diff --git a/services/graph/pkg/middleware/path_lookup.go b/services/graph/pkg/middleware/path_lookup.go
new file mode 100644
index 0000000000..1fc89bcd6c
--- /dev/null
+++ b/services/graph/pkg/middleware/path_lookup.go
@@ -0,0 +1,366 @@
+package middleware
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+
+	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
+	cs3rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
+	storageprovider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
+	"github.com/go-chi/chi/v5"
+
+	"github.com/rs/zerolog"
+
+	"github.com/opencloud-eu/opencloud/pkg/log"
+	"github.com/opencloud-eu/opencloud/services/graph/pkg/errorcode"
+	"github.com/opencloud-eu/reva/v2/pkg/rgrpc/todo/pool"
+	"github.com/opencloud-eu/reva/v2/pkg/storagespace"
+	"github.com/opencloud-eu/reva/v2/pkg/utils"
+)
+
+// The middleware is attached to the /drives/{driveID} sub-routers, so by the
+// time it runs chi has already consumed the {version}/drives/{driveID} prefix
+// and exposes the remainder via chi.RouteContext().RoutePath. parseColonPath
+// therefore only needs to handle the part below the drive:
+//
+//	root-anchored: /root:/<path>[:/<suffix>][:]
+//	item-anchored: /items/{itemID}:/<path>[:/<suffix>][:]
+
+type contextKey string
+
+// OriginalPathContextKey holds the pre-rewrite request path for downstream
+// tracing/logging consumers.
+const OriginalPathContextKey contextKey = "graph.original_path"
+
+// Sentinels distinguishing the resolution outcomes that map to specific HTTP
+// statuses. Anything else surfaces as 500.
+//
+//	errPathNotFound   - path doesn't exist or the user lacks permission to
+//	                    see it. Both collapse to 404 (no existence disclosure).
+//	errInvalidRequest - client sent a malformed input (unparseable drive/item
+//	                    id, drive/item mismatch in item-anchored form). 400.
+//	errUnauthenticated - the gateway said the caller isn't authenticated for
+//	                    the lookup (token expired, cross-storage auth, etc.). 401.
+var (
+	errPathNotFound    = errors.New("path not found")
+	errInvalidRequest  = errors.New("invalid request")
+	errUnauthenticated = errors.New("unauthenticated")
+)
+
+// ResolveGraphPath returns middleware that detects MS Graph colon-syntax path
+// lookup URLs and rewrites chi's internal route path to the canonical
+// /items/{resolvedItemID}{suffix} form so the request lands on the existing
+// /drives/{driveID}/items/{itemID}... routes.
+//
+// It must be attached to the /drives/{driveID} sub-routers (it reads driveID
+// from chi.URLParam and matches against chi.RouteContext().RoutePath). chi runs
+// a sub-router's middleware chain before that sub-router performs its own route
+// matching, so rewriting RoutePath here re-routes the request to a different
+// leaf. (Rewriting r.URL.Path would NOT work at this level: once chi has
+// descended into a sub-router, routeHTTP matches against rctx.RoutePath and
+// ignores r.URL.Path.)
+//
+// Two URL shapes are recognized:
+//
+//	/drives/{driveID}/root:/<path>[:/<suffix>][:]
+//	/drives/{driveID}/items/{itemID}:/<path>[:/<suffix>][:]
+//
+// Path resolution runs as the request user via CS3 Stat. NOT_FOUND and
+// PERMISSION_DENIED collapse to 404 (no existence disclosure); operational
+// failures (gateway selection, RPC transport, unexpected status) surface
+// as 5xx so outages aren't masked.
+//
+// Requests whose RoutePath contains no colon fast-path through untouched.
+func ResolveGraphPath(gws pool.Selectable[gateway.GatewayAPIClient], logger log.Logger) func(http.Handler) http.Handler {
+	l := logger.With().Str("middleware", "graphPathLookup").Logger()
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			rctx := chi.RouteContext(r.Context())
+
+			// Fast-path: skip anything that can't be colon-syntax. RoutePath
+			// is the part below /drives/{driveID}, e.g. "/items/{id}/children"
+			// for a normal request - no colon, so this returns immediately.
+			if rctx == nil || !strings.Contains(rctx.RoutePath, ":") {
+				next.ServeHTTP(w, r)
+				return
+			}
+
+			driveID := chi.URLParam(r, "driveID")
+			original := r.URL.Path
+			rewritten, err := rewriteColonPath(r.Context(), gws, l, driveID, rctx.RoutePath)
+			switch {
+			case errors.Is(err, errPathNotFound):
+				l.Debug().Str("original", original).Msg("colon-path resolution: not found")
+				errorcode.ItemNotFound.Render(w, r, http.StatusNotFound, "item not found")
+				return
+			case errors.Is(err, errInvalidRequest):
+				l.Debug().Str("original", original).Msg("colon-path resolution: invalid request")
+				errorcode.InvalidRequest.Render(w, r, http.StatusBadRequest, "invalid request")
+				return
+			case errors.Is(err, errUnauthenticated):
+				l.Debug().Str("original", original).Msg("colon-path resolution: unauthenticated")
+				errorcode.Unauthenticated.Render(w, r, http.StatusUnauthorized, "unauthenticated")
+				return
+			case err != nil:
+				l.Error().Err(err).Str("original", original).Msg("colon-path resolution: internal error")
+				errorcode.GeneralException.Render(
+					w, r, http.StatusInternalServerError, "internal error resolving path",
+				)
+				return
+			case rewritten == "":
+				// No colon-syntax match - pass through untouched.
+				next.ServeHTTP(w, r)
+				return
+			}
+
+			l.Debug().
+				Str("original", original).
+				Str("rewritten", rewritten).
+				Msg("colon-path resolution: rewrote")
+
+			// Preserve the original (unmodified) request path for downstream
+			// tracing/logging. r.URL.Path itself stays untouched; only chi's
+			// internal RoutePath is rewritten.
+			r = r.WithContext(context.WithValue(r.Context(), OriginalPathContextKey, original))
+			rctx.RoutePath = rewritten
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// colonMatch is the normalized result of parseColonPath for either the root-
+// or item-anchored colon-syntax shape. The two shapes carry different parts;
+// this struct erases that difference for downstream resolution.
+//
+// itemAnchorID, relPath and suffix hold the raw (still percent-encoded)
+// substrings from RoutePath; rewriteColonPath decodes them as needed.
