diff --git a/src/index.js b/src/index.js
index 2db9148a..44dbdcbf 100644
--- a/src/index.js
+++ b/src/index.js
@@ -26,5 +26,8 @@ export {
   getState,
   getStates,
   readStatesAsMap,
-  writeStates
+  writeStates,
+  readDeleteSet,
+  writeDeleteSet,
+  createDeleteSetFromStructStore
 } from './internals.js'
diff --git a/src/structs/AbstractItem.js b/src/structs/AbstractItem.js
index eb6e6367..c5be85f2 100644
--- a/src/structs/AbstractItem.js
+++ b/src/structs/AbstractItem.js
@@ -12,7 +12,7 @@ import {
   addToDeleteSet,
   ItemDeleted,
   findRootTypeKey,
-  ID, AbstractType, Y, Transaction // eslint-disable-line
+  StructStore, ID, AbstractType, Y, Transaction // eslint-disable-line
 } from '../internals.js'
 
 import * as error from 'lib0/error.js'
@@ -24,16 +24,23 @@ import * as binary from 'lib0/binary.js'
 
 /**
  * Split leftItem into two items
- * @param {Transaction} transaction
+ * @param {StructStore} store
  * @param {AbstractItem} leftItem
  * @param {number} diff
  * @return {AbstractItem}
  */
-export const splitItem = (transaction, leftItem, diff) => {
+export const splitItem = (store, leftItem, diff) => {
   const id = leftItem.id
   // create rightItem
-  const rightItem = leftItem.copy(createID(id.client, id.clock + diff), leftItem, leftItem.rightOrigin, leftItem.parent, leftItem.parentSub)
-  rightItem.right = leftItem.right
+  const rightItem = leftItem.copy(
+    createID(id.client, id.clock + diff),
+    leftItem,
+    leftItem.lastId,
+    leftItem.right,
+    leftItem.rightOrigin,
+    leftItem.parent,
+    leftItem.parentSub
+  )
   if (leftItem.deleted) {
     rightItem.deleted = true
   }
@@ -43,20 +50,7 @@ export const splitItem = (transaction, leftItem, diff) => {
   if (rightItem.right !== null) {
     rightItem.right.left = rightItem
   }
-  // update all origins to the right
-  // search all relevant items to the right and update origin
-  // if origin is not it foundOrigins, we don't have to search any longer
-  const foundOrigins = new Set()
-  foundOrigins.add(leftItem)
-  let o = rightItem.right
-  while (o !== null && foundOrigins.has(o.origin)) {
-    if (o.origin === leftItem) {
-      o.origin = rightItem
-    }
-    foundOrigins.add(o)
-    o = o.right
-  }
-  return leftItem.splitAt(transaction, diff)
+  return rightItem
 }
 
 /**
@@ -66,11 +60,13 @@ export class AbstractItem extends AbstractStruct {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any> | null} parent
    * @param {string | null} parentSub
    */
-  constructor (id, left, right, parent, parentSub) {
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub) {
     if (left !== null) {
       parent = left.parent
       parentSub = left.parentSub
@@ -83,10 +79,10 @@ export class AbstractItem extends AbstractStruct {
     super(id)
     /**
      * The item that was originally to the left of this item.
-     * @type {AbstractItem | null}
+     * @type {ID | null}
      * @readonly
      */
-    this.origin = left
+    this.origin = origin
     /**
      * The item that is currently to the left of this item.
      * @type {AbstractItem | null}
@@ -100,9 +96,9 @@ export class AbstractItem extends AbstractStruct {
     /**
      * The item that was originally to the right of this item.
      * @readonly
-     * @type {AbstractItem | null}
+     * @type {ID | null}
      */
-    this.rightOrigin = right
+    this.rightOrigin = rightOrigin
     /**
      * The parent type.
      * @type {AbstractType<any>}
@@ -264,13 +260,15 @@ export class AbstractItem extends AbstractStruct {
    * Creates an Item with the same effect as this Item (without position effect)
    *
    * @param {ID} id
-   * @param {AbstractItem|null} left
-   * @param {AbstractItem|null} right
+   * @param {AbstractItem | null} left
+   * @param {ID | null} origin
+   * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
-   * @param {string|null} parentSub
+   * @param {string | null} parentSub
    * @return {AbstractItem}
    */
-  copy (id, left, right, parent, parentSub) {
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
     throw new Error('unimplemented')
   }
 
