diff --git a/ui/shared/lti/jquery/__tests__/platform_storage.test.js b/ui/shared/lti/jquery/__tests__/platform_storage.test.js
new file mode 100644
index 00000000000..0e2d0496ed6
--- /dev/null
+++ b/ui/shared/lti/jquery/__tests__/platform_storage.test.js
@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) 2021 - present Instructure, Inc.
+ *
+ * This file is part of Canvas.
+ *
+ * Canvas is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Affero General Public License as published by the Free
+ * Software Foundation, version 3 of the License.
+ *
+ * Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU Affero General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import {
+  addToLimit,
+  clearData,
+  clearLimit,
+  getData,
+  getLimit,
+  putData,
+  removeFromLimit
+} from '../platform_storage'
+
+describe('platform_storage', () => {
+  const tool_id = 'tool_id'
+  const key = 'key'
+  const value = 'value'
+
+  beforeEach(() => {
+    clearLimit(tool_id)
+  })
+
+  describe('getLimit', () => {
+    it('defaults counts to 0', () => {
+      const limit = getLimit('tool that does not have limit already')
+      expect(limit.keyCount).toBe(0)
+      expect(limit.charCount).toBe(0)
+    })
+  })
+
+  describe('addToLimit', () => {
+    it('increments key count for tool id', () => {
+      const before = {...getLimit(tool_id)}
+      addToLimit(tool_id, key, value)
+      const after = getLimit(tool_id)
+      expect(after.keyCount).toEqual(before.keyCount + 1)
+    })
+
+    it('adds key and value length to char count for tool', () => {
+      const before = {...getLimit(tool_id)}
+      addToLimit(tool_id, key, value)
+      const after = getLimit(tool_id)
+      expect(after.charCount).toEqual(before.charCount + key.length + value.length)
+    })
+
+    describe('when tool has reached key count limit', () => {
+      beforeEach(() => {
+        getLimit(tool_id).keyCount = 500
+      })
+
+      it('throws a storage_exhaustion error', () => {
+        expect(() => addToLimit(tool_id, key, value)).toThrow('Reached key limit')
+      })
+    })
+
+    describe('when tool has reached char count limit', () => {
+      beforeEach(() => {
+        getLimit(tool_id).charCount = 4096
+      })
+
+      it('throws a storage_exhaustion error', () => {
+        expect(() => addToLimit(tool_id, key, value)).toThrow('Reached byte limit')
+      })
+    })
+  })
+
+  describe('removeFromLimit', () => {
+    beforeEach(() => {
+      addToLimit(tool_id, 'hello', 'world')
+      addToLimit(tool_id, key, value)
+    })
+
+    it('decrements key count for tool id', () => {
+      const before = {...getLimit(tool_id)}
+      removeFromLimit(tool_id, key, value)
+      const after = getLimit(tool_id)
+      expect(after.keyCount).toEqual(before.keyCount - 1)
+    })
+
+    it('removes key and value length from char count for tool', () => {
+      const before = {...getLimit(tool_id)}
+      removeFromLimit(tool_id, key, value)
+      const after = getLimit(tool_id)
+      expect(after.charCount).toEqual(before.charCount - key.length - value.length)
+    })
+
+    describe('when key count goes below 0', () => {
+      beforeEach(() => {
+        removeFromLimit(tool_id, key, value)
+        removeFromLimit(tool_id, key, value)
+        removeFromLimit(tool_id, key, value)
+      })
+
+      it('resets key count to 0', () => {
+        const {keyCount} = getLimit(tool_id)
+        expect(keyCount).toBe(0)
+      })
+    })
+
+    describe('when char count goes below 0', () => {
+      beforeEach(() => {
+        removeFromLimit(tool_id, key, value)
+        removeFromLimit(tool_id, key, value)
+        removeFromLimit(tool_id, key, value)
+      })
+
+      it('resets char count to 0', () => {
+        const {charCount} = getLimit(tool_id)
+        expect(charCount).toBe(0)
+      })
+    })
+  })
+
+  describe('putData', () => {
+    beforeEach(() => {
