diff --git a/Makefile b/Makefile
index 11180f8b03c..d20343f55c6 100644
--- a/Makefile
+++ b/Makefile
@@ -80,6 +80,9 @@ nerpanet: build-devnets
 butterflynet: GOFLAGS+=-tags=butterflynet
 butterflynet: build-devnets
 
+interopnet: GOFLAGS+=-tags=interopnet
+interopnet: build-devnets
+
 lotus: $(BUILD_DEPS)
 	rm -f lotus
 	go build $(GOFLAGS) -o lotus ./cmd/lotus
diff --git a/build/bootstrap/interopnet.pi b/build/bootstrap/interopnet.pi
new file mode 100644
index 00000000000..112d9611382
--- /dev/null
+++ b/build/bootstrap/interopnet.pi
@@ -0,0 +1,2 @@
+/dns4/bootstrap-0.interop.fildev.network/tcp/1347/p2p/12D3KooWN86wA54r3v9M8bBYbc1vK9W1ehHDxVGPRaoeUYuXF8R7
+/dns4/bootstrap-1.interop.fildev.network/tcp/1347/p2p/12D3KooWNZ41kev8mtBZgWe43qam1VX9pJyf87jnaisQP2urZZ2M
diff --git a/build/genesis/interopnet.car b/build/genesis/interopnet.car
new file mode 100644
index 00000000000..80ecd6e7297
Binary files /dev/null and b/build/genesis/interopnet.car differ
diff --git a/build/params_interop.go b/build/params_interop.go
new file mode 100644
index 00000000000..73cc1c7d9ca
--- /dev/null
+++ b/build/params_interop.go
@@ -0,0 +1,104 @@
+// +build interopnet
+
+package build
+
+import (
+	"os"
+	"strconv"
+
+	"github.com/ipfs/go-cid"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/abi"
+	builtin2 "github.com/filecoin-project/specs-actors/v2/actors/builtin"
+
+	"github.com/filecoin-project/lotus/chain/actors/policy"
+)
+
+const BootstrappersFile = "interopnet.pi"
+const GenesisFile = "interopnet.car"
+
+var UpgradeBreezeHeight = abi.ChainEpoch(-1)
+
+const BreezeGasTampingDuration = 0
+
+var UpgradeSmokeHeight = abi.ChainEpoch(-1)
+var UpgradeIgnitionHeight = abi.ChainEpoch(-2)
+var UpgradeRefuelHeight = abi.ChainEpoch(-3)
+var UpgradeTapeHeight = abi.ChainEpoch(-4)
+
+var UpgradeAssemblyHeight = abi.ChainEpoch(-5)
+var UpgradeLiftoffHeight = abi.ChainEpoch(-6)
+
+var UpgradeKumquatHeight = abi.ChainEpoch(-7)
+var UpgradeCalicoHeight = abi.ChainEpoch(-8)
+var UpgradePersianHeight = abi.ChainEpoch(-9)
+var UpgradeOrangeHeight = abi.ChainEpoch(-10)
+var UpgradeClausHeight = abi.ChainEpoch(-11)
+
+var UpgradeTrustHeight = abi.ChainEpoch(-12)
+
+var UpgradeNorwegianHeight = abi.ChainEpoch(-13)
+
+var UpgradeTurboHeight = abi.ChainEpoch(-14)
+
+var UpgradeHyperdriveHeight = abi.ChainEpoch(-15)
+
+var DrandSchedule = map[abi.ChainEpoch]DrandEnum{
+	0: DrandMainnet,
+}
+
+func init() {
+	policy.SetSupportedProofTypes(
+		abi.RegisteredSealProof_StackedDrg2KiBV1,
+		abi.RegisteredSealProof_StackedDrg8MiBV1,
+		abi.RegisteredSealProof_StackedDrg512MiBV1,
+	)
+	policy.SetConsensusMinerMinPower(abi.NewStoragePower(2048))
+	policy.SetMinVerifiedDealSize(abi.NewStoragePower(256))
+	policy.SetPreCommitChallengeDelay(abi.ChainEpoch(10))
+
+	getUpgradeHeight := func(ev string, def abi.ChainEpoch) abi.ChainEpoch {
+		hs, found := os.LookupEnv(ev)
+		if found {
