diff --git a/controlplane/control.go b/controlplane/control.go
index 71d4a3d4..baf7c563 100644
--- a/controlplane/control.go
+++ b/controlplane/control.go
@@ -23,6 +23,7 @@ import (
 	"github.com/cloudflare/tableflip"
 	"github.com/posthog/duckgres/controlplane/configstore"
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"github.com/posthog/duckgres/server/flightsqlingress"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
@@ -630,8 +631,8 @@ func createSessionWithRegisteredCancel(
 	srv *server.Server,
 	timeout time.Duration,
 	key server.BackendKey,
-	createFn func(context.Context) (int32, *server.FlightExecutor, error),
-) (int32, *server.FlightExecutor, error) {
+	createFn func(context.Context) (int32, *flightclient.FlightExecutor, error),
+) (int32, *flightclient.FlightExecutor, error) {
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
 
@@ -982,7 +983,7 @@ func (cp *ControlPlane) handleConnection(conn net.Conn) {
 		cp.srv,
 		cp.cfg.WorkerQueueTimeout,
 		server.BackendKey{Pid: pid, SecretKey: secretKey},
-		func(ctx context.Context) (int32, *server.FlightExecutor, error) {
+		func(ctx context.Context) (int32, *flightclient.FlightExecutor, error) {
 			return sessions.CreateSession(ctx, username, pid, memLimit, threads)
 		},
 	)
diff --git a/controlplane/control_cancel_test.go b/controlplane/control_cancel_test.go
index 5c507aa7..2809bbfb 100644
--- a/controlplane/control_cancel_test.go
+++ b/controlplane/control_cancel_test.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 )
 
 func TestCreateSessionWithRegisteredCancel_CancelQueryCancelsWait(t *testing.T) {
@@ -24,7 +25,7 @@ func TestCreateSessionWithRegisteredCancel_CancelQueryCancelsWait(t *testing.T)
 			srv,
 			200*time.Millisecond,
 			key,
-			func(ctx context.Context) (int32, *server.FlightExecutor, error) {
+			func(ctx context.Context) (int32, *flightclient.FlightExecutor, error) {
 				close(started)
 				<-ctx.Done()
 				return 0, nil, ctx.Err()
diff --git a/controlplane/flight_ingress.go b/controlplane/flight_ingress.go
index 9c444b97..12216399 100644
--- a/controlplane/flight_ingress.go
+++ b/controlplane/flight_ingress.go
@@ -12,6 +12,7 @@ import (
 
 	"github.com/posthog/duckgres/controlplane/configstore"
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"github.com/posthog/duckgres/server/flightsqlingress"
 )
 
@@ -45,7 +46,7 @@ type flightSessionProvider struct {
 	sm *SessionManager
 }
 
-func (p *flightSessionProvider) CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *server.FlightExecutor, error) {
+func (p *flightSessionProvider) CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *flightclient.FlightExecutor, error) {
 	workerPID, executor, err := p.sm.CreateSession(ctx, username, pid, memoryLimit, threads)
 	if err != nil {
 		return 0, nil, err
@@ -74,7 +75,7 @@ type orgRoutedSessionProvider struct {
 	userOrg    map[string]string            // username → orgID (populated during auth)
 }
 
-func (p *orgRoutedSessionProvider) CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *server.FlightExecutor, error) {
+func (p *orgRoutedSessionProvider) CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *flightclient.FlightExecutor, error) {
 	p.mu.RLock()
 	orgID := p.userOrg[username]
 	p.mu.RUnlock()
@@ -141,7 +142,7 @@ func (p *orgRoutedSessionProvider) DurableSessionMetadata(pid int32, username st
 	}, nil
 }
 
-func (p *orgRoutedSessionProvider) ReconnectSession(ctx context.Context, record flightsqlingress.DurableSessionRecord) (int32, *server.FlightExecutor, error) {
+func (p *orgRoutedSessionProvider) ReconnectSession(ctx context.Context, record flightsqlingress.DurableSessionRecord) (int32, *flightclient.FlightExecutor, error) {
 	_, sessions, _, ok := p.orgRouter.StackForOrg(record.OrgID)
 	if !ok {
 		return 0, nil, fmt.Errorf("no org stack for org %q", record.OrgID)
diff --git a/controlplane/k8s_pool.go b/controlplane/k8s_pool.go
index 97af46d1..29b7ea7b 100644
--- a/controlplane/k8s_pool.go
+++ b/controlplane/k8s_pool.go
@@ -21,6 +21,7 @@ import (
 	"github.com/apache/arrow-go/v18/arrow/flight/flightsql"
 	"github.com/posthog/duckgres/controlplane/configstore"
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
 	corev1 "k8s.io/api/core/v1"
@@ -932,8 +933,8 @@ func waitForWorkerTCPWithMetadata(addr, bearerToken string, serverCertPEM []byte
 		var dialOpts []grpc.DialOption
 		dialOpts = append(dialOpts, grpc.WithTransportCredentials(credentials.NewTLS(tlsConfig)))
 		dialOpts = append(dialOpts, grpc.WithDefaultCallOptions(
-			grpc.MaxCallRecvMsgSize(server.MaxGRPCMessageSize),
-			grpc.MaxCallSendMsgSize(server.MaxGRPCMessageSize),
+			grpc.MaxCallRecvMsgSize(flightclient.MaxGRPCMessageSize),
+			grpc.MaxCallSendMsgSize(flightclient.MaxGRPCMessageSize),
 		))
 		dialOpts = append(dialOpts, server.OTELGRPCClientHandler())
 		if bearerToken != "" {
@@ -1640,8 +1641,8 @@ func (p *K8sWorkerPool) connectWorkerDirect(ctx context.Context, podName, podIP,
 	var dialOpts []grpc.DialOption
 	dialOpts = append(dialOpts, grpc.WithTransportCredentials(credentials.NewTLS(tlsConfig)))
 	dialOpts = append(dialOpts, grpc.WithDefaultCallOptions(
-		grpc.MaxCallRecvMsgSize(server.MaxGRPCMessageSize),
-		grpc.MaxCallSendMsgSize(server.MaxGRPCMessageSize),
+		grpc.MaxCallRecvMsgSize(flightclient.MaxGRPCMessageSize),
+		grpc.MaxCallSendMsgSize(flightclient.MaxGRPCMessageSize),
 	))
 	dialOpts = append(dialOpts, server.OTELGRPCClientHandler())
 	if bearerToken != "" {
diff --git a/controlplane/session_mgr.go b/controlplane/session_mgr.go
index c8c659d5..0f06ab10 100644
--- a/controlplane/session_mgr.go
+++ b/controlplane/session_mgr.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 )
 
 // SessionProgress holds cached query progress from a worker health check.
@@ -26,7 +27,7 @@ type ManagedSession struct {
 	WorkerID     int
 	Protocol     string // "postgres" or "flight"
 	SessionToken string
-	Executor     *server.FlightExecutor
+	Executor     *flightclient.FlightExecutor
 	connCloser   io.Closer // TCP connection, closed on worker crash to unblock the message loop
 
 	// Cached query progress from worker health checks.
@@ -68,7 +69,7 @@ func (sm *SessionManager) ReservePID() int32 {
 // CreateSession acquires a worker (reusing an idle one or spawning a new one),
 // creates a session on it, and rebalances memory/thread limits across all active sessions.
 // If pid is 0, a new one is generated.
-func (sm *SessionManager) CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *server.FlightExecutor, error) {
+func (sm *SessionManager) CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *flightclient.FlightExecutor, error) {
 	memoryLimit, threads = sm.resolveSessionLimits(memoryLimit, threads)
 
 	// Acquire a worker: reuses idle pre-warmed workers or spawns a new one.
@@ -102,7 +103,7 @@ func (sm *SessionManager) resolveSessionLimits(memoryLimit string, threads int)
 	return memoryLimit, threads
 }
 
-func (sm *SessionManager) ReconnectFlightSession(ctx context.Context, username string, workerID int, ownerEpoch int64) (int32, *server.FlightExecutor, error) {
+func (sm *SessionManager) ReconnectFlightSession(ctx context.Context, username string, workerID int, ownerEpoch int64) (int32, *flightclient.FlightExecutor, error) {
 	reconnector, ok := sm.pool.(flightReconnectPool)
 	if !ok {
 		return 0, nil, fmt.Errorf("worker pool does not support flight reconnect")
@@ -114,7 +115,7 @@ func (sm *SessionManager) ReconnectFlightSession(ctx context.Context, username s
 	return sm.createSessionOnWorker(ctx, username, 0, "", 0, worker, "flight", false)
 }
 
