diff --git a/develop/untests.lua b/develop/untests.lua
index 04f3a36..b557f5d 100644
--- a/develop/untests.lua
+++ b/develop/untests.lua
@@ -4084,3 +4084,258 @@ do
         assert(last_assign_old_component == nil)
     end
 end
+
+do
+    local f1, f2, f3, f4 = evo.id(4)
+
+    local e1 = evo.entity():set(f1, 11):build()
+    local e2 = evo.entity():set(f1, 21):set(f2, 22):build()
+    local e3 = evo.entity():set(f1, 31):set(f2, 32):set(f3, 33):build()
+    local e4 = evo.entity():set(f1, 41):set(f2, 42):set(f3, 43):set(f4, 44):build()
+
+    do
+        local q = evo.query():include(f1):build()
+
+        assert(evo.batch_multi_insert(q, {}) == 0)
+        assert(evo.batch_multi_insert(q, { f1 }) == 0)
+    end
+
+    do
+        local q = evo.query():include(f3):build()
+
+        assert(evo.batch_multi_insert(q, { f4 }) == 1)
+        assert(evo.get(e3, f1) == 31 and evo.get(e3, f2) == 32 and evo.get(e3, f3) == 33 and evo.get(e3, f4) == true)
+        assert(evo.get(e4, f1) == 41 and evo.get(e4, f2) == 42 and evo.get(e4, f3) == 43 and evo.get(e4, f4) == 44)
+
+        do
+            local c123, c123_es = evo.chunk(f1, f2, f3)
+            assert(c123 and #c123_es == 0)
+            assert(#evo.select(c123, f1) == 0)
+            assert(#evo.select(c123, f2) == 0)
+            assert(#evo.select(c123, f3) == 0)
+
+            local c1234, c1234_es = evo.chunk(f1, f2, f3, f4)
+            assert(c1234 and #c1234_es == 2)
+            assert(#evo.select(c1234, f1) == 2)
+            assert(#evo.select(c1234, f2) == 2)
+            assert(#evo.select(c1234, f3) == 2)
+            assert(#evo.select(c1234, f4) == 2)
+        end
+    end
+
+    do
+        local q = evo.query():include(f1):build()
+
+        assert(evo.batch_multi_insert(q, { f3, f4 }, { 53, 54 }) == 2)
+        assert(evo.get(e1, f1) == 11 and evo.get(e1, f2) == nil and evo.get(e1, f3) == 53 and evo.get(e1, f4) == 54)
+        assert(evo.get(e2, f1) == 21 and evo.get(e2, f2) == 22 and evo.get(e2, f3) == 53 and evo.get(e2, f4) == 54)
+        assert(evo.get(e3, f1) == 31 and evo.get(e3, f2) == 32 and evo.get(e3, f3) == 33 and evo.get(e3, f4) == true)
+        assert(evo.get(e4, f1) == 41 and evo.get(e4, f2) == 42 and evo.get(e4, f3) == 43 and evo.get(e4, f4) == 44)
+
+        do
+            local c1, c1_es = evo.chunk(f1)
+            assert(c1 and #c1_es == 0)
+            assert(#evo.select(c1, f1) == 0)
+        end
+
+        do
+            local c12, c12_es = evo.chunk(f1, f2)
+            assert(c12 and #c12_es == 0)
+            assert(#evo.select(c12, f1) == 0)
+            assert(#evo.select(c12, f2) == 0)
+        end
+
+        do
+            local c134, c134_es = evo.chunk(f1, f3, f4)
+            assert(c134 and #c134_es == 1)
+            assert(#evo.select(c134, f1) == 1)
+            assert(#evo.select(c134, f3) == 1)
+            assert(#evo.select(c134, f4) == 1)
+        end
+
+        do
+            local c1234, c1234_es = evo.chunk(f1, f2, f3, f4)
+            assert(c1234 and #c1234_es == 3)
+            assert(#evo.select(c1234, f1) == 3)
+            assert(#evo.select(c1234, f2) == 3)
+            assert(#evo.select(c1234, f3) == 3)
+            assert(#evo.select(c1234, f4) == 3)
+        end
+    end
+end
+
+do
+    local f1, f2, f3, f4 = evo.id(4)
+
+    evo.set(f2, evo.DEFAULT, 41)
+    evo.set(f3, evo.TAG)
+
+    local e1 = evo.entity():set(f1, 11):build()
+    local e2 = evo.entity():set(f1, 21):set(f2, 22):build()
+    local e3 = evo.entity():set(f1, 31):set(f2, 32):set(f3, 33):build()
+    local e4 = evo.entity():set(f1, 41):set(f2, 42):set(f3, 43):set(f4, 44):build()
+
+    assert(evo.get(e1, f1) == 11 and evo.get(e1, f2) == nil and evo.get(e1, f3) == nil)
+    assert(evo.get(e2, f1) == 21 and evo.get(e2, f2) == 22 and evo.get(e2, f3) == nil)
+    assert(evo.get(e3, f1) == 31 and evo.get(e3, f2) == 32 and evo.get(e3, f3) == nil)
+    assert(evo.get(e4, f1) == 41 and evo.get(e4, f2) == 42 and evo.get(e4, f3) == nil and evo.get(e4, f4) == 44)
+
+    do
