feat(collections): genesis support (#14331)

Co-authored-by: testinginprod <testinginprod@somewhere.idk> Co-authored-by: testinginprod <98415576+testinginprod@users.noreply.github.com> Co-authored-by: Marko <marbar3778@yahoo.com> Co-authored-by: Julien Robert <julien@rbrt.fr> Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com> Co-authored-by: Rafael Tenfen <rafaeltenfen.rt@gmail.com> Co-authored-by: Facundo Medica <14063057+facundomedica@users.noreply.github.com> Co-authored-by: atheeshp <59333759+atheeshp@users.noreply.github.com> Co-authored-by: Likhita Polavarapu <78951027+likhita-809@users.noreply.github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com> Co-authored-by: Matt Kocubinski <mkocubinski@gmail.com> Co-authored-by: Jacob Gadikian <faddat@users.noreply.github.com> Co-authored-by: samricotta <37125168+samricotta@users.noreply.github.com> Co-authored-by: Noel Ukwa <noeluchechukwu@gmail.com> Co-authored-by: JayT106 <JayT106@users.noreply.github.com> Co-authored-by: Julián Toledano <JulianToledano@users.noreply.github.com> Co-authored-by: Amaury <1293565+amaurym@users.noreply.github.com> Co-authored-by: Denver <aeharvlee@gmail.com> Co-authored-by: Hyunwoo Lee <denver@Hyunwoos-MacBook-Pro-2.local> Co-authored-by: Federico Kunze Küllmer <31522760+fedekunze@users.noreply.github.com> Co-authored-by: MalteHerrmann <42640438+MalteHerrmann@users.noreply.github.com> Co-authored-by: Vladislav Varadinov <vladislav.varadinov@gmail.com> Co-authored-by: cipherZ <dev@cipherz.com>
2023-01-17 06:25:10 -05:00 · 2023-01-17 06:25:10 -05:00 · b3c750ca27
commit b3c750ca27
parent afdbc51e47
17 changed files with 689 additions and 23 deletions
--- a/collections/collections.go
+++ b/collections/collections.go
@ -22,6 +22,8 @@ type collection interface {

 	// getPrefix is the unique prefix of the collection within a schema.
 	getPrefix() []byte
+
+	genesisHandler
 }

 // Prefix defines a segregation namespace
@ -85,6 +87,10 @@ type KeyCodec[T any] interface {
 	// to return the maximum varint bytes buffer length, at the risk of
 	// over-estimating in order to pick the most performant path.
 	Size(key T) int
+	// EncodeJSON encodes the value as JSON.
+	EncodeJSON(value T) ([]byte, error)
+	// DecodeJSON decodes the provided JSON bytes into an instance of T.
+	DecodeJSON(b []byte) (T, error)
 	// Stringify returns a string representation of T.
 	Stringify(key T) string
 	// KeyType returns a string identifier for the type of the key.
@ -117,6 +123,10 @@ type ValueCodec[T any] interface {
 	Encode(value T) ([]byte, error)
 	// Decode returns the type T given its binary representation.
 	Decode(b []byte) (T, error)
+	// EncodeJSON encodes the value as JSON.
+	EncodeJSON(value T) ([]byte, error)
+	// DecodeJSON decodes the provided JSON bytes into an instance of T.
+	DecodeJSON(b []byte) (T, error)
 	// Stringify returns a string representation of T.
 	Stringify(value T) string
 	// ValueType returns the identifier for the type.
--- a/collections/collections_test.go
+++ b/collections/collections_test.go
@ -92,6 +92,13 @@ func checkKeyCodec[T any](t *testing.T, keyCodec KeyCodec[T], key T) {
 	require.NoError(t, err)
 	require.Equal(t, len(buffer), read, "encoded non terminal key and pair key read bytes must have same size")
 	require.Equal(t, pairKey, decodedPairKey, "encoding and decoding produces different keys with non terminal encoding")
+
+	// check JSON
+	keyJSON, err := keyCodec.EncodeJSON(key)
+	require.NoError(t, err)
+	decoded, err := keyCodec.DecodeJSON(keyJSON)
+	require.NoError(t, err)
+	require.Equal(t, key, decoded, "json encoding and decoding did not produce the same results")
 }