-func (sm *SessionManager) createSessionOnWorker(ctx context.Context, username string, pid int32, memoryLimit string, threads int, worker *ManagedWorker, protocol string, retireOnFailure bool) (int32, *server.FlightExecutor, error) {
+func (sm *SessionManager) createSessionOnWorker(ctx context.Context, username string, pid int32, memoryLimit string, threads int, worker *ManagedWorker, protocol string, retireOnFailure bool) (int32, *flightclient.FlightExecutor, error) {
 	createStart := time.Now()
 	sessionToken, err := worker.CreateSession(ctx, username, memoryLimit, threads)
 	if err != nil {
@@ -124,7 +125,7 @@ func (sm *SessionManager) createSessionOnWorker(ctx context.Context, username st
 		return 0, nil, fmt.Errorf("create session on worker %d: %w", worker.ID, err)
 	}
 
-	executor := server.NewFlightExecutorFromClient(worker.client, sessionToken)
+	executor := flightclient.NewFlightExecutorFromClient(worker.client, sessionToken)
 	executor.SetControlMetadata(worker.ID, worker.OwnerCPInstanceID(), worker.OwnerEpoch())
 
 	if pid == 0 {
diff --git a/controlplane/session_mgr_test.go b/controlplane/session_mgr_test.go
index 1afc55d1..5488a13e 100644
--- a/controlplane/session_mgr_test.go
+++ b/controlplane/session_mgr_test.go
@@ -8,7 +8,7 @@ import (
 	"sync/atomic"
 	"testing"
 
-	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 )
 
 // mockCloser tracks whether Close was called.
@@ -27,7 +27,7 @@ func TestOnWorkerCrash_MarksExecutorsDead(t *testing.T) {
 	}
 	sm := NewSessionManager(pool, nil)
 
-	executor := &server.FlightExecutor{}
+	executor := &flightclient.FlightExecutor{}
 	pid := int32(1001)
 
 	sm.mu.Lock()
@@ -67,7 +67,7 @@ func TestOnWorkerCrash_ClosesConnections(t *testing.T) {
 	sm := NewSessionManager(pool, nil)
 
 	conn := &mockCloser{}
-	executor := &server.FlightExecutor{}
+	executor := &flightclient.FlightExecutor{}
 	pid := int32(1002)
 
 	sm.mu.Lock()
@@ -93,8 +93,8 @@ func TestOnWorkerCrash_MultipleSessions(t *testing.T) {
 	}
 	sm := NewSessionManager(pool, nil)
 
-	exec1 := &server.FlightExecutor{}
-	exec2 := &server.FlightExecutor{}
+	exec1 := &flightclient.FlightExecutor{}
+	exec2 := &flightclient.FlightExecutor{}
 	conn1 := &mockCloser{}
 	conn2 := &mockCloser{}
 
@@ -228,7 +228,7 @@ func TestDestroySessionAfterOnWorkerCrash(t *testing.T) {
 	sm := NewSessionManager(pool, nil)
 
 	conn := &mockCloser{}
-	executor := &server.FlightExecutor{}
+	executor := &flightclient.FlightExecutor{}
 	pid := int32(1010)
 
 	sm.mu.Lock()
diff --git a/controlplane/worker_mgr.go b/controlplane/worker_mgr.go
index d4039027..eed7845e 100644
--- a/controlplane/worker_mgr.go
+++ b/controlplane/worker_mgr.go
@@ -19,6 +19,7 @@ import (
 	"github.com/apache/arrow-go/v18/arrow/flight"
 	"github.com/apache/arrow-go/v18/arrow/flight/flightsql"
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 )
@@ -454,8 +455,8 @@ func waitForWorker(socketPath, bearerToken string, timeout time.Duration) (*flig
 			var dialOpts []grpc.DialOption
 			dialOpts = append(dialOpts, grpc.WithTransportCredentials(insecure.NewCredentials()))
 			dialOpts = append(dialOpts, grpc.WithDefaultCallOptions(
-				grpc.MaxCallRecvMsgSize(server.MaxGRPCMessageSize),
-				grpc.MaxCallSendMsgSize(server.MaxGRPCMessageSize),
+				grpc.MaxCallRecvMsgSize(flightclient.MaxGRPCMessageSize),
+				grpc.MaxCallSendMsgSize(flightclient.MaxGRPCMessageSize),
 			))
 
 			if bearerToken != "" {
diff --git a/duckdbservice/arrowmap/arrowmap.go b/duckdbservice/arrowmap/arrowmap.go
index 845410f5..1580e805 100644
--- a/duckdbservice/arrowmap/arrowmap.go
+++ b/duckdbservice/arrowmap/arrowmap.go
@@ -305,14 +305,24 @@ func QuoteIdent(ident string) string {
 // and preserves the source MAP ordering.
 //
 // Lives in arrowmap so AppendValue can switch on it without depending on
-// the server package (which transitively links libduckdb). The flight
-// executor in the server package re-exports it as server.OrderedMapValue
-// via a type alias for backward compatibility.
+// the server package, and the flight client + result formatters in
+// server/ can both reference it without creating an import cycle.
 type OrderedMapValue struct {
 	Keys   []any
 	Values []any
 }
 
+// IntervalValue is the duckdb-free representation of an Arrow
+// MonthDayNanoInterval as decoded by the Flight client. It stores the
+// component fields directly (Months/Days/Micros) so result formatters
+// in the server package can switch on the type without importing the
+// flight subpackage (which would create a cycle).
+type IntervalValue struct {
+	Months int32
+	Days   int32
+	Micros int64
+}
+
 // Appender is a hook that handles append for value types arrowmap doesn't
 // know about (typically driver-specific types like duckdb.Interval). It
 // reports whether it handled the value; arrowmap.AppendValue falls back to
diff --git a/duckdbservice/service.go b/duckdbservice/service.go
index eb95c1c3..549fc76e 100644
--- a/duckdbservice/service.go
+++ b/duckdbservice/service.go
@@ -22,6 +22,7 @@ import (
 	"github.com/apache/arrow-go/v18/arrow/flight/flightsql"
 	"github.com/apache/arrow-go/v18/arrow/memory"
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
 )
@@ -289,8 +290,8 @@ func (svc *DuckDBService) Serve(listener net.Listener) error {
 
 	var opts []grpc.ServerOption
 	opts = append(opts,
-		grpc.MaxRecvMsgSize(server.MaxGRPCMessageSize),
-		grpc.MaxSendMsgSize(server.MaxGRPCMessageSize),
+		grpc.MaxRecvMsgSize(flightclient.MaxGRPCMessageSize),
+		grpc.MaxSendMsgSize(flightclient.MaxGRPCMessageSize),
 	)
 	if svc.cfg.BearerToken != "" {
 		opts = append(opts,
diff --git a/server/conn.go b/server/conn.go
index 540e8bc4..e5b0f8fe 100644
--- a/server/conn.go
+++ b/server/conn.go
@@ -26,6 +26,7 @@ import (
 
 	duckdb "github.com/duckdb/duckdb-go/v2"
 	pg_query "github.com/pganalyze/pg_query_go/v6"
+	"github.com/posthog/duckgres/duckdbservice/arrowmap"
 	"github.com/posthog/duckgres/server/auth"
 	"github.com/posthog/duckgres/transpiler"
 	"go.opentelemetry.io/otel/attribute"
@@ -4308,7 +4309,7 @@ func (c *clientConn) formatCopyValue(v interface{}) string {
 		return formatArrayValue(val)
 	case map[string]any:
 		return formatMapValue(val)
-	case OrderedMapValue:
+	case arrowmap.OrderedMapValue:
 		return formatOrderedMapValue(val)
 	default:
 		return fmt.Sprintf("%v", val)
@@ -4512,13 +4513,13 @@ func formatValue(v interface{}) string {
 	case duckdb.Interval:
 		// PostgreSQL interval text format: "1 year 2 mons 3 days 04:05:06.123456"
 		return formatInterval(val)
-	case intervalValue:
-		// Arrow Flight returns intervalValue instead of duckdb.Interval
+	case arrowmap.IntervalValue:
+		// Arrow Flight returns arrowmap.IntervalValue instead of duckdb.Interval
 		return formatInterval(duckdb.Interval{Months: val.Months, Days: val.Days, Micros: val.Micros})
 	case map[string]any:
 		// STRUCT text format: {"key1": val1, "key2": val2}
 		return formatMapValue(val)
-	case OrderedMapValue:
+	case arrowmap.OrderedMapValue:
 		return formatOrderedMapValue(val)
 	default:
 		// For other types, try to convert to string
@@ -4647,7 +4648,7 @@ func formatMapValue(m map[string]any) string {
 
