Add initial PoC for MCP Apps for select tools under Insiders (#1957)

* PoC full flow (hello world example)

* add avatar resource domain

* add postmessage logic and richer UI

* add create issue ui

* update ui for issue creatioon

* fix

* ignore banner

* update docs after rebase

* update toolsnap for get_me

* new UI changes

* update docs

* update workflows that need ui build

* add UI diff

* fix build ui step for windows runners to use git bash

* fix UI diff

* refactor issue creation UI

* add AvatarWithFallback component and update UserCard to use it; enhance CreateIssueApp to manage existing issue data

* fix formatting of button labels

* add create pull request functionality with UI support and insiders

* update docs

* add test for insiders mode handling in ServerTool schema

* remove `show_ui` param for now

* make insiders mode metadata stripping generic

* remove ui diff

* fix CI

* remove redundant mention of old app name

* add node types to fix ide issues for ts code

* remove unused TriangleDownIcon import

* update @primer/behaviors and electron-to-chromium versions in package-lock.json

* add check to ensure base and head are not the same when creating a new PR

* remove old show_ui

* fix gitignore for dist so builds dont break

* add tests for insiders mode handling and metadata stripping in ServerTool

* remove unused state and components from CreatePRApp

* fix ui build

* update docker build to fix npm issue

* remove reference to show_ui

* allow insiders to work for non-ui features

* formalise insiders inventory support

* update docs

* fix overflow issues and replace pull request dropdown with matching UI from dotcom

* fix createpullrequest test

* consolidate fetching tools under `ui_get` tool to remove toolset deps

* fix issue data prefill in issue_write form

* fix link component when updating issue

* fix avatar URL

* fix broken issue update logic

* remove dbg

* fix for new GetFlags

* revert to original required fields for create_pull_request

* fix for UI form submission

* Simplify MCP App UIs for basic branch

Remove advanced features to be kept in mcp-ui-apps-advanced:
- Strip labels, assignees, milestones, issue types, repo picker from issue-write
- Strip repo picker, branch selectors from pr-write
- Delete ui_get tool (ui_tools.go, ui_tools_test.go, ui_get.snap)
- Remove UIGet registration from tools.go

Basic forms retain: title, body, submit with _ui_submitted,
draft/regular split button (PR), MarkdownEditor, and SuccessView.

* Fix header spacing in issue-write and pr-write UIs

Add proper spacing between icon, title text, and repo name in the
header bar for both issue-write and create-pull-request forms.

* fix UI spacing

* Add insiders flag to User-Agent header

When InsidersMode is enabled, append '(insiders)' to the User-Agent
string sent with GitHub API requests, enabling server-side adoption
tracking.

* address ui feedback

* added ui/no-ui support

* improve active state UI for write and preview button. make padding consistent in textarea

* return to prev non ui check

* use hardcoded client name check for ui support

* linter fixes

* merge fix

* linter fix 2

---------

Co-authored-by: tommaso-moro <tommaso-moro@github.com>

Author: mattdholloway

.github/workflows/code-scanning.yml

@@ -74,6 +74,18 @@ jobs:
           go-version: ${{ fromJSON(steps.resolve-environment.outputs.environment).configuration.go.version }}
           cache: false
 
+      - name: Set up Node.js
+        if: matrix.language == 'go'
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+          cache-dependency-path: ui/package-lock.json
+
+      - name: Build UI
+        if: matrix.language == 'go'
+        run: script/build-ui
+
       - name: Autobuild
         uses: github/codeql-action/autobuild@v4
 

.github/workflows/docs-check.yml

@@ -16,6 +16,16 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v6
 
+    - name: Set up Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: "20"
+        cache: "npm"
+        cache-dependency-path: ui/package-lock.json
+
+    - name: Build UI
+      run: script/build-ui
+
     - name: Set up Go
       uses: actions/setup-go@v6
       with:

.github/workflows/go.yml

@@ -25,6 +25,17 @@ jobs:
       - name: Check out code
         uses: actions/checkout@v6
 
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+          cache-dependency-path: ui/package-lock.json
+
+      - name: Build UI
+        shell: bash
+        run: script/build-ui
+
       - name: Set up Go
         uses: actions/setup-go@v6
         with:
@@ -34,6 +45,7 @@ jobs:
         run: go mod tidy -diff
 
       - name: Run unit tests
+        shell: bash
         run: script/test
 
       - name: Build

.github/workflows/goreleaser.yml

@@ -16,6 +16,16 @@ jobs:
       - name: Check out code
         uses: actions/checkout@v6
 
