@@ -7,6 +7,63 @@ on:
   pull_request:
 
 jobs:
+  spec-kit-conformance:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Validate spec-kit artifact set
+        run: |
+          test -f testkit/.specify/memory/constitution.md
+          test -f testkit/.specify/specs/001-polyglot-testkit/spec.md
+          test -f testkit/.specify/specs/001-polyglot-testkit/plan.md
+          test -f testkit/.specify/specs/001-polyglot-testkit/tasks.md
+          test -f testkit/.specify/specs/001-polyglot-testkit/contracts/cli-protocol.json
+          test -f testkit/.specify/specs/001-polyglot-testkit/checklists/quality.md
+
+      - name: Validate spec-kit scaffold and status
+        run: ./testkit/.specify/scripts/validate_specify.sh
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "stable"
+      - name: Build git-testkit CLI binary once
+        run: go build ./cmd/git-testkit-cli
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: "21"
+          cache: maven
+
+      - name: Run Python spec conformance smoke tests
+        run: |
+          cd testkit/python
+          python -m pip install -e ".[dev]"
+          python -m pytest tests/ -v
+      - name: Run Python sample smoke implementations
+        run: |
+          cd testkit/python
+          python -m samples.smoke_repo_flow
+          python -m samples.smoke_snapshot_flow
+
+      - name: Run Java spec conformance smoke tests
+        run: |
+          cd testkit/java
+          mvn test
+      - name: Run Java sample smoke implementations
+        run: |
+          cd testkit/java
+          mvn -Dtest=SampleRepoFlowSmoke,SampleSnapshotFlowSmoke test
+
   test:
     runs-on: ubuntu-latest
     strategy:
@@ -26,5 +83,63 @@ jobs:
       - name: Run vet
         run: go vet ./...
 
+      - name: Check gofmt
+        run: test -z "$(gofmt -l .)"
+
       - name: Run tests
         run: go test ./...
+
+  wrapper-cross-platform:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "stable"
+
+      - name: Build git-testkit CLI binary once
+        shell: bash
+        run: |
+          mkdir -p bin
+          if [[ "${{ matrix.os }}" == "windows-latest" ]]; then
+            go build -o ./bin/git-testkit-cli.exe ./cmd/git-testkit-cli
+          else
+            go build -o ./bin/git-testkit-cli ./cmd/git-testkit-cli
+          fi
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: "21"
+          cache: maven
+
+      - name: Run Python wrapper smoke tests
+        shell: bash
+        env:
+          GIT_TESTKIT_CLI: ${{ matrix.os == 'windows-latest' && './bin/git-testkit-cli.exe' || './bin/git-testkit-cli' }}
+        run: |
+          cd testkit/python
+          python -m pip install -e ".[dev]"
+          python -m pytest tests/test_fixtures.py tests/test_snapshots.py -v
+
+      - name: Run Java wrapper smoke tests
+        shell: bash
+        env:
+          GIT_TESTKIT_CLI: ${{ matrix.os == 'windows-latest' && './bin/git-testkit-cli.exe' || './bin/git-testkit-cli' }}
+        run: |
+          cd testkit/java
+          mvn -Dtest=CliBridgeTest,SampleRepoFlowSmoke,SampleSnapshotFlowSmoke test
@@ -0,0 +1,266 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	testutil "github.com/git-fire/git-testkit"
+)
+
+type request struct {
+	Op       string            `json:"op"`
+	BaseDir  string            `json:"baseDir,omitempty"`
+	RepoPath string            `json:"repoPath,omitempty"`
+	Args     []string          `json:"args,omitempty"`
