> ## Documentation Index > Fetch the complete documentation index at: https://docs.open.cx/llms.txt > Use this file to discover all available pages before exploring further. > Link up to 100 contacts to companies in one call, naming each contact by id, email, or phone. A row that fails returns its own error and does not affect the others. # Link many contacts to companies ## OpenAPI ````yaml post /companies/links openapi: 3.1.0 info: title: OpenCX API description: > OpenCX is an AI-powered, all-in-one platform for customer support and outbound communications. Use this API to manage your OpenCX organization's AI agents, actions, conversations, contacts, and more. To get started, generate a new API key from the dashboard. ## Authentication All API endpoints require authentication using a Bearer token. You can generate an API key from your OpenCX dashboard. ## Rate Limiting API requests are rate limited to ensure fair usage. The current limits are: - 100 requests per minute for standard endpoints - 1000 requests per minute for streaming endpoints ## Error Handling The API uses standard HTTP status codes and returns detailed error messages in the response body. version: 1.0-beta license: name: MIT url: https://opensource.org/licenses/MIT servers: - url: http://localhost:8080 description: Development - url: https://api.open.cx description: Production security: - bearerAuth: [] paths: /companies/links: post: summary: Link many contacts to companies description: >- Links up to 100 contacts in one call. Name each contact by `contact_id`, `contact_email`, or `contact_phone` — exactly one — so a sync can link straight from the identifiers it already holds. Each result carries the resolved `contact_id`. Failures are isolated: a contact that cannot be linked returns an error in its own result entry and does not affect the others, so the call succeeds even when some links do not. Results come back in request order. operationId: bulkLinkContactsToCompanies requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/BulkLinkContactsDto' responses: '201': description: Default Response content: application/json: schema: $ref: '#/components/schemas/BulkLinkContactsOutput' '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/ErrorDto' components: schemas: BulkLinkContactsDto: $schema: https://json-schema.org/draft/2020-12/schema $id: '#/components/schemas/BulkLinkContactsDtoInput' type: object properties: links: minItems: 1 maxItems: 100 type: array items: type: object properties: contact_id: description: The OpenCX contact id, if you already hold it type: string format: uuid pattern: >- ^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$ contact_email: description: Look the contact up by email instead of id type: string format: email pattern: >- ^(?!\.)(?!.*\.\.)([A-Za-z0-9_'+\-\.]*)[A-Za-z0-9_+-]@([A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$ contact_phone: description: >- Look the contact up by phone instead of id. `+15551234567` and `15551234567` both match type: string minLength: 1 external_id: type: string minLength: 1 description: >- The company to link, by the same `external_id` you upserted it with required: - external_id required: - links BulkLinkContactsOutput: $schema: https://json-schema.org/draft/2020-12/schema $id: '#/components/schemas/BulkLinkContactsOutput' type: object properties: results: type: array items: type: object properties: contact_id: anyOf: - type: string - type: 'null' description: >- The resolved contact id. Null when the identifier did not resolve. external_id: type: string outcome: anyOf: - type: string enum: - linked - unchanged - type: 'null' error: anyOf: - type: string - type: 'null' description: Null when this contact linked successfully company: anyOf: - $ref: '#/components/schemas/Company' - type: 'null' required: - contact_id - external_id - outcome - error - company additionalProperties: false description: One entry per requested link, in request order summary: type: object properties: total: type: number linked: type: number unchanged: type: number failed: type: number required: - total - linked - unchanged - failed additionalProperties: false required: - results - summary additionalProperties: false ErrorDto: type: object properties: statusCode: type: integer message: type: string error: type: string Company: $schema: https://json-schema.org/draft/2020-12/schema $id: '#/components/schemas/Company' type: object properties: id: type: string format: uuid pattern: >- ^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|ffffffff-ffff-ffff-ffff-ffffffffffff)$ external_id: type: string description: The organization's own key for this company name: type: string custom_data: anyOf: - type: object propertyNames: type: string additionalProperties: anyOf: - type: string - type: number - type: boolean - type: 'null' created_at: type: string description: ISO 8601 timestamp of when the company was created updated_at: type: string description: ISO 8601 timestamp of when the company was last updated required: - id - external_id - name - custom_data - created_at - updated_at additionalProperties: false securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT ````