4-5",
+		},
+	}
+	req := cliproxyexecutor.Request{
+		Model:   "gitlab-duo",
+		Payload: []byte(`{"model":"gitlab-duo","stream":true,"messages":[{"role":"user","content":"hello"}]}`),
+	}
+
+	result, err := exec.ExecuteStream(context.Background(), auth, req, cliproxyexecutor.Options{
+		SourceFormat: sdktranslator.FromString("openai"),
+	})
+	if err != nil {
+		t.Fatalf("ExecuteStream() error = %v", err)
+	}
+
+	lines := collectStreamLines(t, result)
+	if gotAccept != "text/event-stream" {
+		t.Fatalf("Accept = %q, want text/event-stream", gotAccept)
+	}
+	if gotStreamingHeader != "true" {
+		t.Fatalf("%s = %q, want true", gitLabSSEStreamingHeader, gotStreamingHeader)
+	}
+	if gotEncoding != "identity" {
+		t.Fatalf("Accept-Encoding = %q, want identity", gotEncoding)
+	}
+	if !gotStreamFlag {
+		t.Fatalf("expected upstream request to set stream=true")
+	}
+	if len(lines) < 4 {
+		t.Fatalf("expected translated stream chunks, got %d", len(lines))
+	}
+	if !strings.Contains(strings.Join(lines, "\n"), `"content":"hello"`) {
+		t.Fatalf("expected hello delta in stream, got %q", strings.Join(lines, "\n"))
+	}
+	if !strings.Contains(strings.Join(lines, "\n"), `"content":" world"`) {
+		t.Fatalf("expected world delta in stream, got %q", strings.Join(lines, "\n"))
+	}
+	last := lines[len(lines)-1]
+	if last != "data: [DONE]" && !strings.Contains(last, `"finish_reason":"stop"`) {
+		t.Fatalf("expected stream terminator, got %q", last)
+	}
+}
+
+func TestGitLabExecutorExecuteStreamFallsBackToSyntheticChat(t *testing.T) {
+	chatCalls := 0
+	streamCalls := 0
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case gitLabCodeSuggestionsEndpoint:
+			streamCalls++
+			http.Error(w, "feature unavailable", http.StatusForbidden)
+		case gitLabChatEndpoint:
+			chatCalls++
+			_, _ = w.Write([]byte(`"chat fallback response"`))
+		default:
+			t.Fatalf("unexpected path %q", r.URL.Path)
+		}
+	}))
+	defer srv.Close()
+
+	exec := NewGitLabExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{
+		Provider: "gitlab",
+		Metadata: map[string]any{
+			"base_url":     srv.URL,
+			"access_token": "oauth-access",
+			"model_name":   "claude-sonnet-4-5",
+		},
+	}
+	req := cliproxyexecutor.Request{
+		Model:   "gitlab-duo",
+		Payload: []byte(`{"model":"gitlab-duo","stream":true,"messages":[{"role":"user","content":"hello"}]}`),
+	}
+
+	result, err := exec.ExecuteStream(context.Background(), auth, req, cliproxyexecutor.Options{
+		SourceFormat: sdktranslator.FromString("openai"),
+	})
+	if err != nil {
+		t.Fatalf("ExecuteStream() error = %v", err)
+	}
+
+	lines := collectStreamLines(t, result)
+	if streamCalls != 1 {
+		t.Fatalf("expected streaming endpoint once, got %d", streamCalls)
+	}
+	if chatCalls != 1 {
+		t.Fatalf("expected chat fallback once, got %d", chatCalls)
+	}
+	if !strings.Contains(strings.Join(lines, "\n"), `"content":"chat fallback response"`) {
+		t.Fatalf("expected fallback content in stream, got %q", strings.Join(lines, "\n"))
+	}
+}
+
+func TestGitLabExecutorExecuteStreamUsesAnthropicGateway(t *testing.T) {
+	var gotPath string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		w.Header().Set("Content-Type", "text/event-stream")
+		_, _ = w.Write([]byte("event: message_start\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"message_start\",\"message\":{\"id\":\"msg_1\",\"type\":\"message\",\"role\":\"assistant\",\"model\":\"claude-sonnet-4-5\",\"content\":[],\"stop_reason\":null,\"stop_sequence\":null,\"usage\":{\"input_tokens\":0,\"output_tokens\":0}}}\n\n"))
+		_, _ = w.Write([]byte("event: content_block_start\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"content_block_start\",\"index\":0,\"content_block\":{\"type\":\"text\",\"text\":\"\"}}\n\n"))
+		_, _ = w.Write([]byte("event: content_block_delta\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"content_block_delta\",\"index\":0,\"delta\":{\"type\":\"text_delta\",\"text\":\"hello from gateway\"}}\n\n"))
+		_, _ = w.Write([]byte("event: message_delta\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"end_turn\",\"stop_sequence\":null},\"usage\":{\"input_tokens\":10,\"output_tokens\":3}}\n\n"))
+		_, _ = w.Write([]byte("event: message_stop\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"message_stop\"}\n\n"))
+	}))
+	defer srv.Close()
+
+	exec := NewGitLabExecutor(&config.Config{})
+	auth := &cliproxyauth.Auth{
+		Provider: "gitlab",
+		Metadata: map[string]any{
+			"duo_gateway_base_url": srv.URL,
+			"duo_gateway_token":    "gateway-token",
+			"duo_gateway_headers":  map[string]string{"X-Gitlab-Realm": "saas"},
+			"model_provider":       "anthropic",
+			"model_name":           "claude-sonnet-4-5",
+		},
+	}
+	req := cliproxyexecutor.Request{
+		Model:   "gitlab-duo",
+		Payload: []byte(`{"model":"gitlab-duo","messages":[{"role":"user","content":[{"type":"text","text":"hello"}]}],"max_tokens":64}`),
+	}
+
+	result, err := exec.ExecuteStream(context.Background(), auth, req, cliproxyexecutor.Options{
+		SourceFormat: sdktranslator.FromString("claude"),
+	})
+	if err != nil {
+		t.Fatalf("ExecuteStream() error = %v", err)
+	}
+
+	lines := collectStreamLines(t, result)
+	if gotPath != "/v1/proxy/anthropic/v1/messages" {
+		t.Fatalf("Path = %q, want %q", gotPath, "/v1/proxy/anthropic/v1/messages")
+	}
+	if !strings.Contains(strings.Join(lines, "\n"), "hello from gateway") {
+		t.Fatalf("expected anthropic gateway stream, got %q", strings.Join(lines, "\n"))
+	}
+}
+
+func collectStreamLines(t *testing.T, result *cliproxyexecutor.StreamResult) []string {
+	t.Helper()
+	lines := make([]string, 0, 8)
+	for chunk := range result.Chunks {
+		if chunk.Err != nil {
+			t.Fatalf("unexpected stream error: %v", chunk.Err)
+		}
+		lines = append(lines, string(chunk.Payload))
+	}
+	return lines
+}
+
+func readBody(t *testing.T, r *http.Request) []byte {
+	t.Helper()
+	defer func() { _ = r.Body.Close() }()
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		t.Fatalf("ReadAll() error = %v", err)
+	}
+	return body
+}