+type colonMatch struct {
+	isItemAnchored bool   // item-anchored form: anchor is itemAnchorID, validate against driveID
+	itemAnchorID   string // itemID from the path for the item-anchored form (empty for root-anchored)
+	relPath        string // relative path with leading slash
+	suffix         string // suffix with leading slash (e.g. "/children"); may be empty
+}
+
+// rewriteColonPath returns:
+//   - ""        + nil                - no colon-syntax pattern matched (passthrough)
+//   - rewritten + nil                - matched and resolved to a canonical RoutePath
+//   - ""        + errPathNotFound    - path doesn't exist or user lacks permission (404)
+//   - ""        + errInvalidRequest  - malformed input (400)
+//   - ""        + errUnauthenticated - gateway said caller isn't authenticated (401)
+//   - ""        + other error        - operational / internal failure (5xx)
+//
+// driveIDParam is the {driveID} route param (raw chi.URLParam value); routePath
+// is chi.RouteContext().RoutePath (the part below /drives/{driveID}).
+func rewriteColonPath(
+	ctx context.Context,
+	gws pool.Selectable[gateway.GatewayAPIClient],
+	logger zerolog.Logger,
+	driveIDParam string,
+	routePath string,
+) (string, error) {
+	match, ok := parseColonPath(routePath)
+	if !ok {
+		return "", nil
+	}
+
+	// RoutePath follows chi's RawPath, i.e. the percent-encoded wire form
+	// (e.g. "/Documents/My%20File"). A single PathUnescape reproduces exactly
+	// what net/http put in r.URL.Path; it is NOT a double-decode (a crafted
+	// "%252F" decodes once to "%2F", matching the decoded r.URL.Path, not "/").
+	driveID, err := url.PathUnescape(driveIDParam)
+	if err != nil {
+		logger.Debug().Err(err).Str("driveID", driveIDParam).Msg("undecodable drive id in colon path")
+		return "", errInvalidRequest
+	}
+
+	anchorIDStr := driveID
+	if match.isItemAnchored {
+		anchorIDStr, err = url.PathUnescape(match.itemAnchorID)
+		if err != nil {
+			logger.Debug().Err(err).Str("itemID", match.itemAnchorID).Msg("undecodable item id in colon path")
+			return "", errInvalidRequest
+		}
+	}
+
+	anchor, err := storagespace.ParseID(anchorIDStr)
+	if err != nil {
+		// Unparseable input is malformed by the client, not "not found".
+		logger.Debug().Err(err).Str("anchor", anchorIDStr).Msg("invalid anchor id in colon path")
+		return "", errInvalidRequest
+	}
+
+	// Item-anchored form: the itemID comes from the path, driveID from the
+	// route param. Validate the itemID belongs to the given driveID (storage +
+	// space prefix) - otherwise the request is malformed and we short-circuit
+	// instead of doing an unnecessary CS3 Stat.
+	if match.isItemAnchored {
+		drive, err := storagespace.ParseID(driveID)
+		if err != nil {
+			logger.Debug().Err(err).Str("driveID", driveID).Msg("invalid drive id in colon path")
+			return "", errInvalidRequest
+		}
+		if drive.GetStorageId() != anchor.GetStorageId() || drive.GetSpaceId() != anchor.GetSpaceId() {
+			logger.Debug().
+				Str("driveID", driveID).
+				Str("itemID", anchorIDStr).
+				Msg("drive id does not match item id storage/space")
+			return "", errInvalidRequest
+		}
+	}
+
+	relPath, err := url.PathUnescape(match.relPath)
+	if err != nil {
+		logger.Debug().Err(err).Str("relPath", match.relPath).Msg("undecodable path in colon path")
+		return "", errInvalidRequest
+	}
+
+	itemID, err := resolvePath(ctx, gws, &anchor, relPath)
+	if err != nil {
+		return "", err
+	}
+	return buildCanonicalRoutePath(itemID, match.suffix), nil
+}
+
+// parseColonPath splits a colon-syntax RoutePath (the part below
+// /drives/{driveID}) into its parts, or reports ok=false when the path is not
+// colon-syntax and should pass through untouched.
+//
+// Below the drive the grammar is one of:
+//
+//	/root:/<path>[:/<suffix>][:]
+//	/items/<itemID>:/<path>[:/<suffix>][:]
+//
+// The structural delimiter is ":/" (a colon immediately followed by the
+// leading slash of the path or suffix); a trailing ":" is the no-suffix
+// terminator. For example:
+//
+//	/root:/Documents                 -> path "/Documents"
+//	/root:/Documents:                -> path "/Documents"
+//	/root:/Documents:/children       -> path "/Documents", suffix "/children"
+//	/items/{id}:/notes.txt:/children -> itemID "{id}", path "/notes.txt", suffix "/children"
+//
+// Clients must percent-encode each path segment, exactly as MS Graph requires
+// (an unencoded path is ambiguous). The one OpenCloud-specific point: ':' must
+// be encoded as "%3A". The split is on the literal ":/", so an encoded ':' is
+// never a delimiter and decodes back to ':' with the rest of the path (e.g.
+// "/root:/weird%3A/file.txt" -> "/weird:/file.txt"). OpenCloud allows ':' in
+// names whereas MS Graph/OneDrive forbid it, hence this extra character.
+//
+// The returned fields are the raw (still percent-encoded) substrings; the
+// caller decodes them.
+func parseColonPath(routePath string) (colonMatch, bool) {
+	var m colonMatch
+
+	// The anchor is separated from the path by the first ":/"; no ":/" at all
+	// means this isn't colon syntax and should pass through.
+	anchor, rest, found := strings.Cut(routePath, ":/")
+	if !found {
+		return m, false
+	}
+	// Cut consumed the leading '/' of the path along with the ":/" delimiter;
+	// the path is absolute, so put it back.
+	rest = "/" + rest
+
+	switch {
+	case anchor == "/root":
+		// Root-anchored: path resolution later anchors on the {driveID} route
+		// param, so there's no item id to read from the URL.
+	case strings.HasPrefix(anchor, "/items/"):
+		// Item-anchored: the anchor is /items/{itemID} with a single-segment
+		// id. A '/' inside the id means this is an ordinary /items/{id}/...
+		// request that just happens to contain a ":/" further along.