 // checkValueCodec asserts the correct behaviour of a ValueCodec over the type T.
--- a/collections/genesis.go
+++ b/collections/genesis.go
@ -0,0 +1,153 @@
+package collections
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+)
+
+type genesisHandler interface {
+	validateGenesis(r io.Reader) error
+	importGenesis(ctx context.Context, r io.Reader) error
+	exportGenesis(ctx context.Context, w io.Writer) error
+	defaultGenesis(w io.Writer) error
+}
+
+type jsonMapEntry struct {
+	Key   json.RawMessage `json:"key"`
+	Value json.RawMessage `json:"value,omitempty"`
+}
+
+func (m Map[K, V]) validateGenesis(reader io.Reader) error {
+	return m.doDecodeJson(reader, func(key K, value V) error {
+		return nil
+	})
+}
+
+func (m Map[K, V]) importGenesis(ctx context.Context, reader io.Reader) error {
+	return m.doDecodeJson(reader, func(key K, value V) error {
+		return m.Set(ctx, key, value)
+	})
+}
+
+func (m Map[K, V]) exportGenesis(ctx context.Context, writer io.Writer) error {
+	_, err := writer.Write([]byte("["))
+	if err != nil {
+		return err
+	}
+
+	it, err := m.Iterate(ctx, nil)
+	if err != nil {
+		return err
+	}
+	defer it.Close()
+
+	first := true
+	for ; it.Valid(); it.Next() {
+		// add a comma before encoding the object
+		// for all objects besides the first one.
+		if !first {
+			_, err = writer.Write([]byte(","))
+			if err != nil {
+				return err
+			}
+		}
+		first = false
+
+		key, err := it.Key()
+		if err != nil {
+			return err
+		}
+
+		keyBz, err := m.kc.EncodeJSON(key)
+		if err != nil {
+			return err
+		}
+
+		value, err := it.Value()
+		if err != nil {
+			return err
+		}
+
+		valueBz, err := m.vc.EncodeJSON(value)
+		if err != nil {
+			return err
+		}
+
+		entry := jsonMapEntry{
+			Key:   keyBz,
+			Value: valueBz,
+		}
+
+		bz, err := json.Marshal(entry)
+		if err != nil {
+			return err
+		}
+
+		_, err = writer.Write(bz)
+		if err != nil {
+			return err
+		}
+	}
+
+	_, err = writer.Write([]byte("]"))
+	return err
+}
+
+func (m Map[K, V]) doDecodeJson(reader io.Reader, onEntry func(key K, value V) error) error {
+	decoder := json.NewDecoder(reader)
+	token, err := decoder.Token()
+	if err != nil {
+		return err
+	}
+
+	if token != json.Delim('[') {
+		return fmt.Errorf("expected [ got %s", token)
+	}
+
+	for decoder.More() {
+		var rawJson json.RawMessage
+		err := decoder.Decode(&rawJson)
+		if err != nil {
+			return err
+		}
+
+		var mapEntry jsonMapEntry
+		err = json.Unmarshal(rawJson, &mapEntry)
+		if err != nil {
+			return err
+		}
+
+		key, err := m.kc.DecodeJSON(mapEntry.Key)
+		if err != nil {
+			return err
+		}
+
+		value, err := m.vc.DecodeJSON(mapEntry.Value)
+		if err != nil {
+			return err
+		}
+
+		err = onEntry(key, value)
+		if err != nil {
+			return err
+		}
+	}
+
+	token, err = decoder.Token()
+	if err != nil {
+		return err
+	}
+
+	if token != json.Delim(']') {
+		return fmt.Errorf("expected ] got %s", token)
+	}
+
+	return nil
+}
+
+func (m Map[K, V]) defaultGenesis(writer io.Writer) error {
+	_, err := writer.Write([]byte(`[]`))
+	return err
+}
--- a/collections/genesis_test.go
+++ b/collections/genesis_test.go
@ -0,0 +1,160 @@
+package collections
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"testing"
+
+	"cosmossdk.io/core/appmodule"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDefaultGenesis(t *testing.T) {
+	f := initFixture(t)
+	var writers []*bufCloser
+	require.NoError(t, f.schema.DefaultGenesis(func(field string) (io.WriteCloser, error) {
+		w := newBufCloser(t, "")
+		writers = append(writers, w)
+		return w, nil
+	}))
+	require.Len(t, writers, 4)
+	require.Equal(t, `[]`, writers[0].Buffer.String())
+	require.Equal(t, `[]`, writers[1].Buffer.String())
+	require.Equal(t, `[]`, writers[2].Buffer.String())
+	require.Equal(t, `[]`, writers[3].Buffer.String())
+}
+
+func TestValidateGenesis(t *testing.T) {
+	f := initFixture(t)