sdk/api/handlers/claude/gitlab_duo_handler_test.go

@@ -0,0 +1,151 @@
+package claude
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	internalconfig "github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/registry"
+	runtimeexecutor "github.com/router-for-me/CLIProxyAPI/v6/internal/runtime/executor"
+	"github.com/router-for-me/CLIProxyAPI/v6/sdk/api/handlers"
+	coreauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
+	sdkconfig "github.com/router-for-me/CLIProxyAPI/v6/sdk/config"
+)
+
+func TestClaudeMessagesWithGitLabDuoAnthropicGateway(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	var gotPath, gotAuthHeader, gotRealmHeader string
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		gotAuthHeader = r.Header.Get("Authorization")
+		gotRealmHeader = r.Header.Get("X-Gitlab-Realm")
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"id":"msg_1","type":"message","role":"assistant","model":"claude-sonnet-4-5","content":[{"type":"tool_use","id":"toolu_1","name":"Bash","input":{"cmd":"ls"}}],"stop_reason":"tool_use","stop_sequence":null,"usage":{"input_tokens":11,"output_tokens":4}}`))
+	}))
+	defer upstream.Close()
+
+	manager, _ := registerGitLabDuoAnthropicAuth(t, upstream.URL)
+	base := handlers.NewBaseAPIHandlers(&sdkconfig.SDKConfig{}, manager)
+	h := NewClaudeCodeAPIHandler(base)
+	router := gin.New()
+	router.POST("/v1/messages", h.ClaudeMessages)
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/messages", strings.NewReader(`{
+		"model":"claude-sonnet-4-5",
+		"max_tokens":128,
+		"messages":[{"role":"user","content":"list files"}],
+		"tools":[{"name":"Bash","description":"run bash","input_schema":{"type":"object","properties":{"cmd":{"type":"string"}},"required":["cmd"]}}]
+	}`))
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Anthropic-Version", "2023-06-01")
+	resp := httptest.NewRecorder()
+	router.ServeHTTP(resp, req)
+
+	if resp.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d body=%s", resp.Code, http.StatusOK, resp.Body.String())
+	}
+	if gotPath != "/v1/proxy/anthropic/v1/messages" {
+		t.Fatalf("path = %q, want %q", gotPath, "/v1/proxy/anthropic/v1/messages")
+	}
+	if gotAuthHeader != "Bearer gateway-token" {
+		t.Fatalf("authorization = %q, want Bearer gateway-token", gotAuthHeader)
+	}
+	if gotRealmHeader != "saas" {
+		t.Fatalf("x-gitlab-realm = %q, want saas", gotRealmHeader)
+	}
+	if !strings.Contains(resp.Body.String(), `"tool_use"`) {
+		t.Fatalf("expected tool_use response, got %s", resp.Body.String())
+	}
+	if !strings.Contains(resp.Body.String(), `"Bash"`) {
+		t.Fatalf("expected Bash tool in response, got %s", resp.Body.String())
+	}
+}
+
+func TestClaudeMessagesStreamWithGitLabDuoAnthropicGateway(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	var gotPath string
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		w.Header().Set("Content-Type", "text/event-stream")
+		_, _ = w.Write([]byte("event: message_start\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"message_start\",\"message\":{\"id\":\"msg_1\",\"type\":\"message\",\"role\":\"assistant\",\"model\":\"claude-sonnet-4-5\",\"content\":[],\"stop_reason\":null,\"stop_sequence\":null,\"usage\":{\"input_tokens\":0,\"output_tokens\":0}}}\n\n"))
+		_, _ = w.Write([]byte("event: content_block_start\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"content_block_start\",\"index\":0,\"content_block\":{\"type\":\"text\",\"text\":\"\"}}\n\n"))
+		_, _ = w.Write([]byte("event: content_block_delta\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"content_block_delta\",\"index\":0,\"delta\":{\"type\":\"text_delta\",\"text\":\"hello from duo\"}}\n\n"))
+		_, _ = w.Write([]byte("event: message_delta\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"end_turn\",\"stop_sequence\":null},\"usage\":{\"input_tokens\":10,\"output_tokens\":3}}\n\n"))
+		_, _ = w.Write([]byte("event: message_stop\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"message_stop\"}\n\n"))
+	}))
+	defer upstream.Close()
+
+	manager, _ := registerGitLabDuoAnthropicAuth(t, upstream.URL)
+	base := handlers.NewBaseAPIHandlers(&sdkconfig.SDKConfig{}, manager)
+	h := NewClaudeCodeAPIHandler(base)
+	router := gin.New()
+	router.POST("/v1/messages", h.ClaudeMessages)
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/messages", strings.NewReader(`{
+		"model":"claude-sonnet-4-5",
+		"stream":true,
+		"max_tokens":64,
+		"messages":[{"role":"user","content":"hello"}]
+	}`))
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Anthropic-Version", "2023-06-01")
+	resp := httptest.NewRecorder()
+	router.ServeHTTP(resp, req)
+
+	if resp.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d body=%s", resp.Code, http.StatusOK, resp.Body.String())
+	}
+	if gotPath != "/v1/proxy/anthropic/v1/messages" {
+		t.Fatalf("path = %q, want %q", gotPath, "/v1/proxy/anthropic/v1/messages")
+	}
+	if got := resp.Header().Get("Content-Type"); got != "text/event-stream" {
+		t.Fatalf("content-type = %q, want text/event-stream", got)
+	}
+	if !strings.Contains(resp.Body.String(), "event: content_block_delta") {
+		t.Fatalf("expected streamed claude event, got %s", resp.Body.String())
+	}
+	if !strings.Contains(resp.Body.String(), "hello from duo") {
+		t.Fatalf("expected streamed text, got %s", resp.Body.String())
+	}
+}
+
+func registerGitLabDuoAnthropicAuth(t *testing.T, upstreamURL string) (*coreauth.Manager, string) {
+	t.Helper()
+
+	manager := coreauth.NewManager(nil, nil, nil)
+	manager.RegisterExecutor(runtimeexecutor.NewGitLabExecutor(&internalconfig.Config{}))
+
+	auth := &coreauth.Auth{
+		ID:       "gitlab-duo-claude-handler-test",
+		Provider: "gitlab",
+		Status:   coreauth.StatusActive,
+		Metadata: map[string]any{
+			"duo_gateway_base_url": upstreamURL,
+			"duo_gateway_token":    "gateway-token",
+			"duo_gateway_headers":  map[string]string{"X-Gitlab-Realm": "saas"},
+			"model_provider":       "anthropic",
+			"model_name":           "claude-sonnet-4-5",
+		},
+	}
+	registered, err := manager.Register(context.Background(), auth)
+	if err != nil {
+		t.Fatalf("register auth: %v", err)
+	}
+
+	registry.GetGlobalRegistry().RegisterClient(registered.ID, registered.Provider, runtimeexecutor.GitLabModelsFromAuth(registered))
+	t.Cleanup(func() {
+		registry.GetGlobalRegistry().UnregisterClient(registered.ID)
+	})
+	return manager, registered.ID
+}

