fix(inference): enforce devshard kill switch on escrow create and settle

inference-chain/x/inference/keeper/msg_server_create_devshard_escrow.go

@@ -24,6 +24,13 @@ func (k msgServer) CreateDevshardEscrow(goCtx context.Context, msg *types.MsgCre
 
 	ep := k.GetDevshardEscrowParams(goCtx)
 
+	// Enforce the devshard kill switch: when requests are disabled, refuse to lock
+	// any new funds. Without this check the Guardian-gated kill switch only stops
+	// off-chain hosts from serving while the chain keeps accepting escrows.
+	if !ep.DevshardRequestsEnabled {
+		return nil, fmt.Errorf("devshard requests are currently disabled")
+	}
+
 	if msg.Amount < ep.MinAmount || msg.Amount > ep.MaxAmount {
 		return nil, fmt.Errorf("escrow amount %d out of range [%d, %d]", msg.Amount, ep.MinAmount, ep.MaxAmount)
 	}

inference-chain/x/inference/keeper/msg_server_create_devshard_escrow_test.go

@@ -241,6 +241,7 @@ func TestCreateDevshardEscrow_ParamsOverrideDefaults(t *testing.T) {
 		AllowedCreatorAddresses: nil, // no restriction
 		TokenPrice:              types.DefaultDevshardTokenPrice,
 		MaxNonce:                types.DefaultDevshardMaxNonce,
+		DevshardRequestsEnabled: true,
 	}
 	require.NoError(t, k.SetParams(ctx, params))
 
@@ -293,3 +294,36 @@ func TestCreateDevshardEscrow_ModelGroupMustExist(t *testing.T) {
 	require.Error(t, err)
 	require.Contains(t, err.Error(), "failed to get epoch group for model")
 }
+
+func TestCreateDevshardEscrow_RequestsDisabledBlocks(t *testing.T) {
+	k, ms, ctx, _ := setupDevshardEscrowTest(t)
+
+	setupEpochGroupForDevshard(ctx, k, 5, testDevshardModelID, makeDevshardAddrs(1, 20))
+
+	creator := sdk.AccAddress(make([]byte, 20))
+	creator[0] = 0xFF
+
+	// Kill switch off: allowlist permits everyone, but requests are disabled.
+	params, err := k.GetParams(ctx)
+	require.NoError(t, err)
+	params.DevshardEscrowParams = &types.DevshardEscrowParams{
+		MinAmount:               types.DefaultDevshardEscrowMinAmount,
+		MaxAmount:               types.DefaultDevshardEscrowMaxAmount,
+		MaxEscrowsPerEpoch:      types.DefaultDevshardMaxEscrowsPerEpoch,
+		GroupSize:               types.DefaultDevshardGroupSize,
+		AllowedCreatorAddresses: nil,
+		TokenPrice:              types.DefaultDevshardTokenPrice,
+		MaxNonce:                types.DefaultDevshardMaxNonce,
+		DevshardRequestsEnabled: false,
+	}
+	require.NoError(t, k.SetParams(ctx, params))
+
+	// No bank mock is registered: the handler must reject before locking funds.
+	_, err = ms.CreateDevshardEscrow(ctx, &types.MsgCreateDevshardEscrow{
+		Creator: creator.String(),
+		Amount:  7_000_000_000,
+		ModelId: testDevshardModelID,
+	})
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "devshard requests are currently disabled")
+}

inference-chain/x/inference/keeper/msg_server_settle_devshard_escrow.go

@@ -35,6 +35,12 @@ func (k msgServer) SettleDevshardEscrow(goCtx context.Context, msg *types.MsgSet
 	if devshardParams == nil {
 		return nil, fmt.Errorf("devshard escrow params not configured")
 	}
+	// Enforce the devshard kill switch: when requests are disabled, no escrow may be
+	// settled. This keeps funds frozen in place during an incident instead of letting
+	// a (possibly crafted) settlement drain the module while the switch is off.
+	if !devshardParams.DevshardRequestsEnabled {
+		return nil, fmt.Errorf("devshard requests are currently disabled")
+	}
 	if err := VerifyDevshardSettlement(escrow, msg, devshardParams.MaxNonce, warmKeyChecker); err != nil {
 		return nil, err
 	}

inference-chain/x/inference/keeper/msg_server_settle_devshard_escrow_test.go

@@ -642,3 +642,43 @@ func TestSettleDevshardEscrow_AllowlistBlocks(t *testing.T) {
 	require.Error(t, err)
 	require.Contains(t, err.Error(), "address is not allowed to create devshard escrows")
 }
+
+func TestSettleDevshardEscrow_RequestsDisabledBlocks(t *testing.T) {
+	k, ms, ctx, _ := setupDevshardEscrowTest(t)
+	sdk.GetConfig().SetBech32PrefixForAccount("gonka", "gonka")
+
+	creator := sdk.AccAddress(make([]byte, 20))
+	creator[0] = 0xCC
+	escrow := types.DevshardEscrow{
+		Id:      1,
+		Creator: creator.String(),
+		Amount:  7_000_000_000,
+		Slots:   make([]string, keeper.DevshardGroupSize),
+		Settled: false,
+	}
+	_, err := k.StoreDevshardEscrow(ctx, &escrow, 1)
+	require.NoError(t, err)
+
+	// Kill switch off: allowlist permits everyone, but requests are disabled.
+	params, err := k.GetParams(ctx)
+	require.NoError(t, err)
+	params.DevshardEscrowParams = &types.DevshardEscrowParams{
+		MinAmount:               types.DefaultDevshardEscrowMinAmount,
+		MaxAmount:               types.DefaultDevshardEscrowMaxAmount,
+		MaxEscrowsPerEpoch:      types.DefaultDevshardMaxEscrowsPerEpoch,
+		GroupSize:               types.DefaultDevshardGroupSize,
+		AllowedCreatorAddresses: nil,
+		TokenPrice:              types.DefaultDevshardTokenPrice,
+		MaxNonce:                types.DefaultDevshardMaxNonce,
+		DevshardRequestsEnabled: false,
+	}
+	require.NoError(t, k.SetParams(ctx, params))
+
+	// No bank mock is registered: the handler must reject before moving funds.
+	_, err = ms.SettleDevshardEscrow(ctx, &types.MsgSettleDevshardEscrow{
+		Settler:  creator.String(),
+		EscrowId: 1,
+	})
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "devshard requests are currently disabled")
+}