Distributed nonce pool (#196)

* DB-level changes to support distributed nonce pools

* Initial LocalNoncePool implementation

* Remove deprecated random nonce selection logic

* Setup local nonce pool in gRPC transaction service

* Setup local nonce pool in sequencer service

* Add validation utility to LocalNoncePool for configuration enforcement

* Add nonce and nonce pool method tracing

* Add more edge case tests

Author: jeffyanta

go.mod

@@ -31,14 +31,9 @@ require (
 	github.com/stretchr/testify v1.8.4
 	github.com/vence722/base122-go v0.0.2
 	github.com/ybbus/jsonrpc v2.1.2+incompatible
-	go.etcd.io/etcd/api/v3 v3.5.13
-	go.etcd.io/etcd/client/v3 v3.5.13
-	go.uber.org/zap v1.17.0
 	golang.org/x/crypto v0.32.0
-	golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842
 	golang.org/x/net v0.34.0
 	golang.org/x/text v0.21.0
-	golang.org/x/time v0.5.0
 	google.golang.org/grpc v1.71.1
 	google.golang.org/protobuf v1.36.6
 )
@@ -50,8 +45,6 @@ require (
 	github.com/bits-and-blooms/bitset v1.2.0 // indirect
 	github.com/cenkalti/backoff/v4 v4.1.0 // indirect
 	github.com/containerd/continuity v0.0.0-20190827140505-75bee3e2ccb6 // indirect
-	github.com/coreos/go-semver v0.3.0 // indirect
-	github.com/coreos/go-systemd/v22 v22.3.2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/docker/cli v20.10.7+incompatible // indirect
 	github.com/docker/docker v20.10.7+incompatible // indirect
@@ -90,11 +83,7 @@ require (
 	github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
 	github.com/xeipuuv/gojsonschema v1.2.0 // indirect
-	go.etcd.io/etcd/client/pkg/v3 v3.5.13 // indirect
-	go.uber.org/atomic v1.7.0 // indirect
-	go.uber.org/multierr v1.6.0 // indirect
 	golang.org/x/sys v0.29.0 // indirect
-	google.golang.org/genproto/googleapis/api v0.0.0-20250106144421-5f5ef82da422 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20250115164207-1a7da9e5054f // indirect
 	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 	gopkg.in/ini.v1 v1.51.0 // indirect