sdk/api/handlers/openai/gitlab_duo_handler_test.go

@@ -0,0 +1,143 @@
+package openai
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	internalconfig "github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/registry"
+	runtimeexecutor "github.com/router-for-me/CLIProxyAPI/v6/internal/runtime/executor"
+	_ "github.com/router-for-me/CLIProxyAPI/v6/internal/translator"
+	"github.com/router-for-me/CLIProxyAPI/v6/sdk/api/handlers"
+	coreauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
+	sdkconfig "github.com/router-for-me/CLIProxyAPI/v6/sdk/config"
+)
+
+func TestOpenAIChatCompletionsWithGitLabDuoOpenAIGateway(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	var gotPath, gotAuthHeader, gotRealmHeader string
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		gotAuthHeader = r.Header.Get("Authorization")
+		gotRealmHeader = r.Header.Get("X-Gitlab-Realm")
+		w.Header().Set("Content-Type", "text/event-stream")
+		_, _ = w.Write([]byte("data: {\"type\":\"response.created\",\"response\":{\"id\":\"resp_1\",\"created_at\":1710000000,\"model\":\"gpt-5-codex\"}}\n\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"response.output_text.delta\",\"delta\":\"hello from duo openai\"}\n\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_1\",\"created_at\":1710000000,\"model\":\"gpt-5-codex\",\"status\":\"completed\",\"output\":[{\"type\":\"message\",\"id\":\"msg_1\",\"role\":\"assistant\",\"content\":[{\"type\":\"output_text\",\"text\":\"hello from duo openai\"}]}],\"usage\":{\"input_tokens\":11,\"output_tokens\":4,\"total_tokens\":15}}}\n\n"))
+	}))
+	defer upstream.Close()
+
+	manager := registerGitLabDuoOpenAIAuth(t, upstream.URL)
+	base := handlers.NewBaseAPIHandlers(&sdkconfig.SDKConfig{}, manager)
+	h := NewOpenAIAPIHandler(base)
+	router := gin.New()
+	router.POST("/v1/chat/completions", h.ChatCompletions)
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/chat/completions", strings.NewReader(`{
+		"model":"gpt-5-codex",
+		"messages":[{"role":"user","content":"hello"}]
+	}`))
+	req.Header.Set("Content-Type", "application/json")
+	resp := httptest.NewRecorder()
+	router.ServeHTTP(resp, req)
+
+	if resp.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d body=%s", resp.Code, http.StatusOK, resp.Body.String())
+	}
+	if gotPath != "/v1/proxy/openai/v1/responses" {
+		t.Fatalf("path = %q, want %q", gotPath, "/v1/proxy/openai/v1/responses")
+	}
+	if gotAuthHeader != "Bearer gateway-token" {
+		t.Fatalf("authorization = %q, want Bearer gateway-token", gotAuthHeader)
+	}
+	if gotRealmHeader != "saas" {
+		t.Fatalf("x-gitlab-realm = %q, want saas", gotRealmHeader)
+	}
+	if !strings.Contains(resp.Body.String(), `"content":"hello from duo openai"`) {
+		t.Fatalf("expected translated chat completion, got %s", resp.Body.String())
+	}
+}
+
+func TestOpenAIResponsesStreamWithGitLabDuoOpenAIGateway(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	var gotPath, gotAuthHeader string
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		gotAuthHeader = r.Header.Get("Authorization")
+		w.Header().Set("Content-Type", "text/event-stream")
+		_, _ = w.Write([]byte("data: {\"type\":\"response.created\",\"response\":{\"id\":\"resp_1\",\"created_at\":1710000000,\"model\":\"gpt-5-codex\"}}\n\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"response.output_text.delta\",\"delta\":\"streamed duo output\"}\n\n"))
+		_, _ = w.Write([]byte("data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_1\",\"created_at\":1710000000,\"model\":\"gpt-5-codex\",\"status\":\"completed\",\"output\":[{\"type\":\"message\",\"id\":\"msg_1\",\"role\":\"assistant\",\"content\":[{\"type\":\"output_text\",\"text\":\"streamed duo output\"}]}],\"usage\":{\"input_tokens\":10,\"output_tokens\":3,\"total_tokens\":13}}}\n\n"))
+	}))
+	defer upstream.Close()
+
+	manager := registerGitLabDuoOpenAIAuth(t, upstream.URL)
+	base := handlers.NewBaseAPIHandlers(&sdkconfig.SDKConfig{}, manager)
+	h := NewOpenAIResponsesAPIHandler(base)
+	router := gin.New()
+	router.POST("/v1/responses", h.Responses)
+
+	req := httptest.NewRequest(http.MethodPost, "/v1/responses", strings.NewReader(`{
+		"model":"gpt-5-codex",
+		"stream":true,
+		"input":"hello"
+	}`))
+	req.Header.Set("Content-Type", "application/json")
+	resp := httptest.NewRecorder()
+	router.ServeHTTP(resp, req)
+
+	if resp.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d body=%s", resp.Code, http.StatusOK, resp.Body.String())
+	}
+	if gotPath != "/v1/proxy/openai/v1/responses" {
+		t.Fatalf("path = %q, want %q", gotPath, "/v1/proxy/openai/v1/responses")
+	}
+	if gotAuthHeader != "Bearer gateway-token" {
+		t.Fatalf("authorization = %q, want Bearer gateway-token", gotAuthHeader)
+	}
+	if got := resp.Header().Get("Content-Type"); got != "text/event-stream" {
+		t.Fatalf("content-type = %q, want text/event-stream", got)
+	}
+	if !strings.Contains(resp.Body.String(), `"type":"response.output_text.delta"`) {
+		t.Fatalf("expected streamed responses delta, got %s", resp.Body.String())
+	}
+	if !strings.Contains(resp.Body.String(), `"type":"response.completed"`) {
+		t.Fatalf("expected streamed responses completion, got %s", resp.Body.String())
+	}
+}
+
+func registerGitLabDuoOpenAIAuth(t *testing.T, upstreamURL string) *coreauth.Manager {
+	t.Helper()
+
+	manager := coreauth.NewManager(nil, nil, nil)
+	manager.RegisterExecutor(runtimeexecutor.NewGitLabExecutor(&internalconfig.Config{}))
+
+	auth := &coreauth.Auth{
+		ID:       "gitlab-duo-openai-handler-test",
+		Provider: "gitlab",
+		Status:   coreauth.StatusActive,
+		Metadata: map[string]any{
+			"duo_gateway_base_url": upstreamURL,
+			"duo_gateway_token":    "gateway-token",
+			"duo_gateway_headers":  map[string]string{"X-Gitlab-Realm": "saas"},
+			"model_provider":       "openai",
+			"model_name":           "gpt-5-codex",
+		},
+	}
+	registered, err := manager.Register(context.Background(), auth)
+	if err != nil {
+		t.Fatalf("register auth: %v", err)
+	}
+
+	registry.GetGlobalRegistry().RegisterClient(registered.ID, registered.Provider, runtimeexecutor.GitLabModelsFromAuth(registered))
+	t.Cleanup(func() {
+		registry.GetGlobalRegistry().UnregisterClient(registered.ID)
+	})
+	return manager
+}

