> ## Documentation Index > Fetch the complete documentation index at: https://docs.vocobase.com/llms.txt > Use this file to discover all available pages before exploring further. # Add contacts to a campaign > Adds contacts by phone number. Numbers are canonicalised to E.164 before storage, so the same number written two ways resolves to one contact. Contacts already in your library are reused rather than duplicated, and contacts already on this campaign are counted as `duplicates` and skipped. Adding contacts to a `completed` campaign re-opens it to `paused`, **not** `running` — the response says so via `campaign_reopened`. Dialling does not resume on its own: call `POST /campaigns/{id}/resume`, which re-validates caller IDs and provider access first. Maximum 10,000 contacts per request. ## OpenAPI ````yaml /openapi.json post /campaigns/{id}/contacts openapi: 3.1.0 info: title: Vocobase API version: '2.0' description: >- API for managing voice AI agents, documents, and calls on the Vocobase platform. servers: - url: https://api.vocobase.com/api/v2 description: Production security: - bearerAuth: [] tags: - name: Config description: >- Read and update account configuration, webhook settings, and telephony credentials. - name: Agents description: Create, read, update, and delete voice AI agents. - name: Voices description: >- List voice tiers, available voices, and stream preview audio for agent configuration. - name: Documents description: Upload, manage, and delete knowledge base documents. - name: Agent Documents description: Link and unlink documents to agents for knowledge base integration. - name: Calls description: Initiate outbound calls and view call history. - name: Phone Numbers description: >- Import DIDs, assign agents for inbound routing, and re-sync carrier Application bindings. - name: Inbound Routing Policies description: >- Define pre-answer routing decisions for inbound calls before AI sessions are created. - name: Telephony Connections description: Create, list, rename, and disconnect named V2 telephony connections. - name: VoiceLink Management description: Manage VoiceLink reseller clients, DID mapping, and readiness sync. - name: Projects description: Organize agents into projects. Every agent belongs to exactly one project. - name: Dictionaries description: Speech-recognition dictionary CRUD and agent attachment. - name: Sessions description: Browser-initiated WebRTC voice sessions for in-app voice agents. - name: Campaigns description: Batch outbound calling. - name: Billing description: Balance, transactions, and usage summaries. - name: Custom Functions description: HTTP endpoints the agent can call mid-conversation. - name: Extraction Sets description: Reusable sets of post-call extraction fields. - name: Lifecycle Hooks description: Automatic pre-call and post-call integration steps. - name: Messaging description: Bring-your-own WhatsApp sending. - name: Integration Logs description: Audit trail for integration calls. - name: Connectors description: Catalog of tools an agent can be connected to. - name: Customers description: B2B2B sub-tenants and their tool connections. - name: Agent Tools description: Binding connectors and connections to an agent. paths: /campaigns/{id}/contacts: post: tags: - Campaigns summary: Add contacts to a campaign description: >- Adds contacts by phone number. Numbers are canonicalised to E.164 before storage, so the same number written two ways resolves to one contact. Contacts already in your library are reused rather than duplicated, and contacts already on this campaign are counted as `duplicates` and skipped. Adding contacts to a `completed` campaign re-opens it to `paused`, **not** `running` — the response says so via `campaign_reopened`. Dialling does not resume on its own: call `POST /campaigns/{id}/resume`, which re-validates caller IDs and provider access first. Maximum 10,000 contacts per request. operationId: addCampaignContacts parameters: - name: id in: path required: true schema: type: string format: uuid description: Campaign ID. requestBody: required: true content: application/json: schema: type: object required: - contacts properties: contacts: type: array minItems: 1 maxItems: 10000 items: type: object required: - phone properties: phone: type: string description: E.164, e.g. `+919876543210`. name: type: string nullable: true metadata: type: object nullable: true additionalProperties: true description: >- Arbitrary JSON carried through to the call and returned on webhooks. example: contacts: - phone: '+919876543210' name: Asha Menon metadata: plan: pro renews_on: '2026-09-01' - phone: '+919812345678' name: Ravi Kumar responses: '201': description: Contacts added. content: application/json: schema: type: object properties: success: type: boolean const: true data: type: object properties: added: type: integer description: Contacts newly attached to this campaign. duplicates: type: integer description: Already on this campaign; skipped. contacts_created: type: integer description: New rows created in your contact library. contacts_existing: type: integer description: Reused from your contact library. campaign_reopened: type: boolean description: >- `true` when this request put a finished campaign back to `paused`. It is now an ordinary paused campaign — `POST /campaigns/{id}/resume` is the only way on from here. example: success: true data: added: 2 duplicates: 0 contacts_created: 1 contacts_existing: 1 campaign_reopened: false '400': description: >- `VALIDATION_ERROR` for an empty array, more than 10,000 contacts, or invalid E.164 numbers. `INVALID_STATE` when the campaign is an inbound campaign, or has been stopped — a stopped campaign refuses contacts forever, including after it is relabelled `completed`. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: VALIDATION_ERROR message: 'Invalid E.164 phone numbers: 9876543210, 044-1234' '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/NotFound' '429': $ref: '#/components/responses/RateLimitExceeded' '500': $ref: '#/components/responses/InternalError' components: schemas: ErrorResponse: type: object properties: success: type: boolean const: false error: type: object properties: code: type: string message: type: string required: - code - message required: - success - error responses: Unauthorized: description: Missing or invalid API key. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: UNAUTHORIZED message: Invalid or missing API key NotFound: description: Resource not found. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: NOT_FOUND message: Resource not found RateLimitExceeded: description: Per-account rate limit exceeded. Retry after a short backoff. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: RATE_LIMITED message: Rate limit exceeded. Retry after 60 seconds. InternalError: description: Unexpected server error. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: success: false error: code: INTERNAL_ERROR message: An unexpected error occurred securitySchemes: bearerAuth: type: http scheme: bearer description: >- API key in format: `rg_live_xxxx`. Pass as a Bearer token in the Authorization header. ````