@@ -329,7 +327,7 @@ export class AbstractItem extends AbstractStruct {
         right = right._right
       }
     }
-    this.redone = this.copy(nextID(transaction), left, right, parent, this.parentSub)
+    this.redone = this.copy(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, this.parentSub)
     this.redone.integrate(transaction)
     return true
   }
@@ -374,11 +372,11 @@ export class AbstractItem extends AbstractStruct {
    *
    * This method should only be cally by StructStore.
    *
-   * @param {Transaction} transaction
+   * @param {StructStore} store
    * @param {number} diff
    * @return {AbstractItem}
    */
-  splitAt (transaction, diff) {
+  splitAt (store, diff) {
     throw new Error('unimplemented')
   }
 
@@ -412,9 +410,18 @@ export class AbstractItem extends AbstractStruct {
    * @return {GC|ItemDeleted}
    */
   gc (y) {
-    const r = this.parent._item !== null && this.parent._item.deleted
-      ? new GC(this.id, this.length)
-      : new ItemDeleted(this.id, this.left, this.right, this.parent, this.parentSub, this.length)
+    let r
+    if (this.parent._item !== null && this.parent._item.deleted) {
+      r = new GC(this.id, this.length)
+    } else {
+      r = new ItemDeleted(this.id, this.left, this.origin, this.right, this.rightOrigin, this.parent, this.parentSub, this.length)
+      if (r.left !== null) {
+        r.left.right = r
+      }
+      if (r.right !== null) {
+        r.right.left = r
+      }
+    }
     replaceStruct(y.store, this, r)
     return r
   }
@@ -445,13 +452,13 @@ export class AbstractItem extends AbstractStruct {
     encoding.writeUint8(encoder, info)
     if (this.origin !== null) {
       if (offset === 0) {
-        writeID(encoder, this.origin.lastId)
+        writeID(encoder, this.origin)
       } else {
         writeID(encoder, createID(this.id.client, this.id.clock + offset - 1))
       }
     }
     if (this.rightOrigin !== null) {
-      writeID(encoder, this.rightOrigin.id)
+      writeID(encoder, this.rightOrigin)
     }
     if (this.origin === null && this.rightOrigin === null) {
       const parent = this.parent
diff --git a/src/structs/GC.js b/src/structs/GC.js
index cf6173d7..f2951b45 100644
--- a/src/structs/GC.js
+++ b/src/structs/GC.js
@@ -34,6 +34,8 @@ export class GC extends AbstractStruct {
     return this._len
   }
 
+  delete () {}
+
   /**
    * @param {AbstractStruct} right
    * @return {boolean}
diff --git a/src/structs/ItemBinary.js b/src/structs/ItemBinary.js
index b4b8f342..b790746f 100644
--- a/src/structs/ItemBinary.js
+++ b/src/structs/ItemBinary.js
@@ -24,13 +24,15 @@ export class ItemBinary extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    * @param {ArrayBuffer} content
    */
-  constructor (id, left, right, parent, parentSub, content) {
-    super(id, left, right, parent, parentSub)
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
     this.content = content
   }
   getContent () {
@@ -39,12 +41,14 @@ export class ItemBinary extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    */
-  copy (id, left, right, parent, parentSub) {
-    return new ItemBinary(id, left, right, parent, parentSub, this.content)
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemBinary(id, left, origin, right, rightOrigin, parent, parentSub, this.content)
   }
   /**
    * @param {encoding.Encoder} encoder
@@ -94,8 +98,10 @@ export class ItemBinaryRef extends AbstractItemRef {
 
     return new ItemBinary(
       this.id,
-      this.left === null ? null : getItemCleanEnd(store, transaction, this.left),
-      this.right === null ? null : getItemCleanStart(store, transaction, this.right),
+      this.left === null ? null : getItemCleanEnd(store, this.left),
+      this.left,
+      this.right === null ? null : getItemCleanStart(store, this.right),
+      this.right,
       parent,
       this.parentSub,
       this.content
diff --git a/src/structs/ItemDeleted.js b/src/structs/ItemDeleted.js
index a7b4a354..b4d32603 100644
--- a/src/structs/ItemDeleted.js
+++ b/src/structs/ItemDeleted.js
@@ -12,6 +12,7 @@ import {
   getItemType,
   changeItemRefOffset,
   GC,
+  compareIDs,
   Transaction, ID, AbstractType // eslint-disable-line
 } from '../internals.js'
 
