diff --git a/CHANGELOG.md b/CHANGELOG.md
index 207019f..fe20e2a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Change Log
 
+## [2.2.2] - 2021-10-19
+### Added
+- Added a new `:input-limit` option to transact. When included, the transaction will attempt to keep at or below this number of triples.
+
 ## [2.2.1] - 2021-10-16
 ### Fixed
 - Accepting java.time.Instant objects on the `since` and `as-of` database functions.
@@ -285,7 +289,8 @@
 ### Added
 - Introduced Update Annotations
 
-[Unreleased]: https://github.com/threatgrid/asami/compare/2.2.1...HEAD
+[Unreleased]: https://github.com/threatgrid/asami/compare/2.2.2...HEAD
+[2.2.2]: https://github.com/threatgrid/asami/compare/2.2.1...2.2.2
 [2.2.1]: https://github.com/threatgrid/asami/compare/2.2.0...2.2.1
 [2.2.0]: https://github.com/threatgrid/asami/compare/2.1.3...2.2.0
 [2.1.3]: https://github.com/threatgrid/asami/compare/2.1.2...2.1.3
diff --git a/README.md b/README.md
index 4a224e6..089927f 100644
--- a/README.md
+++ b/README.md
@@ -32,7 +32,7 @@ Asami can be made available to clojure by adding the following to a `deps.edn` f
 ```clojure
 {
   :deps {
-    org.clojars.quoll/asami {:mvn/version "2.2.1"}
+    org.clojars.quoll/asami {:mvn/version "2.2.2"}
   }
 }
 ```
@@ -41,7 +41,7 @@ This makes Asami available to a repl that is launched with the `clj` or `clojure
 
 Alternatively, Asami can be added for the Leiningen build tool by adding this to the `:dependencies` section of the `project.clj` file:
 ```clojure
-[org.clojars.quoll/asami "2.2.1"]
+[org.clojars.quoll/asami "2.2.2"]
 ```
 
 ### Important Note for databases before 2.1.0
diff --git a/project.clj b/project.clj
index e74a91f..4834823 100644
--- a/project.clj
+++ b/project.clj
@@ -1,4 +1,4 @@
-(defproject org.clojars.quoll/asami "2.2.1"
+(defproject org.clojars.quoll/asami "2.2.2"
   :description "An in memory graph store for Clojure and ClojureScript"
   :url "http://github.com/threatgrid/asami"
   :license {:name "Eclipse Public License"
diff --git a/src/asami/core.cljc b/src/asami/core.cljc
index 7c90d92..1940129 100644
--- a/src/asami/core.cljc
+++ b/src/asami/core.cljc
@@ -158,7 +158,8 @@
                                                     (s/one s/Any "attribute")
                                                     (s/one s/Any "value")]]
                      (s/optional-key :executor) s/Any
-                     (s/optional-key :update-fn) (s/pred fn?)}
+                     (s/optional-key :update-fn) (s/pred fn?)
+                     (s/optional-key :input-limit) s/Num}
                     [s/Any]))
 
 (s/defn transact-async
@@ -178,6 +179,7 @@
             Alternatively, a map may have a :tx-triples key. If so, then this is a seq of 3 element vectors.
             Each vector in a :tx-triples seq will contain the raw values for [entity attribute value]
             :executor An optional value in the tx-info containing an executor to be used to run the CompletableFuture
+            :input-limit contains an optional maximum number of statements to insert (approx)
   Entities and assertions may have attributes that are keywords with a trailing ' character.
   When these appear an existing attribute without that character will be replaced. This only occurs for the top level
   entity, and is not applied to attributes appearing in nested structures.
@@ -192,7 +194,7 @@
   :tx-data      sequence of datoms produced by the transaction
   :tempids      mapping of the temporary IDs in entities to the allocated nodes"
   [{:keys [name state] :as connection} :- ConnectionType
-   {:keys [tx-data tx-triples executor update-fn] :as tx-info} :- TransactData]
+   {:keys [tx-data tx-triples executor update-fn input-limit] :as tx-info} :- TransactData]
 
   ;; Detached databases need to be reattached when transacted into
   (check-attachment connection)
@@ -222,7 +224,9 @@
                                                                    (fn [graph]
                                                                      ;; building triples returns a tuple of assertions, retractions, tempids
                                                                      (let [[_ _ tempids :as result]
-                                                                           (entities/build-triples graph (seq-wrapper (or tx-data tx-info)))]
+                                                                           (entities/build-triples graph
+                                                                                                   (seq-wrapper (or tx-data tx-info))
+                                                                                                   input-limit)]
                                                                        (vreset! vtempids tempids)
                                                                        result))))
                      ;; pull out the info captured during the transaction
diff --git a/src/asami/entities.cljc b/src/asami/entities.cljc
index 983c3d6..c85e6d6 100644
--- a/src/asami/entities.cljc
+++ b/src/asami/entities.cljc
@@ -41,6 +41,11 @@
         (some append-attribute? obj-keys)
         (some #(and (map? %) (contains-updates? %)) (vals obj)))))
 