go.sum

@@ -86,12 +86,9 @@ github.com/containerd/continuity v0.0.0-20190827140505-75bee3e2ccb6 h1:NmTXa/uVn
 github.com/containerd/continuity v0.0.0-20190827140505-75bee3e2ccb6/go.mod h1:GL3xCUCBDV3CZiTSEKksMWbLE66hEyuu9qyDOOqM47Y=
 github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
 github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
-github.com/coreos/go-semver v0.3.0 h1:wkHLiw0WNATZnSG7epLsujiMCgPAc9xhjJ4tgnAxmfM=
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
-github.com/coreos/go-systemd/v22 v22.3.2 h1:D9/bQk5vlXQFZ6Kwuu6zaiXJ9oTPe68++AzAJc1DzSI=
-github.com/coreos/go-systemd/v22 v22.3.2/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
@@ -141,7 +138,6 @@ github.com/go-sql-driver/mysql v1.4.0/go.mod h1:zAC/RDZ24gD3HViQzih4MyKcchzm+sOG
 github.com/go-sql-driver/mysql v1.5.0 h1:ozyZYNQW3x3HtqT1jira07DN2PArx2v7/mN66gGcHOs=
 github.com/go-sql-driver/mysql v1.5.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
-github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/gofrs/uuid v4.0.0+incompatible h1:1SD/1F5pU8p29ybwgQSwpQk+mwdRrXCYuPhW6m+TnJw=
 github.com/gofrs/uuid v4.0.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
@@ -467,12 +463,6 @@ github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9de
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/zenazn/goji v0.9.0/go.mod h1:7S9M489iMyHBNxwZnk9/EHS098H4/F6TATF2mIxtB1Q=
 go.etcd.io/bbolt v1.3.2/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=
-go.etcd.io/etcd/api/v3 v3.5.13 h1:8WXU2/NBge6AUF1K1gOexB6e07NgsN1hXK0rSTtgSp4=
-go.etcd.io/etcd/api/v3 v3.5.13/go.mod h1:gBqlqkcMMZMVTMm4NDZloEVJzxQOQIls8splbqBDa0c=
-go.etcd.io/etcd/client/pkg/v3 v3.5.13 h1:RVZSAnWWWiI5IrYAXjQorajncORbS0zI48LQlE2kQWg=
-go.etcd.io/etcd/client/pkg/v3 v3.5.13/go.mod h1:XxHT4u1qU12E2+po+UVPrEeL94Um6zL58ppuJWXSAB8=
-go.etcd.io/etcd/client/v3 v3.5.13 h1:o0fHTNJLeO0MyVbc7I3fsCf6nrOqn5d+diSarKnB2js=
-go.etcd.io/etcd/client/v3 v3.5.13/go.mod h1:cqiAeY8b5DEEcpxvgWKsbLIWNM/8Wy2xJSDMtioMcoI=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.0/go.mod h1:+kGneAE2xo2IficOXnaByMWTGM9T73dGwxeWcUqIpI8=
 go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
@@ -495,19 +485,13 @@ go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
-go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
-go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/multierr v1.3.0/go.mod h1:VgVr7evmIr6uPjLBxg28wmKNXyqE9akIJ5XnfpiKl+4=
 go.uber.org/multierr v1.5.0/go.mod h1:FeouvMocqHpRaaGuG9EjoKcStLC43Zu/fmqdUMPcKYU=
-go.uber.org/multierr v1.6.0 h1:y6IPFStTAIT5Ytl7/XYmHvzXQ7S3g/IeZW9hyZ5thw4=
-go.uber.org/multierr v1.6.0/go.mod h1:cdWPpRnG4AhwMwsgIHip0KRBQjJy5kYEpYjJxpXp9iU=
 go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee/go.mod h1:vJERXedbb3MVM5f9Ejo0C68/HhF8uaILCdgjnY+goOA=
 go.uber.org/zap v1.9.1/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 go.uber.org/zap v1.13.0/go.mod h1:zwrFLgMcdUuIBviXEYEH1YKNaOBnKXsx2IPda5bBwHM=
-go.uber.org/zap v1.17.0 h1:MTjgFu6ZLKvY6Pvaqk97GlxNBuMpV4Hy/3P6tRGlI2U=
-go.uber.org/zap v1.17.0/go.mod h1:MXVU+bhUf/A7Xi2HNOnopQOrmycQ5Ih87HtOu4q5SSo=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181029021203-45a5f77698d3/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
@@ -536,8 +520,6 @@ golang.org/x/exp v0.0.0-20200119233911-0405dc783f0a/go.mod h1:2RIsYlXP63K8oxa1u0
 golang.org/x/exp v0.0.0-20200207192155-f17229e696bd/go.mod h1:J/WKrq2StrnmMY6+EHIKF9dgMWnmCNThgcyBT1FY9mM=
 golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6/go.mod h1:3jZMyOhIsHpP37uCMkUooju7aAi5cS1Q23tOzKc+0MU=
 golang.org/x/exp v0.0.0-20200331195152-e8c3332aa8e5/go.mod h1:4M0jN8W1tt0AVLNr8HDosyJCDCDuyL9N9+3m7wDWgKw=
-golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 h1:vr/HnozRka3pE4EsMEg1lgkXJkTFJCVUX+S/ZT6wYzM=
-golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842/go.mod h1:XtvwrStGgqGPLc4cjQfWqZHG1YFdYs6swckp8vpsjnc=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -685,8 +667,6 @@ golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
-golang.org/x/time v0.5.0 h1:o7cqy6amK/52YcAKIPlM3a+Fpj35zvRj2TP+e1xFSfk=
-golang.org/x/time v0.5.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
 golang.org/x/tools v0.0.0-20180221164845-07fd8470d635/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
@@ -815,8 +795,6 @@ google.golang.org/genproto v0.0.0-20201210142538-e3217bee35cc/go.mod h1:FWY/as6D
 google.golang.org/genproto v0.0.0-20201214200347-8c77b98c765d/go.mod h1:FWY/as6DDZQgahTzZj3fqbO1CbirC29ZNUFHwi0/+no=
 google.golang.org/genproto v0.0.0-20210108203827-ffc7fda8c3d7/go.mod h1:FWY/as6DDZQgahTzZj3fqbO1CbirC29ZNUFHwi0/+no=
 google.golang.org/genproto v0.0.0-20210226172003-ab064af71705/go.mod h1:FWY/as6DDZQgahTzZj3fqbO1CbirC29ZNUFHwi0/+no=
-google.golang.org/genproto/googleapis/api v0.0.0-20250106144421-5f5ef82da422 h1:GVIKPyP/kLIyVOgOnTwFOrvQaQUzOzGMCxgFUOEmm24=
-google.golang.org/genproto/googleapis/api v0.0.0-20250106144421-5f5ef82da422/go.mod h1:b6h1vNKhxaSoEI+5jc3PJUCustfli/mRab7295pY7rw=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20250115164207-1a7da9e5054f h1:OxYkA3wjPsZyBylwymxSHa7ViiW1Sml4ToBrncvFehI=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20250115164207-1a7da9e5054f/go.mod h1:+2Yz8+CLJbIfL9z73EW45avw8Lmge3xVElCP9zEKi50=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
@@ -863,12 +841,10 @@ gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bl
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gotest.tools/v3 v3.0.2 h1:kG1BFyqVHuQoVQiR1bWGnfz/fmHvvuiSPIV7rvl360E=

