diff --git a/services/framecache/src/slot.c b/services/framecache/src/slot.c
index 45972fd..e22cde8 100644
--- a/services/framecache/src/slot.c
+++ b/services/framecache/src/slot.c
@@ -17,17 +17,6 @@
 #define SEM_PREFIX   "/framecache-"
 #define SEM_SUFFIX   "-write"
 
-/* Internal handle used by both server (writer) and client (reader) */
-struct fc_slot {
-    int       shm_fd;
-    void     *base;
-    size_t    shm_size;
-    sem_t    *sem;
-    char      slot_id[FC_MAX_SLOT_ID];
-    char      shm_path[128];
-    char      sem_name[128];
-};
-
 /* ── helpers ─────────────────────────────────────────────────────────── */
 
 static void build_paths(const char *slot_id,
@@ -172,12 +161,6 @@ void fc_slot_write_frame(struct fc_slot *s,
     sem_post(s->sem);
 }
 
-/* Accessors used by HTTP API */
-fc_header_t *fc_slot_header(struct fc_slot *s) { return (fc_header_t *)s->base; }
-const char  *fc_slot_id(struct fc_slot *s)     { return s->slot_id; }
-const char  *fc_slot_shm_path(struct fc_slot *s) { return s->shm_path; }
-const char  *fc_slot_sem_name(struct fc_slot *s) { return s->sem_name; }
-
 /* ── client-side open / read / close (also used by capture-manager) ── */
 
 /**
diff --git a/services/framecache/src/slot.h b/services/framecache/src/slot.h
index 03ca39f..27c3d27 100644
--- a/services/framecache/src/slot.h
+++ b/services/framecache/src/slot.h
@@ -21,6 +21,17 @@
 #define FC_FRAME_HDR_SIZE 24u           /* pts_us(8) + wall_us(8) + size(4) + pad(4) */
 #define FC_MAX_SLOT_ID    64u
 
+/* Internal handle used by both server (writer) and client (reader) */
+struct fc_slot {
+    int       shm_fd;
+    void     *base;
+    size_t    shm_size;
+    sem_t    *sem;
+    char      slot_id[FC_MAX_SLOT_ID];
+    char      shm_path[128];
+    char      sem_name[128];
+};
+
 /* Pixel format codes */
 #define FC_PIX_UYVY422    0u
 
@@ -57,6 +68,12 @@ typedef struct {
 _Static_assert(sizeof(fc_frame_t) == FC_FRAME_HDR_SIZE,
                "fc_frame_t header must be exactly FC_FRAME_HDR_SIZE bytes");
 
+/* Accessor function declarations (implemented in slot.c) */
+fc_header_t *fc_slot_header(struct fc_slot *s);
+const char  *fc_slot_id(struct fc_slot *s);
+const char  *fc_slot_shm_path(struct fc_slot *s);
+const char  *fc_slot_sem_name(struct fc_slot *s);
+
 /**
  * Compute total shm size for a slot given frame_size.
  * = FC_HEADER_SIZE + ring_depth * (FC_FRAME_HDR_SIZE + frame_size)