+			h, err := strconv.Atoi(hs)
+			if err != nil {
+				log.Panicf("failed to parse %s env var", ev)
+			}
+
+			return abi.ChainEpoch(h)
+		}
+
+		return def
+	}
+
+	UpgradeBreezeHeight = getUpgradeHeight("LOTUS_BREEZE_HEIGHT", UpgradeBreezeHeight)
+	UpgradeSmokeHeight = getUpgradeHeight("LOTUS_SMOKE_HEIGHT", UpgradeSmokeHeight)
+	UpgradeIgnitionHeight = getUpgradeHeight("LOTUS_IGNITION_HEIGHT", UpgradeIgnitionHeight)
+	UpgradeRefuelHeight = getUpgradeHeight("LOTUS_REFUEL_HEIGHT", UpgradeRefuelHeight)
+	UpgradeTapeHeight = getUpgradeHeight("LOTUS_TAPE_HEIGHT", UpgradeTapeHeight)
+	UpgradeAssemblyHeight = getUpgradeHeight("LOTUS_ACTORSV2_HEIGHT", UpgradeAssemblyHeight)
+	UpgradeLiftoffHeight = getUpgradeHeight("LOTUS_LIFTOFF_HEIGHT", UpgradeLiftoffHeight)
+	UpgradeKumquatHeight = getUpgradeHeight("LOTUS_KUMQUAT_HEIGHT", UpgradeKumquatHeight)
+	UpgradeCalicoHeight = getUpgradeHeight("LOTUS_CALICO_HEIGHT", UpgradeCalicoHeight)
+	UpgradePersianHeight = getUpgradeHeight("LOTUS_PERSIAN_HEIGHT", UpgradePersianHeight)
+	UpgradeOrangeHeight = getUpgradeHeight("LOTUS_ORANGE_HEIGHT", UpgradeOrangeHeight)
+	UpgradeClausHeight = getUpgradeHeight("LOTUS_CLAUS_HEIGHT", UpgradeClausHeight)
+	UpgradeTrustHeight = getUpgradeHeight("LOTUS_ACTORSV3_HEIGHT", UpgradeTrustHeight)
+	UpgradeNorwegianHeight = getUpgradeHeight("LOTUS_NORWEGIAN_HEIGHT", UpgradeNorwegianHeight)
+	UpgradeTurboHeight = getUpgradeHeight("LOTUS_ACTORSV4_HEIGHT", UpgradeTurboHeight)
+	UpgradeHyperdriveHeight = getUpgradeHeight("LOTUS_HYPERDRIVE_HEIGHT", UpgradeHyperdriveHeight)
+
+	BuildType |= BuildInteropnet
+	SetAddressNetwork(address.Testnet)
+	Devnet = true
+}
+
+const BlockDelaySecs = uint64(builtin2.EpochDurationSeconds)
+
+const PropagationDelaySecs = uint64(6)
+
+// BootstrapPeerThreshold is the minimum number peers we need to track for a sync worker to start
+const BootstrapPeerThreshold = 2
+
+var WhitelistedBlock = cid.Undef
diff --git a/build/params_mainnet.go b/build/params_mainnet.go
index 52c6224798c..e9bf33f5aa9 100644
--- a/build/params_mainnet.go
+++ b/build/params_mainnet.go
@@ -4,6 +4,7 @@
 // +build !calibnet
 // +build !nerpanet
 // +build !butterflynet
+// +build !interopnet
 
 package build
 
diff --git a/build/version.go b/build/version.go
index 12b1058b314..5a4a494fcda 100644
--- a/build/version.go
+++ b/build/version.go
@@ -6,11 +6,12 @@ var CurrentCommit string
 var BuildType int
 
 const (
-	BuildDefault  = 0
-	BuildMainnet  = 0x1
-	Build2k       = 0x2
-	BuildDebug    = 0x3
-	BuildCalibnet = 0x4
+	BuildDefault    = 0
+	BuildMainnet    = 0x1
+	Build2k         = 0x2
+	BuildDebug      = 0x3
+	BuildCalibnet   = 0x4
+	BuildInteropnet = 0x5
 )
 
 func buildType() string {
@@ -25,6 +26,8 @@ func buildType() string {
 		return "+debug"
 	case BuildCalibnet:
 		return "+calibnet"
+	case BuildInteropnet:
+		return "+interopnet"
 	default:
 		return "+huh?"
 	}