sdk/auth/gitlab.go

@@ -0,0 +1,485 @@
+package auth
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strings"
+	"time"
+
+	gitlabauth "github.com/router-for-me/CLIProxyAPI/v6/internal/auth/gitlab"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/browser"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/misc"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
+	coreauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	gitLabLoginModeMetadataKey           = "login_mode"
+	gitLabLoginModeOAuth                 = "oauth"
+	gitLabLoginModePAT                   = "pat"
+	gitLabBaseURLMetadataKey             = "base_url"
+	gitLabOAuthClientIDMetadataKey       = "oauth_client_id"
+	gitLabOAuthClientSecretMetadataKey   = "oauth_client_secret"
+	gitLabPersonalAccessTokenMetadataKey = "personal_access_token"
+)
+
+var gitLabRefreshLead = 5 * time.Minute
+
+type GitLabAuthenticator struct {
+	CallbackPort int
+}
+
+func NewGitLabAuthenticator() *GitLabAuthenticator {
+	return &GitLabAuthenticator{CallbackPort: gitlabauth.DefaultCallbackPort}
+}
+
+func (a *GitLabAuthenticator) Provider() string {
+	return "gitlab"
+}
+
+func (a *GitLabAuthenticator) RefreshLead() *time.Duration {
+	return &gitLabRefreshLead
+}
+
+func (a *GitLabAuthenticator) Login(ctx context.Context, cfg *config.Config, opts *LoginOptions) (*coreauth.Auth, error) {
+	if cfg == nil {
+		return nil, fmt.Errorf("cliproxy auth: configuration is required")
+	}
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if opts == nil {
+		opts = &LoginOptions{}
+	}
+
+	switch strings.ToLower(strings.TrimSpace(opts.Metadata[gitLabLoginModeMetadataKey])) {
+	case "", gitLabLoginModeOAuth:
+		return a.loginOAuth(ctx, cfg, opts)
+	case gitLabLoginModePAT:
+		return a.loginPAT(ctx, cfg, opts)
+	default:
+		return nil, fmt.Errorf("gitlab auth: unsupported login mode %q", opts.Metadata[gitLabLoginModeMetadataKey])
+	}
+}
+
+func (a *GitLabAuthenticator) loginOAuth(ctx context.Context, cfg *config.Config, opts *LoginOptions) (*coreauth.Auth, error) {
+	client := gitlabauth.NewAuthClient(cfg)
+	baseURL := a.resolveString(opts, gitLabBaseURLMetadataKey, gitlabauth.DefaultBaseURL)
+	clientID, err := a.requireInput(opts, gitLabOAuthClientIDMetadataKey, "Enter GitLab OAuth application client ID: ")
+	if err != nil {
+		return nil, err
+	}
+	clientSecret, err := a.optionalInput(opts, gitLabOAuthClientSecretMetadataKey, "Enter GitLab OAuth application client secret (press Enter for public PKCE app): ")
+	if err != nil {
+		return nil, err
+	}
+
+	callbackPort := a.CallbackPort
+	if opts.CallbackPort > 0 {
+		callbackPort = opts.CallbackPort
+	}
+	redirectURI := gitlabauth.RedirectURL(callbackPort)
+
+	pkceCodes, err := gitlabauth.GeneratePKCECodes()
+	if err != nil {
+		return nil, err
+	}
+	state, err := misc.GenerateRandomState()
+	if err != nil {
+		return nil, fmt.Errorf("gitlab state generation failed: %w", err)
+	}
+
+	oauthServer := gitlabauth.NewOAuthServer(callbackPort)
+	if err := oauthServer.Start(); err != nil {
+		return nil, err
+	}
+	defer func() {
+		stopCtx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+		defer cancel()
+		if stopErr := oauthServer.Stop(stopCtx); stopErr != nil {
+			log.Warnf("gitlab oauth server stop error: %v", stopErr)
+		}
+	}()
+
+	authURL, err := client.GenerateAuthURL(baseURL, clientID, redirectURI, state, pkceCodes)
+	if err != nil {
+		return nil, err
+	}
+
+	if !opts.NoBrowser {
+		fmt.Println("Opening browser for GitLab Duo authentication")
+		if !browser.IsAvailable() {
+			log.Warn("No browser available; please open the URL manually")
+			util.PrintSSHTunnelInstructions(callbackPort)
+			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
+		} else if err = browser.OpenURL(authURL); err != nil {
+			log.Warnf("Failed to open browser automatically: %v", err)
+			util.PrintSSHTunnelInstructions(callbackPort)
+			fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
+		}
+	} else {
+		util.PrintSSHTunnelInstructions(callbackPort)
+		fmt.Printf("Visit the following URL to continue authentication:\n%s\n", authURL)
+	}
+
+	fmt.Println("Waiting for GitLab OAuth callback...")
+
+	callbackCh := make(chan *gitlabauth.OAuthResult, 1)
+	callbackErrCh := make(chan error, 1)
+	go func() {
+		result, waitErr := oauthServer.WaitForCallback(5 * time.Minute)
+		if waitErr != nil {
+			callbackErrCh <- waitErr
+			return
+		}
+		callbackCh <- result
+	}()
+
+	var result *gitlabauth.OAuthResult
+	var manualPromptTimer *time.Timer
+	var manualPromptC <-chan time.Time
+	if opts.Prompt != nil {
+		manualPromptTimer = time.NewTimer(15 * time.Second)
+		manualPromptC = manualPromptTimer.C
+		defer manualPromptTimer.Stop()
+	}
+
+waitForCallback:
+	for {
+		select {
+		case result = <-callbackCh:
+			break waitForCallback
+		case err = <-callbackErrCh:
+			return nil, err
+		case <-manualPromptC:
+			manualPromptC = nil
+			if manualPromptTimer != nil {
+				manualPromptTimer.Stop()
+			}
+			input, promptErr := opts.Prompt("Paste the GitLab callback URL (or press Enter to keep waiting): ")
+			if promptErr != nil {
+				return nil, promptErr
+			}
+			parsed, parseErr := misc.ParseOAuthCallback(input)
+			if parseErr != nil {
+				return nil, parseErr
+			}
+			if parsed == nil {
+				continue
+			}
+			result = &gitlabauth.OAuthResult{
+				Code:  parsed.Code,
+				State: parsed.State,
+				Error: parsed.Error,
+			}
+			break waitForCallback
+		}
+	}
+
+	if result.Error != "" {
+		return nil, fmt.Errorf("gitlab oauth returned error: %s", result.Error)
+	}
+	if result.State != state {
+		return nil, fmt.Errorf("gitlab auth: state mismatch")
+	}
+
+	tokenResp, err := client.ExchangeCodeForTokens(ctx, baseURL, clientID, clientSecret, redirectURI, result.Code, pkceCodes.CodeVerifier)
+	if err != nil {
+		return nil, err
+	}
+	accessToken := strings.TrimSpace(tokenResp.AccessToken)
+	if accessToken == "" {
+		return nil, fmt.Errorf("gitlab auth: missing access token")
+	}
+
+	user, err := client.GetCurrentUser(ctx, baseURL, accessToken)
+	if err != nil {
+		return nil, err
+	}
+	direct, err := client.FetchDirectAccess(ctx, baseURL, accessToken)
+	if err != nil {
+		return nil, err
+	}
+
+	identifier := gitLabAccountIdentifier(user)
+	fileName := fmt.Sprintf("gitlab-%s.json", sanitizeGitLabFileName(identifier))
+	metadata := buildGitLabAuthMetadata(baseURL, gitLabLoginModeOAuth, tokenResp, direct)
+	metadata["auth_kind"] = "oauth"
+	metadata[gitLabOAuthClientIDMetadataKey] = clientID
+	if strings.TrimSpace(clientSecret) != "" {
+		metadata[gitLabOAuthClientSecretMetadataKey] = clientSecret
+	}
+	metadata["username"] = strings.TrimSpace(user.Username)
+	if email := strings.TrimSpace(primaryGitLabEmail(user)); email != "" {
+		metadata["email"] = email
+	}
+	metadata["name"] = strings.TrimSpace(user.Name)
+
+	fmt.Println("GitLab Duo authentication successful")
+
+	return &coreauth.Auth{
+		ID:       fileName,
+		Provider: a.Provider(),
+		FileName: fileName,
+		Label:    identifier,
+		Metadata: metadata,
+	}, nil
+}
+
+func (a *GitLabAuthenticator) loginPAT(ctx context.Context, cfg *config.Config, opts *LoginOptions) (*coreauth.Auth, error) {
+	client := gitlabauth.NewAuthClient(cfg)
+	baseURL := a.resolveString(opts, gitLabBaseURLMetadataKey, gitlabauth.DefaultBaseURL)
+	token, err := a.requireInput(opts, gitLabPersonalAccessTokenMetadataKey, "Enter GitLab personal access token: ")
+	if err != nil {
+		return nil, err
+	}
+
+	user, err := client.GetCurrentUser(ctx, baseURL, token)
+	if err != nil {
+		return nil, err
+	}
+	_, err = client.GetPersonalAccessTokenSelf(ctx, baseURL, token)
+	if err != nil {
+		return nil, err
+	}
+	direct, err := client.FetchDirectAccess(ctx, baseURL, token)
+	if err != nil {
+		return nil, err
+	}
+
+	identifier := gitLabAccountIdentifier(user)
+	fileName := fmt.Sprintf("gitlab-%s-pat.json", sanitizeGitLabFileName(identifier))
+	metadata := buildGitLabAuthMetadata(baseURL, gitLabLoginModePAT, nil, direct)
+	metadata["auth_kind"] = "personal_access_token"
+	metadata[gitLabPersonalAccessTokenMetadataKey] = strings.TrimSpace(token)
+	metadata["token_preview"] = maskGitLabToken(token)
+	metadata["username"] = strings.TrimSpace(user.Username)
+	if email := strings.TrimSpace(primaryGitLabEmail(user)); email != "" {
+		metadata["email"] = email
+	}
+	metadata["name"] = strings.TrimSpace(user.Name)
+
+	fmt.Println("GitLab Duo PAT authentication successful")
+
+	return &coreauth.Auth{
+		ID:       fileName,
+		Provider: a.Provider(),
+		FileName: fileName,
+		Label:    identifier + " (PAT)",
+		Metadata: metadata,
+	}, nil
+}
+
+func buildGitLabAuthMetadata(baseURL, mode string, tokenResp *gitlabauth.TokenResponse, direct *gitlabauth.DirectAccessResponse) map[string]any {
+	metadata := map[string]any{
+		"type":                     "gitlab",
+		"auth_method":              strings.TrimSpace(mode),
+		gitLabBaseURLMetadataKey:   gitlabauth.NormalizeBaseURL(baseURL),
+		"last_refresh":             time.Now().UTC().Format(time.RFC3339),
+		"refresh_interval_seconds": 240,
+	}
+	if tokenResp != nil {
+		metadata["access_token"] = strings.TrimSpace(tokenResp.AccessToken)
+		if refreshToken := strings.TrimSpace(tokenResp.RefreshToken); refreshToken != "" {
+			metadata["refresh_token"] = refreshToken
+		}
+		if tokenType := strings.TrimSpace(tokenResp.TokenType); tokenType != "" {
+			metadata["token_type"] = tokenType
+		}
+		if scope := strings.TrimSpace(tokenResp.Scope); scope != "" {
+			metadata["scope"] = scope
+		}
+		if expiry := gitlabauth.TokenExpiry(time.Now(), tokenResp); !expiry.IsZero() {
+			metadata["oauth_expires_at"] = expiry.Format(time.RFC3339)
+		}
+	}
+	mergeGitLabDirectAccessMetadata(metadata, direct)
+	return metadata
+}
+