+(s/defn ^:private minus :- (s/maybe s/Num)
+  [limit :- (s/maybe s/Num)
+   n :- s/Num]
+  (when limit (- limit n)))
+
 (s/defn ^:private entity-triples :- [(s/one [Triple] "New triples")
                                      (s/one [Triple] "Retractions")
                                      (s/one {s/Any s/Any} "New list of ID mappings")
@@ -55,7 +60,8 @@
   [graph :- GraphType
    {id :db/id ident :db/ident ident2 :id :as obj} :- EntityMap
    existing-ids :- {s/Any s/Any}
-   top-ids :- #{s/Any}]
+   top-ids :- #{s/Any}
+   limit :- (s/maybe s/Num)]
   (let [[new-obj removals additions]
         (if (contains-updates? obj)
           (do
@@ -106,10 +112,16 @@
                                            (let [v (obj (append->annotate attr))
                                                  new-node (node/new-node graph)]
                                              [[(find-tail head) :tg/rest new-node] [new-node :tg/first v] [head :tg/contains v]])) attr-heads)]
-              [new-obj removals append-triples]))
+              (if (and limit (> (count append-triples) limit))
+                (throw (ex-info "Limit reached" {:overflow true}))
+                [new-obj removals append-triples])))
           [obj nil nil])
 
-        [triples ids new-top-ids] (writer/ident-map->triples graph new-obj existing-ids top-ids)
+        [triples ids new-top-ids] (writer/ident-map->triples graph
+                                                             new-obj
+                                                             existing-ids
+                                                             top-ids
+                                                             (minus limit (count additions)))
 
         ;; if updates occurred new entity statements are redundant
         triples (if (or (seq removals) (seq additions) (not (identical? obj new-obj)))
@@ -138,29 +150,44 @@
                           (s/one {s/Any s/Any} "ID map of created objects")]
   "Converts a set of transaction data into triples.
   Returns a tuple containing [triples removal-triples tempids]"
-  [graph :- gr/GraphType
-   data :- [s/Any]]
-  (let [[retract-stmts new-data] (util/divide' #(= :db/retract (first %)) data)
-        ref->id (partial resolve-lookup-refs graph)
-        retractions (mapv (comp (partial mapv ref->id) rest) retract-stmts)
-        add-triples (fn [[acc racc ids top-ids] obj]
-                      (if (map? obj)
-                        (let [[triples rtriples new-ids new-top-ids] (entity-triples graph obj ids top-ids)]
-                          [(into acc triples) (into racc rtriples) new-ids new-top-ids])
-                        (if (and (seqable? obj)
-                                 (= 4 (count obj))
-                                 (= :db/add (first obj)))
-                          (or
-                           (when (= (nth obj 2) :db/id)
-                             (let [id (nth obj 3)]
-                               (when (temp-id? id)
-                                 (let [new-id (or (ids id) (node/new-node graph))]
-                                   [(conj acc (assoc (vec-rest obj) 2 new-id))
-                                    racc
-                                    (assoc ids (or id new-id) new-id)
-                                    top-ids]))))
-                           [(conj acc (mapv #(or (ids %) (ref->id %)) (rest obj))) racc ids top-ids])
-                          (throw (ex-info (str "Bad data in transaction: " obj) {:data obj})))))
-        [triples rtriples id-map top-level-ids] (reduce add-triples [[] retractions {} #{}] new-data)
-        triples (writer/backtrack-unlink-top-entities top-level-ids triples)]
-    [triples rtriples id-map]))
+  ([graph :- gr/GraphType
+    data :- [s/Any]]
+   (build-triples graph data nil))
+  ([graph :- gr/GraphType
+    data :- [s/Any]
+    limit :- (s/maybe s/Num)]
+   (let [[retract-stmts new-data] (util/divide' #(= :db/retract (first %)) data)
+         ref->id (partial resolve-lookup-refs graph)
+         retractions (mapv (comp (partial mapv ref->id) rest) retract-stmts)
+         add-triples (fn [[acc racc ids top-ids :as last-result] obj]
+                       (if (and limit (> (count acc) limit))
+                         (reduced last-result)
+                         (if (map? obj)
+                           (try
+                             (let [[triples rtriples new-ids new-top-ids] (entity-triples graph
+                                                                                          obj
+                                                                                          ids
+                                                                                          top-ids
+                                                                                          (minus limit (count acc)))]
+                               [(into acc triples) (into racc rtriples) new-ids new-top-ids])
+                             (catch #?(:clj Exception :cljs :default) e
+                               (if-let [overflow (:overflow (ex-data e))]
+                                 (reduced last-result)
+                                 (throw e))))
+                           (if (and (seqable? obj)
+                                    (= 4 (count obj))
+                                    (= :db/add (first obj)))
+                             (or
+                              (when (= (nth obj 2) :db/id)
+                                (let [id (nth obj 3)]
+                                  (when (temp-id? id)
+                                    (let [new-id (or (ids id) (node/new-node graph))]
+                                      [(conj acc (assoc (vec-rest obj) 2 new-id))
+                                       racc
+                                       (assoc ids (or id new-id) new-id)
+                                       top-ids]))))
+                              [(conj acc (mapv #(or (ids %) (ref->id %)) (rest obj))) racc ids top-ids])
+                             (throw (ex-info (str "Bad data in transaction: " obj) {:data obj}))))))
+         [triples rtriples id-map top-level-ids] (reduce add-triples [[] retractions {} #{}] new-data)
+         triples (writer/backtrack-unlink-top-entities top-level-ids triples)]
+     [triples rtriples id-map])))
diff --git a/src/asami/entities/writer.cljc b/src/asami/entities/writer.cljc
index 14d61dd..e4dd282 100644
--- a/src/asami/entities/writer.cljc
+++ b/src/asami/entities/writer.cljc
@@ -33,6 +33,8 @@
 