+		itemID := strings.TrimPrefix(anchor, "/items/")
+		if itemID == "" || strings.Contains(itemID, "/") {
+			return m, false
+		}
+		m.isItemAnchored = true
+		m.itemAnchorID = itemID
+	default:
+		return m, false
+	}
+
+	// rest is "/<path>[:/<suffix>][:]". Split path from an optional suffix on
+	// the next ":/" (the suffix regains the leading '/' Cut consumed), then
+	// drop a single trailing ':' - the "...:" no-suffix terminator. A suffix
+	// therefore requires an explicit ":/", so "/root:/foo/children" is the path
+	// "/foo/children", not "/foo" with suffix "/children".
+	m.relPath = rest
+	if path, suffix, found := strings.Cut(rest, ":/"); found {
+		m.relPath, m.suffix = path, "/"+suffix
+	}
+	m.relPath = strings.TrimSuffix(m.relPath, ":")
+
+	// Shape requirements: the path must be absolute and non-empty ("/x"), and a
+	// present suffix must be absolute, non-empty and colon-free (suffixes are
+	// fixed API routes like "/children", never file paths).
+	if len(m.relPath) < 2 || m.relPath[0] != '/' {
+		return m, false
+	}
+	if m.suffix != "" && (len(m.suffix) < 2 || strings.Contains(m.suffix, ":")) {
+		return m, false
+	}
+	return m, true
+}
+
+// resolvePath translates a relative filesystem path (anchored at the given
+// CS3 resource id) into the resolved item's id, running with the request
+// user's permissions via CS3 Stat.
+func resolvePath(
+	ctx context.Context,
+	gws pool.Selectable[gateway.GatewayAPIClient],
+	anchor *storageprovider.ResourceId,
+	relPath string,
+) (string, error) {
+	gw, err := gws.Next()
+	if err != nil {
+		return "", fmt.Errorf("gateway selector: %w", err)
+	}
+
+	// relPath is already decoded (PathUnescape'd once by the caller), matching
+	// the form a normal handler would receive from r.URL.Path.
+	statRes, err := gw.Stat(ctx, &storageprovider.StatRequest{
+		Ref: &storageprovider.Reference{
+			ResourceId: anchor,
+			Path:       utils.MakeRelativePath(relPath),
+		},
+	})
+	if err != nil {
+		return "", fmt.Errorf("CS3 Stat: %w", err)
+	}
+
+	switch statRes.GetStatus().GetCode() {
+	case cs3rpc.Code_CODE_OK:
+		// fall through
+	case cs3rpc.Code_CODE_NOT_FOUND, cs3rpc.Code_CODE_PERMISSION_DENIED:
+		return "", errPathNotFound
+	case cs3rpc.Code_CODE_UNAUTHENTICATED:
+		return "", errUnauthenticated
+	default:
+		return "", fmt.Errorf(
+			"CS3 Stat returned %s: %s",
+			statRes.GetStatus().GetCode(),
+			statRes.GetStatus().GetMessage(),
+		)
+	}
+
+	id := statRes.GetInfo().GetId()
+	if id == nil {
+		return "", fmt.Errorf("CS3 Stat returned OK but missing Info.Id")
+	}
+	return storagespace.FormatResourceID(id), nil
+}
+
+// buildCanonicalRoutePath produces the RoutePath chi should match against after
+// the rewrite, relative to /drives/{driveID}: /items/{itemID}{suffix}.
+//
+// itemID is inserted literally (the FormatResourceID output, e.g. with `$` and
+// `!` sub-delims). chi binds it verbatim into the {itemID} param; downstream
+// handlers (parseIDParam, GetDriveAndItemIDParam) call url.PathUnescape on the
+// param, which is a no-op for these literal sub-delims, so the id round-trips.
+func buildCanonicalRoutePath(itemID, suffix string) string {
+	return "/items/" + itemID + suffix
+}
diff --git a/services/graph/pkg/middleware/path_lookup_test.go b/services/graph/pkg/middleware/path_lookup_test.go
new file mode 100644
index 0000000000..fa866d2fed
--- /dev/null
+++ b/services/graph/pkg/middleware/path_lookup_test.go
@@ -0,0 +1,471 @@
+package middleware_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+
+	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
+	cs3rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
+	storageprovider "github.com/cs3org/go-cs3apis/cs3/storage/provider/v1beta1"
+	"github.com/go-chi/chi/v5"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"google.golang.org/grpc"
+
+	"github.com/opencloud-eu/opencloud/pkg/log"
+	"github.com/opencloud-eu/opencloud/services/graph/pkg/middleware"
+	"github.com/opencloud-eu/reva/v2/pkg/rgrpc/todo/pool"
+	cs3mocks "github.com/opencloud-eu/reva/v2/tests/cs3mocks/mocks"
+)
+
+const (
+	testDriveID = "storage-users-1$f503f6fe-2656-4b0f-8289-fb3184962dfd"
+	testItemID  = "storage-users-1$f503f6fe-2656-4b0f-8289-fb3184962dfd!f0e20017-9cba-498a-87e5-3467b976604d"
+)
+
+func newTestSelector(t *testing.T, gw *cs3mocks.GatewayAPIClient) pool.Selectable[gateway.GatewayAPIClient] {
+	t.Helper()
+	// Unique key per test so pool's selector cache doesn't hand back a stale gw.
+	// t.Cleanup removes the entry from pool's global selectors map after the
+	// subtest, so global state doesn't grow across the suite.
+	svcName := "TestGatewaySelector"
+	key := "test.gateway." + t.Name()
+	pool.RemoveSelector(svcName + key)
+	t.Cleanup(func() { pool.RemoveSelector(svcName + key) })
+	return pool.GetSelector[gateway.GatewayAPIClient](
+		svcName,
+		key,
+		func(cc grpc.ClientConnInterface) gateway.GatewayAPIClient { return gw },
+	)
+}
+
+// statResponse builds a CS3 StatResponse with the given status code, optionally
+// returning a resource info populated with testItemID for OK responses.
+func statResponse(code cs3rpc.Code, withInfo bool) *storageprovider.StatResponse {
+	res := &storageprovider.StatResponse{Status: &cs3rpc.Status{Code: code}}
+	if withInfo {
+		res.Info = &storageprovider.ResourceInfo{
+			Id: &storageprovider.ResourceId{
+				StorageId: "storage-users-1",
+				SpaceId:   "f503f6fe-2656-4b0f-8289-fb3184962dfd",
+				OpaqueId:  "f0e20017-9cba-498a-87e5-3467b976604d",
+			},
+		}
+	}
+	return res
+}
+
+// leafCapture records what the matched leaf handler saw, so tests can assert
+// the middleware rewrote chi's route path correctly and the request reached the
+// intended /items/{itemID}... handler with the resolved id bound as a param.