+func mergeGitLabDirectAccessMetadata(metadata map[string]any, direct *gitlabauth.DirectAccessResponse) {
+	if metadata == nil || direct == nil {
+		return
+	}
+	if base := strings.TrimSpace(direct.BaseURL); base != "" {
+		metadata["duo_gateway_base_url"] = base
+	}
+	if token := strings.TrimSpace(direct.Token); token != "" {
+		metadata["duo_gateway_token"] = token
+	}
+	if direct.ExpiresAt > 0 {
+		expiry := time.Unix(direct.ExpiresAt, 0).UTC()
+		metadata["duo_gateway_expires_at"] = expiry.Format(time.RFC3339)
+		now := time.Now().UTC()
+		if ttl := expiry.Sub(now); ttl > 0 {
+			interval := int(ttl.Seconds()) / 2
+			switch {
+			case interval < 60:
+				interval = 60
+			case interval > 240:
+				interval = 240
+			}
+			metadata["refresh_interval_seconds"] = interval
+		}
+	}
+	if len(direct.Headers) > 0 {
+		headers := make(map[string]string, len(direct.Headers))
+		for key, value := range direct.Headers {
+			key = strings.TrimSpace(key)
+			value = strings.TrimSpace(value)
+			if key == "" || value == "" {
+				continue
+			}
+			headers[key] = value
+		}
+		if len(headers) > 0 {
+			metadata["duo_gateway_headers"] = headers
+		}
+	}
+	if direct.ModelDetails != nil {
+		modelDetails := map[string]any{}
+		if provider := strings.TrimSpace(direct.ModelDetails.ModelProvider); provider != "" {
+			modelDetails["model_provider"] = provider
+			metadata["model_provider"] = provider
+		}
+		if model := strings.TrimSpace(direct.ModelDetails.ModelName); model != "" {
+			modelDetails["model_name"] = model
+			metadata["model_name"] = model
+		}
+		if len(modelDetails) > 0 {
+			metadata["model_details"] = modelDetails
+		}
+	}
+}
+
+func (a *GitLabAuthenticator) resolveString(opts *LoginOptions, key, fallback string) string {
+	if opts != nil && opts.Metadata != nil {
+		if value := strings.TrimSpace(opts.Metadata[key]); value != "" {
+			return value
+		}
+	}
+	for _, envKey := range gitLabEnvKeys(key) {
+		if raw, ok := os.LookupEnv(envKey); ok {
+			if trimmed := strings.TrimSpace(raw); trimmed != "" {
+				return trimmed
+			}
+		}
+	}
+	if strings.TrimSpace(fallback) != "" {
+		return fallback
+	}
+	return ""
+}
+
+func (a *GitLabAuthenticator) requireInput(opts *LoginOptions, key, prompt string) (string, error) {
+	if value := a.resolveString(opts, key, ""); value != "" {
+		return value, nil
+	}
+	if opts != nil && opts.Prompt != nil {
+		value, err := opts.Prompt(prompt)
+		if err != nil {
+			return "", err
+		}
+		if trimmed := strings.TrimSpace(value); trimmed != "" {
+			return trimmed, nil
+		}
+	}
+	return "", fmt.Errorf("gitlab auth: missing required %s", key)
+}
+
+func (a *GitLabAuthenticator) optionalInput(opts *LoginOptions, key, prompt string) (string, error) {
+	if value := a.resolveString(opts, key, ""); value != "" {
+		return value, nil
+	}
+	if opts != nil && opts.Prompt != nil {
+		value, err := opts.Prompt(prompt)
+		if err != nil {
+			return "", err
+		}
+		return strings.TrimSpace(value), nil
+	}
+	return "", nil
+}
+
+func primaryGitLabEmail(user *gitlabauth.User) string {
+	if user == nil {
+		return ""
+	}
+	if value := strings.TrimSpace(user.Email); value != "" {
+		return value
+	}
+	return strings.TrimSpace(user.PublicEmail)
+}
+
+func gitLabAccountIdentifier(user *gitlabauth.User) string {
+	if user == nil {
+		return "user"
+	}
+	for _, value := range []string{user.Username, primaryGitLabEmail(user), user.Name} {
+		if trimmed := strings.TrimSpace(value); trimmed != "" {
+			return trimmed
+		}
+	}
+	return "user"
+}
+
+func sanitizeGitLabFileName(value string) string {
+	value = strings.TrimSpace(strings.ToLower(value))
+	if value == "" {
+		return "user"
+	}
+	var builder strings.Builder
+	lastDash := false
+	for _, r := range value {
+		switch {
+		case r >= 'a' && r <= 'z':
+			builder.WriteRune(r)
+			lastDash = false
+		case r >= '0' && r <= '9':
+			builder.WriteRune(r)
+			lastDash = false
+		case r == '-' || r == '_' || r == '.':
+			builder.WriteRune(r)
+			lastDash = false
+		default:
+			if !lastDash {
+				builder.WriteRune('-')
+				lastDash = true
+			}
+		}
+	}
+	result := strings.Trim(builder.String(), "-")
+	if result == "" {
+		return "user"
+	}
+	return result
+}
+
+func maskGitLabToken(token string) string {
+	trimmed := strings.TrimSpace(token)
+	if trimmed == "" {
+		return ""
+	}
+	if len(trimmed) <= 8 {
+		return trimmed
+	}
+	return trimmed[:4] + "..." + trimmed[len(trimmed)-4:]
+}
+
+func gitLabEnvKeys(key string) []string {
+	switch strings.TrimSpace(key) {
+	case gitLabBaseURLMetadataKey:
+		return []string{"GITLAB_BASE_URL"}
+	case gitLabOAuthClientIDMetadataKey:
+		return []string{"GITLAB_OAUTH_CLIENT_ID"}
+	case gitLabOAuthClientSecretMetadataKey:
+		return []string{"GITLAB_OAUTH_CLIENT_SECRET"}
+	case gitLabPersonalAccessTokenMetadataKey:
+		return []string{"GITLAB_PERSONAL_ACCESS_TOKEN"}
+	default:
+		return nil
+	}
+}