@@ -24,13 +25,15 @@ export class ItemDeleted extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    * @param {number} length
    */
-  constructor (id, left, right, parent, parentSub, length) {
-    super(id, left, right, parent, parentSub)
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, length) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
     this._len = length
     this.deleted = true
   }
@@ -40,19 +43,21 @@ export class ItemDeleted extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    */
-  copy (id, left, right, parent, parentSub) {
-    return new ItemDeleted(id, left, right, parent, parentSub, this.length)
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemDeleted(id, left, origin, right, rightOrigin, parent, parentSub, this.length)
   }
   /**
    * @param {ItemDeleted} right
    * @return {boolean}
    */
   mergeWith (right) {
-    if (right.origin === this && this.right === right) {
+    if (compareIDs(right.origin, this.lastId) && this.right === right) {
       this._len += right.length
       return true
     }
@@ -113,8 +118,10 @@ export class ItemDeletedRef extends AbstractItemRef {
 
     return new ItemDeleted(
       this.id,
-      this.left === null ? null : getItemCleanEnd(store, transaction, this.left),
-      this.right === null ? null : getItemCleanStart(store, transaction, this.right),
+      this.left === null ? null : getItemCleanEnd(store, this.left),
+      this.left,
+      this.right === null ? null : getItemCleanStart(store, this.right),
+      this.right,
       parent,
       this.parentSub,
       this.len
diff --git a/src/structs/ItemEmbed.js b/src/structs/ItemEmbed.js
index f9648fa0..8b39a564 100644
--- a/src/structs/ItemEmbed.js
+++ b/src/structs/ItemEmbed.js
@@ -22,24 +22,28 @@ export class ItemEmbed extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    * @param {Object} embed
    */
-  constructor (id, left, right, parent, parentSub, embed) {
-    super(id, left, right, parent, parentSub)
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, embed) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
     this.embed = embed
   }
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    */
-  copy (id, left, right, parent, parentSub) {
-    return new ItemEmbed(id, left, right, parent, parentSub, this.embed)
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemEmbed(id, left, origin, right, rightOrigin, parent, parentSub, this.embed)
   }
   /**
    * @param {encoding.Encoder} encoder
@@ -89,8 +93,10 @@ export class ItemEmbedRef extends AbstractItemRef {
 
     return new ItemEmbed(
       this.id,
-      this.left === null ? null : getItemCleanEnd(store, transaction, this.left),
-      this.right === null ? null : getItemCleanStart(store, transaction, this.right),
+      this.left === null ? null : getItemCleanEnd(store, this.left),
+      this.left,
+      this.right === null ? null : getItemCleanStart(store, this.right),
+      this.right,
       parent,
       this.parentSub,
       this.embed
diff --git a/src/structs/ItemFormat.js b/src/structs/ItemFormat.js
index f699266d..e2618abc 100644
--- a/src/structs/ItemFormat.js
+++ b/src/structs/ItemFormat.js
@@ -22,26 +22,30 @@ export class ItemFormat extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    * @param {string} key
    * @param {any} value
    */
-  constructor (id, left, right, parent, parentSub, key, value) {
-    super(id, left, right, parent, parentSub)
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, key, value) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
     this.key = key
     this.value = value
   }
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    */
-  copy (id, left, right, parent, parentSub) {
-    return new ItemFormat(id, left, right, parent, parentSub, this.key, this.value)
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemFormat(id, left, origin, right, rightOrigin, parent, parentSub, this.key, this.value)
   }
   get countable () {
     return false
@@ -96,8 +100,10 @@ export class ItemFormatRef extends AbstractItemRef {
 
     return new ItemFormat(
       this.id,
-      this.left === null ? null : getItemCleanEnd(store, transaction, this.left),
-      this.right === null ? null : getItemCleanStart(store, transaction, this.right),
+      this.left === null ? null : getItemCleanEnd(store, this.left),
+      this.left,
+      this.right === null ? null : getItemCleanStart(store, this.right),
+      this.right,
       parent,
       this.parentSub,
       this.key,
diff --git a/src/structs/ItemJSON.js b/src/structs/ItemJSON.js
index e5f2ceec..b927b4b8 100644
--- a/src/structs/ItemJSON.js
+++ b/src/structs/ItemJSON.js
@@ -10,9 +10,10 @@ import {
   getItemType,
   splitItem,
   changeItemRefOffset,
+  compareIDs,
   GC,
   ItemDeleted,
-  Transaction, ID, AbstractType // eslint-disable-line
+  StructStore, Transaction, ID, AbstractType // eslint-disable-line
 } from '../internals.js'
 