+type leafCapture struct {
+	hit      string // which leaf was reached ("" = none)
+	urlPath  string // r.URL.Path as seen by the handler (must stay the original)
+	driveID  string // chi.URLParam(driveID)
+	itemID   string // resolved item id, decoded via PathUnescape
+	original any    // OriginalPathContextKey value
+}
+
+// newGraphTestRouter wires ResolveGraphPath into a chi router that mirrors the
+// production /drives/{driveID} nesting for both API versions, including the
+// RawPath workaround Graph.ServeHTTP applies. Driving requests through real chi
+// routing is deliberate: it exercises chi's actual behavior (sub-router
+// middleware ordering, RoutePath encoding, param round-trip) indirectly, so a
+// chi upgrade that changes any of it fails these tests instead of silently
+// breaking colon-path lookups in production.
+func newGraphTestRouter(t *testing.T, gw *cs3mocks.GatewayAPIClient) (http.Handler, *leafCapture) {
+	t.Helper()
+	cap := &leafCapture{}
+	selector := newTestSelector(t, gw)
+
+	leaf := func(name string) http.HandlerFunc {
+		return func(w http.ResponseWriter, r *http.Request) {
+			cap.hit = name
+			cap.urlPath = r.URL.Path
+			cap.driveID = chi.URLParam(r, "driveID")
+			// v1.0 binds the item param as {driveItemID}, v1beta1 as {itemID}.
+			raw := chi.URLParam(r, "itemID")
+			if raw == "" {
+				raw = chi.URLParam(r, "driveItemID")
+			}
+			// Downstream handlers PathUnescape the param before parsing the id;
+			// mirror that here so we assert on the recovered id.
+			cap.itemID, _ = url.PathUnescape(raw)
+			cap.original = r.Context().Value(middleware.OriginalPathContextKey)
+			w.WriteHeader(http.StatusOK)
+		}
+	}
+
+	m := chi.NewMux()
+	// Mirror Graph.ServeHTTP: RawPath drives chi's tree walk, which is what
+	// makes RoutePath carry the percent-encoded wire form.
+	m.Use(func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			r.URL.RawPath = r.URL.EscapedPath()
+			next.ServeHTTP(w, r)
+		})
+	})
+	// Leaf routes mirror production exactly (service.go), per version, so the
+	// tests assert reachability that production actually reproduces: a rewrite
+	// to a suffix that doesn't exist for that version must 404 here too.
+	m.Route("/graph", func(r chi.Router) {
+		r.Route("/v1beta1/drives/{driveID}", func(r chi.Router) {
+			r.Use(middleware.ResolveGraphPath(selector, log.NopLogger()))
+			r.Route("/items/{itemID}", func(r chi.Router) {
+				r.Get("/", leaf("item"))
+				r.Post("/createLink", leaf("createLink"))
+				r.Route("/permissions", func(r chi.Router) {
+					r.Get("/", leaf("permissions"))
+					r.Post("/{permissionID}/setPassword", leaf("setPassword"))
+				})
+			})
+		})
+		r.Route("/v1.0/drives/{driveID}", func(r chi.Router) {
+			r.Use(middleware.ResolveGraphPath(selector, log.NopLogger()))
+			r.Route("/items/{driveItemID}", func(r chi.Router) {
+				r.Get("/", leaf("item"))
+				r.Get("/children", leaf("children"))
+			})
+		})
+	})
+	return m, cap
+}
+
+func TestResolveGraphPath(t *testing.T) {
+	tests := []struct {
+		name             string
+		method           string // defaults to GET when empty
+		urlPath          string
+		statCode         cs3rpc.Code
+		expectStatCalled bool
+		expectStatus     int
+		expectHit        string // leaf the request must land on ("" = none reached)
+		expectItemID     string // resolved item id the leaf must see (after PathUnescape)
+	}{
+		{
+			name:             "non-colon URL routes normally without a Stat",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/items/" + testItemID + "/children",
+			expectStatCalled: false,
+			expectStatus:     http.StatusOK,
+			expectHit:        "children",
+			expectItemID:     testItemID,
+		},
+		{
+			name:             "colon URL not matching the lookup pattern passes through (404, no Stat)",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/items/" + testItemID + "/foo:bar",
+			expectStatCalled: false,
+			expectStatus:     http.StatusNotFound,
+			expectHit:        "",
+		},
+		{
+			// Anchoring: the colon-syntax shape appearing under a junk prefix
+			// (i.e. NOT at the configured HTTP root) must not trigger a rewrite
+			// or a CS3 Stat. Because the middleware is mounted under the
+			// /graph root, chi never routes such a path into it (404 first) -
+			// no /foo/.../v1.0/drives/...:/... can over-match.
+			name:             "colon-syntax under a junk prefix does not match (anchored on HTTP root)",
+			urlPath:          "/foo/graph/v1.0/drives/" + testDriveID + "/root:/Documents:/children",
+			expectStatCalled: false,
+			expectStatus:     http.StatusNotFound,
+			expectHit:        "",
+		},
+		{
+			name:             "v1.0 root-anchored with /children rewrites and routes",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Documents:/children",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "children",
+			expectItemID:     testItemID,
+		},
+		{
+			// Mirrors acceptance scenario 5: v1beta1 root-anchored with a
+			// /permissions suffix (a real v1beta1-only route, GET).
+			name:             "v1beta1 root-anchored with /permissions rewrites and routes",
+			urlPath:          "/graph/v1beta1/drives/" + testDriveID + "/root:/folder1:/permissions",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "permissions",
+			expectItemID:     testItemID,
+		},
+		{
+			// Non-GET colon request: createLink is POST on v1beta1.
+			name:             "v1beta1 root-anchored with /createLink (POST) rewrites and routes",
+			method:           http.MethodPost,
+			urlPath:          "/graph/v1beta1/drives/" + testDriveID + "/root:/folder1:/createLink",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "createLink",
+			expectItemID:     testItemID,
+		},
+		{
+			// Multi-segment suffix: /permissions/{permissionID}/setPassword on
+			// v1beta1 (POST). Pins that parseColonPath carries a suffix with
+			// embedded slashes through the rewrite into a real nested route.
