> ## Documentation Index > Fetch the complete documentation index at: https://docs.base44.com/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Internal links on these pages omit the .md extension. Append .md to a docs page URL, or send an Accept: text/markdown header, to get that page as markdown. # Create branch > This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production. Creates a [branch](/developers/references/app-management/get-started/concepts#branches) of the app from its main branch. The branch has its own copy of the app's code, so its changes don't reach main until you [merge the branch](/api-reference/merge-branch). Set `branch_name` to name the branch, or send `prompt` and Base44 generates a short name from it. `prompt` only names the branch. It isn't sent to the AI. When a generated name is taken, Base44 adds a number to it. A `branch_name` you choose must not belong to another active or merged branch. The branch starts from main's latest saved state. If the AI is working on main at the time, the branch starts from main as it was before that change. Set `from_message_id` to start from an earlier point instead. Send at least one of `branch_name`, `prompt`, and `from_message_id`. In this response, `created_by_name` is always `null`. [Get branch](/api-reference/get-branch) returns it. This endpoint is limited to 30 requests per minute, shared with Create branch, Delete branch and Merge branch. You can't send chat messages to a branch through the API yet, so a branch gets changes of its own only from work in the Base44 editor. Until it has some, [Merge branch](/api-reference/merge-branch) refuses it with a 409. This endpoint accepts a personal API key belonging to a user with editor access to the app. A read-only key is refused, and workspace API keys are not accepted. The response includes fields beyond the ones documented here. Don't rely on undocumented response fields, as they can change at any time. Send only the fields documented here. Other request fields are not supported and their behavior can change. ## OpenAPI ````yaml /developers/references/app-management/app-management-openapi.json post /api/apps/{app_id}/branches openapi: 3.1.0 info: title: Base44 App Management API version: 1.0.0 servers: - url: https://app.base44.com security: - PersonalAccessTokenAuth: [] paths: /api/apps/{app_id}/branches: post: summary: Create branch description: >- This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production. Creates a [branch](/developers/references/app-management/get-started/concepts#branches) of the app from its main branch. The branch has its own copy of the app's code, so its changes don't reach main until you [merge the branch](/api-reference/merge-branch). Set `branch_name` to name the branch, or send `prompt` and Base44 generates a short name from it. `prompt` only names the branch. It isn't sent to the AI. When a generated name is taken, Base44 adds a number to it. A `branch_name` you choose must not belong to another active or merged branch. The branch starts from main's latest saved state. If the AI is working on main at the time, the branch starts from main as it was before that change. Set `from_message_id` to start from an earlier point instead. Send at least one of `branch_name`, `prompt`, and `from_message_id`. In this response, `created_by_name` is always `null`. [Get branch](/api-reference/get-branch) returns it. This endpoint is limited to 30 requests per minute, shared with Create branch, Delete branch and Merge branch. You can't send chat messages to a branch through the API yet, so a branch gets changes of its own only from work in the Base44 editor. Until it has some, [Merge branch](/api-reference/merge-branch) refuses it with a 409. This endpoint accepts a personal API key belonging to a user with editor access to the app. A read-only key is refused, and workspace API keys are not accepted. The response includes fields beyond the ones documented here. Don't rely on undocumented response fields, as they can change at any time. Send only the fields documented here. Other request fields are not supported and their behavior can change. operationId: create_branch_api_apps__app_id__branches_post parameters: - name: app_id in: path required: true schema: type: string description: ID of the app to create the branch in. title: App Id description: ID of the app to create the branch in. example: 6820f3a4e7b91d003c45a1f2 requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateBranchRequest' responses: '200': description: The new branch. content: application/json: schema: $ref: '#/components/schemas/BranchSummary' '400': description: >- `branch_name` is `main`, or you set `from_message_id` on an app imported from GitHub, or the message's saved version belongs to a branch rather than main. '401': description: Missing or invalid credentials. '403': description: >- You don't have editor access to this app, the app is blocked, your API key is read-only, or you used a workspace API key. '404': description: >- App not found, or `from_message_id` isn't in main's conversation or has no saved version to start from. '409': description: An active or merged branch is already named `branch_name`. '422': description: >- None of `branch_name`, `prompt`, and `from_message_id` is set, `branch_name` breaks the naming rules or is over 100 characters, or `from_message_id` is over 64 characters. '429': description: >- Rate limit exceeded. The base limit is 30 requests per minute. See [Rate limits](/developers/references/apps-api/get-started/rate-limits) for the multiplier your plan gets. components: schemas: CreateBranchRequest: properties: branch_name: anyOf: - type: string maxLength: 100 minLength: 1 - type: 'null' title: Branch Name description: >- Name of the branch. It starts with a letter or digit and contains only letters, digits, `.