 import * as encoding from 'lib0/encoding.js'
@@ -24,13 +25,15 @@ export class ItemJSON extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    * @param {Array<any>} content
    */
-  constructor (id, left, right, parent, parentSub, content) {
-    super(id, left, right, parent, parentSub)
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, content) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
     /**
      * @type {Array<any>}
      */
@@ -39,12 +42,14 @@ export class ItemJSON extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    */
-  copy (id, left, right, parent, parentSub) {
-    return new ItemJSON(id, left, right, parent, parentSub, this.content)
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemJSON(id, left, origin, right, rightOrigin, parent, parentSub, this.content)
   }
   get length () {
     return this.content.length
@@ -53,15 +58,15 @@ export class ItemJSON extends AbstractItem {
     return this.content
   }
   /**
-   * @param {Transaction} transaction
+   * @param {StructStore} store
    * @param {number} diff
    */
-  splitAt (transaction, diff) {
+  splitAt (store, diff) {
     /**
      * @type {ItemJSON}
      */
     // @ts-ignore
-    const right = splitItem(transaction, this, diff)
+    const right = splitItem(this, diff)
     right.content = this.content.splice(diff)
     return right
   }
@@ -70,7 +75,7 @@ export class ItemJSON extends AbstractItem {
    * @return {boolean}
    */
   mergeWith (right) {
-    if (right.origin === this && this.right === right) {
+    if (compareIDs(right.origin, this.lastId) && this.right === right) {
       this.content = this.content.concat(right.content)
       return true
     }
@@ -144,8 +149,10 @@ export class ItemJSONRef extends AbstractItemRef {
     }
     return new ItemJSON(
       this.id,
-      this.left === null ? null : getItemCleanEnd(store, transaction, this.left),
-      this.right === null ? null : getItemCleanStart(store, transaction, this.right),
+      this.left === null ? null : getItemCleanEnd(store, this.left),
+      this.left,
+      this.right === null ? null : getItemCleanStart(store, this.right),
+      this.right,
       parent,
       this.parentSub,
       this.content
diff --git a/src/structs/ItemString.js b/src/structs/ItemString.js
index e71ea692..532e243d 100644
--- a/src/structs/ItemString.js
+++ b/src/structs/ItemString.js
@@ -9,27 +9,30 @@ import {
   getItemType,
   splitItem,
   changeItemRefOffset,
+  compareIDs,
   ItemDeleted,
   GC,
-  Transaction, ID, AbstractType // eslint-disable-line
+  StructStore, Transaction, ID, AbstractType // eslint-disable-line
 } from '../internals.js'
 
 import * as encoding from 'lib0/encoding.js'
 import * as decoding from 'lib0/decoding.js'
 
 export const structStringRefNumber = 6
-
+// TODO: we can probably try to omit rightOrigin. We can just use .right
 export class ItemString extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    * @param {string} string
    */
-  constructor (id, left, right, parent, parentSub, string) {
-    super(id, left, right, parent, parentSub)
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, string) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
     /**
      * @type {string}
      */
@@ -38,12 +41,14 @@ export class ItemString extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    */
-  copy (id, left, right, parent, parentSub) {
-    return new ItemString(id, left, right, parent, parentSub, this.string)
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemString(id, left, origin, right, rightOrigin, parent, parentSub, this.string)
   }
   getContent () {
     return this.string.split('')
@@ -52,16 +57,16 @@ export class ItemString extends AbstractItem {
     return this.string.length
   }
   /**
-   * @param {Transaction} transaction
+   * @param {StructStore} store
    * @param {number} diff
    * @return {ItemString}
    */
-  splitAt (transaction, diff) {
+  splitAt (store, diff) {
     /**
      * @type {ItemString}
      */
     // @ts-ignore
-    const right = splitItem(transaction, this, diff)
+    const right = splitItem(store, this, diff)
     right.string = this.string.slice(diff)
     this.string = this.string.slice(0, diff)
     return right
@@ -71,7 +76,7 @@ export class ItemString extends AbstractItem {
    * @return {boolean}
    */
   mergeWith (right) {
-    if (right.origin === this && this.right === right) {
+    if (compareIDs(right.origin, this.lastId) && this.right === right) {
       this.string += right.string
       return true
     }
@@ -132,8 +137,10 @@ export class ItemStringRef extends AbstractItemRef {
 
     return new ItemString(
       this.id,
-      this.left === null ? null : getItemCleanEnd(store, transaction, this.left),
-      this.right === null ? null : getItemCleanStart(store, transaction, this.right),
+      this.left === null ? null : getItemCleanEnd(store, this.left),
+      this.left,
+      this.right === null ? null : getItemCleanStart(store, this.right),
+      this.right,
       parent,
       this.parentSub,
       this.string
diff --git a/src/structs/ItemType.js b/src/structs/ItemType.js
index 4fc9e6c3..69bb3fa3 100644
--- a/src/structs/ItemType.js
+++ b/src/structs/ItemType.js
@@ -61,13 +61,15 @@ export class ItemType extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    * @param {AbstractType<any>} type
    */
-  constructor (id, left, right, parent, parentSub, type) {
-    super(id, left, right, parent, parentSub)
+  constructor (id, left, origin, right, rightOrigin, parent, parentSub, type) {
+    super(id, left, origin, right, rightOrigin, parent, parentSub)
     this.type = type
   }
 