sdk/auth/gitlab_test.go

@@ -0,0 +1,66 @@
+package auth
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+)
+
+func TestGitLabAuthenticatorLoginPAT(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/api/v4/user":
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"id":       42,
+				"username": "duo-user",
+				"email":    "duo@example.com",
+				"name":     "Duo User",
+			})
+		case "/api/v4/personal_access_tokens/self":
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"id":     5,
+				"name":   "CLIProxyAPI",
+				"scopes": []string{"api"},
+			})
+		case "/api/v4/code_suggestions/direct_access":
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"base_url":   "https://cloud.gitlab.example.com",
+				"token":      "gateway-token",
+				"expires_at": 1710003600,
+				"headers":    map[string]string{"X-Gitlab-Realm": "saas"},
+				"model_details": map[string]any{
+					"model_provider": "anthropic",
+					"model_name":     "claude-sonnet-4-5",
+				},
+			})
+		default:
+			t.Fatalf("unexpected path %q", r.URL.Path)
+		}
+	}))
+	defer srv.Close()
+
+	authenticator := NewGitLabAuthenticator()
+	record, err := authenticator.Login(context.Background(), &config.Config{}, &LoginOptions{
+		Metadata: map[string]string{
+			"login_mode":            "pat",
+			"base_url":              srv.URL,
+			"personal_access_token": "glpat-test-token",
+		},
+	})
+	if err != nil {
+		t.Fatalf("Login() error = %v", err)
+	}
+	if record.Provider != "gitlab" {
+		t.Fatalf("expected gitlab provider, got %q", record.Provider)
+	}
+	if got := record.Metadata["model_name"]; got != "claude-sonnet-4-5" {
+		t.Fatalf("expected discovered model, got %#v", got)
+	}
+	if got := record.Metadata["auth_kind"]; got != "personal_access_token" {
+		t.Fatalf("expected personal_access_token auth kind, got %#v", got)
+	}
+}

