> ## 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. # Update branch from main > This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production. Brings main's latest changes into an active branch. When main's code changed, Base44 merges it into the branch. Messages sent on main since the branch was created or last updated are added to the branch's conversation as context for the AI. When nothing changed on main, nothing happens and `updated` is `false`. If main's changes conflict with the branch's, the AI resolves the conflicts on the branch before the request returns. That's an AI turn: it uses credits like a chat message, and the request can stay open for several minutes. If the AI needs your input to finish, `sync_status.sync_state` is `needs_input`. The branch then stays locked until you answer in the Base44 editor, and it can't be updated, merged, or deleted until then. If the AI can't resolve the conflicts, the request fails and the branch is restored to how it was before the update. In this response, `branch.created_by_name` is always `null`. [Get branch](/api-reference/get-branch) returns it. This endpoint is limited to 10 requests per minute. A 409 response carries an `extra_data.reason` code that says why the request was refused. 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. ## OpenAPI ````yaml /developers/references/app-management/app-management-openapi.json post /api/apps/{app_id}/branches/{branch_id}/sync-from-main 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/{branch_id}/sync-from-main: post: summary: Update branch from main description: >- This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production. Brings main's latest changes into an active branch. When main's code changed, Base44 merges it into the branch. Messages sent on main since the branch was created or last updated are added to the branch's conversation as context for the AI. When nothing changed on main, nothing happens and `updated` is `false`. If main's changes conflict with the branch's, the AI resolves the conflicts on the branch before the request returns. That's an AI turn: it uses credits like a chat message, and the request can stay open for several minutes. If the AI needs your input to finish, `sync_status.sync_state` is `needs_input`. The branch then stays locked until you answer in the Base44 editor, and it can't be updated, merged, or deleted until then. If the AI can't resolve the conflicts, the request fails and the branch is restored to how it was before the update. In this response, `branch.created_by_name` is always `null`. [Get branch](/api-reference/get-branch) returns it. This endpoint is limited to 10 requests per minute. A 409 response carries an `extra_data.reason` code that says why the request was refused. 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. operationId: >- sync_branch_from_main_api_apps__app_id__branches__branch_id__sync_from_main_post parameters: - name: branch_id in: path required: true schema: type: string description: >- ID of the branch, as returned by [List branches](/api-reference/list-branches). title: Branch Id description: >- ID of the branch, as returned by [List branches](/api-reference/list-branches). example: 68f1a2b3c4d5e6f708192a3b - name: app_id in: path required: true schema: type: string description: ID of the app the branch belongs to. title: App Id description: ID of the app the branch belongs to. example: 6820f3a4e7b91d003c45a1f2 responses: '200': description: The branch after the update. content: application/json: schema: $ref: '#/components/schemas/BranchSyncResult' '400': description: >- The update needs the AI to resolve conflicts, and you've run out of credits. '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 the app has no active branch with this ID. '409': description: >- The branch can't be updated right now. `extra_data.reason` is `app_processing` or `branch_processing` while the AI is working on main or on the branch, `branch_sync_in_progress` while another update runs or waits for input, and `branch_sync_branch_moved` when the branch changed during the update. Any other reason means recent changes are still being saved. Try again shortly. '429': description: >- Rate limit exceeded. The base limit is 10 requests per minute. See [Rate limits](/developers/references/apps-api/get-started/rate-limits) for the multiplier your plan gets. components: schemas: BranchSyncResult: properties: branch: $ref: '#/components/schemas/BranchSummary' description: The branch after the update. sync_status: $ref: '#/components/schemas/BranchSyncStatus' description: How the branch stands against main after the update. updated: type: boolean title: Updated description: >- `false` when the branch was already up to date with main, so nothing changed. `true` when the update was applied, or when it's waiting for your input (`sync_status.sync_state` is `needs_input`). example: true type: object required: - branch - sync_status - updated title: BranchSyncResult description: The branch after the update. 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. BranchSyncStatus: properties: new_main_message_count: type: integer title: New Main Message Count description: >- How many chat messages people sent on main since the branch was created or last updated from main. example: 2 main_code_changed: type: boolean title: Main Code Changed description: >- `true` when main's code changed since the branch was created or last updated from main. example: true conflict_state: type: string enum: - clear - overlap - unavailable title: Conflict State description: >- Whether updating the branch from main is expected to conflict. `clear` when main's code hasn't changed, so an update can't conflict. `overlap` when the update is expected to conflict, or while conflicts from an update are being resolved. `unavailable` when Base44 can't tell, including while an update runs. Once main's code has changed, it's never `clear`, even when the update would apply cleanly. example: unavailable sync_state: type: string enum: - idle - updating - resolving - needs_input title: Sync State description: >- `idle` when no update is running. `updating` while main's changes are being applied, `resolving` while the AI resolves conflicts, and `needs_input` when the AI needs an answer to finish resolving them. Answer it in the Base44 editor. Until the state is back to `idle`, the branch can't be merged or deleted. example: idle blocked_reason: anyOf: - type: string enum: - app_processing - branch_processing - type: 'null' title: Blocked Reason description: >- Why [Update branch from main](/api-reference/update-branch-from-main) would be refused right now: `app_processing` while the AI is working on main, and `branch_processing` while it's working on the branch. `null` when neither applies. An update is also refused while `sync_state` is `resolving` or `needs_input`. example: app_processing type: object required: - new_main_message_count - main_code_changed - conflict_state - sync_state - blocked_reason title: BranchSyncStatus description: How the branch stands against main. 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.