@@ -77,13 +79,15 @@ export class ItemType extends AbstractItem {
   /**
    * @param {ID} id
    * @param {AbstractItem | null} left
+   * @param {ID | null} origin
    * @param {AbstractItem | null} right
+   * @param {ID | null} rightOrigin
    * @param {AbstractType<any>} parent
    * @param {string | null} parentSub
    * @return {AbstractItem} TODO, returns itemtype
    */
-  copy (id, left, right, parent, parentSub) {
-    return new ItemType(id, left, right, parent, parentSub, this.type._copy())
+  copy (id, left, origin, right, rightOrigin, parent, parentSub) {
+    return new ItemType(id, left, origin, right, rightOrigin, parent, parentSub, this.type._copy())
   }
   /**
    * @param {Transaction} transaction
@@ -189,10 +193,13 @@ export class ItemTypeRef extends AbstractItemRef {
       parent = y.get(this.parentYKey)
     }
 
+    // TODO: we can probably only feed AbstractType with origins
     return new ItemType(
       this.id,
-      this.left === null ? null : getItemCleanEnd(store, transaction, this.left),
-      this.right === null ? null : getItemCleanStart(store, transaction, this.right),
+      this.left === null ? null : getItemCleanEnd(store, this.left),
+      this.left,
+      this.right === null ? null : getItemCleanStart(store, this.right),
+      this.right,
       parent,
       this.parentSub,
       this.type
diff --git a/src/types/AbstractType.js b/src/types/AbstractType.js
index a3342fbd..63770a59 100644
--- a/src/types/AbstractType.js
+++ b/src/types/AbstractType.js
@@ -335,7 +335,7 @@ export const typeArrayInsertGenericsAfter = (transaction, parent, referenceItem,
   let jsonContent = []
   const packJsonContent = () => {
     if (jsonContent.length > 0) {
-      const item = new ItemJSON(nextID(transaction), left, right, parent, null, jsonContent)
+      const item = new ItemJSON(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, jsonContent)
       item.integrate(transaction)
       jsonContent = []
     }
@@ -353,11 +353,11 @@ export const typeArrayInsertGenericsAfter = (transaction, parent, referenceItem,
         switch (c.constructor) {
           case ArrayBuffer:
             // @ts-ignore c is definitely an ArrayBuffer
-            new ItemBinary(nextID(transaction), left, right, parent, null, c).integrate(transaction)
+            new ItemBinary(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, c).integrate(transaction)
             break
           default:
             if (c instanceof AbstractType) {
-              new ItemType(nextID(transaction), left, right, parent, null, c).integrate(transaction)
+              new ItemType(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, c).integrate(transaction)
             } else {
               throw new Error('Unexpected content type in insert operation')
             }
@@ -383,7 +383,7 @@ export const typeArrayInsertGenerics = (transaction, parent, index, content) =>
       if (index <= n.length) {
         if (index < n.length) {
           // insert in-between
-          getItemCleanStart(transaction.y.store, transaction, createID(n.id.client, n.id.clock + index))
+          getItemCleanStart(transaction.y.store, createID(n.id.client, n.id.clock + index))
         }
         break
       }
@@ -405,7 +405,7 @@ export const typeArrayDelete = (transaction, parent, index, length) => {
     if (!n.deleted && n.countable) {
       if (index <= n.length) {
         if (index < n.length) {
-          n = getItemCleanStart(transaction.y.store, transaction, createID(n.id.client, n.id.clock + index))
+          n = getItemCleanStart(transaction.y.store, createID(n.id.client, n.id.clock + index))
         }
         break
       }
@@ -415,7 +415,7 @@ export const typeArrayDelete = (transaction, parent, index, length) => {
   while (length > 0 && n !== null) {
     if (!n.deleted) {
       if (length < n.length) {
-        getItemCleanEnd(transaction.y.store, transaction, createID(n.id.client, n.id.clock + length))
+        getItemCleanEnd(transaction.y.store, createID(n.id.client, n.id.clock + length))
       }
       n.delete(transaction)
       length -= n.length
@@ -445,7 +445,7 @@ export const typeMapDelete = (transaction, parent, key) => {
 export const typeMapSet = (transaction, parent, key, value) => {
   const right = parent._map.get(key) || null
   if (value == null) {
-    new ItemJSON(nextID(transaction), null, right, parent, key, [value]).integrate(transaction)
+    new ItemJSON(nextID(transaction), null, null, right, right === null ? null : right.id, parent, key, [value]).integrate(transaction)
     return
   }
   switch (value.constructor) {
@@ -453,14 +453,14 @@ export const typeMapSet = (transaction, parent, key, value) => {
     case Object:
     case Array:
     case String:
-      new ItemJSON(nextID(transaction), null, right, parent, key, [value]).integrate(transaction)
+      new ItemJSON(nextID(transaction), null, null, right, right === null ? null : right.id, parent, key, [value]).integrate(transaction)
       break
     case ArrayBuffer:
-      new ItemBinary(nextID(transaction), null, right, parent, key, value).integrate(transaction)
+      new ItemBinary(nextID(transaction), null, null, right, right === null ? null : right.id, parent, key, value).integrate(transaction)
       break
     default:
       if (value instanceof AbstractType) {
-        new ItemType(nextID(transaction), null, right, parent, key, value).integrate(transaction)