 (def ^:dynamic *triples* nil)
 
+(def ^:dynamic *limit* nil)
+
 (def ^:dynamic *current-entity* nil)
 
 (def ^:dynamic *top-level-entities* nil)
@@ -43,6 +45,13 @@
 
 (declare value-triples map->triples)
 
+(defn add-triples!
+  [op data]
+  (vswap! *triples* op data)
+  (when (and *limit*
+             (> (count @*triples*) *limit*))
+    (throw (ex-info "overflow" {:overflow true}))))
+
 (defn list-triples
   "Creates the triples for a list. Returns a node and list of nodes representing contents of the list."
   [vlist]
@@ -52,9 +61,9 @@
         [list-ref value-nodes]
         (let [node-ref (node/new-node *current-graph*)
               _ (when last-ref
-                  (vswap! *triples* conj [last-ref :tg/rest node-ref]))
+                  (add-triples! conj [last-ref :tg/rest node-ref]))
               value-ref (value-triples v)]
-          (vswap! *triples* conj [node-ref (node/data-attribute *current-graph* value-ref) value-ref])
+          (add-triples! conj [node-ref (node/data-attribute *current-graph* value-ref) value-ref])
           (recur (or list-ref node-ref) node-ref (conj value-nodes value-ref) vs))))))
 
 (s/defn value-triples-list
@@ -62,7 +71,7 @@
   (if (seq vlist)
     (let [[node value-nodes] (list-triples vlist)]
       (doseq [vn value-nodes]
-        (vswap! *triples* conj [node (node/container-attribute *current-graph* vn) vn]))
+        (add-triples! conj [node (node/container-attribute *current-graph* vn) vn]))
       node)
     :tg/empty-list))
 
@@ -86,7 +95,7 @@
   (when-not (or (= node *current-entity*)
                 (@*top-level-entities* node)
                 (= node :tg/empty-list))
-    (vswap! *triples* conj [*current-entity* :tg/owns node]))
+    (add-triples! conj [*current-entity* :tg/owns node]))
   node)
 
 (defn value-triples
@@ -110,9 +119,9 @@
   (if (set? value)
     (doseq [v value]
       (let [vr (value-triples v)]
-        (vswap! *triples* conj [entity-ref property vr])))
+        (add-triples! conj [entity-ref property vr])))
     (let [v (value-triples value)]
-      (vswap! *triples* conj [entity-ref property v]))))
+      (add-triples! conj [entity-ref property v]))))
 
 (defn new-node
   [id]
@@ -185,22 +194,24 @@
   "Converts a single map to triples for an ID'ed map"
   ([graph :- GraphType
     j :- EntityMap]
-   (ident-map->triples graph j {} #{}))
+   (ident-map->triples graph j {} #{} nil))
   ([graph :- GraphType
     j :- EntityMap
     id-map :- {s/Any s/Any}
-    top-level-ids :- #{s/Any}]
+    top-level-ids :- #{s/Any}
+    limit :- (s/maybe s/Num)]
    (binding [*current-graph* graph
              *id-map* (volatile! id-map)
              *triples* (volatile! [])
+             *limit* limit
              *top-level-entities* (volatile! top-level-ids)]
      (let [derefed-id-map (ident-map->triples j)]
        [@*triples* derefed-id-map @*top-level-entities*])))
   ([j :- EntityMap]
    (let [node-ref (map->triples j)]
      (if (:db/ident j)
-       (vswap! *triples* conj [node-ref :tg/entity true])
-       (vswap! *triples* into [[node-ref :db/ident (name-for node-ref)] [node-ref :tg/entity true]]))
+       (add-triples! conj [node-ref :tg/entity true])
+       (add-triples! into [[node-ref :db/ident (name-for node-ref)] [node-ref :tg/entity true]]))
      @*id-map*)))
 