+        local q = evo.query():include(f1):build()
+        assert(evo.batch_multi_insert(q, {}) == 0)
+    end
+
+    do
+        local q = evo.query():include(f1):build()
+        assert(evo.batch_multi_insert(q, { f2 }) == 1)
+
+        assert(evo.get(e1, f1) == 11 and evo.get(e1, f2) == 41 and evo.get(e1, f3) == nil)
+        assert(evo.get(e2, f1) == 21 and evo.get(e2, f2) == 22 and evo.get(e2, f3) == nil)
+        assert(evo.get(e3, f1) == 31 and evo.get(e3, f2) == 32 and evo.get(e3, f3) == nil)
+        assert(evo.get(e4, f1) == 41 and evo.get(e4, f2) == 42 and evo.get(e4, f3) == nil and evo.get(e4, f4) == 44)
+    end
+end
+
+do
+    local f1, f2, f3, f4, f5 = evo.id(5)
+
+    evo.set(f2, evo.DEFAULT, 42)
+    evo.set(f3, evo.TAG)
+
+    local sum_entity = 0
+    local last_insert_entity = 0
+    local last_insert_component = 0
+
+    evo.set(f1, evo.ON_INSERT, function(e, f, c)
+        assert(f == f1)
+        sum_entity = sum_entity + e
+        last_insert_entity = e
+        last_insert_component = c
+    end)
+
+    evo.set(f2, evo.ON_INSERT, function(e, f, c)
+        assert(f == f2)
+        sum_entity = sum_entity + e
+        last_insert_entity = e
+        last_insert_component = c
+    end)
+
+    evo.set(f3, evo.ON_INSERT, function(e, f, c)
+        assert(f == f3)
+        sum_entity = sum_entity + e
+        last_insert_entity = e
+        last_insert_component = c
+    end)
+
+    evo.set(f4, evo.ON_INSERT, function(e, f, c)
+        assert(f == f4)
+        sum_entity = sum_entity + e
+        last_insert_entity = e
+        last_insert_component = c
+    end)
+
+    evo.set(f5, evo.ON_INSERT, function(e, f, c)
+        assert(f == f5)
+        sum_entity = sum_entity + e
+        last_insert_entity = e
+        last_insert_component = c
+    end)
+
+    local e1 = evo.entity():set(f1, 11):build()
+    local e2 = evo.entity():set(f1, 21):set(f2, 22):build()
+    local e3 = evo.entity():set(f1, 31):set(f2, 32):set(f3, 33):build()
+
+    do
+        local q = evo.query():include(f1):build()
+
+        sum_entity = 0
+        last_insert_entity = 0
+        last_insert_component = 0
+
+        assert(evo.batch_multi_insert(q, { f2 }) == 1)
+        assert(sum_entity == e1)
+        assert(last_insert_entity == e1)
+        assert(last_insert_component == 42)
+        assert(evo.has(e1, f1) and evo.has(e1, f2) and not evo.has(e1, f3))
+        assert(evo.has(e2, f1) and evo.has(e2, f2) and not evo.has(e2, f3))
+        assert(evo.has(e3, f1) and evo.has(e3, f2) and evo.has(e3, f3))
+        assert(evo.get(e1, f1) == 11 and evo.get(e1, f2) == 42 and evo.get(e1, f3) == nil)
+        assert(evo.get(e2, f1) == 21 and evo.get(e2, f2) == 22 and evo.get(e2, f3) == nil)
+        assert(evo.get(e3, f1) == 31 and evo.get(e3, f2) == 32 and evo.get(e3, f3) == nil)
+    end
+
+    do
+        local q = evo.query():include(f2):build()
+
+        sum_entity = 0
+        last_insert_entity = 0
+        last_insert_component = 0
+
+        assert(evo.batch_multi_insert(q, { f3 }) == 2)
+        assert(sum_entity == e1 + e2)
+        assert(last_insert_entity == e1)
+        assert(last_insert_component == nil)
+        assert(evo.has(e1, f1) and evo.has(e1, f2) and evo.has(e1, f3))
+        assert(evo.has(e2, f1) and evo.has(e2, f2) and evo.has(e2, f3))
+        assert(evo.has(e3, f1) and evo.has(e3, f2) and evo.has(e3, f3))
+        assert(evo.get(e1, f1) == 11 and evo.get(e1, f2) == 42 and evo.get(e1, f3) == nil)
+        assert(evo.get(e2, f1) == 21 and evo.get(e2, f2) == 22 and evo.get(e2, f3) == nil)
+        assert(evo.get(e3, f1) == 31 and evo.get(e3, f2) == 32 and evo.get(e3, f3) == nil)
+    end
+
+    do
+        local q = evo.query():include(f1, f2, f3):build()
+
+        sum_entity = 0
+        last_insert_entity = 0
+        last_insert_component = 0
+
+        assert(evo.batch_multi_insert(q, { f3, f4, f5, f5 }, { 53, 54, 55, 65 }) == 3)
+        assert(sum_entity == e1 + e2 + e3 + e1 + e2 + e3)
+        assert(last_insert_entity == e1)
+        assert(last_insert_component == 55)