+        new ItemType(nextID(transaction), null, null, right, right === null ? null : right.id, parent, key, value).integrate(transaction)
       } else {
         throw new Error('Unexpected content type')
       }
diff --git a/src/types/YText.js b/src/types/YText.js
index cc018b98..4482c9ca 100644
--- a/src/types/YText.js
+++ b/src/types/YText.js
@@ -36,7 +36,7 @@ const findNextPosition = (transaction, store, currentAttributes, left, right, co
       case ItemString:
         if (!right.deleted) {
           if (count < right.length) {
-            right = getItemCleanStart(store, transaction, createID(right.id.client, right.id.clock + count))
+            right = getItemCleanStart(store, createID(right.id.client, right.id.clock + count))
             left = right.left
             count = 0
           } else {
@@ -102,7 +102,7 @@ const insertNegatedAttributes = (transaction, parent, left, right, negatedAttrib
     right = right.right
   }
   for (let [key, val] of negatedAttributes) {
-    left = new ItemFormat(nextID(transaction), left, right, parent, null, key, val)
+    left = new ItemFormat(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, key, val)
     left.integrate(transaction)
   }
   return {left, right}
@@ -171,7 +171,7 @@ const insertAttributes = (transaction, parent, left, right, currentAttributes, a
     if (currentVal !== val) {
       // save negated attribute (set null if currentVal undefined)
       negatedAttributes.set(key, currentVal || null)
-      left = new ItemFormat(nextID(transaction), left, right, parent, null, key, val)
+      left = new ItemFormat(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, key, val)
       left.integrate(transaction)
     }
   }
@@ -199,9 +199,9 @@ const insertText = (transaction, parent, left, right, currentAttributes, text, a
   const insertPos = insertAttributes(transaction, parent, minPos.left, minPos.right, currentAttributes, attributes)
   // insert content
   if (text.constructor === String) {
-    left = new ItemString(nextID(transaction), insertPos.left, insertPos.right, parent, null, text)
+    left = new ItemString(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, text)
   } else {
-    left = new ItemEmbed(nextID(transaction), insertPos.left, insertPos.right, parent, null, text)
+    left = new ItemEmbed(nextID(transaction), left, left === null ? null : left.lastId, right, right === null ? null : right.id, parent, null, text)
   }
   left.integrate(transaction)
   return insertNegatedAttributes(transaction, parent, left, insertPos.right, insertPos.negatedAttributes)
@@ -249,7 +249,7 @@ const formatText = (transaction, parent, left, right, currentAttributes, length,
         case ItemEmbed:
         case ItemString:
           if (length < right.length) {
-            getItemCleanStart(transaction.y.store, transaction, createID(right.id.client, right.id.clock + length))
+            getItemCleanStart(transaction.y.store, createID(right.id.client, right.id.clock + length))
           }
           length -= right.length
           break
@@ -282,7 +282,7 @@ const deleteText = (transaction, parent, left, right, currentAttributes, length)
         case ItemEmbed:
         case ItemString:
           if (length < right.length) {
-            getItemCleanStart(transaction.y.store, transaction, createID(right.id.client, right.id.clock + length))
+            getItemCleanStart(transaction.y.store, createID(right.id.client, right.id.clock + length))
           }
           length -= right.length
           right.delete(transaction)
diff --git a/src/utils/DeleteSet.js b/src/utils/DeleteSet.js
index dd3d8493..c82e1d99 100644
--- a/src/utils/DeleteSet.js
+++ b/src/utils/DeleteSet.js
@@ -60,8 +60,10 @@ export const findIndexDS = (dis, clock) => {
         return midindex
       }
       left = midindex
-    } else {
+    } else if (right !== midindex) {
       right = midindex
+    } else {
+      break
     }
   }
   return null
@@ -125,14 +127,16 @@ export const createDeleteSetFromStructStore = ss => {
     const dsitems = []
     for (let i = 0; i < structs.length; i++) {
       const struct = structs[i]
-      const clock = struct.id.clock
-      let len = struct.length
-      if (i + 1 < structs.length) {
-        for (let next = structs[i + 1]; i + 1 < structs.length && next.id.clock === clock + len; i++) {
-          len += next.length
+      if (struct.deleted) {
+        const clock = struct.id.clock
+        let len = struct.length
+        if (i + 1 < structs.length) {
+          for (let next = structs[i + 1]; i + 1 < structs.length && next.id.clock === clock + len; i++) {
+            len += next.length
+          }
         }
+        dsitems.push(new DeleteItem(clock, len))
       }
-      dsitems.push(new DeleteItem(clock, len))
     }
     if (dsitems.length > 0) {
       ds.clients.set(client, dsitems)
@@ -172,7 +176,7 @@ export const readDeleteSet = (decoder, ss, transaction) => {
     for (let i = 0; i < len; i++) {
       const clock = decoding.readVarUint(decoder)
       const len = decoding.readVarUint(decoder)
-      getItemRange(ss, transaction, client, clock, len).forEach(struct => struct.delete(transaction))
+      getItemRange(ss, client, clock, len).forEach(struct => struct.delete(transaction))
     }
   }
 }
diff --git a/src/utils/ID.js b/src/utils/ID.js
index 114f7c47..133fb449 100644
--- a/src/utils/ID.js
+++ b/src/utils/ID.js
@@ -50,8 +50,8 @@ export class ID {
 }
 