+	require.NoError(t, f.schema.ValidateGenesis(createTestGenesisSource(t)))
+}
+
+func TestImportGenesis(t *testing.T) {
+	f := initFixture(t)
+	require.NoError(t, f.schema.InitGenesis(f.ctx, createTestGenesisSource(t)))
+	// assert map correct genesis
+	mapIt, err := f.m.Iterate(f.ctx, nil)
+	require.NoError(t, err)
+	defer mapIt.Close()
+
+	kvs, err := mapIt.KeyValues()
+	require.NoError(t, err)
+	require.Equal(t, KeyValue[string, uint64]{Key: "abc", Value: 1}, kvs[0])
+	require.Equal(t, KeyValue[string, uint64]{Key: "def", Value: 2}, kvs[1])
+
+	// assert item correct genesis
+	x, err := f.i.Get(f.ctx)
+	require.NoError(t, err)
+	require.Equal(t, "superCoolItem", x)
+
+	// assert keyset correct genesis
+	ksIt, err := f.ks.Iterate(f.ctx, nil)
+	require.NoError(t, err)
+	defer ksIt.Close()
+
+	keys, err := ksIt.Keys()
+	require.NoError(t, err)
+	require.Equal(t, []string{"0", "1", "2"}, keys)
+
+	// assert sequence correct genesis
+	seq, err := f.s.Peek(f.ctx)
+	require.NoError(t, err)
+	require.Equal(t, uint64(1000), seq)
+}
+
+func TestExportGenesis(t *testing.T) {
+	f := initFixture(t)
+	require.NoError(t, f.schema.InitGenesis(f.ctx, createTestGenesisSource(t)))
+
+	var writers []*bufCloser
+	require.NoError(t, f.schema.ExportGenesis(f.ctx, func(field string) (io.WriteCloser, error) {
+		w := newBufCloser(t, "")
+		writers = append(writers, w)
+		return w, nil
+	}))
+	require.Len(t, writers, 4)
+	require.Equal(t, expectedItemGenesis, writers[0].Buffer.String())
+	require.Equal(t, expectedKeySetGenesis, writers[1].Buffer.String())
+	require.Equal(t, expectedMapGenesis, writers[2].Buffer.String())
+	require.Equal(t, expectedSequenceGenesis, writers[3].Buffer.String())
+}
+
+type testFixture struct {
+	schema Schema
+	ctx    context.Context
+	m      Map[string, uint64]
+	i      Item[string]
+	s      Sequence
+	ks     KeySet[string]
+}
+
+func initFixture(t *testing.T) *testFixture {
+	sk, ctx := deps()
+	schemaBuilder := NewSchemaBuilder(sk)
+	m := NewMap(schemaBuilder, NewPrefix(1), "map", StringKey, Uint64Value)
+	i := NewItem(schemaBuilder, NewPrefix(2), "item", StringValue)
+	s := NewSequence(schemaBuilder, NewPrefix(3), "sequence")
+	ks := NewKeySet(schemaBuilder, NewPrefix(4), "key_set", StringKey)
+	schema, err := schemaBuilder.Build()
+	require.NoError(t, err)
+	return &testFixture{
+		schema: schema,
+		ctx:    ctx,
+		m:      m,
+		i:      i,
+		s:      s,
+		ks:     ks,
+	}
+}
+
+func createTestGenesisSource(t *testing.T) appmodule.GenesisSource {
+	expectedOrder := []string{"item", "key_set", "map", "sequence"}
+	currentIndex := 0
+	return func(field string) (io.ReadCloser, error) {
+		require.Equal(t, expectedOrder[currentIndex], field, "unordered genesis")
+		currentIndex++
+
+		switch field {
+		case "map":
+			return newBufCloser(t, expectedMapGenesis), nil
+		case "item":
+			return newBufCloser(t, expectedItemGenesis), nil
+		case "key_set":
+			return newBufCloser(t, expectedKeySetGenesis), nil
+		case "sequence":
+			return newBufCloser(t, expectedSequenceGenesis), nil
+		default:
+			return nil, nil
+		}
+	}
+}
+
+const (
+	expectedMapGenesis      = `[{"key":"abc","value":"1"},{"key":"def","value":"2"}]`
+	expectedItemGenesis     = `[{"key":"item","value":"superCoolItem"}]`
+	expectedKeySetGenesis   = `[{"key":"0"},{"key":"1"},{"key":"2"}]`
+	expectedSequenceGenesis = `[{"key":"item","value":"1000"}]`
+)
+
+type bufCloser struct {
+	*bytes.Buffer
+	closed bool
+}
+
+func (b *bufCloser) Close() error {
+	b.closed = true
+	return nil
+}
+
+func newBufCloser(t *testing.T, str string) *bufCloser {
+	b := &bufCloser{
+		Buffer: bytes.NewBufferString(str),
+		closed: false,
+	}
+	// this ensures Close was called by the implementation
+	t.Cleanup(func() {
+		require.True(t, b.closed)
+	})
+	return b
+}
--- a/collections/go.mod
+++ b/collections/go.mod
@ -10,6 +10,8 @@ require (
 )