+        assert(evo.has_all(e1, f1, f2, f3, f4, f5))
+        assert(evo.has_all(e2, f1, f2, f3, f4, f5))
+        assert(evo.has_all(e3, f1, f2, f3, f4, f5))
+        assert(evo.get(e1, f1) == 11 and evo.get(e1, f2) == 42 and evo.get(e1, f3) == nil)
+        assert(evo.get(e2, f1) == 21 and evo.get(e2, f2) == 22 and evo.get(e2, f3) == nil)
+        assert(evo.get(e3, f1) == 31 and evo.get(e3, f2) == 32 and evo.get(e3, f3) == nil)
+        assert(evo.get(e1, f4) == 54 and evo.get(e1, f5) == 55)
+        assert(evo.get(e2, f4) == 54 and evo.get(e2, f5) == 55)
+        assert(evo.get(e3, f4) == 54 and evo.get(e3, f5) == 55)
+    end
+end
+
+do
+    local f1, f2, f3 = evo.id(3)
+
+    local e1 = evo.entity():set(f1, 11):build()
+    local e2 = evo.entity():set(f1, 21):set(f2, 22):build()
+    local e3 = evo.entity():set(f1, 31):set(f2, 32):set(f3, 33):build()
+
+    assert(evo.defer())
+    do
+        local q = evo.query():include(f1):build()
+        do
+            local n, d = evo.batch_multi_insert(q, { f2 }, { 42 })
+            assert(n == 0 and d == true)
+        end
+        do
+            local n, d = evo.batch_multi_assign(q, { f3 }, { 43 })
+            assert(n == 0 and d == true)
+        end
+        do
+            local n, d = evo.batch_multi_remove(q, { f1 })
+            assert(n == 0 and d == true)
+        end
+        assert(evo.get(e1, f1) == 11 and evo.get(e1, f2) == nil and evo.get(e1, f3) == nil)
+        assert(evo.get(e2, f1) == 21 and evo.get(e2, f2) == 22 and evo.get(e2, f3) == nil)
+        assert(evo.get(e3, f1) == 31 and evo.get(e3, f2) == 32 and evo.get(e3, f3) == 33)
+    end
+    assert(evo.commit())
+    do
+        assert(evo.get(e1, f1) == nil and evo.get(e1, f2) == 42 and evo.get(e1, f3) == nil)
+        assert(evo.get(e2, f1) == nil and evo.get(e2, f2) == 22 and evo.get(e2, f3) == nil)
+        assert(evo.get(e3, f1) == nil and evo.get(e3, f2) == 32 and evo.get(e3, f3) == 43)
+    end
+end
diff --git a/evolved.lua b/evolved.lua
index dac0d27..6106a5e 100644
--- a/evolved.lua
+++ b/evolved.lua
@@ -1473,7 +1473,152 @@ end
 ---@param components evolved.component[]
 ---@return integer inserted_count
 local function __chunk_multi_insert(chunk, fragments, components)
-    error('not implemented yet', 2)
+    if __defer_depth <= 0 then
+        error('batched chunk operations should be deferred', 2)
+    end
+
+    local fragment_count = #fragments
+
+    if fragment_count == 0 then
+        return 0
+    end
+
+    local old_chunk = chunk
+    local new_chunk = __chunk_with_fragment_list(chunk, fragments)
+
+    if not new_chunk or old_chunk == new_chunk then
+        return 0
+    end
+
+    local old_entities = old_chunk.__entities
+    local old_size = #old_entities
+
+    local old_fragment_set = old_chunk.__fragment_set
+    local old_component_storages = old_chunk.__component_storages
+    local old_component_fragments = old_chunk.__component_fragments
+
+    local new_entities = new_chunk.__entities
+    local new_size = #new_entities
+
+    local new_component_indices = new_chunk.__component_indices
+    local new_component_storages = new_chunk.__component_storages
+
+    do
+        __table_move(
+            old_entities, 1, old_size,
+            new_size + 1, new_entities)
+
+        for i = 1, #old_component_fragments do
+            local old_f = old_component_fragments[i]
+            local old_cs = old_component_storages[i]
+            local new_ci = new_component_indices[old_f]
+            if new_ci then
+                local new_cs = new_component_storages[new_ci]
+                __table_move(old_cs, 1, old_size, new_size + 1, new_cs)
+            end
+        end
+    end
+
+    local inserted_set = __acquire_table(__TABLE_POOL_TAG__FRAGMENT_SET, 0, fragment_count)
+
+    for i = 1, fragment_count do
+        local fragment = fragments[i]
+        if not inserted_set[fragment] and not old_fragment_set[fragment] then
+            inserted_set[fragment] = true
+            if new_chunk.__has_set_or_insert_hooks and __fragment_has_set_or_insert_hooks(fragment) then