 /**
- * @param {ID} a
- * @param {ID} b
+ * @param {ID | null} a
+ * @param {ID | null} b
  * @return {boolean}
  */
 export const compareIDs = (a, b) => a === b || (a !== null && b !== null && a.client === b.client && a.clock === b.clock)
diff --git a/src/utils/StructStore.js b/src/utils/StructStore.js
index 14c18f00..b07c417d 100644
--- a/src/utils/StructStore.js
+++ b/src/utils/StructStore.js
@@ -129,13 +129,12 @@ export const getItemType = (store, id) => find(store, id)
 /**
  * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
  * @param {StructStore} store
- * @param {Transaction} transaction
  * @param {ID} id
  * @return {AbstractItem}
  *
  * @private
  */
-export const getItemCleanStart = (store, transaction, id) => {
+export const getItemCleanStart = (store, id) => {
   /**
    * @type {Array<AbstractItem>}
    */
@@ -147,7 +146,7 @@ export const getItemCleanStart = (store, transaction, id) => {
    */
   let struct = structs[index]
   if (struct.id.clock < id.clock) {
-    struct = struct.splitAt(transaction, id.clock - struct.id.clock)
+    struct = struct.splitAt(store, id.clock - struct.id.clock)
     structs.splice(index, 0, struct)
   }
   return struct
@@ -156,13 +155,12 @@ export const getItemCleanStart = (store, transaction, id) => {
 /**
  * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
  * @param {StructStore} store
- * @param {Transaction} transaction
  * @param {ID} id
  * @return {AbstractItem}
  *
  * @private
  */
-export const getItemCleanEnd = (store, transaction, id) => {
+export const getItemCleanEnd = (store, id) => {
   /**
    * @type {Array<AbstractItem>}
    */
@@ -171,7 +169,7 @@ export const getItemCleanEnd = (store, transaction, id) => {
   const index = findIndexSS(structs, id.clock)
   const struct = structs[index]
   if (id.clock !== struct.id.clock + struct.length - 1) {
-    structs.splice(index, 0, struct.splitAt(transaction, id.clock - struct.id.clock + 1))
+    structs.splice(index, 0, struct.splitAt(store, id.clock - struct.id.clock + 1))
   }
   return struct
 }
@@ -179,7 +177,6 @@ export const getItemCleanEnd = (store, transaction, id) => {
 /**
  * Expects that id is actually in store. This function throws or is an infinite loop otherwise.
  * @param {StructStore} store
- * @param {Transaction} transaction
  * @param {number} client
  * @param {number} clock
  * @param {number} len
@@ -187,7 +184,7 @@ export const getItemCleanEnd = (store, transaction, id) => {
  *
  * @private
  */
-export const getItemRange = (store, transaction, client, clock, len) => {
+export const getItemRange = (store, client, clock, len) => {
   /**
    * @type {Array<AbstractItem>}
    */
@@ -196,17 +193,24 @@ export const getItemRange = (store, transaction, client, clock, len) => {
   let index = findIndexSS(structs, clock)
   let struct = structs[index]
   let range = []
-  if (struct.id.clock < clock) {
-    struct = struct.splitAt(transaction, clock - struct.id.clock)
-    structs.splice(index, 0, struct)
-  }
-  while (struct.id.clock + struct.length <= clock + len) {
+  if (struct.id.clock <= clock) {
+    if (struct.id.clock < clock) {
+      struct = struct.splitAt(store, clock - struct.id.clock)
+      structs.splice(index, 0, struct)