+			name:             "v1beta1 root-anchored with multi-segment suffix rewrites and routes",
+			method:           http.MethodPost,
+			urlPath:          "/graph/v1beta1/drives/" + testDriveID + "/root:/folder1:/permissions/perm-1/setPassword",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "setPassword",
+			expectItemID:     testItemID,
+		},
+		{
+			// Item-anchored colon syntax on v1beta1 (POST createLink).
+			name:             "v1beta1 item-anchored with /createLink (POST) rewrites and routes",
+			method:           http.MethodPost,
+			urlPath:          "/graph/v1beta1/drives/" + testDriveID + "/items/" + testItemID + ":/notes.txt:/createLink",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "createLink",
+			expectItemID:     testItemID,
+		},
+		{
+			name:             "trailing colon (no suffix) rewrites to bare item URL",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Documents:",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "item",
+			expectItemID:     testItemID,
+		},
+		{
+			name:             "no trailing colon, no suffix rewrites to bare item URL",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Documents",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "item",
+			expectItemID:     testItemID,
+		},
+		{
+			name:             "deep path rewrites correctly",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Documents/Reports:/children",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "children",
+			expectItemID:     testItemID,
+		},
+		{
+			// A trailing segment that looks like a suffix ("children") is only a
+			// suffix when a SECOND colon introduces it. Without it, the whole
+			// thing is the path, so this must resolve to the bare item (GET "/"),
+			// NOT to /items/{id}/children. If the parser wrongly split it, the
+			// request would land on the "children" leaf and this fails.
+			name:             "trailing suffix-looking segment without a second colon stays in the path",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Documents/children",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "item",
+			expectItemID:     testItemID,
+		},
+		{
+			name:             "item-anchored colon syntax rewrites",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/items/" + testItemID + ":/notes.txt:/children",
+			statCode:         cs3rpc.Code_CODE_OK,
+			expectStatCalled: true,
+			expectStatus:     http.StatusOK,
+			expectHit:        "children",
+			expectItemID:     testItemID,
+		},
+		{
+			name:             "Stat NOT_FOUND returns 404 without reaching a leaf",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Missing:",
+			statCode:         cs3rpc.Code_CODE_NOT_FOUND,
+			expectStatCalled: true,
+			expectStatus:     http.StatusNotFound,
+			expectHit:        "",
+		},
+		{
+			// CRITICAL security test: PERMISSION_DENIED must not leak existence.
+			// We collapse it to 404, identical to NOT_FOUND, so an unauthorized
+			// caller can't distinguish "doesn't exist" from "exists but hidden".
+			name:             "Stat PERMISSION_DENIED returns 404 (not 403) - don't disclose existence",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Restricted:",
+			statCode:         cs3rpc.Code_CODE_PERMISSION_DENIED,
+			expectStatCalled: true,
+			expectStatus:     http.StatusNotFound,
+			expectHit:        "",
+		},
+		{
+			// Operational/unexpected CS3 statuses must NOT collapse to 404 -
+			// that would mask outages. Surface as 500 like other graph handlers.
+			name:             "Stat unexpected status returns 500 (not 404 - don't mask outages)",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Anything:",
+			statCode:         cs3rpc.Code_CODE_INTERNAL,
+			expectStatCalled: true,
+			expectStatus:     http.StatusInternalServerError,
+			expectHit:        "",
+		},
+		{
+			// UNAUTHENTICATED is its own distinct outcome - must surface as 401,
+			// not 500, so clients can detect "your token is bad" vs "server error".
+			name:             "Stat UNAUTHENTICATED returns 401",
+			urlPath:          "/graph/v1.0/drives/" + testDriveID + "/root:/Documents:",
+			statCode:         cs3rpc.Code_CODE_UNAUTHENTICATED,
+			expectStatCalled: true,
+			expectStatus:     http.StatusUnauthorized,
+			expectHit:        "",
+		},
+		{
+			// Item-anchored form with a driveID that doesn't match the itemID's
+			// storage/space - the request is malformed; short-circuit to 400
+			// instead of doing a Stat that would only fail downstream.
+			name:             "drive id and item id storage/space mismatch returns 400",
+			urlPath:          "/graph/v1.0/drives/storage-users-2$other-space-id/items/" + testItemID + ":/notes.txt:/children",
+			expectStatCalled: false,
+			expectStatus:     http.StatusBadRequest,
+			expectHit:        "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gw := &cs3mocks.GatewayAPIClient{}
+			if tt.expectStatCalled {
+				gw.On("Stat", mock.Anything, mock.Anything).
+					Return(statResponse(tt.statCode, tt.statCode == cs3rpc.Code_CODE_OK), nil)
+			}
+
+			method := tt.method
+			if method == "" {
+				method = http.MethodGet
+			}
+			router, cap := newGraphTestRouter(t, gw)
+			req := httptest.NewRequest(method, "http://localhost"+tt.urlPath, nil)
+			rr := httptest.NewRecorder()
+			router.ServeHTTP(rr, req)
+
+			assert.Equal(t, tt.expectStatus, rr.Code, "status code")
+			assert.Equal(t, tt.expectHit, cap.hit, "leaf handler reached")
+
+			if tt.expectHit != "" {
+				assert.Equal(t, testDriveID, cap.driveID, "driveID param")
+				assert.Equal(t, tt.expectItemID, cap.itemID, "resolved item id seen by leaf")
+				// r.URL.Path must stay the original; only chi's RoutePath is rewritten.
+				assert.Equal(t, tt.urlPath, cap.urlPath, "r.URL.Path must remain the original request path")
+			}
+
+			if tt.expectStatCalled {
+				gw.AssertCalled(t, "Stat", mock.Anything, mock.Anything)
+			} else {
+				gw.AssertNotCalled(t, "Stat", mock.Anything, mock.Anything)
+			}
+		})
+	}
+}
+
+// TestResolveGraphPath_DecodesEncodedPath pins the decoding contract: chi's
+// RoutePath carries the percent-encoded wire form (because Graph.ServeHTTP sets
+// RawPath), and the middleware must hand CS3 Stat the decoded path - exactly
+// what a normal handler reading r.URL.Path would get. Driving this through real
+// chi routing means a chi change to RoutePath encoding would break this test.
