> ## Documentation Index > Fetch the complete documentation index at: https://docs.orbit.devotel.io/llms.txt > Use this file to discover all available pages before exploring further. # Enrol a contact or list into a flow > Friendly journey-enrolment endpoint for programmatic and agentic callers. Enrol a single contact (`contact_id`) or fan out across every member of a list (`list_id`); an optional `context` object is passed through to the flow's trigger data. Exactly one of `contact_id` or `list_id` is required. Lists over 500 members are rejected (413) — use bulk enrolment for large audiences. Rate-limited and concurrency-gated like execute. Requires an operator role and the `flows:write` scope. ## OpenAPI ````yaml /openapi.yaml post /api/v1/flows/{id}/start openapi: 3.1.0 info: title: Devotel CPaaS API description: Orbit by Devotel — Communications Platform as a Service API version: 1.0.0 contact: name: Devotel url: https://devotel.io email: support@devotel.io license: name: Proprietary servers: - url: https://api.orbit.devotel.io description: Production security: - Bearer: [] - ApiKey: [] tags: - name: Messages description: >- Send and manage messages across all channels (SMS, WhatsApp, RCS, Email, Viber, etc.) - name: Fax description: >- List and track fax (MMS/T.38) transmissions on Telnyx-backed fax numbers (sending flows through the Messaging API) - name: Agents description: AI agent creation, configuration, and execution - name: Voice description: Voice calls, IVR, conferencing, and SIP trunking - name: OnCall description: On-call rotations and escalation policy planning for incident alerting - name: Webhooks description: Webhook endpoint management and delivery logs - name: Numbers description: Phone number search, provisioning, and configuration - name: Brand Identity description: >- Unified cross-channel brand trust posture (10DLC, toll-free, WhatsApp, RCS, branded calling, number KYC) - name: Contacts description: Contact management, segmentation, and lifecycle tracking - name: Campaigns description: Marketing campaign orchestration and analytics - name: Flows description: Automation flow builder and execution engine - name: Templates description: Message template management and approval workflows - name: Settings description: Organization, channel, and user preference settings - name: Verify description: OTP generation and verification across channels - name: Push description: Push notification delivery via FCM and APNs - name: Integrations description: Third-party service connections and OAuth management - name: CDP description: >- Customer Data Platform — activation surface (CRM object sync, streaming destinations, ad-audience activation) - name: Files description: >- Server-to-server media upload, listing, retrieval, and deletion (signed-URL backed) - name: Commerce description: >- Omnichannel conversational-commerce — persistent cart + checkout state machine, channel-agnostic hosted pay-by-link, native WhatsApp checkout, and AP2-style agent payment mandates. - name: Sync description: >- Real-time shared-state primitive (Twilio Sync parity) — Documents, Maps, Lists, and ephemeral Streams, with change events relayed over the /api/v1/ws/sync WebSocket gateway - name: Risk description: >- Unified cross-channel Trust & Fraud risk scoring — fuses SMS-pumping, URL-reputation, Verify Fraud Guard, and Voice Biometrics signals into one composite verdict queryable before a send or a call. - name: Orby description: >- In-dashboard Orby operator assistant: streamed assistant turns, conversation threads, product knowledge-base search, and the tool-action approval gate. Available to signed-in operators only (dashboard session auth — API-key requests are rejected). paths: /api/v1/flows/{id}/start: post: tags: - Flows summary: Enrol a contact or list into a flow description: >- Friendly journey-enrolment endpoint for programmatic and agentic callers. Enrol a single contact (`contact_id`) or fan out across every member of a list (`list_id`); an optional `context` object is passed through to the flow's trigger data. Exactly one of `contact_id` or `list_id` is required. Lists over 500 members are rejected (413) — use bulk enrolment for large audiences. Rate-limited and concurrency-gated like execute. Requires an operator role and the `flows:write` scope. parameters: - in: path name: id required: true schema: type: string description: Flow identifier. requestBody: required: true content: application/json: schema: type: object properties: contact_id: type: string maxLength: 200 description: >- Enrol this single contact. Mutually exclusive with `list_id`. list_id: type: string maxLength: 200 description: >- Enrol every member of this list (max 500). Mutually exclusive with `contact_id`. context: type: object description: Extra context merged into the flow's trigger data. example: contact_id: contact_123 context: campaign: summer_promo responses: '202': description: >- Enrolment accepted. Single-contact mode returns the `execution` row; list mode returns the number `enrolled`. content: application/json: schema: type: object properties: data: type: object properties: mode: type: string enum: - single - list execution: type: object description: The created execution (single-contact mode). list_id: type: string description: The enrolled list (list mode). attempted: type: integer description: Members read from the list (list mode). enrolled: type: integer description: Members successfully enrolled (list mode). meta: $ref: '#/components/schemas/ResponseMeta' '413': description: The list has more than 500 members — use bulk enrolment instead. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' components: schemas: ResponseMeta: type: object required: - request_id - timestamp additionalProperties: false properties: request_id: type: string description: Unique request identifier (also returned as X-Request-Id header) timestamp: type: string format: date-time docs_url: type: string format: uri nullable: true ErrorEnvelope: type: object required: - error - meta additionalProperties: false properties: error: type: object required: - code - message - status additionalProperties: false properties: code: type: string message: type: string status: type: integer details: type: object nullable: true additionalProperties: true meta: type: object required: - request_id - timestamp additionalProperties: false properties: request_id: type: string description: Unique request identifier (also returned as X-Request-Id header) timestamp: type: string format: date-time docs_url: type: string format: uri nullable: true securitySchemes: Bearer: type: http scheme: bearer bearerFormat: JWT description: Dashboard JWT token from Clerk ApiKey: type: apiKey name: X-API-Key in: header description: Server-to-server API key (dv_live_sk_*) ````