# Add modules to your dapp · Tic Tac Toe on Chromia with Rell and Unity · Learn Chromia > Start applying this by splitting your code into smaller modules. Create a folder at Tic_tac_toe_Rell/src/tic_tac_toe and add a module.rell file to it: Source: https://chromia.com/learn/tic-tac-toe/module-one/project-structure/incorporate-modules/ Tic Tac Toe on Chromia with Rell and UnityLesson 14 of 20 1. [01Tic Tac Toe on Chromia with Rell and Unity](https://chromia.com/learn/tic-tac-toe/introduction/) 2. [02Set up your project](https://chromia.com/learn/tic-tac-toe/setup/) Module 1: A Rell backend with FT4 accounts 1. [03Overview](https://chromia.com/learn/tic-tac-toe/module-one/) 2. [04Part 1: Database design, operations and queries](https://chromia.com/learn/tic-tac-toe/module-one/data-modeling/) 3. [05Design the data model](https://chromia.com/learn/tic-tac-toe/module-one/data-modeling/tables/) 4. [06Perform basic operations](https://chromia.com/learn/tic-tac-toe/module-one/data-modeling/basic-operations/) 5. [07Write basic queries](https://chromia.com/learn/tic-tac-toe/module-one/data-modeling/write-queries/) 6. [08Part 2: Set up accounts](https://chromia.com/learn/tic-tac-toe/module-one/create-accounts/) 7. [09Configure FT4 accounts](https://chromia.com/learn/tic-tac-toe/module-one/create-accounts/install-configure-ft4/) 8. [10Authentication with FT4 accounts](https://chromia.com/learn/tic-tac-toe/module-one/create-accounts/authentication/) 9. [11Update tests](https://chromia.com/learn/tic-tac-toe/module-one/create-accounts/update-tests/) 10. [12Part 3: How the dapp project is organized](https://chromia.com/learn/tic-tac-toe/module-one/project-structure/) 11. [13Work with Rell modules](https://chromia.com/learn/tic-tac-toe/module-one/project-structure/modules/) 12. [14Add modules to your dapp](https://chromia.com/learn/tic-tac-toe/module-one/project-structure/incorporate-modules/) Module 2: The Unity project 1. [15Overview](https://chromia.com/learn/tic-tac-toe/module-two/) 2. [16Set up the project](https://chromia.com/learn/tic-tac-toe/module-two/setup/) 3. [17Project scaffold](https://chromia.com/learn/tic-tac-toe/module-two/scaffold/) 4. [18Link the client to the blockchain](https://chromia.com/learn/tic-tac-toe/module-two/connecting-the-client/) 5. [19Summary and manual testing](https://chromia.com/learn/tic-tac-toe/module-two/summary-and-tests/) 1. [20What next?](https://chromia.com/learn/tic-tac-toe/what-next/) [Learn](https://chromia.com/learn/)[Tic Tac Toe on Chromia with Rell and Unity](https://chromia.com/learn/tic-tac-toe/) 14 / 20Module 1: A Rell backend with FT4 accounts # Add modules to your dapp Start applying this by splitting your code into smaller modules. Create a folder at `Tic_tac_toe_Rell/src/tic_tac_toe` and add a `module.rell` file to it: src/news\_feed/module.rell ```nolines module; ``` Then add a file at `src/tic_tac_toe/entities.rell` and move your entity definitions there. src/main/entities.rell ``` entity game { created_by: account; created_at: timestamp = get_last_block_time(); mutable player2_account_rowid: rowid = rowid(0); mutable last_step_by: rowid; mutable last_step_at: timestamp = get_last_block_time(); mutable winner: rowid = rowid(0); mutable status: game_status = game_status.created; mutable slot_1: slot_states = slot_states.free; mutable slot_2: slot_states = slot_states.free; mutable slot_3: slot_states = slot_states.free; mutable slot_4: slot_states = slot_states.free; mutable slot_5: slot_states = slot_states.free; mutable slot_6: slot_states = slot_states.free; mutable slot_7: slot_states = slot_states.free; mutable slot_8: slot_states = slot_states.free; mutable slot_9: slot_states = slot_states.free; } ``` Move the import of the `account` entity from the `ft4-library` into `module.rell` as well. Placing it there gives every file in the module access to it. src/news\_feed/module.rell ``` module; import lib.ft4.accounts.{ account: account }; import ft4_auth: lib.ft4.auth; ``` Next, add a file in the `src/test/tic_tac_toe` folder and declare it as a module, which creates a new module called `module`: src/test/tic\_tac\_toe/module.rell ``` @test module; import tic_tac_toe.{ game, game_status, slot_states }; import tic_tac_toe.external.{ create_game, get_games_by_status, join_game, make_move, get_game_by_id }; import lib.ft4.accounts.{ account: account, auth_descriptor }; import lib.ft4.core.accounts.strategies.open.{ ras_open }; import lib.ft4.test.core. { create_auth_descriptor, ft_auth_operation_for }; import lib.ft4.external.accounts.strategies.{ register_account }; ``` To switch your dapp's entry point between the `main` module and the `development` module, change the `module:` tag in the `blockchains` definition of your `chromia.yml` file: chromia.yml ``` blockchains: tic_tac_toe: module: main moduleArgs: lib.ft4.core.admin: admin_pubkey: x"023BEE5A479CE5AF31F6F64EDE7BEAD394E92E4D973E1727782DB577A55E878563" # It can be completely random for learning purposes. compile: rellVersion: 0.14.9 database: schema: schema_tic_tac_toe test: modules: - test.tic_tac_toe moduleArgs: lib.ft4.core.admin: admin_pubkey: x"023BEE5A479CE5AF31F6F64EDE7BEAD394E92E4D973E1727782DB577A55E878563" # It can be completely random for learning purposes. libs: ft4: registry: https://gitlab.com/chromaway/ft4-lib.git path: rell/src/lib/ft4 tagOrBranch: v1.2.0r rid: x"E96915FD7C9A5DD4E183D86F4A5B4BB5083A7CC1EDEB1465EDFFC926E67C93F6" insecure: false iccf: registry: https://gitlab.com/chromaway/core/directory-chain path: src/lib/iccf tagOrBranch: 1.87.0 rid: x"9C359787B75927733034EA1CEE74EEC8829D2907E4FC94790B5E9ABE4396575D" insecure: false ``` Your project is now organized with Rell modules. The file structure should look similar to this: text ``` ├── main.rell ├── tic_tac_toe │ ├── auth.rell │ ├── entities.rell │ ├── enums.rell │ ├── functions.rell │ ├── mappers.rell │ ├── module.rell │ ├── utils.rell │ ├── require.rell │ └── external │ ├── module.rell │ ├── operations.rell │ ├── queries.rell └── test/tic_tac_toe ├── create_account_test.rell ├── create_full_game.rell ├── create_game_test.rell ├── helpers.rell ├── join_game_test.rell ├── make_move_test.rell └── module.rell ``` Written for this site from Chromia’s public course. Code samples are the course’s own. [← Previous**Work with Rell modules**](https://chromia.com/learn/tic-tac-toe/module-one/project-structure/modules/)[Next →**Module 2: The Unity project**](https://chromia.com/learn/tic-tac-toe/module-two/)