 // formatOrderedMapValue formats an OrderedMapValue as a key-value text
 // representation, preserving the original insertion order from the Arrow array.
-func formatOrderedMapValue(m OrderedMapValue) string {
+func formatOrderedMapValue(m arrowmap.OrderedMapValue) string {
 	var buf strings.Builder
 	buf.WriteByte('{')
 	for i, k := range m.Keys {
diff --git a/server/flight_executor.go b/server/flightclient/flight_executor.go
similarity index 93%
rename from server/flight_executor.go
rename to server/flightclient/flight_executor.go
index f1846df6..b5e69848 100644
--- a/server/flight_executor.go
+++ b/server/flightclient/flight_executor.go
@@ -1,4 +1,4 @@
-package server
+package flightclient
 
 import (
 	"context"
@@ -20,6 +20,7 @@ import (
 	"github.com/apache/arrow-go/v18/arrow/flight/flightsql"
 	"github.com/apache/arrow-go/v18/arrow/memory"
 	"github.com/posthog/duckgres/duckdbservice/arrowmap"
+	"github.com/posthog/duckgres/server"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/metadata"
@@ -32,12 +33,6 @@ const MaxGRPCMessageSize = 1 << 30 // 1GB
 // ErrWorkerDead is returned when the backing worker process has crashed.
 var ErrWorkerDead = errors.New("flight worker is dead")
 
-// OrderedMapValue is an alias for arrowmap.OrderedMapValue. The type was
-// moved into arrowmap so AppendValue's MAP branch can switch on it without
-// arrowmap depending on the server package. The alias preserves the
-// existing server.OrderedMapValue spelling for current call sites.
-type OrderedMapValue = arrowmap.OrderedMapValue
-
 // FlightExecutor implements QueryExecutor backed by an Arrow Flight SQL client.
 // It routes queries to a duckdb-service worker process over a Unix socket.
 type FlightExecutor struct {
@@ -75,7 +70,7 @@ func NewFlightExecutor(addr, bearerToken, sessionToken string) (*FlightExecutor,
 
 	// Propagate OTEL trace context across gRPC to worker pods.
 	// Filtered to query RPCs only (GetFlightInfo, DoGet).
-	dialOpts = append(dialOpts, OTELGRPCClientHandler())
+	dialOpts = append(dialOpts, server.OTELGRPCClientHandler())
 
 	if bearerToken != "" {
 		dialOpts = append(dialOpts, grpc.WithPerRPCCredentials(&bearerCreds{token: bearerToken}))
@@ -161,14 +156,14 @@ func recoverClientPanic(err *error) {
 	}
 }
 
-func (e *FlightExecutor) QueryContext(ctx context.Context, query string, args ...any) (rs RowSet, err error) {
+func (e *FlightExecutor) QueryContext(ctx context.Context, query string, args ...any) (rs server.RowSet, err error) {
 	if e.dead.Load() {
 		return nil, ErrWorkerDead
 	}
 
 	// Return empty results for queries that are only semicolons, whitespace,
 	// and/or comments. These represent PostgreSQL client pings (e.g., pgx sends "-- ping").
-	if IsEmptyQuery(query) {
+	if server.IsEmptyQuery(query) {
 		return &emptyRowSet{}, nil
 	}
 
@@ -226,13 +221,13 @@ func (e *FlightExecutor) QueryContext(ctx context.Context, query string, args ..
 	}, nil
 }
 
-func (e *FlightExecutor) ExecContext(ctx context.Context, query string, args ...any) (result ExecResult, err error) {
+func (e *FlightExecutor) ExecContext(ctx context.Context, query string, args ...any) (result server.ExecResult, err error) {
 	if e.dead.Load() {
 		return nil, ErrWorkerDead
 	}
 
 	// Return zero rows affected for empty/comment-only queries.
-	if IsEmptyQuery(query) {
+	if server.IsEmptyQuery(query) {
 		return &flightExecResult{rowsAffected: 0}, nil
 	}
 
@@ -257,15 +252,15 @@ func (e *FlightExecutor) ExecContext(ctx context.Context, query string, args ...
 	return &flightExecResult{rowsAffected: affected}, nil
 }
 
-func (e *FlightExecutor) Query(query string, args ...any) (RowSet, error) {
+func (e *FlightExecutor) Query(query string, args ...any) (server.RowSet, error) {
 	return e.QueryContext(context.Background(), query, args...)
 }
 
-func (e *FlightExecutor) Exec(query string, args ...any) (ExecResult, error) {
+func (e *FlightExecutor) Exec(query string, args ...any) (server.ExecResult, error) {
 	return e.ExecContext(context.Background(), query, args...)
 }
 
-func (e *FlightExecutor) ConnContext(ctx context.Context) (RawConn, error) {
+func (e *FlightExecutor) ConnContext(ctx context.Context) (server.RawConn, error) {
 	return nil, fmt.Errorf("ConnContext not supported in Flight mode (use batched INSERT for COPY FROM)")
 }
 
@@ -346,8 +341,8 @@ func (r *FlightRowSet) Columns() ([]string, error) {
 	return names, nil
 }
 
-func (r *FlightRowSet) ColumnTypes() ([]ColumnTyper, error) {
-	types := make([]ColumnTyper, r.schema.NumFields())
+func (r *FlightRowSet) ColumnTypes() ([]server.ColumnTyper, error) {
+	types := make([]server.ColumnTyper, r.schema.NumFields())
 	for i := 0; i < r.schema.NumFields(); i++ {
 		types[i] = &arrowColumnType{dt: r.schema.Field(i).Type}
 	}
@@ -433,7 +428,7 @@ func (r *FlightRowSet) Err() error {
 type emptyRowSet struct{}
 
 func (e *emptyRowSet) Columns() ([]string, error)          { return nil, nil }
-func (e *emptyRowSet) ColumnTypes() ([]ColumnTyper, error) { return nil, nil }
+func (e *emptyRowSet) ColumnTypes() ([]server.ColumnTyper, error) { return nil, nil }
 func (e *emptyRowSet) Next() bool                          { return false }
 func (e *emptyRowSet) Scan(dest ...any) error              { return fmt.Errorf("no rows") }
 func (e *emptyRowSet) Close() error                        { return nil }
@@ -455,8 +450,8 @@ func (e *emptySchemaRowSet) Columns() ([]string, error) {
 	return cols, nil
 }
 
-func (e *emptySchemaRowSet) ColumnTypes() ([]ColumnTyper, error) {
-	types := make([]ColumnTyper, e.schema.NumFields())
+func (e *emptySchemaRowSet) ColumnTypes() ([]server.ColumnTyper, error) {
+	types := make([]server.ColumnTyper, e.schema.NumFields())
 	for i := 0; i < e.schema.NumFields(); i++ {
 		types[i] = &arrowColumnType{dt: e.schema.Field(i).Type}
 	}
@@ -634,7 +629,7 @@ func extractArrowValue(col arrow.Array, row int) interface{} {
 			ks = append(ks, extractArrowValue(keys, i))
 			vs = append(vs, extractArrowValue(items, i))
 		}
-		return OrderedMapValue{Keys: ks, Values: vs}
+		return arrowmap.OrderedMapValue{Keys: ks, Values: vs}
 	default:
 		// Fallback: use String representation
 		return arr.ValueStr(row)
@@ -683,14 +678,8 @@ func decimalToBigInt(val decimal128.Num, dt *arrow.Decimal128Type) interface{} {
 	return result
 }
 
