{source-materialize}-postgres: support JSONB

go.mod

@@ -39,7 +39,7 @@ require (
 	github.com/dropbox/dropbox-sdk-go-unofficial/v6 v6.0.5
 	github.com/duckdb/duckdb-go/v2 v2.10502.0
 	github.com/elastic/go-elasticsearch/v8 v8.9.0
-	github.com/estuary/flow v0.6.4
+	github.com/estuary/flow v0.6.9
 	github.com/estuary/vitess v0.15.10
 	github.com/evanphx/json-patch/v5 v5.9.11
 	github.com/go-mysql-org/go-mysql v0.0.0-20250907131429-558ed11751bc
@@ -76,7 +76,7 @@ require (
 	github.com/tidwall/gjson v1.17.3
 	github.com/tidwall/sjson v1.2.5
 	github.com/wk8/go-ordered-map/v2 v2.1.8
-	go.gazette.dev/core v0.102.0
+	go.gazette.dev/core v0.103.1-0.20260505142537-ce718ada37ee
 	go.mongodb.org/mongo-driver v1.17.4
 	golang.org/x/crypto v0.49.0
 	golang.org/x/exp v0.0.0-20260312153236-7ab1446f8b90

go.sum

@@ -409,8 +409,12 @@ github.com/envoyproxy/go-control-plane/ratelimit v0.1.0/go.mod h1:Wk+tMFAFbCXaJP
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/envoyproxy/protoc-gen-validate v1.3.0 h1:TvGH1wof4H33rezVKWSpqKz5NXWg5VPuZ0uONDT6eb4=
 github.com/envoyproxy/protoc-gen-validate v1.3.0/go.mod h1:HvYl7zwPa5mffgyeTUHA9zHIH36nmrm7oCbo4YKoSWA=
-github.com/estuary/flow v0.6.4 h1:MpermXN5h1U85zJspZftGSC7XbdTUWv22/FM/tvofSc=
-github.com/estuary/flow v0.6.4/go.mod h1:xihzOEpeEzcLTsgU2LFvjLs0f5UvbTeAQGnwno6ondk=
+github.com/estuary/flow v0.6.8 h1:HK9zYKV2HvF6jPI8eSDGdLy4nVUW2FWB+CA37PyuPLI=
+github.com/estuary/flow v0.6.8/go.mod h1:SYiOTbPZ0ZlCh8qNVARPMjRF6/aVWY7xQuHFK9BSELk=
+github.com/estuary/flow v0.6.9-0.20260520113844-a3d8595811ed h1:+pm+QyY8+bhC2gxJdRa735NX+QawxO0Piuv5c1CUj0w=
+github.com/estuary/flow v0.6.9-0.20260520113844-a3d8595811ed/go.mod h1:jdQeVWS9sw520EU2u9UPYryE5iEo1Gu9Ju99LXJ8r7Y=
+github.com/estuary/flow v0.6.9 h1:1cGdwmlB4UxNhRnvujTDGwmx1ABvBS9iqWYIIStRaRI=
+github.com/estuary/flow v0.6.9/go.mod h1:jdQeVWS9sw520EU2u9UPYryE5iEo1Gu9Ju99LXJ8r7Y=
 github.com/estuary/go-mysql v0.0.0-20250918155720-90d473fd1a3e h1:stJOXFppEkEksGtqpJjIIfufID+RUkrkMCFKgu4Vfaw=
 github.com/estuary/go-mysql v0.0.0-20250918155720-90d473fd1a3e/go.mod h1:FQxw17uRbFvMZFK+dPtIPufbU46nBdrGaxOw0ac9MFs=
 github.com/estuary/vitess v0.15.10 h1:oXJgcG0HGZWuwjdvSp4pIFIAXtKLaR9Fl9VBynSszFA=
@@ -1109,8 +1113,8 @@ go.etcd.io/etcd/client/pkg/v3 v3.6.5 h1:Duz9fAzIZFhYWgRjp/FgNq2gO1jId9Yae/rLn3Rr
 go.etcd.io/etcd/client/pkg/v3 v3.6.5/go.mod h1:8Wx3eGRPiy0qOFMZT/hfvdos+DjEaPxdIDiCDUv/FQk=
 go.etcd.io/etcd/client/v3 v3.6.5 h1:yRwZNFBx/35VKHTcLDeO7XVLbCBFbPi+XV4OC3QJf2U=
 go.etcd.io/etcd/client/v3 v3.6.5/go.mod h1:ZqwG/7TAFZ0BJ0jXRPoJjKQJtbFo/9NIY8uoFFKcCyo=
-go.gazette.dev/core v0.102.0 h1:S1FFQn4Ws4qThrnwQhZ75jghg++Tfev++fPdq6PVlGw=
-go.gazette.dev/core v0.102.0/go.mod h1:4qMw9JDecqIx6EijHy6ndbueTYeglm6LW4qKxEUOZ8M=
+go.gazette.dev/core v0.103.1-0.20260505142537-ce718ada37ee h1:yceN2m1184/i4YSN4tlfMSdpnV+xnePgnUf4KFa00oE=
+go.gazette.dev/core v0.103.1-0.20260505142537-ce718ada37ee/go.mod h1:4qMw9JDecqIx6EijHy6ndbueTYeglm6LW4qKxEUOZ8M=
 go.mongodb.org/mongo-driver v1.11.4/go.mod h1:PTSz5yu21bkT/wXpkS7WR5f0ddqw5quethTUn9WM+2g=
 go.mongodb.org/mongo-driver v1.17.4 h1:jUorfmVzljjr0FLzYQsGP8cgN/qzzxlY9Vh0C9KFXVw=
 go.mongodb.org/mongo-driver v1.17.4/go.mod h1:Hy04i7O2kC4RS06ZrhPRqj/u4DTYkFDAAccj+rVKqgQ=