 require (
+	cosmossdk.io/api v0.2.6 // indirect
+	cosmossdk.io/depinject v1.0.0-alpha.3 // indirect
 	github.com/DataDog/zstd v1.4.5 // indirect
 	github.com/HdrHistogram/hdrhistogram-go v1.1.2 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
@ -18,9 +20,11 @@ require (
 	github.com/cockroachdb/pebble v0.0.0-20220817183557-09c6e030a677 // indirect
 	github.com/cockroachdb/redact v1.0.8 // indirect
 	github.com/cockroachdb/sentry-go v0.6.1-cockroachdb.2 // indirect
+	github.com/cosmos/cosmos-proto v1.0.0-beta.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/fsnotify/fsnotify v1.6.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/btree v1.1.2 // indirect
 	github.com/hashicorp/errwrap v1.1.0 // indirect
@ -38,5 +42,9 @@ require (
 	golang.org/x/exp v0.0.0-20221019170559-20944726eadf // indirect
 	golang.org/x/net v0.3.0 // indirect
 	golang.org/x/sys v0.3.0 // indirect
+	golang.org/x/text v0.5.0 // indirect
+	google.golang.org/genproto v0.0.0-20221118155620-16455021b5e6 // indirect
+	google.golang.org/grpc v1.51.0 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
--- a/collections/go.sum
+++ b/collections/go.sum
@ -1,6 +1,10 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
+cosmossdk.io/api v0.2.6 h1:AoNwaLLapcLsphhMK6+o0kZl+D6MMUaHVqSdwinASGU=
+cosmossdk.io/api v0.2.6/go.mod h1:u/d+GAxil0nWpl1XnQL8nkziQDIWuBDhv8VnDm/s6dI=
 cosmossdk.io/core v0.4.1 h1:5icpjPmw8J4uFp6w8OoLJPxsw6X3kRi9nAtTr3qp2Ok=
 cosmossdk.io/core v0.4.1/go.mod h1:Zqd1GB+krTF3bzhTnPNwzy3NTtXu+MKLX/9sPQXTIDE=
+cosmossdk.io/depinject v1.0.0-alpha.3 h1:6evFIgj//Y3w09bqOUOzEpFj5tsxBqdc5CfkO7z+zfw=
+cosmossdk.io/depinject v1.0.0-alpha.3/go.mod h1:eRbcdQ7MRpIPEM5YUJh8k97nxHpYbc3sMUnEtt8HPWU=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/AndreasBriese/bbloom v0.0.0-20190306092124-e2d15f34fcf9/go.mod h1:bOvUY6CB00SOBii9/FifXqc0awNKxLFCL/+pkDPuyl8=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
@ -16,6 +20,7 @@ github.com/Joker/jade v1.0.1-0.20190614124447-d475f43051e7/go.mod h1:6E6s8o2AE4K
 github.com/Shopify/goreferrer v0.0.0-20181106222321-ec9c9a553398/go.mod h1:a1uqRtAwp2Xwc6WNPJEufxJ7fx3npB4UV/JOLmbu5I0=
 github.com/ajg/form v1.5.1/go.mod h1:uL1WgH+h2mgNtvBq0339dVnzXdBETtL2LeUXaIv25UY=
 github.com/ajstarks/svgo v0.0.0-20180226025133-644b8db467af/go.mod h1:K08gAheRH3/J6wwsYMMT4xOr94bZjxIelGM0+d/wbFw=
+github.com/alecthomas/participle/v2 v2.0.0-alpha7 h1:cK4vjj0VSgb3lN1nuKA5F7dw+1s1pWBe5bx7nNCnN+c=
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/aymerick/raymond v2.0.3-0.20180322193309-b565731e1464+incompatible/go.mod h1:osfaiScAUVup+UC9Nfq76eWqDhXlp+4UYaA8uhTBO6g=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
@ -24,6 +29,7 @@ github.com/cespare/xxhash/v2 v2.1.2 h1:YRXhKfTDauu4ajMg1TPgFO5jnlC2HCbmLXMcTG5cb
 github.com/cespare/xxhash/v2 v2.1.2/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
+github.com/cockroachdb/apd/v3 v3.1.0 h1:MK3Ow7LH0W8zkd5GMKA1PvS9qG3bWFI95WaVNfyZJ/w=
 github.com/cockroachdb/datadriven v1.0.0/go.mod h1:5Ib8Meh+jk1RlHIXej6Pzevx/NLlNvQB9pmSBZErGA4=
 github.com/cockroachdb/errors v1.6.1/go.mod h1:tm6FTP5G81vwJ5lC0SizQo374JNCOPrHyXGitRJoDqM=
 github.com/cockroachdb/errors v1.8.1 h1:A5+txlVZfOqFBDa4mGz2bUWSp0aHElvHX2bKkdbQu+Y=
@ -42,8 +48,12 @@ github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8Nz
 github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/cosmos/cosmos-db v0.0.0-20221226095112-f3c38ecb5e32 h1:zlCp9n3uwQieELltZWHRmwPmPaZ8+XoL2Sj+A2YJlr8=
 github.com/cosmos/cosmos-db v0.0.0-20221226095112-f3c38ecb5e32/go.mod h1:kwMlEC4wWvB48zAShGKVqboJL6w4zCLesaNQ3YLU2BQ=
+github.com/cosmos/cosmos-proto v1.0.0-beta.1 h1:iDL5qh++NoXxG8hSy93FdYJut4XfgbShIocllGaXx/0=
+github.com/cosmos/cosmos-proto v1.0.0-beta.1/go.mod h1:8k2GNZghi5sDRFw/scPL8gMSowT1vDA+5ouxL8GjaUE=
 github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/cucumber/common/gherkin/go/v22 v22.0.0 h1:4K8NqptbvdOrjL9DEea6HFjSpbdT9+Q5kgLpmmsHYl0=
+github.com/cucumber/common/messages/go/v17 v17.1.1 h1:RNqopvIFyLWnKv0LfATh34SWBhXeoFTJnSrgm9cT/Ts=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@ -79,6 +89,7 @@ github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0/go.mod h1:fyg78
 github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee/go.mod h1:L0fX3K22YWvt/FAX9NnzrNzcI4wNYi9Yku4O0LKYflo=
 github.com/gobwas/pool v0.2.0/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
 github.com/gobwas/ws v1.0.2/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM=
+github.com/gofrs/uuid v4.2.0+incompatible h1:yyYWMnhkhrKwwr8gAOcOCYxOOscHgDS9yZgBrnJfGa0=
 github.com/gogo/googleapis v0.0.0-20180223154316-0cd9801be74a/go.mod h1:gf4bu3Q80BeJ6H1S1vYPm8/ELATdvryBaNFGgqEef3s=