+	Options  *repoOptionsInput `json:"options,omitempty"`
+
+	SnapshotPath string `json:"snapshotPath,omitempty"`
+}
+
+type repoOptionsInput struct {
+	Name          string            `json:"name"`
+	Dirty         bool              `json:"dirty,omitempty"`
+	Files         map[string]string `json:"files,omitempty"`
+	Remotes       map[string]string `json:"remotes,omitempty"`
+	Branches      []string          `json:"branches,omitempty"`
+	InitialCommit string            `json:"initialCommit,omitempty"`
+}
+
+type response struct {
+	OK bool `json:"ok"`
+
+	Error string `json:"error,omitempty"`
+
+	RepoPath     string            `json:"repoPath,omitempty"`
+	RemotePath   string            `json:"remotePath,omitempty"`
+	FSRoot       string            `json:"fsRoot,omitempty"`
+	Output       *string           `json:"output,omitempty"`
+	Dirty        *bool             `json:"dirty,omitempty"`
+	Remotes      map[string]string `json:"remotes,omitempty"`
+	SHA          string            `json:"sha,omitempty"`
+	Branches     []string          `json:"branches,omitempty"`
+	SnapshotName string            `json:"snapshotName,omitempty"`
+	SnapshotSize *int              `json:"snapshotSize,omitempty"`
+	RestorePath  string            `json:"restorePath,omitempty"`
+}
+
+func main() {
+	req, err := parseRequest()
+	if err != nil {
+		writeResponse(response{OK: false, Error: err.Error()})
+		os.Exit(1)
+	}
+
+	res, err := handle(req)
+	if err != nil {
+		writeResponse(response{OK: false, Error: err.Error()})
+		os.Exit(1)
+	}
+	writeResponse(res)
+}
+
+func parseRequest() (request, error) {
+	var req request
+	if err := json.NewDecoder(os.Stdin).Decode(&req); err != nil {
+		return request{}, fmt.Errorf("invalid JSON request: %w", err)
+	}
+	if strings.TrimSpace(req.Op) == "" {
+		return request{}, fmt.Errorf("missing required field: op")
+	}
+	return req, nil
+}
+
+func handle(req request) (response, error) {
+	switch req.Op {
+	case "create_test_repo":
+		base, err := ensureBaseDir(req.BaseDir)
+		if err != nil {
+			return response{}, err
+		}
+		if req.Options == nil {
+			return response{}, fmt.Errorf("missing options")
+		}
+		repoPath, err := testutil.CreateTestRepoInDir(base, testutil.RepoOptions{
+			Name:          req.Options.Name,
+			Dirty:         req.Options.Dirty,
+			Files:         req.Options.Files,
+			Remotes:       req.Options.Remotes,
+			Branches:      req.Options.Branches,
+			InitialCommit: req.Options.InitialCommit,
+		})
+		if err != nil {
+			return response{}, err
+		}
+		return response{OK: true, RepoPath: repoPath}, nil
+
+	case "create_bare_remote":
+		base, err := ensureBaseDir(req.BaseDir)
+		if err != nil {
+			return response{}, err
+		}
+		if req.Options == nil || req.Options.Name == "" {
+			return response{}, fmt.Errorf("missing options.name")
+		}
+		remotePath, err := testutil.CreateBareRemoteInDir(base, req.Options.Name)
+		if err != nil {
+			return response{}, err
+		}
+		return response{OK: true, RemotePath: remotePath}, nil
+
+	case "setup_fake_filesystem":
+		base, err := ensureBaseDir(req.BaseDir)
+		if err != nil {
+			return response{}, err
+		}
+		root, err := testutil.SetupFakeFilesystemInDir(base)
+		if err != nil {
+			return response{}, err
+		}
+		return response{OK: true, FSRoot: root}, nil
+
+	case "run_git_cmd":
+		if req.RepoPath == "" {
+			return response{}, fmt.Errorf("missing repoPath")
+		}
+		output, err := testutil.RunGitCmdE(req.RepoPath, req.Args...)