materialize-postgres/.snapshots/TestSQLGeneration

@@ -344,4 +344,20 @@ BEGIN
 END $$;
 --- End Fence Update ---
 
+--- Begin createTargetTable [jsonb contentMediaType] ---
+
+CREATE TABLE IF NOT EXISTS "public".jsonb_round_trip (
+		id BIGINT NOT NULL,
+		plain_json JSON,
+		jsonb_col JSONB,
+
+		PRIMARY KEY (id)
+);
+
+COMMENT ON TABLE "public".jsonb_round_trip IS 'Generated for materialize-postgres jsonb round-trip test';
+COMMENT ON COLUMN "public".jsonb_round_trip.id IS '';
+COMMENT ON COLUMN "public".jsonb_round_trip.plain_json IS '';
+COMMENT ON COLUMN "public".jsonb_round_trip.jsonb_col IS '';
+--- End createTargetTable [jsonb contentMediaType] ---
+
 

materialize-postgres/sqlgen.go

@@ -34,18 +34,36 @@ func createPgDialect(featureFlags map[string]bool) sql.Dialect {
 		binaryMapping = sql.MapStatic("BYTEA", sql.UsingConverter(sql.Base64Decoder))
 	}
 
+	// Fields originating from a PostgreSQL JSONB column carry this
+	// (non-standard, vendor-tree) contentMediaType so they can be recreated
+	// as JSONB at the destination instead of collapsing onto JSON. Anything
+	// without the annotation defaults to JSON, preserving the historical
+	// behavior for existing materializations and non-Postgres sources.
+	jsonbContentMediaType := "application/vnd.estuary.postgresql.jsonb+json"
+	jsonOrJsonb := func(jsonMapper, jsonbMapper sql.MapProjectionFn) sql.MapProjectionFn {
+		return func(p *sql.Projection) (sql.DDLer, sql.CompatibleColumnTypes, sql.ElementConverter) {
+			if p.Inference.ContentMediaType == jsonbContentMediaType {
+				return jsonbMapper(p)
+			}
+			return jsonMapper(p)
+		}
+	}
+
 	mapper := sql.NewDDLMapper(
 		sql.FlatTypeMappings{
 			sql.INTEGER: sql.MapSignedInt64(
 				sql.MapStatic("BIGINT", sql.AlsoCompatibleWith("integer")),
 				sql.MapStatic("NUMERIC"),
 			),
-			sql.NUMBER:         sql.MapStatic("DOUBLE PRECISION"),
-			sql.BOOLEAN:        sql.MapStatic("BOOLEAN"),
-			sql.OBJECT:         sql.MapStatic("JSON"),
-			sql.ARRAY:          sql.MapStatic("JSON"),
-			sql.BINARY:         binaryMapping,
-			sql.MULTIPLE:       sql.MapStatic("JSON", sql.UsingConverter(sql.ToJsonBytes)),
+			sql.NUMBER:  sql.MapStatic("DOUBLE PRECISION"),
+			sql.BOOLEAN: sql.MapStatic("BOOLEAN"),
+			sql.OBJECT:  jsonOrJsonb(sql.MapStatic("JSON"), sql.MapStatic("JSONB")),
+			sql.ARRAY:   jsonOrJsonb(sql.MapStatic("JSON"), sql.MapStatic("JSONB")),
+			sql.BINARY:  binaryMapping,
+			sql.MULTIPLE: jsonOrJsonb(
+				sql.MapStatic("JSON", sql.UsingConverter(sql.ToJsonBytes)),
+				sql.MapStatic("JSONB", sql.UsingConverter(sql.ToJsonBytes)),
+			),
 			sql.STRING_INTEGER: sql.MapStatic("NUMERIC"),
 			sql.STRING_NUMBER:  sql.MapStatic("DECIMAL", sql.AlsoCompatibleWith("numeric")),
 			sql.STRING: sql.MapString(sql.StringMappings{
@@ -80,7 +98,12 @@ func createPgDialect(featureFlags map[string]bool) sql.Dialect {
 			"text":                     {sql.NewMigrationSpec([]string{"bytea"}, sql.WithCastSQL(stringToByteaCast))},
 			"character varying":        {sql.NewMigrationSpec([]string{"bytea"}, sql.WithCastSQL(stringToByteaCast))},
 			"bytea":                    {sql.NewMigrationSpec([]string{"text"}, sql.WithCastSQL(byteaToStringCast))},
