diff --git a/contracts/agents-api/sandbox-deployment.md b/contracts/agents-api/sandbox-deployment.md
index c039345a9..062309863 100644
--- a/contracts/agents-api/sandbox-deployment.md
+++ b/contracts/agents-api/sandbox-deployment.md
@@ -230,6 +230,16 @@ Preserve identities, provider receipts, history and storage. This version does n
 automatically adopt the old database or delete its resources; removing an
 environment variable alone does not complete that migration.
 
+A Web-managed Docker or microsandbox selection saved before specifications has
+the empty migration default. Core loads it for draining only. Retained nodes
+without a recorded digest or generation authenticate while the deployment is in
+this state. GET omits `specification` and `specification_digest`. Fresh hosted
+sandboxes are refused with the same error as during maintenance. Enrollment
+tokens return 409 `sandbox_deployment_conflict`; node configuration reads and
+enrollment are refused.
+The ordinary maintenance, archive and PUT sequence records a specification and
+retires those nodes. See the [operator upgrade notes](../../docs/getting-started/operations.md#data-and-upgrades).
+
 Unit tests, database tests and provider inspection are separate from live
 execution acceptance. This contract does not assert that every resource profile,
 provider deployment or host-reboot recovery path has been qualified.
diff --git a/docs/getting-started/operations.md b/docs/getting-started/operations.md
index 90820e16e..100478438 100644
--- a/docs/getting-started/operations.md
+++ b/docs/getting-started/operations.md
@@ -156,6 +156,17 @@ Keep the original business data, credential key, Runtime history and private pro
 state. There is no automatic old-database conversion, force reset or resource deletion.
 The supported current path uses a database-managed deployment.
 
+A Web-selected Docker or microsandbox deployment saved before deployment
+specifications existed has an empty specification after migration. Current Core
+loads it only to drain: nodes enrolled under the previous release reconnect with
+their existing node service, and their sandboxes stay reachable for archive and
+cleanup. Fresh sandbox creation, node configuration reads and enrollment are
+refused. Back up as above, replace Core and Web, then use steps 1–4 with a Runtime
+release from the new distribution. The replacement retires the old nodes. Stop each
+retired node service, move its identity directory aside as a backup, and add the
+host again with a new command from Web. Node IDs change; Session history and
+persisted Files/Artifacts remain. E2B deployments from that period are not covered.
+
 ## Exposure and network policy
 
 API and console bind to host loopback. With native Core, PostgreSQL publishes an
diff --git a/services/agents-api/internal/store/runtime_deployment.go b/services/agents-api/internal/store/runtime_deployment.go
index 6319181ab..a2bf62c5a 100644
--- a/services/agents-api/internal/store/runtime_deployment.go
+++ b/services/agents-api/internal/store/runtime_deployment.go
@@ -109,6 +109,9 @@ func checkRuntimeDeploymentAdmission(ctx context.Context, q *sqlc.Queries, insta
 	if current.Maintenance {
 		return fmt.Errorf("%w: sandbox creation is paused for provider maintenance", ErrEnvironmentUnavailable)
 	}
+	if unspecifiedNodeDeployment(current) {