+func TestResolveGraphPath_DecodesEncodedPath(t *testing.T) {
+	tests := []struct {
+		name         string
+		urlPath      string
+		expectedStat string
+	}{
+		{
+			name:         "space encoded as %20 is decoded for Stat",
+			urlPath:      "/graph/v1.0/drives/" + testDriveID + "/root:/Documents/My%20File:/children",
+			expectedStat: "./Documents/My File",
+		},
+		{
+			// A crafted double-encoding must be decoded exactly once (to the
+			// literal "%2F"), never twice into a path separator.
+			name:         "double-encoded %252F decodes once, not twice",
+			urlPath:      "/graph/v1.0/drives/" + testDriveID + "/root:/a%252Fb:/children",
+			expectedStat: "./a%2Fb",
+		},
+		{
+			// Without a second colon the whole remainder is the path: Stat must
+			// receive "/Documents/children", not "/Documents" (which would mean
+			// "/children" was wrongly treated as a suffix).
+			name:         "suffix-looking segment without a second colon is part of the Stat path",
+			urlPath:      "/graph/v1.0/drives/" + testDriveID + "/root:/Documents/children",
+			expectedStat: "./Documents/children",
+		},
+		{
+			// Clients percent-encode ':' as "%3A" to put it in a name. "%3A" is
+			// never seen as the ":/" delimiter and decodes back to a literal ':'
+			// - here a directory named "weird:".
+			name:         "percent-encoded colon (%3A) reaches Stat as a literal colon",
+			urlPath:      "/graph/v1.0/drives/" + testDriveID + "/root:/weird%3A/file.txt",
+			expectedStat: "./weird:/file.txt",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var statPath string
+			gw := &cs3mocks.GatewayAPIClient{}
+			gw.On("Stat", mock.Anything, mock.Anything).
+				Run(func(args mock.Arguments) {
+					req := args.Get(1).(*storageprovider.StatRequest)
+					statPath = req.GetRef().GetPath()
+				}).
+				Return(statResponse(cs3rpc.Code_CODE_OK, true), nil)
+
+			router, _ := newGraphTestRouter(t, gw)
+			req := httptest.NewRequest(http.MethodGet, "http://localhost"+tt.urlPath, nil)
+			rr := httptest.NewRecorder()
+			router.ServeHTTP(rr, req)
+
+			assert.Equal(t, http.StatusOK, rr.Code)
+			assert.Equal(t, tt.expectedStat, statPath, "path passed to CS3 Stat must be decoded exactly once")
+		})
+	}
+}
+
+// TestResolveGraphPath_ItemIDRoundTrip guards the sub-delimiter round-trip: the
+// resolved id contains `$` and `!`, and after the RoutePath rewrite chi must
+// bind it to the {itemID} param such that the downstream PathUnescape recovers
+// the original id. This exercises chi's param binding indirectly; a regression
+// in how chi stores matched segments would surface here.
+func TestResolveGraphPath_ItemIDRoundTrip(t *testing.T) {
+	gw := &cs3mocks.GatewayAPIClient{}
+	gw.On("Stat", mock.Anything, mock.Anything).
+		Return(statResponse(cs3rpc.Code_CODE_OK, true), nil)
+
+	router, cap := newGraphTestRouter(t, gw)
+	req := httptest.NewRequest(
+		http.MethodGet,
+		"http://localhost/graph/v1.0/drives/"+testDriveID+"/root:/Documents:/children",
+		nil,
+	)
+	rr := httptest.NewRecorder()
+	router.ServeHTTP(rr, req)
+
+	assert.Equal(t, http.StatusOK, rr.Code, "chi must route the rewritten path to the leaf")
+	assert.Equal(t, "children", cap.hit)
+	assert.Equal(t, testItemID, cap.itemID,
+		"PathUnescape(chi.URLParam(itemID)) must recover the original id (with `$` and `!`)")
+}
+
+// TestResolveGraphPath_OriginalPathContext verifies the original URL is
+// preserved in request context for downstream tracing/logging, and that
+// r.URL.Path itself is left untouched by the rewrite.
+func TestResolveGraphPath_OriginalPathContext(t *testing.T) {
+	gw := &cs3mocks.GatewayAPIClient{}
+	gw.On("Stat", mock.Anything, mock.Anything).
+		Return(statResponse(cs3rpc.Code_CODE_OK, true), nil)
+
+	original := "/graph/v1.0/drives/" + testDriveID + "/root:/Documents:/children"
+	router, cap := newGraphTestRouter(t, gw)
+	req := httptest.NewRequest(http.MethodGet, "http://localhost"+original, nil)
+	rr := httptest.NewRecorder()
+	router.ServeHTTP(rr, req)
+
+	assert.Equal(t, http.StatusOK, rr.Code)
+	assert.Equal(t, original, cap.original, "original URL must be available via OriginalPathContextKey")
+	assert.Equal(t, original, cap.urlPath, "r.URL.Path must remain the original request path")
+}
diff --git a/services/graph/pkg/service/v0/service.go b/services/graph/pkg/service/v0/service.go
index ecce7f69e1..fb5e490851 100644
--- a/services/graph/pkg/service/v0/service.go
+++ b/services/graph/pkg/service/v0/service.go
@@ -265,6 +265,12 @@ func NewService(opts ...Option) (Graph, error) { //nolint:maintidx
 			r.Route("/drives", func(r chi.Router) {
 				r.Get("/", svc.GetAllDrives(APIVersion_1_Beta_1))
 				r.Route("/{driveID}", func(r chi.Router) {
+					// Rewrites MS Graph colon-syntax lookups (root:/path,
+					// items/{id}:/path) to /items/{resolvedID}... before chi
+					// matches the leaf route. Must sit here, on the
+					// /drives/{driveID} sub-router, so it can rewrite the
+					// remaining RoutePath. See graphm.ResolveGraphPath.
+					r.Use(graphm.ResolveGraphPath(options.GatewaySelector, options.Logger))
 					r.Route("/root", func(r chi.Router) {
 						r.Post("/children", drivesDriveItemApi.CreateDriveItem)
 						r.Post("/invite", driveItemPermissionsApi.SpaceRootInvite)
@@ -367,6 +373,12 @@ func NewService(opts ...Option) (Graph, error) { //nolint:maintidx
 				r.Get("/", svc.GetAllDrives(APIVersion_1))
 				r.Post("/", svc.CreateDrive)
 				r.Route("/{driveID}", func(r chi.Router) {
+					// Rewrites MS Graph colon-syntax lookups (root:/path,
+					// items/{id}:/path) to /items/{resolvedID}... before chi
+					// matches the leaf route. Must sit here, on the
+					// /drives/{driveID} sub-router, so it can rewrite the
+					// remaining RoutePath. See graphm.ResolveGraphPath.