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+          cache-dependency-path: ui/package-lock.json
+
+      - name: Build UI
+        run: script/build-ui
+
       - name: Set up Go
         uses: actions/setup-go@v6
         with:

.github/workflows/license-check.yml

@@ -32,6 +32,16 @@ jobs:
           GH_TOKEN: ${{ github.token }}
         run: gh pr checkout ${{ github.event.pull_request.number }}
 
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+          cache-dependency-path: ui/package-lock.json
+
+      - name: Build UI
+        run: script/build-ui
+
       - name: Set up Go
         uses: actions/setup-go@v6
         with:

.github/workflows/lint.yml

@@ -14,6 +14,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "npm"
+          cache-dependency-path: ui/package-lock.json
+      - name: Build UI
+        run: script/build-ui
       - uses: actions/setup-go@v6
         with:
           go-version: '1.25'

.github/workflows/mcp-diff.yml

@@ -19,6 +19,14 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Build UI
+        run: script/build-ui
+
       - name: Run MCP Server Diff
         uses: SamMorrowDrums/mcp-server-diff@v2.3.5
         with:

.gitignore

@@ -23,3 +23,12 @@ e2e.test
 
 .history
 conformance-report/
+
+# UI build artifacts
+ui/dist/
+ui/node_modules/
+
+# Embedded UI assets (built from ui/)
+pkg/github/ui_dist/*
+!pkg/github/ui_dist/.gitkeep
+!pkg/github/ui_dist/.placeholder.html

Dockerfile

@@ -1,3 +1,12 @@
+FROM node:20-alpine AS ui-build
+WORKDIR /app
+COPY ui/package*.json ./ui/
+RUN cd ui && npm ci
+COPY ui/ ./ui/
+# Create output directory and build - vite outputs directly to pkg/github/ui_dist/
+RUN mkdir -p ./pkg/github/ui_dist && \
+    cd ui && npm run build
+
 FROM golang:1.25.7-alpine AS build
 ARG VERSION="dev"
 
@@ -8,11 +17,15 @@ WORKDIR /build
 RUN --mount=type=cache,target=/var/cache/apk \
     apk add git
 
+# Copy source code (including ui_dist placeholder)
+COPY . .
+
+# Copy built UI assets over the placeholder
+COPY --from=ui-build /app/pkg/github/ui_dist/* ./pkg/github/ui_dist/
+
 # Build the server
-# go build automatically download required module dependencies to /go/pkg/mod
 RUN --mount=type=cache,target=/go/pkg/mod \
     --mount=type=cache,target=/root/.cache/go-build \
-    --mount=type=bind,target=. \
     CGO_ENABLED=0 go build -ldflags="-s -w -X main.version=${VERSION} -X main.commit=$(git rev-parse HEAD) -X main.date=$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
     -o /bin/github-mcp-server ./cmd/github-mcp-server
 

internal/ghmcp/server.go

@@ -136,7 +136,8 @@ func NewStdioMCPServer(ctx context.Context, cfg github.MCPServerConfig) (*mcp.Se
 		WithToolsets(github.ResolvedEnabledToolsets(cfg.DynamicToolsets, cfg.EnabledToolsets, cfg.EnabledTools)).
 		WithTools(github.CleanTools(cfg.EnabledTools)).
 		WithServerInstructions().
-		WithFeatureChecker(featureChecker)
+		WithFeatureChecker(featureChecker).
+		WithInsidersMode(cfg.InsidersMode)
 
 	// Apply token scope filtering if scopes are known (for PAT filtering)
 	if cfg.TokenScopes != nil {
@@ -153,6 +154,13 @@ func NewStdioMCPServer(ctx context.Context, cfg github.MCPServerConfig) (*mcp.Se
 		return nil, fmt.Errorf("failed to create GitHub MCP server: %w", err)
 	}
 
+	// Register MCP App UI resources if available (requires running script/build-ui).
+	// We check availability to allow Insiders mode to work for non-UI features
+	// even when UI assets haven't been built.
+	if cfg.InsidersMode && github.UIAssetsAvailable() {
+		github.RegisterUIResources(ghServer)
+	}
+
 	ghServer.AddReceivingMiddleware(addUserAgentsMiddleware(cfg, clients.rest, clients.gqlHTTP))
 
 	return ghServer, nil
@@ -345,6 +353,9 @@ func addUserAgentsMiddleware(cfg github.MCPServerConfig, restClient *gogithub.Cl
 				message.Params.ClientInfo.Name,
 				message.Params.ClientInfo.Version,
 			)
+			if cfg.InsidersMode {
+				userAgent += " (insiders)"
+			}
 
 			restClient.UserAgent = userAgent