+		return fmt.Errorf("%w: sandbox creation requires a deployment specification", ErrEnvironmentUnavailable)
+	}
 	if installation != "" {
 		id, err := parseConnectionGeneration(installation)
 		if err != nil || id != current.InstallationID {
diff --git a/services/agents-api/internal/store/runtime_nodes.go b/services/agents-api/internal/store/runtime_nodes.go
index 0a753b205..cd5050baf 100644
--- a/services/agents-api/internal/store/runtime_nodes.go
+++ b/services/agents-api/internal/store/runtime_nodes.go
@@ -105,7 +105,7 @@ func (s *Store) CreateRuntimeEnrollment(ctx context.Context, capacity RuntimeNod
 	token := hex.EncodeToString(bytes[:])
 	var expires time.Time
 	err := s.runtimeManagerTransaction(ctx, func(q *sqlc.Queries, d sqlc.RuntimeDeployment) error {
-		if d.Mode != "nodes" || d.Maintenance {
+		if d.Mode != "nodes" || d.Maintenance || unspecifiedNodeDeployment(d) {
 			return ErrSandboxDeploymentConflict
 		}
 		if err := q.CreateRuntimeEnrollment(ctx, sqlc.CreateRuntimeEnrollmentParams{TokenSha256: runtimeTokenDigest(token), InstallationID: d.InstallationID, MaxActive: int32(capacity.MaxActive), MaxRetained: int32(capacity.MaxRetained)}); err != nil {
@@ -190,6 +190,12 @@ func (s *Store) AuthenticateRuntimeNode(ctx context.Context, nodeID, credential
 	if n.InstallationID != d.InstallationID || d.Mode != "nodes" {
 		return RuntimeNodeIdentity{}, ErrRuntimeNodeCredential
 	}
+	if unspecifiedNodeDeployment(d) {
+		if n.SpecificationDigest != "" || n.DeploymentGeneration != 0 {
+			return RuntimeNodeIdentity{}, ErrRuntimeSpecificationMismatch
+		}
+		return nodeIdentity(n, d.ProviderKind), nil
+	}
 	spec, err := deploymentSpecification(d)
 	if err != nil || n.SpecificationDigest != spec.Digest(d.ProviderKind) || n.DeploymentGeneration != d.Generation {
 		return RuntimeNodeIdentity{}, ErrRuntimeSpecificationMismatch
diff --git a/services/agents-api/internal/store/sandbox_deployment_setup.go b/services/agents-api/internal/store/sandbox_deployment_setup.go
index 926fa27fe..573083bc6 100644
--- a/services/agents-api/internal/store/sandbox_deployment_setup.go
+++ b/services/agents-api/internal/store/sandbox_deployment_setup.go
@@ -49,7 +49,7 @@ func (s *Store) GetSandboxSetup(ctx context.Context) (SandboxSetup, error) {
 	if err := json.Unmarshal(d.Specification, &result.Specification); err != nil {
 		return SandboxSetup{}, err
 	}
-	if d.ProviderKind != "" {
+	if d.ProviderKind != "" && !unspecifiedNodeDeployment(d) {
 		if err := result.Specification.Validate(d.ProviderKind); err != nil {
 			return SandboxSetup{}, err
 		}
diff --git a/services/agents-api/internal/store/sandbox_deployment_switch_test.go b/services/agents-api/internal/store/sandbox_deployment_switch_test.go
index f0571e8a5..b02d4f670 100644
--- a/services/agents-api/internal/store/sandbox_deployment_switch_test.go
+++ b/services/agents-api/internal/store/sandbox_deployment_switch_test.go
@@ -302,3 +302,65 @@ func TestSandboxSwitchPreservesReleasedAllocationAndItemHistory(t *testing.T) {
 		}
 	}
 }
+
+// Migration 000069 leaves a node-backed selection saved before specifications
+// with an empty specification and its nodes with empty digests. The retained
+// node reconnects to drain resources; fresh admission and node configuration
+// stay closed until an administrator replaces the selection.
