diff --git a/compactor2/src/test_util.rs b/compactor2/src/test_util.rs
index 5f147b9be8..15c8252d69 100644
--- a/compactor2/src/test_util.rs
+++ b/compactor2/src/test_util.rs
@@ -10,6 +10,7 @@ use data_types::{
     ColumnId, ColumnSchema, ColumnSet, ColumnType, CompactionLevel, Namespace, NamespaceId,
     NamespaceSchema, ParquetFile, ParquetFileId, Partition, PartitionId, PartitionKey, QueryPoolId,
     SequenceNumber, ShardId, SkippedCompaction, Table, TableId, TableSchema, Timestamp, TopicId,
+    TRANSITION_SHARD_NUMBER,
 };
 use datafusion::arrow::record_batch::RecordBatch;
 use futures::TryStreamExt;
@@ -259,7 +260,7 @@ impl SkippedCompactionBuilder {
     }
 }
 
-const SHARD_INDEX: i32 = 1234;
+const SHARD_INDEX: i32 = TRANSITION_SHARD_NUMBER;
 const PARTITION_THRESHOLD: Duration = Duration::from_secs(10 * 60); // 10min
 const MAX_DESIRE_FILE_SIZE: u64 = 100 * 1024;
 const PERCENTAGE_MAX_FILE_SIZE: u16 = 5;
diff --git a/data_types/src/lib.rs b/data_types/src/lib.rs
index 836e748c3b..59cfde3261 100644
--- a/data_types/src/lib.rs
+++ b/data_types/src/lib.rs
@@ -37,6 +37,13 @@ use std::{
 };
 use uuid::Uuid;
 
+/// Magic number to be used shard indices and shard ids in "kafkaless".
+pub const TRANSITION_SHARD_NUMBER: i32 = 1234;
+/// In kafkaless mode all new persisted data uses this shard id.
+pub const TRANSITION_SHARD_ID: ShardId = ShardId::new(TRANSITION_SHARD_NUMBER as i64);
+/// In kafkaless mode all new persisted data uses this shard index.
+pub const TRANSITION_SHARD_INDEX: ShardIndex = ShardIndex::new(TRANSITION_SHARD_NUMBER);
+
 /// Compaction levels
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Hash, sqlx::Type)]
 #[repr(i16)]
diff --git a/ingest_replica/src/lib.rs b/ingest_replica/src/lib.rs
index 8103157c63..090b993771 100644
--- a/ingest_replica/src/lib.rs
+++ b/ingest_replica/src/lib.rs
@@ -31,7 +31,7 @@ use crate::{buffer::Buffer, cache::SchemaCache, grpc::GrpcDelegate};
 use arrow_flight::flight_service_server::{FlightService, FlightServiceServer};
 use async_trait::async_trait;
 use data_types::sequence_number_set::SequenceNumberSet;
-use data_types::{NamespaceId, PartitionId, SequenceNumber, ShardIndex, TableId};
+use data_types::{NamespaceId, PartitionId, SequenceNumber, TableId, TRANSITION_SHARD_INDEX};
 use generated_types::influxdata::iox::ingester::v1::replication_service_server::{
     ReplicationService, ReplicationServiceServer,
 };
@@ -51,11 +51,6 @@ pub enum BufferError {
     MutableBatch(#[from] mutable_batch::Error),
 }
 
-/// During the testing of ingest replica, the catalog will require a ShardIndex for
-/// various operations. This is a const value for these occasions. Look up the ShardId for this
-/// ShardIndex when needed.
-const TRANSITION_SHARD_INDEX: ShardIndex = ShardIndex::new(1234);
-
 /// Acquire opaque handles to the IngestReplica RPC service implementations.
 ///
 /// This trait serves as the public crate API boundary - callers external to the
diff --git a/ingester2/src/lib.rs b/ingester2/src/lib.rs
index b4d45d5958..36b736f0a8 100644
--- a/ingester2/src/lib.rs
+++ b/ingester2/src/lib.rs
@@ -44,7 +44,7 @@
     missing_docs
 )]
 
-use data_types::ShardIndex;
+use data_types::TRANSITION_SHARD_INDEX;
 
 /// A macro to conditionally prepend `pub` to the inner tokens for benchmarking
 /// purposes, should the `benches` feature be enabled.
@@ -71,11 +71,6 @@ macro_rules! maybe_pub {
     };
 }
 
-/// During the testing of ingester2, the catalog will require a ShardIndex for
-/// various operations. This is a const value for these occasions. Look up the ShardId for this
-/// ShardIndex when needed.
-const TRANSITION_SHARD_INDEX: ShardIndex = ShardIndex::new(1234);
-
 /// Ingester initialisation methods & types.
 ///
 /// This module defines the public API boundary of the Ingester crate.
diff --git a/ioxd_compactor2/src/lib.rs b/ioxd_compactor2/src/lib.rs
index cbe05ba171..b1317c07f0 100644
--- a/ioxd_compactor2/src/lib.rs
+++ b/ioxd_compactor2/src/lib.rs
@@ -2,7 +2,7 @@ use async_trait::async_trait;
 use backoff::BackoffConfig;
 use clap_blocks::compactor2::Compactor2Config;
 use compactor2::{compactor::Compactor2, config::Config};
-use data_types::PartitionId;
+use data_types::{PartitionId, TRANSITION_SHARD_NUMBER};
 use hyper::{Body, Request, Response};
 use iox_catalog::interface::Catalog;
 use iox_query::exec::Executor;
@@ -27,7 +27,7 @@ use trace::TraceCollector;
 
 // There is only one shard with index 1
 const TOPIC: &str = "iox-shared";
-const TRANSITION_SHARD_INDEX: i32 = 1234; // see ingester2 crate
+const TRANSITION_SHARD_INDEX: i32 = TRANSITION_SHARD_NUMBER;
 
 pub struct Compactor2ServerType {
     compactor: Compactor2,