+		if err != nil {
+			return response{}, err
+		}
+		return response{OK: true, Output: stringPtr(output)}, nil
+
+	case "is_dirty":
+		if req.RepoPath == "" {
+			return response{}, fmt.Errorf("missing repoPath")
+		}
+		dirty, err := testutil.IsDirtyE(req.RepoPath)
+		if err != nil {
+			return response{}, err
+		}
+		return response{OK: true, Dirty: &dirty}, nil
+
+	case "get_remotes":
+		if req.RepoPath == "" {
+			return response{}, fmt.Errorf("missing repoPath")
+		}
+		remotes, err := testutil.GetRemotesE(req.RepoPath)
+		if err != nil {
+			return response{}, err
+		}
+		return response{OK: true, Remotes: remotes}, nil
+
+	case "get_current_sha":
+		if req.RepoPath == "" {
+			return response{}, fmt.Errorf("missing repoPath")
+		}
+		sha, err := testutil.GetCurrentSHAE(req.RepoPath)
+		if err != nil {
+			return response{}, err
+		}
+		return response{OK: true, SHA: sha}, nil
+
+	case "get_branches":
+		if req.RepoPath == "" {
+			return response{}, fmt.Errorf("missing repoPath")
+		}
+		branches, err := testutil.GetBranchesE(req.RepoPath)
+		if err != nil {
+			return response{}, err
+		}
+		return response{OK: true, Branches: branches}, nil
+
+	case "snapshot_repo":
+		if req.RepoPath == "" {
+			return response{}, fmt.Errorf("missing repoPath")
+		}
+		snapshot, err := testutil.SnapshotRepoE(req.RepoPath)
+		if err != nil {
+			return response{}, err
+		}
+		return response{
+			OK:           true,
+			SnapshotName: snapshot.Name(),
+			SnapshotSize: intPtr(snapshot.Size()),
+		}, nil
+
+	case "snapshot_save":
+		if req.RepoPath == "" || req.SnapshotPath == "" {
+			return response{}, fmt.Errorf("missing repoPath or snapshotPath")
+		}
+		snapshot, err := testutil.SnapshotRepoE(req.RepoPath)
+		if err != nil {
+			return response{}, err
+		}
+		if err := testutil.SaveSnapshotToDiskE(snapshot, req.SnapshotPath); err != nil {
+			return response{}, err
+		}
+		return response{
+			OK:           true,
+			SnapshotName: snapshot.Name(),
+			SnapshotSize: intPtr(snapshot.Size()),
+		}, nil
+
+	case "snapshot_load_restore":
+		if req.SnapshotPath == "" {
+			return response{}, fmt.Errorf("missing snapshotPath")
+		}
+		base, err := ensureBaseDir(req.BaseDir)
+		if err != nil {
+			return response{}, err
+		}
+		snapshot, err := testutil.LoadSnapshotFromDiskE(req.SnapshotPath)
+		if err != nil {
+			return response{}, err
+		}
+		restorePath, err := testutil.RestoreSnapshotToDir(snapshot, base)
+		if err != nil {
+			return response{}, err
+		}
+		return response{
+			OK:           true,
+			RestorePath:  restorePath,
+			SnapshotName: snapshot.Name(),
+			SnapshotSize: intPtr(snapshot.Size()),
+		}, nil
+
+	default:
+		return response{}, fmt.Errorf("unsupported op: %s", req.Op)
+	}
+}
+
+func ensureBaseDir(baseDir string) (string, error) {
+	if strings.TrimSpace(baseDir) == "" {
+		return "", fmt.Errorf("missing baseDir")
+	}
+	clean := filepath.Clean(baseDir)
+	if err := os.MkdirAll(clean, 0755); err != nil {
+		return "", err
+	}
+	return clean, nil
+}
+
+func writeResponse(res response) {
+	enc := json.NewEncoder(os.Stdout)
+	enc.SetEscapeHTML(false)
+	if err := enc.Encode(res); err != nil {
+		fallback := response{
+			OK:    false,
+			Error: fmt.Sprintf("failed writing response: %s", err.Error()),
+		}
+		stderrEnc := json.NewEncoder(os.Stderr)
+		stderrEnc.SetEscapeHTML(false)
+		if encodeErr := stderrEnc.Encode(fallback); encodeErr != nil {
+			fmt.Fprintf(os.Stderr, "failed writing fallback response: %v\n", encodeErr)
+		}
+	}
+}
+
+func intPtr(v int) *int {
+	return &v
+}
+
+func stringPtr(v string) *string {
+	return &v
+}