+func TestUnspecifiedNodeDeploymentDrainsBeforeReplacement(t *testing.T) {
+	_, pool := newManagedTestStore(t)
+	cipher, _ := credentialcrypto.New(bytes.Repeat([]byte{7}, 32))
+	s := NewWithCredentialCipher(pool, cipher)
+	w := executionLease(t, s).Store()
+	id := uuid.NewString()
+	if err := w.ClaimWebSandboxDeployment(t.Context(), id); err != nil {
+		t.Fatal(err)
+	}
+	spec := SandboxDeploymentTestSpec("docker")
+	selection := SandboxDeploymentSetupRequest{DeploymentSpec: spec, Provider: "docker", CoreURL: "https://core.example"}
+	if _, err := w.InitializeSandboxDeployment(t.Context(), id, selection); err != nil {
+		t.Fatal(err)
+	}
+	token, _, err := s.CreateRuntimeEnrollment(t.Context(), RuntimeNodeCapacity{MaxActive: 2, MaxRetained: 4})
+	if err != nil {
+		t.Fatal(err)
+	}
+	node := RuntimeNodeEnrollment{DeploymentGeneration: 1, SpecificationDigest: spec.Digest("docker"), NodeID: uuid.NewString(), Name: "Legacy", Provider: "docker", Credential: strings.Repeat("l", 64), BackendFingerprint: strings.Repeat("b", 64)}
+	if _, err := s.EnrollRuntimeNode(t.Context(), token, node); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := pool.Exec(t.Context(), "UPDATE runtime_deployment SET specification='{}'"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := pool.Exec(t.Context(), "UPDATE runtime_nodes SET specification_digest='', deployment_generation=0"); err != nil {
+		t.Fatal(err)
+	}
+
+	if setup, err := s.GetSandboxSetup(t.Context()); err != nil || setup.Provider != "docker" {
+		t.Fatal("unspecified deployment could not load for draining", err)
+	}
+	identity, err := s.AuthenticateRuntimeNode(t.Context(), node.NodeID, node.Credential)
+	if err != nil || identity.SpecificationDigest != "" || identity.DeploymentGeneration != 0 {
+		t.Fatal("retained unspecified node could not reconnect", identity, err)
+	}
+	if _, err := s.RuntimeNodeConfiguration(t.Context(), node.NodeID, node.Credential); !errors.Is(err, ErrRuntimeSpecificationMismatch) {
+		t.Fatal("node configuration served without a specification", err)
+	}
+	if _, err := s.CreateSession(t.Context(), uuid.NewString(), managerSessionInput(uuid.NewString(), "")); !errors.Is(err, ErrEnvironmentUnavailable) {
+		t.Fatal("unspecified deployment admitted a fresh sandbox", err)
+	}
+	if _, _, err := s.CreateRuntimeEnrollment(t.Context(), RuntimeNodeCapacity{MaxActive: 2, MaxRetained: 4}); !errors.Is(err, ErrSandboxDeploymentConflict) {
+		t.Fatal("unspecified deployment issued an enrollment token", err)
+	}
+
+	if _, err := w.SetSandboxMaintenance(t.Context(), id, SandboxMaintenanceRequest{Maintenance: true, ExpectedGeneration: 1}); err != nil {
+		t.Fatal(err)
+	}
+	view, err := w.UpdateSandboxDeployment(t.Context(), id, SandboxDeploymentUpdateRequest{SandboxDeploymentSetupRequest: selection, ExpectedGeneration: 1})
+	if err != nil || view.Generation != 2 || view.Specification == nil {
+		t.Fatal("replacement did not record the specification", view, err)
+	}
+	if _, err := s.AuthenticateRuntimeNode(t.Context(), node.NodeID, node.Credential); !errors.Is(err, ErrRuntimeNodeCredential) {
+		t.Fatal("unspecified node survived replacement", err)
+	}
+}
diff --git a/services/agents-api/internal/store/sandbox_specification.go b/services/agents-api/internal/store/sandbox_specification.go
index 8ed755ed3..5f5c19b72 100644
--- a/services/agents-api/internal/store/sandbox_specification.go
+++ b/services/agents-api/internal/store/sandbox_specification.go
@@ -41,6 +41,14 @@ func SandboxSetupForSelection(installationID string, input SandboxDeploymentSetu
 	return result, nil
 }
 
+// unspecifiedNodeDeployment identifies a node-backed selection saved before
+// deployments carried a specification; migration left the empty default. Its
+// retained nodes may reconnect to drain resources, but it cannot create
+// sandboxes or enroll nodes until an administrator replaces the selection.
+func unspecifiedNodeDeployment(d sqlc.RuntimeDeployment) bool {
+	return d.WebManaged && d.Mode == "nodes" && (d.ProviderKind == "docker" || d.ProviderKind == "microsandbox") && string(d.Specification) == "{}"
+}
+
 func deploymentSpecification(d sqlc.RuntimeDeployment) (sandbox.DeploymentSpec, error) {
 	var spec sandbox.DeploymentSpec
 	if json.Unmarshal(d.Specification, &spec) != nil || spec.Validate(d.ProviderKind) != nil {