-type intervalValue struct {
-	Months int32
-	Days   int32
-	Micros int64
-}
-
-func monthDayNanoToInterval(val arrow.MonthDayNanoInterval) intervalValue {
-	return intervalValue{
+func monthDayNanoToInterval(val arrow.MonthDayNanoInterval) arrowmap.IntervalValue {
+	return arrowmap.IntervalValue{
 		Months: val.Months,
 		Days:   val.Days,
 		Micros: val.Nanoseconds / 1000,
diff --git a/server/flight_executor_arrow_test.go b/server/flightclient/flight_executor_arrow_test.go
similarity index 92%
rename from server/flight_executor_arrow_test.go
rename to server/flightclient/flight_executor_arrow_test.go
index de4aa8bd..dbfd9dc8 100644
--- a/server/flight_executor_arrow_test.go
+++ b/server/flightclient/flight_executor_arrow_test.go
@@ -1,4 +1,4 @@
-package server
+package flightclient
 
 import (
 	"fmt"
@@ -7,6 +7,7 @@ import (
 	"github.com/apache/arrow-go/v18/arrow"
 	"github.com/apache/arrow-go/v18/arrow/array"
 	"github.com/apache/arrow-go/v18/arrow/memory"
+	"github.com/posthog/duckgres/duckdbservice/arrowmap"
 )
 
 // Tests for arrowTypeToDuckDB — verifies that Arrow types are mapped back to
@@ -80,7 +81,7 @@ func TestArrowTypeToDuckDB_ListOfStruct(t *testing.T) {
 //
 // Expected return types (matching what conn.go formatValue consumes):
 //   STRUCT → map[string]interface{}
-//   MAP    → OrderedMapValue (keys preserve original Arrow types and insertion order)
+//   MAP    → arrowmap.OrderedMapValue (keys preserve original Arrow types and insertion order)
 
 func TestExtractArrowValue_Struct(t *testing.T) {
 	alloc := memory.NewGoAllocator()
@@ -211,9 +212,9 @@ func TestExtractArrowValue_Map(t *testing.T) {
 
 	// Row 0: single-entry map
 	val := extractArrowValue(rec.Column(0), 0)
-	m, ok := val.(OrderedMapValue)
+	m, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("extractArrowValue(MAP) row 0 returned %T, want OrderedMapValue", val)
+		t.Fatalf("extractArrowValue(MAP) row 0 returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if len(m.Keys) != 1 {
 		t.Fatalf("expected 1 map entry, got %d", len(m.Keys))
@@ -227,9 +228,9 @@ func TestExtractArrowValue_Map(t *testing.T) {
 
 	// Row 1: two-entry map
 	val = extractArrowValue(rec.Column(0), 1)
-	m, ok = val.(OrderedMapValue)
+	m, ok = val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("extractArrowValue(MAP) row 1 returned %T, want OrderedMapValue", val)
+		t.Fatalf("extractArrowValue(MAP) row 1 returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if len(m.Keys) != 2 {
 		t.Fatalf("expected 2 map entries, got %d", len(m.Keys))
@@ -378,9 +379,9 @@ func TestExtractArrowValue_MapEmpty(t *testing.T) {
 	defer rec.Release()
 
 	val := extractArrowValue(rec.Column(0), 0)
-	m, ok := val.(OrderedMapValue)
+	m, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("extractArrowValue(empty MAP) returned %T, want OrderedMapValue", val)
+		t.Fatalf("extractArrowValue(empty MAP) returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if len(m.Keys) != 0 {
 		t.Errorf("expected empty map, got %d entries", len(m.Keys))
@@ -410,9 +411,9 @@ func TestExtractArrowValue_MapIntegerKeys(t *testing.T) {
 	defer rec.Release()
 
 	val := extractArrowValue(rec.Column(0), 0)
-	m, ok := val.(OrderedMapValue)
+	m, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("extractArrowValue(MAP int keys) returned %T, want OrderedMapValue", val)
+		t.Fatalf("extractArrowValue(MAP int keys) returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if m.Keys[0] != int32(1) {
 		t.Errorf("Keys[0] = %v (%T), want int32(1)", m.Keys[0], m.Keys[0])
@@ -450,9 +451,9 @@ func TestExtractArrowValue_MapWithNullValues(t *testing.T) {
 	defer rec.Release()
 
 	val := extractArrowValue(rec.Column(0), 0)
-	m, ok := val.(OrderedMapValue)
+	m, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("extractArrowValue(MAP with null values) returned %T, want OrderedMapValue", val)
+		t.Fatalf("extractArrowValue(MAP with null values) returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if m.Values[0] != int32(42) {
 		t.Errorf("m[\"present\"] = %v, want int32(42)", m.Values[0])
@@ -529,9 +530,9 @@ func TestExtractArrowValue_MapMultipleRows(t *testing.T) {
 
 	// Row 0
 	val := extractArrowValue(rec.Column(0), 0)
-	m0, ok := val.(OrderedMapValue)
+	m0, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("row 0: returned %T, want OrderedMapValue", val)
+		t.Fatalf("row 0: returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if len(m0.Keys) != 1 || m0.Values[0] != int32(1) {
 		t.Errorf("row 0: got %v, want {a:1}", m0)
@@ -539,9 +540,9 @@ func TestExtractArrowValue_MapMultipleRows(t *testing.T) {
 
 	// Row 1 (empty)
 	val = extractArrowValue(rec.Column(0), 1)
-	m1, ok := val.(OrderedMapValue)
+	m1, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("row 1: returned %T, want OrderedMapValue", val)
+		t.Fatalf("row 1: returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if len(m1.Keys) != 0 {
 		t.Errorf("row 1: expected empty map, got %v", m1)
@@ -549,9 +550,9 @@ func TestExtractArrowValue_MapMultipleRows(t *testing.T) {
 
 	// Row 2
 	val = extractArrowValue(rec.Column(0), 2)
-	m2, ok := val.(OrderedMapValue)
+	m2, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("row 2: returned %T, want OrderedMapValue", val)
+		t.Fatalf("row 2: returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if len(m2.Keys) != 3 || m2.Values[2] != int32(30) {
 		t.Errorf("row 2: got %v, want {x:10,y:20,z:30}", m2)
@@ -631,16 +632,16 @@ func TestExtractArrowValue_ListOfMap(t *testing.T) {
 	if len(elems) != 2 {
 		t.Fatalf("expected 2 elements, got %d", len(elems))
 	}
-	m0, ok := elems[0].(OrderedMapValue)
+	m0, ok := elems[0].(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("element 0 returned %T, want OrderedMapValue", elems[0])
+		t.Fatalf("element 0 returned %T, want arrowmap.OrderedMapValue", elems[0])
 	}
 	if m0.Values[0] != int32(1) {
 		t.Errorf("elem[0][\"a\"] = %v, want int32(1)", m0.Values[0])
 	}
-	m1, ok := elems[1].(OrderedMapValue)
+	m1, ok := elems[1].(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("element 1 returned %T, want OrderedMapValue", elems[1])
+		t.Fatalf("element 1 returned %T, want arrowmap.OrderedMapValue", elems[1])
 	}
 	if len(m1.Keys) != 2 {
 		t.Errorf("elem[1] has %d entries, want 2", len(m1.Keys))
@@ -671,13 +672,13 @@ func TestExtractArrowValue_MapOfMapValues(t *testing.T) {
 	defer rec.Release()
 
 	val := extractArrowValue(rec.Column(0), 0)
-	m, ok := val.(OrderedMapValue)
+	m, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("extractArrowValue(MAP of MAP) returned %T, want OrderedMapValue", val)
+		t.Fatalf("extractArrowValue(MAP of MAP) returned %T, want arrowmap.OrderedMapValue", val)
 	}
-	inner_val, ok := m.Values[0].(OrderedMapValue)
+	inner_val, ok := m.Values[0].(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("inner map returned %T, want OrderedMapValue", m.Values[0])
+		t.Fatalf("inner map returned %T, want arrowmap.OrderedMapValue", m.Values[0])
 	}
 	if inner_val.Values[0] != int32(99) {
 		t.Errorf("inner[\"inner_key\"] = %v, want int32(99)", inner_val.Values[0])
@@ -708,9 +709,9 @@ func TestExtractArrowValue_MapOfListValues(t *testing.T) {
 	defer rec.Release()
 