 github.com/gogo/protobuf v1.2.0/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.3.1/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXPKa29o=
@ -98,6 +109,9 @@ github.com/golang/protobuf v1.4.0-rc.2/go.mod h1:LlEzMj4AhA7rCAGe4KMBDvJI+AwstrU
 github.com/golang/protobuf v1.4.0-rc.4.0.20200313231945-b860323f09d0/go.mod h1:WU3c8KckQ9AFe+yFwt9sWVRKCVIyN9cPHBJSNnbL67w=
 github.com/golang/protobuf v1.4.0/go.mod h1:jodUvKwWbYaEsadDk5Fwe5c77LiNKVO9IDvqG2KuDX0=
 github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
+github.com/golang/protobuf v1.5.2 h1:ROPKBNFfQgOUMifHyP+KYbvpjbdoFNs+aK7DXlji0Tw=
+github.com/golang/protobuf v1.5.2/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/golang/snappy v0.0.3/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/golang/snappy v0.0.4 h1:yAGX7huGHXlcLOEtBnF4w7FQwA26wojNCwOYAEhLjQM=
 github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
@ -109,6 +123,7 @@ github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-querystring v1.0.0/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
 github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
@ -177,7 +192,6 @@ github.com/moul/http2curl v1.0.0/go.mod h1:8UbvGypXm98wA/IqH45anm5Y2Z6ep6O31QGOA
 github.com/nats-io/nats.go v1.8.1/go.mod h1:BrFz9vVn0fU3AcH9Vn4Kd7W0NpJ651tD5omQ3M8LwxM=
 github.com/nats-io/nkeys v0.0.2/go.mod h1:dab7URMsZm6Z/jp9Z5UGa87Uutgc2mVpXLC4B7TDb/4=
 github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
-github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
 github.com/nxadm/tail v1.4.8 h1:nPr65rt6Y5JFSKQO7qToXr7pePgD6Gwiw05lkbyAQTE=
@ -202,6 +216,7 @@ github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/regen-network/gocuke v0.6.2 h1:pHviZ0kKAq2U2hN2q3smKNxct6hS0mGByFMHGnWA97M=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
 github.com/rogpeppe/go-internal v1.8.1 h1:geMPLpDpQOgVyCg5z5GoRwLHepNdb71NXb67XFkP+Eg=
 github.com/rogpeppe/go-internal v1.8.1/go.mod h1:JeRgkft04UBgHMgCIwADu4Pn6Mtm5d4nPKWu0nJ5d+o=
@ -329,6 +344,7 @@ golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.5.0 h1:OLmvp0KP+FVG99Ct/qFiL/Fhk4zp4QQnZ7b2U+5piUM=
+golang.org/x/text v0.5.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/tools v0.0.0-20180525024113-a5b4c53f6e8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20181030221726-6c7e314b6563/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
@ -360,22 +376,30 @@ google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7
 google.golang.org/genproto v0.0.0-20180518175338-11a468237815/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/genproto v0.0.0-20190819201941-24fa4b261c55/go.mod h1:DMBHOl98Agz4BDEuKkezgsaosCRResVns1a3J2ZsMNc=
+google.golang.org/genproto v0.0.0-20221118155620-16455021b5e6 h1:a2S6M0+660BgMNl++4JPlcAO/CjkqYItDEZwkoDQK7c=
+google.golang.org/genproto v0.0.0-20221118155620-16455021b5e6/go.mod h1:rZS5c/ZVYMaOGBfO68GWtjOw/eLaZM1X6iVtgjZ+EWg=
 google.golang.org/grpc v1.12.0/go.mod h1:yo6s7OP7yaDglbqo1J04qKzAhqBH6lvTonzMVmEdcZw=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
 google.golang.org/grpc v1.23.0/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
 google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQciAY=
 google.golang.org/grpc v1.29.1/go.mod h1:itym6AZVZYACWQqET3MqgPpjcuV5QH3BxFS3IjizoKk=
+google.golang.org/grpc v1.51.0 h1:E1eGv1FTqoLIdnBCZufiSHgKjlqG6fKFf6pPWtMTh8U=
+google.golang.org/grpc v1.51.0/go.mod h1:wgNDFcnuBGmxLKI/qn4T+m5BtEBYXJPvibbUPsAIPww=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
 google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=
 google.golang.org/protobuf v1.20.1-0.20200309200217-e05f789c0967/go.mod h1:A+miEFZTKqfCUM6K7xSMQL9OKL/b6hQv+e19PK+JZNE=
 google.golang.org/protobuf v1.21.0/go.mod h1:47Nbq4nVaFHyn7ilMalzfO3qCViNmqZ2kzikPIcrTAo=
 google.golang.org/protobuf v1.23.0/go.mod h1:EGpADcykh3NcUnDUJcl1+ZksZNG86OlYog2l/sGQquU=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
+google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175w=
+google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
 gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
 gopkg.in/go-playground/assert.v1 v1.2.1/go.mod h1:9RXL0bg/zibRAgZUYszZSwO/z8Y/a8bDuhia5mkpMnE=
@ -389,6 +413,8 @@ gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/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 v3.4.0 h1:ZazjZUfuVeZGLAmlKKuyv3IKP5orXcwtOwDQH6YVr6o=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
+pgregory.net/rapid v0.5.3 h1:163N50IHFqr1phZens4FQOdPgfJscR7a562mjQqeo4M=
 rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4=
--- a/collections/item.go
+++ b/collections/item.go
@ -1,7 +1,9 @@
 package collections