-			"*":                        {sql.NewMigrationSpec([]string{"json"}, sql.WithCastSQL(toJsonCast))},
+			// PostgreSQL accepts implicit casts in both directions between
+			// json and jsonb, so columns can move freely as the upstream
+			// source type annotation flips.
+			"json":  {sql.NewMigrationSpec([]string{"jsonb"})},
+			"jsonb": {sql.NewMigrationSpec([]string{"json"})},
+			"*":     {sql.NewMigrationSpec([]string{"json", "jsonb"}, sql.WithCastSQL(toJsonCast))},
 		},
 		TableLocatorer: sql.TableLocatorFn(func(path []string) sql.InfoTableLocation {
 			if len(path) == 1 {

materialize-postgres/sqlgen_test.go

@@ -41,9 +41,80 @@ func TestSQLGeneration(t *testing.T) {
 		},
 	)
 
+	// Exercise the source-postgres -> materialize-postgres JSONB round-trip:
+	// a value field carrying the application/vnd.postgresql.jsonb+json
+	// contentMediaType must render as JSONB, while a sibling field without
+	// the annotation stays on JSON.
+	jsonbTable := buildJSONBTestTable(t)
+	jsonbName := "createTargetTable [jsonb contentMediaType]"
+	snap.WriteString("--- Begin " + jsonbName + " ---\n")
+	require.NoError(t, testTemplates.createTargetTable.Execute(snap, &jsonbTable))
+	snap.WriteString("--- End " + jsonbName + " ---\n\n")
+
 	cupaloy.SnapshotT(t, snap.String())
 }
 
+// buildJSONBTestTable assembles a synthetic Table with two value projections:
+// one carrying the jsonb contentMediaType so it should map to JSONB, and one
+// without so it should default to JSON.
+func buildJSONBTestTable(t *testing.T) sql.Table {
+	t.Helper()
+
+	const jsonbMediaType = "application/vnd.estuary.postgresql.jsonb+json"
+	multipleTypes := []string{"object", "string", "array", "number", "boolean", "null"}
+
+	mkValue := func(field, contentType string) sql.Column {
+		p := sql.Projection{
+			Projection: pf.Projection{
+				Field: field,
+				Ptr:   "/" + field,
+				Inference: pf.Inference{
+					Types:            multipleTypes,
+					ContentMediaType: contentType,
+					Exists:           pf.Inference_MAY,
+				},
+			},
+		}
+		return sql.Column{
+			Projection: p,
+			MappedType: testDialect.MapType(&p, sql.FieldConfig{}),
+			Identifier: testDialect.Identifier(field),
+		}
+	}
+
+	keyProj := sql.Projection{
+		Projection: pf.Projection{
+			Field:        "id",
+			Ptr:          "/id",
+			IsPrimaryKey: true,
+			Inference: pf.Inference{
+				Types:  []string{"integer"},
+				Exists: pf.Inference_MUST,
+			},
+		},
+	}
+	keyCol := sql.Column{
+		Projection: keyProj,
+		MappedType: testDialect.MapType(&keyProj, sql.FieldConfig{}),
+		Identifier: testDialect.Identifier("id"),
+		MustExist:  true,
+	}
+
+	tableName := "jsonb_round_trip"
+	return sql.Table{
+		TableShape: sql.TableShape{
+			Path:    []string{"public", tableName},
+			Comment: "Generated for materialize-postgres jsonb round-trip test",
+		},
+		Identifier: testDialect.Identifier("public", tableName),
+		Keys:       []sql.Column{keyCol},
+		Values: []sql.Column{
+			mkValue("plain_json", ""),
+			mkValue("jsonb_col", jsonbMediaType),
+		},
+	}
+}
+
 func TestDateTimeColumn(t *testing.T) {
 