+      jest.spyOn(window.localStorage, 'setItem')
+    })
+
+    it('namespaces key with tool id', () => {
+      putData(tool_id, key, value)
+      expect(window.localStorage.setItem).toHaveBeenCalledWith(
+        `lti|platform_storage|${tool_id}|${key}`,
+        value
+      )
+    })
+  })
+
+  describe('getData', () => {
+    beforeEach(() => {
+      jest.spyOn(window.localStorage, 'getItem')
+      putData(tool_id, key, value)
+    })
+
+    it('namespaces key with tool id', () => {
+      getData(tool_id, key)
+      expect(window.localStorage.getItem).toHaveBeenCalledWith(
+        `lti|platform_storage|${tool_id}|${key}`
+      )
+    })
+  })
+
+  describe('clearData', () => {
+    beforeEach(() => {
+      jest.spyOn(window.localStorage, 'removeItem')
+    })
+
+    describe('when key does not exist', () => {
+      it('does nothing', () => {
+        expect(window.localStorage.removeItem).not.toHaveBeenCalled()
+      })
+    })
+
+    describe('when key is already stored', () => {
+      beforeEach(() => {
+        jest.spyOn(window.localStorage, 'getItem').mockImplementation(() => value)
+        putData(tool_id, key, value)
+      })
+
+      it('namespaces key with tool id', () => {
+        clearData(tool_id, key)
+        expect(window.localStorage.removeItem).toHaveBeenCalledWith(
+          `lti|platform_storage|${tool_id}|${key}`
+        )
+      })
+    })
+  })
+})
diff --git a/ui/shared/lti/jquery/platform_storage.js b/ui/shared/lti/jquery/platform_storage.js
new file mode 100644
index 00000000000..cb067aa1f80
--- /dev/null
+++ b/ui/shared/lti/jquery/platform_storage.js
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2021 - present Instructure, Inc.
+ *
+ * This file is part of Canvas.
+ *
+ * Canvas is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Affero General Public License as published by the Free
+ * Software Foundation, version 3 of the License.
+ *
+ * Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU Affero General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+const STORAGE_CHAR_LIMIT = 4096 // IMS minimum storage limit is 4096 bytes so 4096 chars is more than enough
+const STORAGE_KEY_LIMIT = 500
+
+const limits = {}
+
+const createLimit = tool_id => {
+  if (!limits[tool_id]) {
+    limits[tool_id] = {keyCount: 0, charCount: 0}
+  }
+}
+
+const getLimit = tool_id => {
+  createLimit(tool_id)
+  return limits[tool_id]
+}
+
+const clearLimit = tool_id => {
+  delete limits[tool_id]
+}
+
+const addToLimit = (tool_id, key, value) => {
+  createLimit(tool_id)
+  const length = key.length + value.length
+
+  if (limits[tool_id].keyCount >= STORAGE_KEY_LIMIT) {
+    const e = new Error('Reached key limit for tool')
+    e.code = 'storage_exhaustion'
+    throw e
+  }
+
+  if (limits[tool_id].charCount + length > STORAGE_CHAR_LIMIT) {
+    const e = new Error('Reached byte limit for tool')
+    e.code = 'storage_exhaustion'
+    throw e
+  }
+
+  limits[tool_id].keyCount++
+  limits[tool_id].charCount += length
+}
+
+const removeFromLimit = (tool_id, key, value) => {
+  limits[tool_id].keyCount--
+  limits[tool_id].charCount -= key.length + value.length
+
+  if (limits[tool_id].keyCount < 0) {
+    limits[tool_id].keyCount = 0
+  }
+  if (limits[tool_id].charCount < 0) {
+    limits[tool_id].charCount = 0
+  }
+}
+
+const getKey = (tool_id, key) => `lti|platform_storage|${tool_id}|${key}`
+
+const putData = (tool_id, key, value) => {
+  addToLimit(tool_id, key, value)
+  window.localStorage.setItem(getKey(tool_id, key), value)
+}
+
+const getData = (tool_id, key) => window.localStorage.getItem(getKey(tool_id, key))
+
+const clearData = (tool_id, key) => {
+  const value = getData(tool_id, key)
+  if (value) {
+    removeFromLimit(tool_id, key, value)
+    window.localStorage.removeItem(getKey(tool_id, key))
+  }
+}
+
+export {getLimit, clearLimit, addToLimit, removeFromLimit, clearData, getData, putData}