 import (
+	"bytes"
 	"context"
+	"fmt"
 )

 // Item is a type declaration based on Map
@ -17,8 +19,7 @@ func NewItem[V any](
 	name string,
 	valueCodec ValueCodec[V],
 ) Item[V] {
-	item := (Item[V])(newMap[noKey](schema, prefix, name, noKey{}, valueCodec))
-	schema.addCollection(item)
+	item := (Item[V])(NewMap[noKey](schema, prefix, name, noKey{}, valueCodec))
 	return item
 }

@ -55,11 +56,18 @@ func (i Item[V]) Remove(ctx context.Context) error {
 // noKey defines a KeyCodec which decodes nothing.
 type noKey struct{}

-func (noKey) Stringify(_ noKey) string                           { return "no_key" }
-func (noKey) KeyType() string                                    { return "no_key" }
-func (noKey) Size(_ noKey) int                                   { return 0 }
-func (noKey) Encode(_ []byte, _ noKey) (int, error)              { return 0, nil }
-func (noKey) Decode(_ []byte) (int, noKey, error)                { return 0, noKey{}, nil }
+func (noKey) Stringify(_ noKey) string              { return "no_key" }
+func (noKey) KeyType() string                       { return "no_key" }
+func (noKey) Size(_ noKey) int                      { return 0 }
+func (noKey) Encode(_ []byte, _ noKey) (int, error) { return 0, nil }
+func (noKey) Decode(_ []byte) (int, noKey, error)   { return 0, noKey{}, nil }
+func (noKey) EncodeJSON(_ noKey) ([]byte, error)    { return []byte(`"item"`), nil }
+func (noKey) DecodeJSON(b []byte) (noKey, error) {
+	if !bytes.Equal(b, []byte(`"item"`)) {
+		return noKey{}, fmt.Errorf("%w: invalid item json key bytes", ErrEncoding)
+	}
+	return noKey{}, nil
+}
 func (k noKey) EncodeNonTerminal(_ []byte, _ noKey) (int, error) { panic("must not be called") }
 func (k noKey) DecodeNonTerminal(_ []byte) (int, noKey, error)   { panic("must not be called") }
 func (k noKey) SizeNonTerminal(_ noKey) int                      { panic("must not be called") }
--- a/collections/iter.go
+++ b/collections/iter.go
@ -2,9 +2,10 @@ package collections

 import (
 	"context"
-	"cosmossdk.io/core/store"
 	"errors"
 	"fmt"
+
+	"cosmossdk.io/core/store"
 )

 // ErrInvalidIterator is returned when an Iterate call resulted in an invalid iterator.
--- a/collections/keys.go
+++ b/collections/keys.go
@ -3,6 +3,7 @@ package collections
 import (
 	"bytes"
 	"encoding/binary"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"strconv"
@ -37,6 +38,14 @@ func (uint64Key) Decode(buffer []byte) (int, uint64, error) {
 	return 8, binary.BigEndian.Uint64(buffer), nil
 }

+func (uint64Key) EncodeJSON(value uint64) ([]byte, error) {
+	return uint64EncodeJSON(value)
+}
+
+func (uint64Key) DecodeJSON(b []byte) (uint64, error) {
+	return uint64DecodeJSON(b)
+}
+
 func (uint64Key) Size(_ uint64) int { return 8 }

 func (u uint64Key) EncodeNonTerminal(buffer []byte, key uint64) (int, error) {
@ -69,6 +78,16 @@ func (stringKey) Decode(buffer []byte) (int, string, error) {
 	return len(buffer), string(buffer), nil
 }

+func (stringKey) EncodeJSON(value string) ([]byte, error) {
+	return json.Marshal(value)
+}
+
+func (stringKey) DecodeJSON(b []byte) (string, error) {
+	var value string
+	err := json.Unmarshal(b, &value)
+	return value, err
+}
+
 func (stringKey) Size(key string) int {
 	return len(key)
 }
--- a/collections/keys_test.go
+++ b/collections/keys_test.go
@ -7,7 +7,7 @@ import (
 )

 func TestUint64Key(t *testing.T) {
-	t.Run("bijective", func(t *testing.T) {
+	t.Run("correctness", func(t *testing.T) {
 		checkKeyCodec(t, Uint64Key, 55)
 	})

--- a/collections/keyset.go
+++ b/collections/keyset.go
@ -61,6 +61,17 @@ const noValueValueType = "no_value"

 type noValue struct{}

+func (n noValue) EncodeJSON(_ noValue) ([]byte, error) {
+	return nil, nil
+}
+
+func (n noValue) DecodeJSON(b []byte) (noValue, error) {
+	if b != nil {
+		return noValue{}, fmt.Errorf("%w: expected nil json bytes, got: %x", ErrEncoding, b)
+	}
+	return noValue{}, nil
+}
+
 func (noValue) Encode(_ noValue) ([]byte, error) {
 	return []byte{}, nil
 }
--- a/collections/map.go
+++ b/collections/map.go
@ -30,22 +30,15 @@ func NewMap[K, V any](
 	keyCodec KeyCodec[K],
 	valueCodec ValueCodec[V],
 ) Map[K, V] {
-	m := newMap(schemaBuilder, prefix, name, keyCodec, valueCodec)
-	schemaBuilder.addCollection(m)
-	return m
-}
-
-func newMap[K, V any](
-	schemaBuilder *SchemaBuilder, prefix Prefix, name string,
-	keyCodec KeyCodec[K], valueCodec ValueCodec[V],
-) Map[K, V] {
-	return Map[K, V]{
+	m := Map[K, V]{
 		kc:     keyCodec,
 		vc:     valueCodec,
 		sa:     schemaBuilder.schema.storeAccessor,
 		prefix: prefix.Bytes(),
 		name:   name,
 	}
+	schemaBuilder.addCollection(m)
+	return m
 }

 func (m Map[K, V]) getName() string {
--- a/collections/pair.go
+++ b/collections/pair.go
@ -1,6 +1,7 @@
 package collections

 import (
+	"encoding/json"
 	"fmt"
 	"strings"
 )
@ -174,6 +175,41 @@ func (p pairKeyCodec[K1, K2]) SizeNonTerminal(key Pair[K1, K2]) int {
 	return size
 }