 	var mapped = testDialect.MapType(&sql.Projection{
@@ -62,6 +133,35 @@ func TestDateTimeColumn(t *testing.T) {
 	require.NoError(t, err)
 }
 
+func TestJSONBContentMediaType(t *testing.T) {
+	jsonbMediaType := "application/vnd.estuary.postgresql.jsonb+json"
+
+	mapWithMediaType := func(types []string, contentType string) string {
+		return testDialect.MapType(&sql.Projection{
+			Projection: pf.Projection{
+				Inference: pf.Inference{
+					Types:            types,
+					ContentMediaType: contentType,
+					Exists:           pf.Inference_MUST,
+				},
+			},
+		}, sql.FieldConfig{}).DDL
+	}
+
+	require.Equal(t,
+		"JSONB NOT NULL",
+		mapWithMediaType([]string{"object", "string", "array", "number", "boolean"}, jsonbMediaType),
+		"MULTIPLE-typed field with jsonb contentMediaType should map to JSONB")
+	require.Equal(t,
+		"JSON NOT NULL",
+		mapWithMediaType([]string{"object", "string", "array", "number", "boolean"}, "application/json"),
+		"MULTIPLE-typed field with application/json contentMediaType should map to JSON")
+	require.Equal(t,
+		"JSON NOT NULL",
+		mapWithMediaType([]string{"object", "string", "array", "number", "boolean"}, ""),
+		"MULTIPLE-typed field without contentMediaType should default to JSON")
+}
+
 func TestTruncatedIdentifier(t *testing.T) {
 	tests := []struct {
 		name  string

source-postgres/.snapshots/TestDiscoveryComplex

@@ -36,10 +36,12 @@ sql> COMMENT ON COLUMN test.discoverycomplex_934635.k1 IS 'I think this is a key
             ]
           },
           "doc": {
-            "description": "(source type: json)"
+            "description": "(source type: json)",
+            "contentMediaType": "application/json"
           },
           "doc/bin": {
-            "description": "(source type: non-nullable jsonb)"
+            "description": "(source type: non-nullable jsonb)",
+            "contentMediaType": "application/vnd.estuary.postgresql.jsonb+json"
           },
           "foo": {
             "description": "This is a text field! (source type: text)",

source-postgres/discovery.go

@@ -267,10 +267,11 @@ func (db *postgresDatabase) TranslateDBToJSONType(column sqlcapture.ColumnInfo,
 }
 
 type columnSchema struct {
-	contentEncoding string
-	format          string
-	nullable        bool
-	jsonTypes       []string
+	contentEncoding  string
+	contentMediaType string
+	format           string
+	nullable         bool
+	jsonTypes        []string
 }
 
 func (s columnSchema) toType() *jsonschema.Schema {
@@ -283,6 +284,10 @@ func (s columnSchema) toType() *jsonschema.Schema {
 		out.Extras["contentEncoding"] = s.contentEncoding // New in 2019-09.
 	}
 
+	if s.contentMediaType != "" {
+		out.Extras["contentMediaType"] = s.contentMediaType // New in 2019-09.
+	}
+
 	if s.jsonTypes != nil {
 		var types = append([]string(nil), s.jsonTypes...)
 		if s.nullable {
@@ -338,8 +343,12 @@ var postgresTypeToJSON = map[string]columnSchema{
 	"bit":     {jsonTypes: []string{"string"}},
 	"varbit":  {jsonTypes: []string{"string"}},
 
-	"json":     {},
-	"jsonb":    {},
+	// json and jsonb columns capture arbitrary JSON values, so we don't constrain
+	// the JSON Schema type. The contentMediaType annotation distinguishes the two
+	// at the wire so downstream connectors (e.g. materialize-postgres) can
+	// recreate the original column type instead of collapsing both onto json.
+	"json":     {contentMediaType: "application/json"},
+	"jsonb":    {contentMediaType: "application/vnd.estuary.postgresql.jsonb+json"},
 	"jsonpath": {jsonTypes: []string{"string"}},
 
 	// Domain-Specific Types