`, `_`, `/` and `-`. It can't contain `..` or `//`, end with `/` or `.`, start with `b44/`, or be `main`, and no part between slashes can start with `.` or end with `.lock`. Leave it out to have Base44 name the branch from `prompt`. example: add-contact-form prompt: anyOf: - type: string - type: 'null' title: Prompt description: >- Text to name the branch from when you leave out `branch_name`. Base44 generates a short name from it. An empty string names the branch after your first name and today's date. example: Add a contact form to the home page from_message_id: anyOf: - type: string maxLength: 64 - type: 'null' title: From Message Id description: >- ID of a message in main's conversation, from [Read conversation messages](/api-reference/read-conversation-messages). The branch starts from the app as it was when that message was sent, instead of from main's latest state. Without `branch_name`, the branch is named after the last user message before that one, and `prompt` is ignored. example: 7f3a1c88-52d4-4a0e-9b31-2c6f0d8e4a19 type: object title: CreateBranchRequest description: The new branch's name, or text to name it from. BranchSummary: properties: id: type: string title: Id description: ID of the branch. example: 68f1a2b3c4d5e6f708192a3b app_id: type: string title: App Id description: ID of the app the branch belongs to. example: 6820f3a4e7b91d003c45a1f2 branch_name: type: string title: Branch Name description: Name of the branch. example: add-contact-form status: type: string enum: - active - merged - deleted title: Status description: >- `active` while the branch can still be worked on, `merged` once it was merged into main, and `deleted` once it was deleted. example: active run_state: anyOf: - $ref: '#/components/schemas/BranchRunState' - type: 'null' description: >- State of the AI's work on the branch, or `null` if no turn has run on it yet. code_state: type: string enum: - unchanged - changed title: Code State description: >- `unchanged` when the branch has no code changes of its own to merge into main. `changed` otherwise, including when Base44 can't tell yet. example: changed base_checkpoint_id: anyOf: - type: string - type: 'null' title: Base Checkpoint Id description: >- ID of the main [checkpoint](/api-reference/list-checkpoints) the branch started from, or `null` if the app had no checkpoint yet. example: 6886b8d390dc7e2f4a2c91b3 created_by_id: type: string title: Created By Id description: ID of the user who created the branch. example: 68a0c1d2e3f4a5b6c7d8e9f0 created_by_name: anyOf: - type: string - type: 'null' title: Created By Name description: >- Display name of the user who created the branch, or the part of their email before the `@` when they have no name. `null` when Base44 can't name them, for example when their account no longer exists. example: Jane Doe created_date: type: string format: date-time title: Created Date description: When the branch was created, as a UTC timestamp in ISO 8601 format. example: '2026-09-28T10:15:00' merged_at: anyOf: - type: string format: date-time - type: 'null' title: Merged At description: >- When the branch was merged into main, as a UTC timestamp in ISO 8601 format, or `null` if it wasn't. example: '2026-09-29T08:02:11' merged_by_id: anyOf: - type: string - type: 'null' title: Merged By Id description: >- ID of the user who merged the branch, or `null` if it wasn't merged or Base44 doesn't know who did, as for a branch whose pull request was merged on GitHub. example: 68a0c1d2e3f4a5b6c7d8e9f0 static_preview_url: type: string title: Static Preview Url description: >- URL of the branch's preview. It shows the branch only while it's active and once it has been built. example: https://preview--6820f3a4e7b91d003c45a1f2--b-d8c647b.base44.app type: object required: - id - app_id - branch_name - status - run_state - code_state - base_checkpoint_id - created_by_id - created_by_name - created_date - merged_at - merged_by_id - static_preview_url title: BranchSummary description: A branch of an app. BranchRunState: properties: state: type: string enum: - ready - processing - error title: State description: >- `processing` while the AI is working on the branch, `ready` once it's idle, and `error` when the last turn on the branch failed. example: ready details: anyOf: - type: string - type: 'null' title: Details description: >- Short note about the state, such as why the last turn failed, or `null` when there's nothing to report. example: Restoring checkpoint last_updated_date: type: string format: date-time title: Last Updated Date description: When the state last changed, as a UTC timestamp in ISO 8601 format. example: '2026-09-28T10:18:40' type: object required: - state - details - last_updated_date title: BranchRunState securitySchemes: PersonalAccessTokenAuth: type: http scheme: bearer description: 'Personal access token, sent as `Authorization: Bearer `.' ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.