+                local new_component_index = new_component_indices[fragment]
+                if new_component_index then
+                    local new_component_storage = new_component_storages[new_component_index]
+                    if new_chunk.__has_defaults_or_constructs and __fragment_has_default_or_construct(fragment) then
+                        local new_component = components[i]
+
+                        if new_component == nil then
+                            new_component = evolved.get(fragment, evolved.DEFAULT)
+                        end
+
+                        if new_component == nil then
+                            new_component = true
+                        end
+
+                        for new_place = new_size + 1, new_size + old_size do
+                            local entity = new_entities[new_place]
+                            new_component_storage[new_place] = new_component
+                            __fragment_call_set_and_insert_hooks(entity, fragment, new_component)
+                        end
+                    else
+                        local new_component = components[i]
+
+                        if new_component == nil then
+                            new_component = true
+                        end
+
+                        for new_place = new_size + 1, new_size + old_size do
+                            local entity = new_entities[new_place]
+                            new_component_storage[new_place] = new_component
+                            __fragment_call_set_and_insert_hooks(entity, fragment, new_component)
+                        end
+                    end
+                else
+                    for new_place = new_size + 1, new_size + old_size do
+                        local entity = new_entities[new_place]
+                        __fragment_call_set_and_insert_hooks(entity, fragment)
+                    end
+                end
+            else
+                local new_component_index = new_component_indices[fragment]
+                if new_component_index then
+                    local new_component_storage = new_component_storages[new_component_index]
+                    if new_chunk.__has_defaults_or_constructs and __fragment_has_default_or_construct(fragment) then
+                        local new_component = components[i]
+
+                        if new_component == nil then
+                            new_component = evolved.get(fragment, evolved.DEFAULT)
+                        end
+
+                        if new_component == nil then
+                            new_component = true
+                        end
+
+                        for new_place = new_size + 1, new_size + old_size do
+                            new_component_storage[new_place] = new_component
+                        end
+                    else
+                        local new_component = components[i]
+
+                        if new_component == nil then
+                            new_component = true
+                        end
+
+                        for new_place = new_size + 1, new_size + old_size do
+                            new_component_storage[new_place] = new_component
+                        end
+                    end
+                else
+                    -- nothing
+                end
+            end
+        end
+    end
+
+    __release_table(__TABLE_POOL_TAG__FRAGMENT_SET, inserted_set)
+
+    for new_place = new_size + 1, new_size + old_size do
+        local entity = new_entities[new_place]
+        local entity_index = entity % 0x100000
+        __entity_chunks[entity_index] = new_chunk
+        __entity_places[entity_index] = new_place
+    end
+
+    do
+        old_chunk.__entities = {}
+
+        for i = 1, #old_component_storages do
+            old_component_storages[i] = {}
+        end
+    end
+
+    __structural_changes = __structural_changes + old_size
+    return old_size
 end
 
 ---@param chunk evolved.chunk