 	val := extractArrowValue(rec.Column(0), 0)
-	m, ok := val.(OrderedMapValue)
+	m, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("extractArrowValue(MAP of LIST) returned %T, want OrderedMapValue", val)
+		t.Fatalf("extractArrowValue(MAP of LIST) returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	nums, ok := m.Values[0].([]any)
 	if !ok {
@@ -754,9 +755,9 @@ func TestExtractArrowValue_StructContainingMap(t *testing.T) {
 	if m["id"] != int32(1) {
 		t.Errorf("id = %v, want int32(1)", m["id"])
 	}
-	meta, ok := m["meta"].(OrderedMapValue)
+	meta, ok := m["meta"].(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("meta field returned %T, want OrderedMapValue", m["meta"])
+		t.Fatalf("meta field returned %T, want arrowmap.OrderedMapValue", m["meta"])
 	}
 	if meta.Values[0] != "red" {
 		t.Errorf("meta[\"color\"] = %v, want \"red\"", meta.Values[0])
@@ -967,9 +968,9 @@ func TestExtractArrowValue_MapMixedNullNonNullRows(t *testing.T) {
 	defer rec.Release()
 
 	val := extractArrowValue(rec.Column(0), 0)
-	m, ok := val.(OrderedMapValue)
+	m, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("row 0: returned %T, want OrderedMapValue", val)
+		t.Fatalf("row 0: returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if m.Values[0] != int32(1) {
 		t.Errorf("row 0: a = %v, want 1", m.Values[0])
@@ -980,9 +981,9 @@ func TestExtractArrowValue_MapMixedNullNonNullRows(t *testing.T) {
 	}
 
 	val = extractArrowValue(rec.Column(0), 2)
-	m, ok = val.(OrderedMapValue)
+	m, ok = val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("row 2: returned %T, want OrderedMapValue", val)
+		t.Fatalf("row 2: returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	if m.Values[0] != int32(2) {
 		t.Errorf("row 2: b = %v, want 2", m.Values[0])
@@ -1170,9 +1171,9 @@ func TestExtractArrowValue_MapWithStructValues(t *testing.T) {
 	defer rec.Release()
 
 	val := extractArrowValue(rec.Column(0), 0)
-	m, ok := val.(OrderedMapValue)
+	m, ok := val.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("returned %T, want OrderedMapValue", val)
+		t.Fatalf("returned %T, want arrowmap.OrderedMapValue", val)
 	}
 	// MAP values that are STRUCTs come back as map[string]interface{} from extractArrowValue
 	point, ok := m.Values[0].(map[string]interface{})
@@ -1362,13 +1363,13 @@ func TestExtractThenAppend_MapBasic(t *testing.T) {
 	// Verify the rebuilt MAP is not null and has correct values
 	col := dst.Column(0).(*array.Map)
 	if col.IsNull(0) {
-		t.Fatal("rebuilt MAP is null — AppendValue did not recognize extractArrowValue's OrderedMapValue")
+		t.Fatal("rebuilt MAP is null — AppendValue did not recognize extractArrowValue's arrowmap.OrderedMapValue")
 	}
 	// Re-extract from rebuilt record to verify data
 	rebuilt := extractArrowValue(col, 0)
-	rm, ok := rebuilt.(OrderedMapValue)
+	rm, ok := rebuilt.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("re-extracted value is %T, want OrderedMapValue", rebuilt)
+		t.Fatalf("re-extracted value is %T, want arrowmap.OrderedMapValue", rebuilt)
 	}
 	if rm.Keys[0] != "a" || rm.Keys[1] != "b" {
 		t.Errorf("rebuilt Keys = %v, want [a, b]", rm.Keys)
@@ -1411,9 +1412,9 @@ func TestExtractThenAppend_MapIntegerKeys(t *testing.T) {
 		t.Fatal("rebuilt MAP(INT,VARCHAR) is null")
 	}
 	rebuilt := extractArrowValue(col, 0)
-	rm, ok := rebuilt.(OrderedMapValue)
+	rm, ok := rebuilt.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("re-extracted value is %T, want OrderedMapValue", rebuilt)
+		t.Fatalf("re-extracted value is %T, want arrowmap.OrderedMapValue", rebuilt)
 	}
 	if rm.Keys[0] != int32(1) {
 		t.Errorf("rebuilt Keys[0] = %v (%T), want int32(1)", rm.Keys[0], rm.Keys[0])
@@ -1483,9 +1484,9 @@ func TestExtractThenAppend_MapEmpty(t *testing.T) {
 		t.Fatal("rebuilt empty MAP should not be null")
 	}
 	rebuilt := extractArrowValue(col, 0)
-	rm, ok := rebuilt.(OrderedMapValue)
+	rm, ok := rebuilt.(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("re-extracted value is %T, want OrderedMapValue", rebuilt)
+		t.Fatalf("re-extracted value is %T, want arrowmap.OrderedMapValue", rebuilt)
 	}
 	if len(rm.Keys) != 0 {
 		t.Errorf("rebuilt MAP has %d entries, want 0", len(rm.Keys))
@@ -1539,7 +1540,7 @@ func TestExtractThenAppend_MapMultipleRows(t *testing.T) {
 	if col.IsNull(0) {
 		t.Fatal("row 0: should not be null")
 	}
-	r0 := extractArrowValue(col, 0).(OrderedMapValue)
+	r0 := extractArrowValue(col, 0).(arrowmap.OrderedMapValue)
 	if r0.Values[0] != int32(10) {
 		t.Errorf("row 0: x = %v, want 10", r0.Values[0])
 	}
@@ -1553,7 +1554,7 @@ func TestExtractThenAppend_MapMultipleRows(t *testing.T) {
 	if col.IsNull(2) {
 		t.Fatal("row 2: should not be null")
 	}
-	r2 := extractArrowValue(col, 2).(OrderedMapValue)
+	r2 := extractArrowValue(col, 2).(arrowmap.OrderedMapValue)
 	if len(r2.Keys) != 0 {
 		t.Errorf("row 2: expected empty, got %v", r2)
 	}
@@ -1562,7 +1563,7 @@ func TestExtractThenAppend_MapMultipleRows(t *testing.T) {
 	if col.IsNull(3) {
 		t.Fatal("row 3: should not be null")
 	}
-	r3 := extractArrowValue(col, 3).(OrderedMapValue)
+	r3 := extractArrowValue(col, 3).(arrowmap.OrderedMapValue)
 	if len(r3.Keys) != 3 || r3.Values[0] != int32(1) || r3.Values[1] != int32(2) || r3.Values[2] != int32(3) {
 		t.Errorf("row 3: got %v, want {a:1,b:2,c:3}", r3)
 	}
@@ -1600,7 +1601,7 @@ func TestExtractThenAppend_MapWithNullValues(t *testing.T) {
 	if col.IsNull(0) {
 		t.Fatal("rebuilt MAP with null values should not itself be null")
 	}
-	rebuilt := extractArrowValue(col, 0).(OrderedMapValue)
+	rebuilt := extractArrowValue(col, 0).(arrowmap.OrderedMapValue)
 	if rebuilt.Values[0] != int32(42) {
 		t.Errorf("present = %v, want 42", rebuilt.Values[0])
 	}
@@ -1643,10 +1644,10 @@ func TestExtractThenAppend_MapOfMap(t *testing.T) {
 	if col.IsNull(0) {
 		t.Fatal("rebuilt nested MAP is null")
 	}
-	rebuilt := extractArrowValue(col, 0).(OrderedMapValue)
-	innerMap, ok := rebuilt.Values[0].(OrderedMapValue)
+	rebuilt := extractArrowValue(col, 0).(arrowmap.OrderedMapValue)
+	innerMap, ok := rebuilt.Values[0].(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("inner value is %T, want OrderedMapValue", rebuilt.Values[0])
+		t.Fatalf("inner value is %T, want arrowmap.OrderedMapValue", rebuilt.Values[0])
 	}
 	if innerMap.Values[0] != int32(99) {
 		t.Errorf("inner[\"inner\"] = %v, want 99", innerMap.Values[0])
@@ -1693,9 +1694,9 @@ func TestExtractThenAppend_StructContainingMap(t *testing.T) {
 	if rebuilt["id"] != int32(1) {
 		t.Errorf("id = %v, want 1", rebuilt["id"])
 	}
-	meta, ok := rebuilt["meta"].(OrderedMapValue)
+	meta, ok := rebuilt["meta"].(arrowmap.OrderedMapValue)
 	if !ok {
-		t.Fatalf("meta is %T, want OrderedMapValue", rebuilt["meta"])
+		t.Fatalf("meta is %T, want arrowmap.OrderedMapValue", rebuilt["meta"])
 	}
 	if meta.Values[0] != "red" {
 		t.Errorf("meta[color] = %v, want red", meta.Values[0])
@@ -1739,7 +1740,7 @@ func TestExtractThenAppend_MapWithStructValues(t *testing.T) {
 	if col.IsNull(0) {
 		t.Fatal("rebuilt MAP(VARCHAR,STRUCT) is null")
 	}
-	rebuilt := extractArrowValue(col, 0).(OrderedMapValue)
+	rebuilt := extractArrowValue(col, 0).(arrowmap.OrderedMapValue)
 	point, ok := rebuilt.Values[0].(map[string]interface{})
 	if !ok {
 		t.Fatalf("point value is %T, want map[string]interface{}", rebuilt.Values[0])
@@ -1788,11 +1789,11 @@ func TestExtractThenAppend_ListOfMap(t *testing.T) {
 	if len(rebuilt) != 2 {
 		t.Fatalf("expected 2 elements, got %d", len(rebuilt))
 	}
-	e0 := rebuilt[0].(OrderedMapValue)
+	e0 := rebuilt[0].(arrowmap.OrderedMapValue)
 	if e0.Values[0] != int32(1) {
 		t.Errorf("elem[0] = %v, want {a:1}", e0)
 	}
-	e1 := rebuilt[1].(OrderedMapValue)
+	e1 := rebuilt[1].(arrowmap.OrderedMapValue)
 	if e1.Values[0] != int32(2) {
 		t.Errorf("elem[1] = %v, want {b:2}", e1)
 	}
@@ -1836,7 +1837,7 @@ func appendValue(builder array.Builder, val interface{}) {
 		}
 	case *array.MapBuilder:
 		switch v := val.(type) {
-		case OrderedMapValue:
+		case arrowmap.OrderedMapValue:
 			b.Append(true)
 			for i, k := range v.Keys {
 				appendValue(b.KeyBuilder(), k)
@@ -1855,49 +1856,3 @@ func appendValue(builder array.Builder, val interface{}) {
 	}
 }
 