+// GENESIS
+
+type jsonPairKey [2]json.RawMessage
+
+func (p pairKeyCodec[K1, K2]) EncodeJSON(v Pair[K1, K2]) ([]byte, error) {
+	k1Json, err := p.keyCodec1.EncodeJSON(v.K1())
+	if err != nil {
+		return nil, err
+	}
+	k2Json, err := p.keyCodec2.EncodeJSON(v.K2())
+	if err != nil {
+		return nil, err
+	}
+	return json.Marshal(jsonPairKey{k1Json, k2Json})
+}
+
+func (p pairKeyCodec[K1, K2]) DecodeJSON(b []byte) (Pair[K1, K2], error) {
+	pairJSON := jsonPairKey{}
+	err := json.Unmarshal(b, &pairJSON)
+	if err != nil {
+		return Pair[K1, K2]{}, err
+	}
+
+	k1, err := p.keyCodec1.DecodeJSON(pairJSON[0])
+	if err != nil {
+		return Pair[K1, K2]{}, err
+	}
+	k2, err := p.keyCodec2.DecodeJSON(pairJSON[1])
+	if err != nil {
+		return Pair[K1, K2]{}, err
+	}
+
+	return Join(k1, k2), nil
+}
+
 // NewPrefixedPairRange creates a new PairRange which will prefix over all the keys
 // starting with the provided prefix.
 func NewPrefixedPairRange[K1, K2 any](prefix K1) *PairRange[K1, K2] {
--- a/collections/pair_test.go
+++ b/collections/pair_test.go
@ -19,6 +19,12 @@ func TestPair(t *testing.T) {
 		s = keyCodec.Stringify(Pair[string, string]{})
 		require.Equal(t, `(<nil>, <nil>)`, s)
 	})
+
+	t.Run("json", func(t *testing.T) {
+		b, err := keyCodec.EncodeJSON(Join("k1", "k2"))
+		require.NoError(t, err)
+		require.Equal(t, []byte(`["k1","k2"]`), b)
+	})
 }

 func TestPairRange(t *testing.T) {
--- a/collections/schema.go
+++ b/collections/schema.go
@ -4,8 +4,11 @@ import (
 	"context"
 	"fmt"
 	"regexp"
+	"sort"
 	"strings"

+	"cosmossdk.io/core/appmodule"
+
 	"cosmossdk.io/core/store"

 	"github.com/hashicorp/go-multierror"
@ -58,9 +61,17 @@ func (s *SchemaBuilder) Build() (Schema, error) {
 		}
 	}

+	// compute ordered collections
+	collectionsOrdered := make([]string, 0, len(s.schema.collectionsByName))
+	for name := range s.schema.collectionsByName {
+		collectionsOrdered = append(collectionsOrdered, name)
+	}
+	sort.Strings(collectionsOrdered)
+	s.schema.collectionsOrdered = collectionsOrdered
+
 	if s.schema == nil {
 		// explicit panic to avoid nil pointer dereference
-		panic("schema is nil")
+		panic("builder already used to construct a schema")
 	}

