> ## Documentation Index > Fetch the complete documentation index at: https://docs.monaco.com/llms.txt > Use this file to discover all available pages before exploring further. # Merge Contacts > Merges the contact `source_contact_id` into the contact in the path. This is irreversible, like deleting a contact: the source contact is deleted, the kept contact's empty fields are filled from it, its notes are appended, its sequences, tasks, tags, audience memberships, opportunity links, custom field values move to the kept contact, and its live sequences are stopped. When live sequences would be stopped the request is rejected with 409 `sequence_stop_confirmation_required` unless `confirm_sequence_stop` is true. The merge runs in one transaction: on 422 `merge_failed` nothing was changed. Retrying a merge that already completed returns 404, because the source contact no longer exists. ## OpenAPI ````yaml https://api.monaco.com/openapi.json post /v1/contacts/{contact_id}/merge openapi: 3.2.1 info: title: Monaco Public API description: Public API for Monaco version: 1.0.0 servers: - url: https://api.monaco.com security: [] paths: /v1/contacts/{contact_id}/merge: post: tags: - Contacts summary: Merge Contacts description: >- Merges the contact `source_contact_id` into the contact in the path. This is irreversible, like deleting a contact: the source contact is deleted, the kept contact's empty fields are filled from it, its notes are appended, its sequences, tasks, tags, audience memberships, opportunity links, custom field values move to the kept contact, and its live sequences are stopped. When live sequences would be stopped the request is rejected with 409 `sequence_stop_confirmation_required` unless `confirm_sequence_stop` is true. The merge runs in one transaction: on 422 `merge_failed` nothing was changed. Retrying a merge that already completed returns 404, because the source contact no longer exists. operationId: merge_contacts parameters: - name: contact_id in: path required: true schema: type: string format: uuid title: Contact Id requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ContactMergeRequest' responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/PublicItemResponse_ContactMergeResponse_' '409': description: Confirmation required to stop live sequences content: application/json: schema: $ref: '#/components/schemas/ContactMergeErrorResponse' '422': description: The merge request is invalid, or the merge failed content: application/json: schema: $ref: '#/components/schemas/ContactMergeErrorResponse' 4XX: description: Client error content: application/json: schema: $ref: '#/components/schemas/PublicErrorResponse' components: schemas: ContactMergeRequest: properties: source_contact_id: type: string format: uuid title: Source Contact Id description: >- ID of the contact to merge into the contact in the path. It is deleted when the merge is applied. Both contacts must be on the same account. confirm_sequence_stop: type: boolean title: Confirm Sequence Stop description: >- Confirms that the live sequences listed under `blocking_sequences` in the preview may be stopped. Without it, a merge that would stop live sequences is rejected with `sequence_stop_confirmation_required`. default: false additionalProperties: false type: object required: - source_contact_id title: ContactMergeRequest PublicItemResponse_ContactMergeResponse_: properties: data: $ref: '#/components/schemas/ContactMergeResponse' meta: $ref: '#/components/schemas/ResponseMeta' type: object required: - data title: PublicItemResponse[ContactMergeResponse] ContactMergeErrorResponse: properties: error: $ref: '#/components/schemas/ContactMergeErrorDetail' type: object required: - error title: ContactMergeErrorResponse PublicErrorResponse: properties: error: $ref: '#/components/schemas/ErrorDetail' type: object required: - error title: PublicErrorResponse ContactMergeResponse: properties: target_contact_id: type: string title: Target Contact Id source_contact_id: type: string title: Source Contact Id plays_moved: type: integer title: Plays Moved user_tasks_moved: type: integer title: User Tasks Moved tags_merged: type: integer title: Tags Merged fields_filled_from_source: items: type: string type: array title: Fields Filled From Source audience_memberships_moved: type: integer title: Audience Memberships Moved opportunity_links_moved: type: integer title: Opportunity Links Moved custom_fields_filled: type: integer title: Custom Fields Filled sequences_stopped: items: type: string type: array title: Sequences Stopped description: IDs of the source's sequences stopped sequences_dismissed: items: type: string type: array title: Sequences Dismissed description: IDs of the source's unstarted sequences dismissed deleted_at: type: string format: date-time title: Deleted At description: When the source contact was deleted type: object required: - target_contact_id - source_contact_id - plays_moved - user_tasks_moved - tags_merged - fields_filled_from_source - audience_memberships_moved - opportunity_links_moved - custom_fields_filled - sequences_stopped - sequences_dismissed - deleted_at title: ContactMergeResponse ResponseMeta: properties: timestamp: type: string format: date-time title: Timestamp description: Server timestamp of the response type: object title: ResponseMeta ContactMergeErrorDetail: properties: code: type: string title: Code description: Machine-readable error code examples: - not_found message: type: string title: Message description: Human-readable error message examples: - Resource not found blocking_sequence_count: anyOf: - type: integer - type: 'null' title: Blocking Sequence Count description: >- For `sequence_stop_confirmation_required`, how many live sequences would stop type: object required: - code - message title: ContactMergeErrorDetail ErrorDetail: properties: code: type: string title: Code description: Machine-readable error code examples: - not_found message: type: string title: Message description: Human-readable error message examples: - Resource not found type: object required: - code - message title: ErrorDetail ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.