diff --git a/checks.go b/checks.go
index 1c5df91bc..8770dd1af 100644
--- a/checks.go
+++ b/checks.go
@@ -49,7 +49,7 @@ func checkPieces(ctx context.Context, si SectorInfo, api sealingApi) error {
 			}
 			continue
 		}
-		deal, err := api.StateMarketStorageDeal(ctx, *piece.DealID, nil)
+		deal, err := api.StateMarketStorageDeal(ctx, *piece.DealID, types.EmptyTSK)
 		if err != nil {
 			return &ErrApi{xerrors.Errorf("getting deal %d for piece %d: %w", piece.DealID, i, err)}
 		}
@@ -83,7 +83,7 @@ func checkSeal(ctx context.Context, maddr address.Address, si SectorInfo, api se
 		return &ErrApi{xerrors.Errorf("getting chain head: %w", err)}
 	}
 
-	ssize, err := api.StateMinerSectorSize(ctx, maddr, head)
+	ssize, err := api.StateMinerSectorSize(ctx, maddr, head.Key())
 	if err != nil {
 		return &ErrApi{err}
 	}
@@ -105,7 +105,7 @@ func checkSeal(ctx context.Context, maddr address.Address, si SectorInfo, api se
 		Method:   builtin.MethodsMarket.ComputeDataCommitment,
 		Params:   ccparams,
 	}
-	r, err := api.StateCall(ctx, ccmt, nil)
+	r, err := api.StateCall(ctx, ccmt, types.EmptyTSK)
 	if err != nil {
 		return &ErrApi{xerrors.Errorf("calling ComputeDataCommitment: %w", err)}
 	}
diff --git a/sealing.go b/sealing.go
index ce30be446..facd88840 100644
--- a/sealing.go
+++ b/sealing.go
@@ -32,23 +32,23 @@ type TicketFn func(context.Context) (*sectorbuilder.SealTicket, error)
 
 type sealingApi interface { // TODO: trim down
 	// Call a read only method on actors (no interaction with the chain required)
-	StateCall(context.Context, *types.Message, *types.TipSet) (*api.MethodCall, error)
-	StateMinerWorker(context.Context, address.Address, *types.TipSet) (address.Address, error)
-	StateMinerPostState(ctx context.Context, actor address.Address, ts *types.TipSet) (*miner.PoStState, error)
-	StateMinerSectors(context.Context, address.Address, *types.TipSet) ([]*api.ChainSectorInfo, error)
-	StateMinerProvingSet(context.Context, address.Address, *types.TipSet) ([]*api.ChainSectorInfo, error)
-	StateMinerSectorSize(context.Context, address.Address, *types.TipSet) (abi.SectorSize, error)
+	StateCall(context.Context, *types.Message, types.TipSetKey) (*api.MethodCall, error)
+	StateMinerWorker(context.Context, address.Address, types.TipSetKey) (address.Address, error)
+	StateMinerPostState(ctx context.Context, actor address.Address, ts types.TipSetKey) (*miner.PoStState, error)
+	StateMinerSectors(context.Context, address.Address, types.TipSetKey) ([]*api.ChainSectorInfo, error)
+	StateMinerProvingSet(context.Context, address.Address, types.TipSetKey) ([]*api.ChainSectorInfo, error)
+	StateMinerSectorSize(context.Context, address.Address, types.TipSetKey) (abi.SectorSize, error)
 	StateWaitMsg(context.Context, cid.Cid) (*api.MsgWait, error) // TODO: removeme eventually
-	StateGetActor(ctx context.Context, actor address.Address, ts *types.TipSet) (*types.Actor, error)
-	StateGetReceipt(context.Context, cid.Cid, *types.TipSet) (*types.MessageReceipt, error)
-	StateMarketStorageDeal(context.Context, abi.DealID, *types.TipSet) (*api.MarketDeal, error)
+	StateGetActor(ctx context.Context, actor address.Address, ts types.TipSetKey) (*types.Actor, error)
+	StateGetReceipt(context.Context, cid.Cid, types.TipSetKey) (*types.MessageReceipt, error)
+	StateMarketStorageDeal(context.Context, abi.DealID, types.TipSetKey) (*api.MarketDeal, error)
 
 	MpoolPushMessage(context.Context, *types.Message) (*types.SignedMessage, error)
 
-	ChainHead(context.Context) (*types.TipSet, error)
+	ChainHead(context.Context) (types.TipSetKey, error)
 	ChainNotify(context.Context) (<-chan []*store.HeadChange, error)
 	ChainGetRandomness(ctx context.Context, tsk types.TipSetKey, personalization crypto.DomainSeparationTag, randEpoch abi.ChainEpoch, entropy []byte) (abi.Randomness, error)
-	ChainGetTipSetByHeight(context.Context, abi.ChainEpoch, *types.TipSet) (*types.TipSet, error)
+	ChainGetTipSetByHeight(context.Context, abi.ChainEpoch, types.TipSetKey) (*types.TipSet, error)
 	ChainGetBlockMessages(context.Context, cid.Cid) (*api.BlockMessages, error)
 	ChainReadObj(context.Context, cid.Cid) ([]byte, error)
 	ChainHasObj(context.Context, cid.Cid) (bool, error)
diff --git a/states_failed.go b/states_failed.go
index 7d851b0e8..f6ccc5057 100644
--- a/states_failed.go
+++ b/states_failed.go
@@ -13,6 +13,7 @@ import (
 	"github.com/filecoin-project/lotus/api/apibstore"
 	"github.com/filecoin-project/lotus/chain/actors"
 	"github.com/filecoin-project/lotus/chain/store"
+	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/lotus/lib/statemachine"
 )
 
@@ -33,7 +34,7 @@ func failedCooldown(ctx statemachine.Context, sector SectorInfo) error {
 }
 
 func (m *Sealing) checkPreCommitted(ctx statemachine.Context, sector SectorInfo) (*miner.SectorPreCommitOnChainInfo, bool) {
-	act, err := m.api.StateGetActor(ctx.Context(), m.maddr, nil)
+	act, err := m.api.StateGetActor(ctx.Context(), m.maddr, types.EmptyTSK)
 	if err != nil {
 		log.Errorf("handleSealFailed(%d): temp error: %+v", sector.SectorID, err)
 		return nil, true