 	schema := *s.schema
@ -105,6 +116,7 @@ var nameRegex = regexp.MustCompile("^" + NameRegex + "$")
 // clients.
 type Schema struct {
 	storeAccessor       func(context.Context) store.KVStore
+	collectionsOrdered  []string
 	collectionsByPrefix map[string]collection
 	collectionsByName   map[string]collection
 }
@ -138,3 +150,148 @@ func NewSchemaFromAccessor(accessor func(context.Context) store.KVStore) Schema
 		collectionsByPrefix: map[string]collection{},
 	}
 }
+
+func (s Schema) addCollection(collection collection) {
+	prefix := collection.getPrefix()
+	name := collection.getName()
+
+	if _, ok := s.collectionsByPrefix[string(prefix)]; ok {
+		panic(fmt.Errorf("prefix %v already taken within schema", prefix))
+	}
+
+	if _, ok := s.collectionsByName[name]; ok {
+		panic(fmt.Errorf("name %s already taken within schema", name))
+	}
+
+	if !nameRegex.MatchString(name) {
+		panic(fmt.Errorf("name must match regex %s, got %s", NameRegex, name))
+	}
+
+	s.collectionsByPrefix[string(prefix)] = collection
+	s.collectionsByName[name] = collection
+}
+
+// DefaultGenesis implements the appmodule.HasGenesis.DefaultGenesis method.
+func (s Schema) DefaultGenesis(target appmodule.GenesisTarget) error {
+	for _, name := range s.collectionsOrdered {
+		err := s.defaultGenesis(target, name)
+		if err != nil {
+			return fmt.Errorf("failed to instantiate default genesis for %s: %w", name, err)
+		}
+	}
+
+	return nil
+}
+
+func (s Schema) defaultGenesis(target appmodule.GenesisTarget, name string) error {
+	wc, err := target(name)
+	if err != nil {
+		return err
+	}
+	defer wc.Close()
+
+	coll, err := s.getCollection(name)
+	if err != nil {
+		return err
+	}
+
+	return coll.defaultGenesis(wc)
+}
+
+// ValidateGenesis implements the appmodule.HasGenesis.ValidateGenesis method.
+func (s Schema) ValidateGenesis(source appmodule.GenesisSource) error {
+	for _, name := range s.collectionsOrdered {
+		err := s.validateGenesis(source, name)
+		if err != nil {
+			return fmt.Errorf("failed genesis validation of %s: %w", name, err)
+		}
+	}
+	return nil
+}
+
+func (s Schema) validateGenesis(source appmodule.GenesisSource, name string) error {
+	rc, err := source(name)
+	if err != nil {
+		return err
+	}
+	defer rc.Close()
+
+	coll, err := s.getCollection(name)
+	if err != nil {
+		return err
+	}
+
+	err = coll.validateGenesis(rc)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// InitGenesis implements the appmodule.HasGenesis.InitGenesis method.
+func (s Schema) InitGenesis(ctx context.Context, source appmodule.GenesisSource) error {
+	for _, name := range s.collectionsOrdered {
+		err := s.initGenesis(ctx, source, name)
+		if err != nil {
+			return fmt.Errorf("failed genesis initialisation of %s: %w", name, err)
+		}
+	}
+
+	return nil
+}
+
+func (s Schema) initGenesis(ctx context.Context, source appmodule.GenesisSource, name string) error {
+	rc, err := source(name)
+	if err != nil {
+		return err
+	}
+	defer rc.Close()
+
+	coll, err := s.getCollection(name)
+	if err != nil {
+		return err
+	}
+
+	err = coll.importGenesis(ctx, rc)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// ExportGenesis implements the appmodule.HasGenesis.ExportGenesis method.
+func (s Schema) ExportGenesis(ctx context.Context, target appmodule.GenesisTarget) error {
+	for _, name := range s.collectionsOrdered {
+		err := s.exportGenesis(ctx, target, name)
+		if err != nil {
+			return fmt.Errorf("failed to export genesis for %s: %w", name, err)
+		}
+	}
+
+	return nil
+}
+
+func (s Schema) exportGenesis(ctx context.Context, target appmodule.GenesisTarget, name string) error {
+	wc, err := target(name)
+	if err != nil {
+		return err
+	}
+	defer wc.Close()
+
+	coll, err := s.getCollection(name)
+	if err != nil {
+		return err
+	}
+
+	return coll.exportGenesis(ctx, wc)
+}
+
+func (s Schema) getCollection(name string) (collection, error) {
+	coll, ok := s.collectionsByName[name]
+	if !ok {
+		return nil, fmt.Errorf("unknown collection: %s", name)
+	}
+	return coll, nil
+}
--- a/collections/values.go
+++ b/collections/values.go
@ -2,10 +2,18 @@ package collections

 import (
 	"encoding/binary"
+	"encoding/json"
 	"fmt"
+	"strconv"
 )

-var Uint64Value ValueCodec[uint64] = uint64Value{}
+var (
+	// Uint64Value implements a ValueCodec for uint64. It converts the uint64 to big endian bytes.
+	// The JSON representation is the string format of uint64.
+	Uint64Value ValueCodec[uint64] = uint64Value{}
+	// StringValue implements a ValueCodec for string.
+	StringValue ValueCodec[string] = stringValue{}
+)

 type uint64Value struct{}

@ -27,3 +35,56 @@ func (u uint64Value) Stringify(value uint64) string {
 func (u uint64Value) ValueType() string {
 	return Uint64Key.KeyType()
 }
+
+func (u uint64Value) EncodeJSON(value uint64) ([]byte, error) {
+	return uint64EncodeJSON(value)
+}
+
+func (u uint64Value) DecodeJSON(b []byte) (uint64, error) {
+	return uint64DecodeJSON(b)
+}
+
+func uint64EncodeJSON(value uint64) ([]byte, error) {
+	str := `"` + strconv.FormatUint(value, 10) + `"`
+	return []byte(str), nil
+}
+
+func uint64DecodeJSON(b []byte) (uint64, error) {
+	var str string
+	err := json.Unmarshal(b, &str)
+	if err != nil {
+		return 0, err
+	}
+	return strconv.ParseUint(str, 10, 64)
+}
+
+type stringValue struct{}
+
+func (stringValue) Encode(value string) ([]byte, error) {
+	return []byte(value), nil
+}
+
+func (stringValue) Decode(b []byte) (string, error) {
+	return string(b), nil
+}
+
+func (stringValue) EncodeJSON(value string) ([]byte, error) {
+	return json.Marshal(value)
+}
+
+func (stringValue) DecodeJSON(b []byte) (string, error) {
+	var s string
+	err := json.Unmarshal(b, &s)
+	if err != nil {
+		return "", err
+	}
+	return s, nil
+}
+
+func (stringValue) Stringify(value string) string {
+	return value
+}
+
+func (stringValue) ValueType() string {
+	return "string"
+}
--- a/collections/values_test.go
+++ b/collections/values_test.go
@ -16,3 +16,13 @@ func TestUint64Value(t *testing.T) {
 		require.ErrorIs(t, err, ErrEncoding)
 	})
 }
+
+func TestUInt64JSON(t *testing.T) {
+	var x uint64 = 3076
+	bz, err := uint64EncodeJSON(x)
+	require.NoError(t, err)
+	require.Equal(t, []byte(`"3076"`), bz)
+	y, err := uint64DecodeJSON(bz)
+	require.NoError(t, err)
+	require.Equal(t, x, y)
+}