+    }
     range.push(struct)
-    struct = structs[++index]
   }
-  if (clock < struct.id.clock + struct.length) {
-    structs.splice(index, 0, struct.splitAt(transaction, clock + len - struct.id.clock))
-    range.push(struct)
+  index++
+  while (index < structs.length) {
+    struct = structs[index++]
+    if (struct.id.clock < clock + len) {
+      range.push(struct)
+    } else {
+      break
+    }
+  }
+  if (struct.id.clock < clock + len && struct.id.clock + struct.length > clock + len) {
+    structs.splice(index, 0, struct.splitAt(store, clock + len - struct.id.clock))
   }
   return range
 }
diff --git a/src/utils/Transaction.js b/src/utils/Transaction.js
index f446429d..66a04fb7 100644
--- a/src/utils/Transaction.js
+++ b/src/utils/Transaction.js
@@ -86,8 +86,8 @@ export class Transaction {
   get updateMessage () {
     if (this._updateMessage === null) {
       const encoder = encoding.createEncoder()
-      writeStructsFromTransaction(encoder, this)
       sortAndMergeDeleteSet(this.deleteSet)
+      writeStructsFromTransaction(encoder, this)
       writeDeleteSet(encoder, this.deleteSet)
       this._updateMessage = encoder
     }
diff --git a/src/utils/structEncoding.js b/src/utils/structEncoding.js
index b5980b4d..887f9e49 100644
--- a/src/utils/structEncoding.js
+++ b/src/utils/structEncoding.js
@@ -140,12 +140,13 @@ export const readStructs = (decoder, transaction, store) => {
    */
   const stack = []
   const localState = getStates(store)
+  let lastStructReader = null
   for (let i = 0; i < clientbeforeState; i++) {
     const nextID = readID(decoder)
     const decoderPos = decoder.pos + decoding.readUint32(decoder)
-    const structReaderDecoder = decoding.clone(decoder, decoderPos)
-    const numberOfStructs = decoding.readVarUint(structReaderDecoder)
-    structReaders.set(nextID.client, createStructReaderIterator(structReaderDecoder, numberOfStructs, nextID, localState.get(nextID.client) || 0))
+    lastStructReader = decoding.clone(decoder, decoderPos)
+    const numberOfStructs = decoding.readVarUint(lastStructReader)
+    structReaders.set(nextID.client, createStructReaderIterator(lastStructReader, numberOfStructs, nextID, localState.get(nextID.client) || 0))
   }
   for (const it of structReaders.values()) {
     // todo try for in of it
@@ -172,4 +173,8 @@ export const readStructs = (decoder, transaction, store) => {
       }
     }
   }
+  // if we read some structs, this points to the end of the transaction
+  if (lastStructReader !== null) {
+    decoder.pos = lastStructReader.pos
+  }
 }
diff --git a/tests/testHelper.js b/tests/testHelper.js
index d25187b2..4baddabe 100644
--- a/tests/testHelper.js
+++ b/tests/testHelper.js
@@ -321,8 +321,8 @@ export const compareStructStores = (ss1, ss2) => {
           !(s2 instanceof AbstractItem) ||
           !compareItemIDs(s1.left, s2.left) ||
           !compareItemIDs(s1.right, s2.right) ||
-          !compareItemIDs(s1.origin, s2.origin) ||
-          !compareItemIDs(s1.rightOrigin, s2.rightOrigin) ||
+          !Y.compareIDs(s1.origin, s2.origin) ||
+          !Y.compareIDs(s1.rightOrigin, s2.rightOrigin) ||
           s1.parentSub !== s2.parentSub
         ) {
           t.fail('Items dont match')