pkg/code/async/nonce/metrics.go

@@ -31,6 +31,7 @@ func (p *service) metricsGaugeWorker(ctx context.Context) error {
 				nonce.StateAvailable,
 				nonce.StateReserved,
 				nonce.StateInvalid,
+				nonce.StateClaimed,
 			} {
 				count, err := p.data.GetNonceCountByStateAndPurpose(ctx, nonce.EnvironmentCvm, common.CodeVmAccount.PublicKey().ToBase58(), state, nonce.PurposeClientTransaction)
 				if err != nil {

pkg/code/async/nonce/pool.go

@@ -95,31 +95,36 @@ func (p *service) handle(ctx context.Context, record *nonce.Record) error {
 					blockhash yet.
 
 				StateAvailable:
-					Available to be used by a payment intent, subscription, or
-					other nonce-related transaction/instruction.
+					Available to be by a fulfillment for a virtual instruction
+					or transaction.
 
 				StateReserved:
-					Reserved by a payment intent, subscription, or other
-					nonce-related transaction/instruction.
+					Reserved by a by a fulfillment for a virtual instruction
+					or transaction.
 
 				StateInvalid:
 					The nonce account is invalid (e.g. insufficient funds, etc).
 
+				StateClaimed:
+					The nonce is claimed by a process for future use (identified
+					by a node ID)
+
 			Transitions:
 				StateUnknown
 					-> StateInvalid
 					-> StateReleased
 				StateReleased
 					-> StateAvailable
 				StateAvailable
-					-> [externally] StateReserved (nonce used in a new transaction)
+					-> [externally] StateClaimed (nonce claimed by a process for future use)
+				StateClaimed
+					-> [externally] StateAvailable (nonce released by the process that claimed it)
+					-> [externally] StateReserved (nonce reserved for future use in a virtual instruction or transaction)
 				StateReserved
-					-> [externally] StateReleased (nonce used in a submitted transaction)
-					-> [externally] StateAvailable (nonce will never be submitted in the transaction - eg. it became revoked)
+					-> [externally] StateReleased (nonce used in a submitted virtual instruction or transaction)
+					-> [externally] StateAvailable (nonce will never be submitted in the virtual instruction or transaction - eg. it became revoked)
 	*/
 
-	// todo: distributed lock on the nonce
-
 	switch record.State {
 	case nonce.StateUnknown:
 		return p.handleUnknown(ctx, record)
@@ -131,6 +136,8 @@ func (p *service) handle(ctx context.Context, record *nonce.Record) error {
 		return p.handleReserved(ctx, record)
 	case nonce.StateInvalid:
 		return p.handleInvalid(ctx, record)
+	case nonce.StateClaimed:
+		return p.handleClaimed(ctx, record)
 	default:
 		return nil
 	}
@@ -259,3 +266,8 @@ func (p *service) handleInvalid(ctx context.Context, record *nonce.Record) error
 	// as is for further investigation.
 	return nil
 }
+
+func (p *service) handleClaimed(ctx context.Context, record *nonce.Record) error {
+	// Nothing to do here
+	return nil
+}

pkg/code/async/sequencer/fulfillment_handler.go

@@ -46,7 +46,7 @@ type FulfillmentHandler interface {
 	// to the blockchain. This is an optimization for the nonce pool. Implementations
 	// should not modify the provided fulfillment record or selected nonce, but rather
 	// use relevant fields to make the corresponding transaction.
-	MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.SelectedNonce) (*solana.Transaction, error)
+	MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.Nonce) (*solana.Transaction, error)
 
 	// OnSuccess is a callback function executed on a finalized transaction.
 	OnSuccess(ctx context.Context, fulfillmentRecord *fulfillment.Record, txnRecord *transaction.Record) error
@@ -123,7 +123,7 @@ func (h *InitializeLockedTimelockAccountFulfillmentHandler) SupportsOnDemandTran
 	return true
 }
 
-func (h *InitializeLockedTimelockAccountFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.SelectedNonce) (*solana.Transaction, error) {
+func (h *InitializeLockedTimelockAccountFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.Nonce) (*solana.Transaction, error) {
 	if fulfillmentRecord.FulfillmentType != fulfillment.InitializeLockedTimelockAccount {
 		return nil, errors.New("invalid fulfillment type")
 	}
@@ -268,7 +268,7 @@ func (h *NoPrivacyTransferWithAuthorityFulfillmentHandler) SupportsOnDemandTrans
 	return true
 }
 