-// --- formatOrderedMapValue tests ---
-
-func TestFormatOrderedMapValue_Basic(t *testing.T) {
-	m := OrderedMapValue{Keys: []any{"a"}, Values: []any{int32(1)}}
-	got := formatOrderedMapValue(m)
-	if got != "{a=1}" {
-		t.Errorf("formatOrderedMapValue = %q, want %q", got, "{a=1}")
-	}
-}
-
-func TestFormatOrderedMapValue_IntegerKeys(t *testing.T) {
-	m := OrderedMapValue{Keys: []any{int32(1)}, Values: []any{"one"}}
-	got := formatOrderedMapValue(m)
-	if got != "{1=one}" {
-		t.Errorf("formatOrderedMapValue = %q, want %q", got, "{1=one}")
-	}
-}
-
-func TestFormatOrderedMapValue_Empty(t *testing.T) {
-	m := OrderedMapValue{Keys: []any{}, Values: []any{}}
-	got := formatOrderedMapValue(m)
-	if got != "{}" {
-		t.Errorf("formatOrderedMapValue = %q, want %q", got, "{}")
-	}
-}
-
-func TestFormatOrderedMapValue_NilValue(t *testing.T) {
-	m := OrderedMapValue{Keys: []any{"k"}, Values: []any{nil}}
-	got := formatOrderedMapValue(m)
-	if got != "{k=}" {
-		t.Errorf("formatOrderedMapValue = %q, want %q", got, "{k=}")
-	}
-}
-
-func TestFormatOrderedMapValue_PreservesOrder(t *testing.T) {
-	// Verifies that key order in output matches Keys slice.
-	m := OrderedMapValue{
-		Keys:   []any{"z", "a", "m"},
-		Values: []any{int32(1), int32(2), int32(3)},
-	}
-	got := formatOrderedMapValue(m)
-	expected := "{z=1, a=2, m=3}"
-	if got != expected {
-		t.Errorf("formatOrderedMapValue = %q, want %q", got, expected)
-	}
-}
diff --git a/server/flight_executor_test.go b/server/flightclient/flight_executor_test.go
similarity index 97%
rename from server/flight_executor_test.go
rename to server/flightclient/flight_executor_test.go
index a60ddeae..fc2e1705 100644
--- a/server/flight_executor_test.go
+++ b/server/flightclient/flight_executor_test.go
@@ -1,4 +1,4 @@
-package server
+package flightclient
 
 import (
 	"context"
diff --git a/server/flightsqlingress/ingress.go b/server/flightsqlingress/ingress.go
index 6d0d84ce..a3169f25 100644
--- a/server/flightsqlingress/ingress.go
+++ b/server/flightsqlingress/ingress.go
@@ -24,6 +24,7 @@ import (
 	"github.com/apache/arrow-go/v18/arrow/memory"
 	"github.com/posthog/duckgres/duckdbservice/arrowmap"
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
@@ -64,7 +65,7 @@ type Config struct {
 }
 
 type SessionProvider interface {
-	CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *server.FlightExecutor, error)
+	CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *flightclient.FlightExecutor, error)
 	DestroySession(int32)
 }
 
@@ -108,7 +109,7 @@ type sessionMetadataProvider interface {
 }
 
 type sessionReconnector interface {
-	ReconnectSession(ctx context.Context, record DurableSessionRecord) (int32, *server.FlightExecutor, error)
+	ReconnectSession(ctx context.Context, record DurableSessionRecord) (int32, *flightclient.FlightExecutor, error)
 }
 
 type durableSessionStoreProvider interface {
@@ -225,8 +226,8 @@ func NewFlightIngressFromListener(baseListener net.Listener, tlsConfig *tls.Conf
 	handler.rateLimiter = opts.RateLimiter
 
 	grpcOpts := []grpc.ServerOption{
-		grpc.MaxRecvMsgSize(server.MaxGRPCMessageSize),
-		grpc.MaxSendMsgSize(server.MaxGRPCMessageSize),
+		grpc.MaxRecvMsgSize(flightclient.MaxGRPCMessageSize),
+		grpc.MaxSendMsgSize(flightclient.MaxGRPCMessageSize),
 	}
 
 	srv := flight.NewServerWithMiddleware(nil, grpcOpts...)
@@ -1118,7 +1119,7 @@ type flightClientSession struct {
 	pid      int32
 	token    string
 	username string
-	executor *server.FlightExecutor
+	executor *flightclient.FlightExecutor
 	queryFn  func(context.Context, string, ...any) (server.RowSet, error)
 	execFn   func(context.Context, string, ...any) (server.ExecResult, error)
 
@@ -1141,7 +1142,7 @@ type flightClientSession struct {
 	afterTxnControlExecHook func(string)
 }
 
-func newFlightClientSession(pid int32, username string, executor *server.FlightExecutor) *flightClientSession {
+func newFlightClientSession(pid int32, username string, executor *flightclient.FlightExecutor) *flightClientSession {
 	s := &flightClientSession{
 		pid:      pid,
 		username: username,
@@ -1408,7 +1409,7 @@ type flightAuthSessionStore struct {
 	workerQueueTimeout time.Duration
 	hooks              Hooks
 