sdk/auth/refresh_registry.go

@@ -17,6 +17,7 @@ func init() {
 	registerRefreshLead("kimi", func() Authenticator { return NewKimiAuthenticator() })
 	registerRefreshLead("kiro", func() Authenticator { return NewKiroAuthenticator() })
 	registerRefreshLead("github-copilot", func() Authenticator { return NewGitHubCopilotAuthenticator() })
+	registerRefreshLead("gitlab", func() Authenticator { return NewGitLabAuthenticator() })
 }
 
 func registerRefreshLead(provider string, factory func() Authenticator) {

sdk/cliproxy/auth/types.go

@@ -390,6 +390,27 @@ func (a *Auth) AccountInfo() (string, string) {
 
 	// Check metadata for email first (OAuth-style auth)
 	if a.Metadata != nil {
+		if method, ok := a.Metadata["auth_method"].(string); ok {
+			switch strings.ToLower(strings.TrimSpace(method)) {
+			case "oauth":
+				for _, key := range []string{"email", "username", "name"} {
+					if value, okValue := a.Metadata[key].(string); okValue {
+						if trimmed := strings.TrimSpace(value); trimmed != "" {
+							return "oauth", trimmed
+						}
+					}
+				}
+			case "pat", "personal_access_token":
+				for _, key := range []string{"username", "email", "name", "token_preview"} {
+					if value, okValue := a.Metadata[key].(string); okValue {
+						if trimmed := strings.TrimSpace(value); trimmed != "" {
+							return "personal_access_token", trimmed
+						}
+					}
+				}
+				return "personal_access_token", ""
+			}
+		}
 		if v, ok := a.Metadata["email"].(string); ok {
 			email := strings.TrimSpace(v)
 			if email != "" {

sdk/cliproxy/service.go

@@ -119,6 +119,7 @@ func newDefaultAuthManager() *sdkAuth.Manager {
 		sdkAuth.NewCodexAuthenticator(),
 		sdkAuth.NewClaudeAuthenticator(),
 		sdkAuth.NewQwenAuthenticator(),
+		sdkAuth.NewGitLabAuthenticator(),
 	)
 }
 
@@ -444,6 +445,8 @@ func (s *Service) ensureExecutorsForAuthWithMode(a *coreauth.Auth, forceReplace
 		s.coreManager.RegisterExecutor(executor.NewKiloExecutor(s.cfg))
 	case "github-copilot":
 		s.coreManager.RegisterExecutor(executor.NewGitHubCopilotExecutor(s.cfg))
+	case "gitlab":
+		s.coreManager.RegisterExecutor(executor.NewGitLabExecutor(s.cfg))
 	default:
 		providerKey := strings.ToLower(strings.TrimSpace(a.Provider))
 		if providerKey == "" {
@@ -891,7 +894,7 @@ func (s *Service) registerModelsForAuth(a *coreauth.Auth) {
 		models = applyExcludedModels(models, excluded)
 	case "kimi":
 		models = registry.GetKimiModels()
-    models = applyExcludedModels(models, excluded)
+		models = applyExcludedModels(models, excluded)
 	case "github-copilot":
 		ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
 		defer cancel()
@@ -903,6 +906,9 @@ func (s *Service) registerModelsForAuth(a *coreauth.Auth) {
 	case "kilo":
 		models = executor.FetchKiloModels(context.Background(), a, s.cfg)
 		models = applyExcludedModels(models, excluded)
+	case "gitlab":
+		models = executor.GitLabModelsFromAuth(a)
+		models = applyExcludedModels(models, excluded)
 	default:
 		// Handle OpenAI-compatibility providers by name using config
 		if s.cfg != nil {

sdk/cliproxy/service_gitlab_models_test.go

@@ -0,0 +1,48 @@
+package cliproxy
+
+import (
+	"testing"
+
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/registry"
+	coreauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
+	"github.com/router-for-me/CLIProxyAPI/v6/sdk/config"
+)
+
+func TestRegisterModelsForAuth_GitLabUsesDiscoveredModels(t *testing.T) {
+	service := &Service{cfg: &config.Config{}}
+	auth := &coreauth.Auth{
+		ID:       "gitlab-auth.json",
+		Provider: "gitlab",
+		Status:   coreauth.StatusActive,
+		Metadata: map[string]any{
+			"model_details": map[string]any{
+				"model_provider": "anthropic",
+				"model_name":     "claude-sonnet-4-5",
+			},
+		},
+	}
+
+	reg := registry.GetGlobalRegistry()
+	reg.UnregisterClient(auth.ID)
+	t.Cleanup(func() { reg.UnregisterClient(auth.ID) })
+
+	service.registerModelsForAuth(auth)
+	models := reg.GetModelsForClient(auth.ID)
+	if len(models) < 2 {
+		t.Fatalf("expected stable alias and discovered model, got %d entries", len(models))
+	}
+
+	seenAlias := false
+	seenDiscovered := false
+	for _, model := range models {
+		switch model.ID {
+		case "gitlab-duo":
+			seenAlias = true
+		case "claude-sonnet-4-5":
+			seenDiscovered = true
+		}
+	}
+	if !seenAlias || !seenDiscovered {
+		t.Fatalf("expected gitlab-duo and discovered model, got %+v", models)
+	}
+}