> ## Documentation Index > Fetch the complete documentation index at: https://docs.useboom.ai/llms.txt > Use this file to discover all available pages before exploring further. # Batch link / unlink > Link or unlink up to 1000 relationships in one request. ## OpenAPI ````yaml /api-reference/openapi.json post /api/v1/cdp/relationships/batch openapi: 3.1.0 info: title: Boom API version: 1.0.0 description: >- Boom's public REST API — one uniform surface over every platform capability. CDP: upsert people and custom objects, define object and relationship types, link and unlink relationships, and record behavioral events — one record per request or up to 1000 per request via the `/batch` endpoints. Segments: read (list, read, membership) and full authoring — discover the filterable catalog, validate a filter, create and update segments, preview match counts, and trigger evaluation. Initiatives: create and configure outreach initiatives, link WhatsApp templates, drive the lifecycle (launch, cancel, archive), and read collected-data summaries. Participants: enroll people into an active initiative, track their status, read conversation transcripts, and stop outreach. Journeys: read-only access to always-on message flows and their metrics. WhatsApp templates: list your WhatsApp numbers and list, read, and create message templates. The same capabilities are exposed as MCP tools with identical schemas. servers: - url: https://www.useboom.ai description: Production - url: https://dev.useboom.ai description: Development (sandbox — use a development organization API key) security: - bearerAuth: [] paths: /api/v1/cdp/relationships/batch: post: tags: - CDP Relationships summary: Batch link / unlink description: Link or unlink up to 1000 relationships in one request. operationId: cdp_relationships_batch requestBody: required: true content: application/json: schema: $schema: https://json-schema.org/draft/2020-12/schema type: object properties: items: minItems: 1 maxItems: 1000 type: array items: oneOf: - type: object properties: kind: type: string const: person_to_co personExternalId: type: string minLength: 1 maxLength: 255 description: Person externalId. customObjectExternalId: type: string minLength: 1 maxLength: 255 description: Custom object externalId. relationshipTypeId: type: string minLength: 1 maxLength: 255 description: >- Relationship type id (from the relationship-types list). remove: description: Set true to unlink (soft-delete) instead of link. type: boolean required: - kind - personExternalId - customObjectExternalId - relationshipTypeId - type: object properties: kind: type: string const: co_to_co parentExternalId: type: string minLength: 1 maxLength: 255 description: Parent custom object externalId. childExternalId: type: string minLength: 1 maxLength: 255 description: Child custom object externalId. relationshipTypeId: type: string minLength: 1 maxLength: 255 description: >- Relationship type id (from the relationship-types list). remove: description: Set true to unlink (soft-delete) instead of link. type: boolean required: - kind - parentExternalId - childExternalId - relationshipTypeId description: Relationships to link or unlink. required: - items responses: '200': description: Success content: application/json: schema: $schema: https://json-schema.org/draft/2020-12/schema type: object properties: summary: type: object properties: total: type: integer minimum: -9007199254740991 maximum: 9007199254740991 created: type: integer minimum: -9007199254740991 maximum: 9007199254740991 reactivated: type: integer minimum: -9007199254740991 maximum: 9007199254740991 description: Previously-unlinked edges that were re-activated. removed: type: integer minimum: -9007199254740991 maximum: 9007199254740991 failed: type: integer minimum: -9007199254740991 maximum: 9007199254740991 required: - total - created - reactivated - removed - failed additionalProperties: false errors: type: array items: type: object properties: index: type: integer minimum: -9007199254740991 maximum: 9007199254740991 description: Zero-based index of the failed item. externalId: type: string error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message additionalProperties: false required: - index - error additionalProperties: false required: - summary - errors additionalProperties: false '400': description: Validation failed or the request cannot proceed. content: application/json: schema: type: object properties: error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message required: - error '401': description: Missing, malformed, or revoked API key. content: application/json: schema: type: object properties: error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message required: - error '404': description: The resource does not exist in this organization. content: application/json: schema: type: object properties: error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message required: - error '409': description: >- Conflicts with the current state (duplicates, wrong lifecycle state). content: application/json: schema: type: object properties: error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message required: - error '422': description: The request is well-formed but semantically invalid. content: application/json: schema: type: object properties: error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message required: - error '429': description: Rate limit exceeded — retry after `Retry-After`. content: application/json: schema: type: object properties: error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message required: - error '500': description: Internal server error. content: application/json: schema: type: object properties: error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message required: - error '503': description: Transient error — retry with a narrower request. content: application/json: schema: type: object properties: error: type: object properties: code: type: string description: Stable machine-readable error code (snake_case). message: type: string required: - code - message required: - error components: securitySchemes: bearerAuth: type: http scheme: bearer description: 'Organization API key, sent as `Authorization: Bearer boom_org_...`.' ````