-	createSessionFn  func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error)
+	createSessionFn  func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error)
 	destroySessionFn func(int32)
 	metadataProvider sessionMetadataProvider
 	reconnector      sessionReconnector
@@ -1438,7 +1439,7 @@ func (r *lockedRowSet) Close() error {
 }
 
 func newFlightAuthSessionStore(provider SessionProvider, idleTTL, reapInterval, handleIdleTTL, tokenTTL, workerQueueTimeout time.Duration, opts Options) *flightAuthSessionStore {
-	createFn := func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+	createFn := func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 		return 0, nil, fmt.Errorf("session provider is not configured")
 	}
 	destroyFn := func(int32) {}
diff --git a/server/flightsqlingress/ingress_test.go b/server/flightsqlingress/ingress_test.go
index 2f10e128..4db0d5da 100644
--- a/server/flightsqlingress/ingress_test.go
+++ b/server/flightsqlingress/ingress_test.go
@@ -15,6 +15,7 @@ import (
 	"github.com/apache/arrow-go/v18/arrow/flight"
 	"github.com/apache/arrow-go/v18/arrow/flight/flightsql"
 	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"github.com/prometheus/client_golang/prometheus"
 	dto "github.com/prometheus/client_model/go"
 	"google.golang.org/grpc"
@@ -163,14 +164,14 @@ func (s *captureDurableSessionStore) CloseSession(sessionToken string, closedAt
 }
 
 type testDurableSessionProvider struct {
-	createSessionFn    func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error)
+	createSessionFn    func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error)
 	destroySessionFn   func(int32)
 	metadataFn         func(pid int32, username string) (DurableSessionMetadata, error)
-	reconnectSessionFn func(context.Context, DurableSessionRecord) (int32, *server.FlightExecutor, error)
+	reconnectSessionFn func(context.Context, DurableSessionRecord) (int32, *flightclient.FlightExecutor, error)
 	durableStore       DurableSessionStore
 }
 
-func (p *testDurableSessionProvider) CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *server.FlightExecutor, error) {
+func (p *testDurableSessionProvider) CreateSession(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *flightclient.FlightExecutor, error) {
 	return p.createSessionFn(ctx, username, pid, memoryLimit, threads)
 }
 
@@ -187,7 +188,7 @@ func (p *testDurableSessionProvider) DurableSessionMetadata(pid int32, username
 	return p.metadataFn(pid, username)
 }
 
-func (p *testDurableSessionProvider) ReconnectSession(ctx context.Context, record DurableSessionRecord) (int32, *server.FlightExecutor, error) {
+func (p *testDurableSessionProvider) ReconnectSession(ctx context.Context, record DurableSessionRecord) (int32, *flightclient.FlightExecutor, error) {
 	return p.reconnectSessionFn(ctx, record)
 }
 
@@ -324,7 +325,7 @@ func testFlightHandlerWithStoreAndRateLimiter(t *testing.T, users map[string]str
 		sessions:      make(map[string]*flightClientSession),
 		stopCh:        make(chan struct{}),
 		doneCh:        make(chan struct{}),
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 1234, nil, nil
 		},
 		destroySessionFn: func(int32) {},
@@ -579,7 +580,7 @@ func TestSessionFromContextAcceptsServerIssuedSessionTokenWithoutBasicAuth(t *te
 
 func TestSessionFromContextRejectsUnknownSessionTokenEvenWithBasicAuth(t *testing.T) {
 	store := &flightAuthSessionStore{
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 9876, nil, nil
 		},
 		destroySessionFn: func(int32) {},
@@ -682,7 +683,7 @@ func TestSessionFromContextTokenPathDoesNotClearRateLimiterFailures(t *testing.T
 func TestSessionFromContextWithoutTokenCreatesDistinctSessions(t *testing.T) {
 	var createCalls atomic.Int32
 	store := &flightAuthSessionStore{
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return createCalls.Add(1), nil, nil
 		},
 		destroySessionFn: func(int32) {},
@@ -834,7 +835,7 @@ func TestFlightSessionTokenLifecycleIssueValidateRevokeExpiryMatrix(t *testing.T
 		idleTTL:       time.Minute,
 		handleIdleTTL: time.Minute,
 		tokenTTL:      time.Hour,
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 1234, nil, nil
 		},
 		destroySessionFn: func(pid int32) {
@@ -947,7 +948,7 @@ func TestFlightAuthSessionStorePersistsDurableSessionRecordOnCreate(t *testing.T
 	durable := &captureDurableSessionStore{}
 	provider := &testDurableSessionProvider{
 		durableStore: durable,
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 4321, nil, nil
 		},
 		metadataFn: func(pid int32, username string) (DurableSessionMetadata, error) {
@@ -1026,10 +1027,10 @@ func TestFlightAuthSessionStoreReconnectsDurableSessionByToken(t *testing.T) {
 				CPInstanceID: "cp-old:boot-a",
 			}, nil
 		},
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 0, nil, fmt.Errorf("unexpected create path")
 		},
-		reconnectSessionFn: func(ctx context.Context, record DurableSessionRecord) (int32, *server.FlightExecutor, error) {
+		reconnectSessionFn: func(ctx context.Context, record DurableSessionRecord) (int32, *flightclient.FlightExecutor, error) {
 			reconnected = record
 			return 9876, nil, nil
 		},
@@ -1081,10 +1082,10 @@ func TestFlightAuthSessionStoreRejectsClosedDurableSessionToken(t *testing.T) {
 	reconnectCalls := 0
 	provider := &testDurableSessionProvider{
 		durableStore: durable,
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 0, nil, fmt.Errorf("unexpected create path")
 		},
-		reconnectSessionFn: func(ctx context.Context, record DurableSessionRecord) (int32, *server.FlightExecutor, error) {
+		reconnectSessionFn: func(ctx context.Context, record DurableSessionRecord) (int32, *flightclient.FlightExecutor, error) {
 			reconnectCalls++
 			return 9876, nil, nil
 		},
@@ -1129,10 +1130,10 @@ func TestFlightAuthSessionStoreReconnectRefreshesDurableSessionMetadata(t *testi
 				CPInstanceID: "cp-new:boot-b",
 			}, nil
 		},
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 0, nil, fmt.Errorf("unexpected create path")
 		},
-		reconnectSessionFn: func(ctx context.Context, record DurableSessionRecord) (int32, *server.FlightExecutor, error) {
+		reconnectSessionFn: func(ctx context.Context, record DurableSessionRecord) (int32, *flightclient.FlightExecutor, error) {
 			return 9876, nil, nil
 		},
 	}
@@ -1203,7 +1204,7 @@ func TestFlightAuthSessionStoreReconnectFailureUpdatesDurableSessionState(t *tes
 			reconnectCalls := 0
 			provider := &testDurableSessionProvider{
 				durableStore: durable,
-				reconnectSessionFn: func(ctx context.Context, record DurableSessionRecord) (int32, *server.FlightExecutor, error) {
+				reconnectSessionFn: func(ctx context.Context, record DurableSessionRecord) (int32, *flightclient.FlightExecutor, error) {
 					reconnectCalls++
 					return 0, nil, tt.reconnectErr
 				},
@@ -1237,7 +1238,7 @@ func TestFlightAuthSessionStoreReconnectFailureUpdatesDurableSessionState(t *tes
 
 func TestFlightAuthSessionStoreRejectsNewSessionsWhileDraining(t *testing.T) {
 	provider := &testDurableSessionProvider{
-		createSessionFn: func(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *flightclient.FlightExecutor, error) {
 			return 321, nil, nil
 		},
 	}
@@ -1265,7 +1266,7 @@ func TestFlightAuthSessionStoreRejectsNewSessionsWhileDraining(t *testing.T) {
 