+					r.Use(graphm.ResolveGraphPath(options.GatewaySelector, options.Logger))
 					r.Patch("/", svc.UpdateDrive)
 					r.Get("/", svc.GetSingleDrive)
 					r.Delete("/", svc.DeleteDrive)
diff --git a/tests/acceptance/bootstrap/GraphContext.php b/tests/acceptance/bootstrap/GraphContext.php
index cf350be6be..70254354c0 100644
--- a/tests/acceptance/bootstrap/GraphContext.php
+++ b/tests/acceptance/bootstrap/GraphContext.php
@@ -3334,4 +3334,169 @@ class GraphContext implements Context {
 		$response = $this->unmarkFavorite($user, $itemId);
 		$this->featureContext->theHTTPStatusCodeShouldBe(204, '', $response);
 	}
+
+	/**
+	 * Encode a colon-syntax path segment so slashes survive but the
+	 * structural ":" delimiters of the Graph URL remain literal.
+	 *
+	 * @param string $path
+	 *
+	 * @return string
+	 */
+	private function encodeColonPathSegment(string $path): string {
+		$path = \ltrim($path, '/');
+		$parts = \explode('/', $path);
+		$encoded = \array_map('rawurlencode', $parts);
+		return \implode('/', $encoded);
+	}
+
+	/**
+	 * Send a Graph API request and capture the response on FeatureContext.
+	 *
+	 * @param string $user
+	 * @param string $method
+	 * @param string $relativeUrl
+	 *
+	 * @return void
+	 */
+	private function sendGraphRequestAndCaptureResponse(
+		string $user,
+		string $method,
+		string $relativeUrl
+	): void {
+		$response = $this->featureContext->sendingToWithDirectUrl($user, $method, $relativeUrl);
+		$this->featureContext->setResponse($response);
+	}
+
+	/**
+	 * @When /^user "([^"]*)" gets the drive item with colon path "([^"]*)" of space "([^"]*)" using the Graph API version "(v1\.0|v1beta1)"$/
+	 *
+	 * Hits /graph/{version}/drives/{driveID}/root:/{path}, exercising the
+	 * colon-syntax path lookup middleware (root-anchored, no suffix).
+	 *
+	 * @param string $user
+	 * @param string $path
+	 * @param string $spaceName
+	 * @param string $apiVersion
+	 *
+	 * @return void
+	 */
+	public function userGetsDriveItemWithColonPathOfSpace(
+		string $user,
+		string $path,
+		string $spaceName,
+		string $apiVersion
+	): void {
+		$driveId = $this->spacesContext->getSpaceIdByName($user, $spaceName);
+		$encoded = $this->encodeColonPathSegment($path);
+		$url = "/graph/$apiVersion/drives/$driveId/root:/$encoded";
+		$this->sendGraphRequestAndCaptureResponse($user, "GET", $url);
+	}
+
+	/**
+	 * @When /^user "([^"]*)" gets the drive item with colon path "([^"]*)" of space "([^"]*)" with trailing colon using the Graph API version "(v1\.0|v1beta1)"$/
+	 *
+	 * Hits /graph/{version}/drives/{driveID}/root:/{path}: with the optional
+	 * trailing ":" — verifies the middleware accepts both forms.
+	 *
+	 * @param string $user
+	 * @param string $path
+	 * @param string $spaceName
+	 * @param string $apiVersion
+	 *
+	 * @return void
+	 */
+	public function userGetsDriveItemWithColonPathOfSpaceWithTrailingColon(
+		string $user,
+		string $path,
+		string $spaceName,
+		string $apiVersion
+	): void {
+		$driveId = $this->spacesContext->getSpaceIdByName($user, $spaceName);
+		$encoded = $this->encodeColonPathSegment($path);
+		$url = "/graph/$apiVersion/drives/$driveId/root:/$encoded:";
+		$this->sendGraphRequestAndCaptureResponse($user, "GET", $url);
+	}
+
+	/**
+	 * @When /^user "([^"]*)" gets the drive item with colon path "([^"]*)" relative to folder "([^"]*)" of space "([^"]*)" using the Graph API version "(v1\.0|v1beta1)"$/
+	 *
+	 * Hits /graph/{version}/drives/{driveID}/items/{itemID}:/{relPath}, the
+	 * item-anchored colon-syntax form.
+	 *
+	 * @param string $user
+	 * @param string $relPath
+	 * @param string $folderName
+	 * @param string $spaceName
+	 * @param string $apiVersion
+	 *
+	 * @return void
+	 */
+	public function userGetsDriveItemWithColonPathRelativeToFolderOfSpace(
+		string $user,
+		string $relPath,
+		string $folderName,
+		string $spaceName,
+		string $apiVersion
+	): void {
+		$driveId = $this->spacesContext->getSpaceIdByName($user, $spaceName);
+		$folderId = $this->spacesContext->getResourceId($user, $spaceName, $folderName);
+		$encoded = $this->encodeColonPathSegment($relPath);
+		$url = "/graph/$apiVersion/drives/$driveId/items/$folderId:/$encoded";
+		$this->sendGraphRequestAndCaptureResponse($user, "GET", $url);
+	}
+
+	/**
+	 * @When /^user "([^"]*)" lists permissions of the drive item with colon path "([^"]*)" of space "([^"]*)" using the Graph API version "(v1\.0|v1beta1)"$/
+	 *
+	 * Hits /graph/{version}/drives/{driveID}/root:/{path}:/permissions, the
+	 * "colon path with suffix" form (root-anchored colon path + canonical
+	 * sub-route).