-func (h *NoPrivacyTransferWithAuthorityFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.SelectedNonce) (*solana.Transaction, error) {
+func (h *NoPrivacyTransferWithAuthorityFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.Nonce) (*solana.Transaction, error) {
 	virtualSignatureBytes, err := base58.Decode(*fulfillmentRecord.VirtualSignature)
 	if err != nil {
 		return nil, err
@@ -444,7 +444,7 @@ func (h *NoPrivacyWithdrawFulfillmentHandler) SupportsOnDemandTransactions() boo
 	return true
 }
 
-func (h *NoPrivacyWithdrawFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.SelectedNonce) (*solana.Transaction, error) {
+func (h *NoPrivacyWithdrawFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.Nonce) (*solana.Transaction, error) {
 	virtualSignatureBytes, err := base58.Decode(*fulfillmentRecord.VirtualSignature)
 	if err != nil {
 		return nil, err
@@ -634,7 +634,7 @@ func (h *CloseEmptyTimelockAccountFulfillmentHandler) SupportsOnDemandTransactio
 	return true
 }
 
-func (h *CloseEmptyTimelockAccountFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.SelectedNonce) (*solana.Transaction, error) {
+func (h *CloseEmptyTimelockAccountFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.Nonce) (*solana.Transaction, error) {
 	if fulfillmentRecord.FulfillmentType != fulfillment.CloseEmptyTimelockAccount {
 		return nil, errors.New("invalid fulfillment type")
 	}

pkg/code/async/sequencer/service.go

@@ -14,6 +14,8 @@ import (
 	"github.com/code-payments/code-server/pkg/code/data/action"
 	"github.com/code-payments/code-server/pkg/code/data/fulfillment"
 	"github.com/code-payments/code-server/pkg/code/data/intent"
+	"github.com/code-payments/code-server/pkg/code/data/nonce"
+	"github.com/code-payments/code-server/pkg/code/transaction"
 )
 
 var (
@@ -28,22 +30,28 @@ type service struct {
 	data                      code_data.Provider
 	scheduler                 Scheduler
 	vmIndexerClient           indexerpb.IndexerClient
+	noncePool                 *transaction.LocalNoncePool
 	fulfillmentHandlersByType map[fulfillment.Type]FulfillmentHandler
 	actionHandlersByType      map[action.Type]ActionHandler
 	intentHandlersByType      map[intent.Type]IntentHandler
 }
 
-func New(data code_data.Provider, scheduler Scheduler, vmIndexerClient indexerpb.IndexerClient, configProvider ConfigProvider) async.Service {
+func New(data code_data.Provider, scheduler Scheduler, vmIndexerClient indexerpb.IndexerClient, noncePool *transaction.LocalNoncePool, configProvider ConfigProvider) (async.Service, error) {
+	if err := noncePool.Validate(nonce.EnvironmentSolana, nonce.EnvironmentInstanceSolanaMainnet, nonce.PurposeOnDemandTransaction); err != nil {
+		return nil, err
+	}
+
 	return &service{
 		log:                       logrus.StandardLogger().WithField("service", "sequencer"),
 		conf:                      configProvider(),
 		data:                      data,
 		scheduler:                 scheduler,
 		vmIndexerClient:           vmIndexerClient,
+		noncePool:                 noncePool, // todo: validate configuration
 		fulfillmentHandlersByType: getFulfillmentHandlers(data, vmIndexerClient),
 		actionHandlersByType:      getActionHandlers(data),
 		intentHandlersByType:      getIntentHandlers(data),
-	}
+	}, nil
 }
 
 func (p *service) Start(ctx context.Context, interval time.Duration) error {

pkg/code/async/sequencer/testutil.go

@@ -4,12 +4,12 @@ import (
 	"context"
 	"errors"
 
-	"github.com/code-payments/code-server/pkg/solana"
-	"github.com/code-payments/code-server/pkg/solana/memo"
 	"github.com/code-payments/code-server/pkg/code/common"
 	"github.com/code-payments/code-server/pkg/code/data/fulfillment"
 	"github.com/code-payments/code-server/pkg/code/data/transaction"
 	transaction_util "github.com/code-payments/code-server/pkg/code/transaction"
+	"github.com/code-payments/code-server/pkg/solana"
+	"github.com/code-payments/code-server/pkg/solana/memo"
 )
 
 type mockScheduler struct {
@@ -42,7 +42,7 @@ func (h *mockFulfillmentHandler) SupportsOnDemandTransactions() bool {
 	return h.supportsOnDemandTxnCreation
 }
 
-func (h *mockFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.SelectedNonce) (*solana.Transaction, error) {
+func (h *mockFulfillmentHandler) MakeOnDemandTransaction(ctx context.Context, fulfillmentRecord *fulfillment.Record, selectedNonce *transaction_util.Nonce) (*solana.Transaction, error) {
 	if !h.supportsOnDemandTxnCreation {
 		return nil, errors.New("not supported")
 	}