 func TestFlightAuthSessionStoreWaitForZeroSessions(t *testing.T) {
 	provider := &testDurableSessionProvider{
-		createSessionFn: func(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(ctx context.Context, username string, pid int32, memoryLimit string, threads int) (int32, *flightclient.FlightExecutor, error) {
 			return 654, nil, nil
 		},
 	}
@@ -1357,7 +1358,7 @@ func TestCloseSessionRevokesTokenAndDestroysWorker(t *testing.T) {
 func TestCloseSessionMissingTokenDoesNotBootstrap(t *testing.T) {
 	var createCalls atomic.Int32
 	store := &flightAuthSessionStore{
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			createCalls.Add(1)
 			return 1234, nil, nil
 		},
@@ -1389,7 +1390,7 @@ func TestCloseSessionTokenOnlyRevokesTokenAndDoesNotBootstrap(t *testing.T) {
 	var createCalls atomic.Int32
 	var destroyed []int32
 	store := &flightAuthSessionStore{
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			createCalls.Add(1)
 			return 9876, nil, nil
 		},
@@ -1631,7 +1632,7 @@ func TestFlightAuthSessionStoreReapHookReceivesTrigger(t *testing.T) {
 				reapedCount = count
 			},
 		},
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 0, nil, fmt.Errorf("not used")
 		},
 		destroySessionFn: func(int32) {},
@@ -1666,7 +1667,7 @@ func TestFlightAuthSessionStoreReapKeepsSessionWithFreshHandle(t *testing.T) {
 		},
 		stopCh: make(chan struct{}),
 		doneCh: make(chan struct{}),
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 0, nil, fmt.Errorf("not used")
 		},
 		destroySessionFn: func(pid int32) {
@@ -1703,7 +1704,7 @@ func TestFlightAuthSessionStoreReapStaleHandleAllowsSessionReap(t *testing.T) {
 		},
 		stopCh: make(chan struct{}),
 		doneCh: make(chan struct{}),
-		createSessionFn: func(context.Context, string, int32, string, int) (int32, *server.FlightExecutor, error) {
+		createSessionFn: func(context.Context, string, int32, string, int) (int32, *flightclient.FlightExecutor, error) {
 			return 0, nil, fmt.Errorf("not used")
 		},
 		destroySessionFn: func(pid int32) {
diff --git a/server/format_ordered_map_test.go b/server/format_ordered_map_test.go
new file mode 100644
index 00000000..9e9d1f2f
--- /dev/null
+++ b/server/format_ordered_map_test.go
@@ -0,0 +1,56 @@
+package server
+
+import (
+	"testing"
+
+	"github.com/posthog/duckgres/duckdbservice/arrowmap"
+)
+
+// formatOrderedMapValue tests. Live here in package server because the
+// function under test calls formatValue (defined in conn.go) which switches
+// on the duckdb-go driver's value types — it can't move to a duckdb-free
+// subpackage.
+
+func TestFormatOrderedMapValue_Basic(t *testing.T) {
+	m := arrowmap.OrderedMapValue{Keys: []any{"a"}, Values: []any{int32(1)}}
+	got := formatOrderedMapValue(m)
+	if got != "{a=1}" {
+		t.Errorf("formatOrderedMapValue = %q, want %q", got, "{a=1}")
+	}
+}
+
+func TestFormatOrderedMapValue_IntegerKeys(t *testing.T) {
+	m := arrowmap.OrderedMapValue{Keys: []any{int32(1)}, Values: []any{"one"}}
+	got := formatOrderedMapValue(m)
+	if got != "{1=one}" {
+		t.Errorf("formatOrderedMapValue = %q, want %q", got, "{1=one}")
+	}
+}
+
+func TestFormatOrderedMapValue_Empty(t *testing.T) {
+	m := arrowmap.OrderedMapValue{Keys: []any{}, Values: []any{}}
+	got := formatOrderedMapValue(m)
+	if got != "{}" {
+		t.Errorf("formatOrderedMapValue = %q, want %q", got, "{}")
+	}
+}
+
+func TestFormatOrderedMapValue_NilValue(t *testing.T) {
+	m := arrowmap.OrderedMapValue{Keys: []any{"k"}, Values: []any{nil}}
+	got := formatOrderedMapValue(m)
+	if got != "{k=}" {
+		t.Errorf("formatOrderedMapValue = %q, want %q", got, "{k=}")
+	}
+}
+
+func TestFormatOrderedMapValue_PreservesOrder(t *testing.T) {
+	m := arrowmap.OrderedMapValue{
+		Keys:   []any{"z", "a", "m"},
+		Values: []any{int32(1), int32(2), int32(3)},
+	}
+	got := formatOrderedMapValue(m)
+	expected := "{z=1, a=2, m=3}"
+	if got != expected {
+		t.Errorf("formatOrderedMapValue = %q, want %q", got, expected)
+	}
+}
diff --git a/server/types.go b/server/types.go
index 9d158a6f..f59dd238 100644
--- a/server/types.go
+++ b/server/types.go
@@ -12,6 +12,7 @@ import (
 	"time"
 
 	duckdb "github.com/duckdb/duckdb-go/v2"
+	"github.com/posthog/duckgres/duckdbservice/arrowmap"
 )
 
 // PostgreSQL type OIDs
@@ -616,8 +617,8 @@ func encodeInterval(v interface{}) []byte {
 		binary.BigEndian.PutUint64(buf[0:8], uint64(val.Micros))
 		binary.BigEndian.PutUint32(buf[8:12], uint32(val.Days))
 		binary.BigEndian.PutUint32(buf[12:16], uint32(val.Months))
-	case intervalValue:
-		// Arrow Flight returns intervalValue instead of duckdb.Interval
+	case arrowmap.IntervalValue:
+		// Arrow Flight returns arrowmap.IntervalValue instead of duckdb.Interval
 		binary.BigEndian.PutUint64(buf[0:8], uint64(val.Micros))
 		binary.BigEndian.PutUint32(buf[8:12], uint32(val.Days))
 		binary.BigEndian.PutUint32(buf[12:16], uint32(val.Months))
diff --git a/tests/controlplane/flight_ingress_test.go b/tests/controlplane/flight_ingress_test.go
index 8db8034d..f5ec7990 100644
--- a/tests/controlplane/flight_ingress_test.go
+++ b/tests/controlplane/flight_ingress_test.go
@@ -17,7 +17,7 @@ import (
 	"github.com/apache/arrow-go/v18/arrow/flight/flightsql"
 	"github.com/apache/arrow-go/v18/arrow/flight/flightsql/schema_ref"
 	"github.com/apache/arrow-go/v18/arrow/memory"
-	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/metadata"
@@ -35,8 +35,8 @@ func newFlightClient(t *testing.T, port int) *flightsql.Client {
 	client, err := flightsql.NewClient(addr, nil, nil,
 		grpc.WithTransportCredentials(credentials.NewTLS(tlsCfg)),
 		grpc.WithDefaultCallOptions(
-			grpc.MaxCallRecvMsgSize(server.MaxGRPCMessageSize),
-			grpc.MaxCallSendMsgSize(server.MaxGRPCMessageSize),
+			grpc.MaxCallRecvMsgSize(flightclient.MaxGRPCMessageSize),
+			grpc.MaxCallSendMsgSize(flightclient.MaxGRPCMessageSize),
 		),
 	)
 	if err != nil {
diff --git a/tests/perf/drivers/flight/driver.go b/tests/perf/drivers/flight/driver.go
index 80caf680..0e535d1e 100644
--- a/tests/perf/drivers/flight/driver.go
+++ b/tests/perf/drivers/flight/driver.go
@@ -8,7 +8,7 @@ import (
 	"time"
 
 	"github.com/apache/arrow-go/v18/arrow/flight/flightsql"
-	"github.com/posthog/duckgres/server"
+	"github.com/posthog/duckgres/server/flightclient"
 	"github.com/posthog/duckgres/tests/perf/core"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials"
@@ -36,8 +36,8 @@ func NewFromAddress(addr, username, password string, insecureSkipVerify bool) (*
 		nil,
 		grpc.WithTransportCredentials(credentials.NewTLS(tlsCfg)),
 		grpc.WithDefaultCallOptions(
-			grpc.MaxCallRecvMsgSize(server.MaxGRPCMessageSize),
-			grpc.MaxCallSendMsgSize(server.MaxGRPCMessageSize),
+			grpc.MaxCallRecvMsgSize(flightclient.MaxGRPCMessageSize),
+			grpc.MaxCallSendMsgSize(flightclient.MaxGRPCMessageSize),
 		),
 	)
 	if err != nil {
@@ -49,7 +49,7 @@ func NewFromAddress(addr, username, password string, insecureSkipVerify bool) (*
 		_ = client.Close()
 		return nil, err
 	}
-	exec := server.NewFlightExecutorFromClient(client, token)
+	exec := flightclient.NewFlightExecutorFromClient(client, token)
 	return &Driver{
 		exec: &flightExecutor{
 			client: client,
@@ -87,7 +87,7 @@ func (d *Driver) Close() error {
 
 type flightExecutor struct {
 	client *flightsql.Client
-	exec   *server.FlightExecutor
+	exec   *flightclient.FlightExecutor
 }
 
 func (e *flightExecutor) Execute(ctx context.Context, query string, args []any) (int64, error) {