 (defn backtrack-unlink-top-entities
diff --git a/test/asami/api_test.cljc b/test/asami/api_test.cljc
index f1dcd22..e46ac7c 100644
--- a/test/asami/api_test.cljc
+++ b/test/asami/api_test.cljc
@@ -42,6 +42,26 @@
     (is (instance? asami.multi_graph.MultiGraph (:graph (:db @(:state cm)))))
     (is (= "banana" (:name cm)))))
 
+(deftest test-input-limit
+  (let [c (connect "asami:mem://limit1")
+        maksim {:db/id -1
+                :name  "Maksim"
+                :age   45
+                :wife {:db/id -2}
+                :aka   ["Maks Otto von Stirlitz", "Jack Ryan"]}
+        anna   {:db/id -2
+                :name  "Anna"
+                :age   31
+                :husband {:db/id -1}
+                :aka   ["Anitzka"]}
+        {:keys [tx-data]} @(transact c {:tx-data [maksim anna]})
+        c2 (connect "asami:mem://limit2")
+        {tx-data2 :tx-data} @(transact c2 {:tx-data [maksim anna] :input-limit 15})]
+    (is (= 21 (count tx-data)))
+    (is (= 21 (q '[:find (count *) . :where [?s ?p ?o]] c)))
+    (is (= 13 (count tx-data2)))
+    (is (= 13 (q '[:find (count *) . :where [?s ?p ?o]] c2)))))
+
 (deftest load-data
   (let [c (connect "asami:mem://test1")
         r (transact c {:tx-data [{:db/ident "bobid"
diff --git a/test/asami/entities/test_entity.cljc b/test/asami/entities/test_entity.cljc
index 5825e59..c5c782a 100644
--- a/test/asami/entities/test_entity.cljc
+++ b/test/asami/entities/test_entity.cljc
@@ -14,7 +14,8 @@
                :cljs [schema.test :as st :refer-macros [deftest]])
             #?(:clj  [clojure.test :as t :refer [is]]
                :cljs [clojure.test :as t :refer-macros [is]]))
-  #?(:clj (:import [java.time ZonedDateTime])
+  #?(:clj (:import [java.time ZonedDateTime]
+                   [clojure.lang ExceptionInfo])
      :cljs (:import [goog.date DateTime])))
 
 (defn parseDateTime [s]
@@ -287,6 +288,23 @@
     (is (= data obj1))
     (is (= (assoc data :sub (dissoc d0 :db/ident)) obj2))))
 
+(deftest test-entity-limits
+  (let [m1 {:prop "val"}
+        m2 {:prop "val", :p2 2}
+        m3 {:prop "val", :p2 22, :p3 [42 54]}
+        m4 {:prop "val"}
+        m5 {:prop "val2"}
+        m6 {:prop "val" :arr [{:a 1} {:a 2} ["nested"]]}
+        m7 {:prop "val", :p2 22, :p3 []}]
+    (is (= 3 (count (first (ident-map->triples empty-graph m1 {} #{} 18)))))
+    (is (= 4 (count (first (ident-map->triples empty-graph m2 {} #{} 18)))))
+    (is (= 11 (count (first (ident-map->triples empty-graph m3 {} #{} 18)))))
+    (is (= 3 (count (first (ident-map->triples empty-graph m4 {} #{} 18)))))
+    (is (= 3 (count (first (ident-map->triples empty-graph m5 {} #{} 18)))))
+    (is (thrown-with-msg? ExceptionInfo #"overflow"
+                          (ident-map->triples empty-graph m6 {} #{} 18)))
+    (is (= 5 (count (first (ident-map->triples empty-graph m7 {} #{} 18)))))))
+
 (deftest test-looped-ref->entity
   (let [d1 {:db/ident :t1, :task/name "Task 1", :task/requires [#:db{:ident :t3}]}
         d2 {:db/ident :t2, :task/name "Task 2", :task/requires [#:db{:ident :t1}]}
@@ -306,7 +324,7 @@
 (defn ident-map->graph
   ([m] (ident-map->graph m {}))
   ([m mp]
-   (let [[triples result-map] (ident-map->triples empty-graph m mp #{})]
+   (let [[triples result-map] (ident-map->triples empty-graph m mp #{} nil)]
      [(set triples) result-map])))
 
 (deftest test-ident-map->triples