+	 *
+	 * @param string $user
+	 * @param string $path
+	 * @param string $spaceName
+	 * @param string $apiVersion
+	 *
+	 * @return void
+	 */
+	public function userListsPermissionsOfDriveItemWithColonPathOfSpace(
+		string $user,
+		string $path,
+		string $spaceName,
+		string $apiVersion
+	): void {
+		$driveId = $this->spacesContext->getSpaceIdByName($user, $spaceName);
+		$encoded = $this->encodeColonPathSegment($path);
+		$url = "/graph/$apiVersion/drives/$driveId/root:/$encoded:/permissions";
+		$this->sendGraphRequestAndCaptureResponse($user, "GET", $url);
+	}
+
+	/**
+	 * @When /^user "([^"]*)" gets the drive item with colon path "([^"]*)" of the personal space of "([^"]*)" using the Graph API version "(v1\.0|v1beta1)"$/
+	 *
+	 * Same as userGetsDriveItemWithColonPathOfSpace, but the request is
+	 * issued by :user against the personal space drive ID of :owner. Used
+	 * for security tests where one user attempts to reach another user's
+	 * resource via colon syntax — should be indistinguishable from a
+	 * not-found result.
+	 *
+	 * @param string $user
+	 * @param string $path
+	 * @param string $owner
+	 * @param string $apiVersion
+	 *
+	 * @return void
+	 */
+	public function userGetsDriveItemWithColonPathOfPersonalSpaceOf(
+		string $user,
+		string $path,
+		string $owner,
+		string $apiVersion
+	): void {
+		$driveId = $this->spacesContext->getSpaceIdByName($owner, "Personal");
+		$encoded = $this->encodeColonPathSegment($path);
+		$url = "/graph/$apiVersion/drives/$driveId/root:/$encoded";
+		$this->sendGraphRequestAndCaptureResponse($user, "GET", $url);
+	}
 }
diff --git a/tests/acceptance/features/apiGraph/colonSyntaxPathLookup.feature b/tests/acceptance/features/apiGraph/colonSyntaxPathLookup.feature
new file mode 100644
index 0000000000..6cd45ab8b1
--- /dev/null
+++ b/tests/acceptance/features/apiGraph/colonSyntaxPathLookup.feature
@@ -0,0 +1,120 @@
+Feature: colon-syntax path lookup on the Graph API
+  As a client
+  I want to address drive items by path using colon-syntax URLs on the Graph API
+  So that I do not have to walk the path with successive lookups before issuing a request
+
+  The colon-syntax shapes recognised by the path-lookup middleware are:
+
+    /graph/{version}/drives/{driveID}/root:/<path>[:/<suffix>][:]
+    /graph/{version}/drives/{driveID}/items/{itemID}:/<relativePath>[:/<suffix>][:]
+
+  Both /v1.0 and /v1beta1 are supported. NOT_FOUND and PERMISSION_DENIED
+  collapse to 404 so the middleware never discloses the existence of
+  resources the caller is not allowed to see.
+
+  Clients must percent-encode each path segment, exactly as MS Graph requires.
+  The only OpenCloud-specific point: ':' must be encoded as "%3A" (the split is
+  on the literal ":/", so an encoded ':' is never a delimiter). OpenCloud allows
+  ':' in names whereas MS Graph/OneDrive forbid it, so "%3A" is the one extra
+  character to encode.
+
+  Background:
+    Given user "Alice" has been created with default attributes
+    And user "Alice" has created folder "folder1"
+    And user "Alice" has created folder "folder1/sub"
+    And user "Alice" has uploaded file with content "hello" to "folder1/file.txt"
+    And user "Alice" has uploaded file with content "deep" to "folder1/sub/deep.txt"
+
+
+  Scenario: get a drive item by root-anchored colon path
+    When user "Alice" gets the drive item with colon path "folder1/file.txt" of space "Personal" using the Graph API version "v1.0"
+    Then the HTTP status code should be "200"
+    And the JSON data of the response should match
+      """
+      {
+        "type": "object",
+        "required": ["id", "name", "parentReference"],
+        "properties": {
+          "id": {
+            "type": "string",
+            "pattern": "^%file_id_pattern%$"
+          },
+          "name": {
+            "const": "file.txt"
+          }
+        }
+      }
+      """
+
+
+  Scenario: get a drive item by root-anchored colon path with a deep path
+    When user "Alice" gets the drive item with colon path "folder1/sub/deep.txt" of space "Personal" using the Graph API version "v1.0"
+    Then the HTTP status code should be "200"
+    And the JSON data of the response should match
+      """
+      {
+        "type": "object",
+        "required": ["id", "name"],
+        "properties": {
+          "name": {
+            "const": "deep.txt"
+          }
+        }
+      }
+      """
+
+
+  Scenario: get a drive item by root-anchored colon path with a trailing colon
+    When user "Alice" gets the drive item with colon path "folder1/file.txt" of space "Personal" with trailing colon using the Graph API version "v1.0"
+    Then the HTTP status code should be "200"
+    And the JSON data of the response should match
+      """
+      {
+        "type": "object",
+        "required": ["id", "name"],
+        "properties": {
+          "name": {
+            "const": "file.txt"
+          }
+        }
+      }
+      """
+
+
+  Scenario: get a drive item by item-anchored colon path
+    When user "Alice" gets the drive item with colon path "file.txt" relative to folder "folder1" of space "Personal" using the Graph API version "v1.0"
+    Then the HTTP status code should be "200"
+    And the JSON data of the response should match
+      """
+      {
+        "type": "object",
+        "required": ["id", "name"],
+        "properties": {
+          "name": {
+            "const": "file.txt"
+          }
+        }
+      }
+      """
+
+
+  Scenario: list permissions of a drive item via colon path with a sub-route suffix on v1beta1
+    # Exercises the "/<path>:/<suffix>" rewrite shape and, at the same time,
+    # the v1beta1 mount of the middleware. The /permissions sub-route is only
+    # registered at /v1beta1/, and the canonical /v1beta1 GetDriveItem
+    # handler is share-jail-only, so this is the cleanest way to assert that
+    # the v1beta1 colon-syntax path actually reaches a working handler for
+    # regular drive items.
+    When user "Alice" lists permissions of the drive item with colon path "folder1" of space "Personal" using the Graph API version "v1beta1"
+    Then the HTTP status code should be "200"
+
+
+  Scenario: non-existent colon path returns 404
+    When user "Alice" gets the drive item with colon path "folder1/does-not-exist.txt" of space "Personal" using the Graph API version "v1.0"
+    Then the HTTP status code should be "404"
+
+
+  Scenario: another user cannot disclose existence of a resource via colon path
+    Given user "Brian" has been created with default attributes
+    When user "Brian" gets the drive item with colon path "folder1/file.txt" of the personal space of "Alice" using the Graph API version "v1.0"
+    Then the HTTP status code should be "404"