> ## Documentation Index > Fetch the complete documentation index at: https://docs.wave.sa/llms.txt > Use this file to discover all available pages before exploring further. # Resume the session's held call > Takes the session's held call off hold; the audio comes back both ways. The calling SDK calls this for you (`holdCall()` / `resumeCall()`). Send the session token `wcs` in the body — no API key and no `Authorization` header. Wave finds the session's own live call from the session; a session can never hold another call. The token is not rotated. A `200` means the voice engine accepted the command. No webhook is sent. Only an agent or caller session that has its own SIP user can use it; otherwise the API answers `409 CALL_NOT_ACTIVE`. Ships dark behind in-call control (`503 CALL_CONTROL_DISABLED` until it is enabled on the environment). ## OpenAPI ````yaml /api-reference/openapi.json post /v1/webrtc/call/unhold openapi: 3.1.0 info: title: Wave API version: 1.0.0 description: >- Wave API Platform — voice, numbers, and messaging for Saudi Arabia. Request schemas are GENERATED from the @wave-sa/shared Zod schemas — do not edit by hand (run `pnpm --filter @wave-sa/api generate:openapi`). servers: - url: https://api.wave.sa security: - bearerAuth: [] paths: /v1/webrtc/call/unhold: post: tags: - Web Calling summary: Resume the session's held call description: >- Takes the session's held call off hold; the audio comes back both ways. The calling SDK calls this for you (`holdCall()` / `resumeCall()`). Send the session token `wcs` in the body — no API key and no `Authorization` header. Wave finds the session's own live call from the session; a session can never hold another call. The token is not rotated. A `200` means the voice engine accepted the command. No webhook is sent. Only an agent or caller session that has its own SIP user can use it; otherwise the API answers `409 CALL_NOT_ACTIVE`. Ships dark behind in-call control (`503 CALL_CONTROL_DISABLED` until it is enabled on the environment). operationId: unholdWebrtcCall requestBody: required: true content: application/json: schema: type: object properties: wcs: type: string description: The current Web Calling session token (`wcs_…`). required: - wcs responses: '200': description: The voice engine accepted the command content: application/json: schema: type: object properties: action: type: string enum: - unhold session_id: type: string format: uuid request_id: type: string required: - action - session_id - request_id '400': description: The body has no valid session token (VALIDATION_ERROR) content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: >- The session token is unknown, expired, revoked or already replaced (WCS_NOT_FOUND, WCS_EXPIRED, WCS_REVOKED, WCS_REUSE_DETECTED) content: application/json: schema: $ref: '#/components/schemas/Error' '409': description: >- The session has no live call (CALL_NOT_ACTIVE), or the call is not answered yet (CALL_NOT_ANSWERED) content: application/json: schema: $ref: '#/components/schemas/Error' '501': description: >- In-call actions are not supported on this environment (CALL_CONTROL_UNSUPPORTED) content: application/json: schema: $ref: '#/components/schemas/Error' '502': description: The voice engine refused or failed (CALL_CONTROL_FAILED) content: application/json: schema: $ref: '#/components/schemas/Error' '503': description: In-call control is not enabled (CALL_CONTROL_DISABLED) content: application/json: schema: $ref: '#/components/schemas/Error' security: [] components: schemas: Error: type: object description: Wave's standard bilingual error envelope. required: - error_code - message - message_ar - request_id - docs_url properties: error_code: type: string enum: - INVALID_API_KEY - EXPIRED_API_KEY - REVOKED_API_KEY - SANDBOX_KEY_NOT_ALLOWED - INSUFFICIENT_PERMISSIONS - API_KEY_REVEAL_UNAVAILABLE - RATE_LIMIT_EXCEEDED - RECAPTCHA_FAILED - SANDBOX_EXPIRED - OTP_INVALID - OTP_EXPIRED - OTP_TOO_MANY_ATTEMPTS - OTP_RESEND_TOO_SOON - OTP_SEND_FAILED - INVALID_PHONE_NUMBER - CALLBACK_NOT_FOUND - CALLBACK_ALREADY_CANCELLED - CALLBACK_NOT_CANCELLABLE - CALL_NOT_FOUND - CALL_FAILED - INSUFFICIENT_CREDITS - CALL_NOT_CONTROLLABLE - CALL_NOT_ACTIVE - CALL_NOT_ANSWERED - AGENT_LEG_NOT_CONNECTED - CALL_CONTROL_FAILED - CALL_CONTROL_UNSUPPORTED - CALL_CONTROL_DISABLED - INVALID_PLAY_URL - TRANSFER_IN_PROGRESS - TRANSFER_TARGET_INVALID - TRANSFER_LIMIT_REACHED - CALL_VELOCITY_EXCEEDED - CALLING_SUSPENDED - CONFERENCE_FULL - CALL_ALREADY_IN_CONFERENCE - CONFERENCE_NOT_FOUND - CONFERENCE_ENDED - CAMPAIGNS_DISABLED - CAMPAIGN_NOT_FOUND - CAMPAIGN_INVALID_STATE - CAMPAIGN_LIMIT_REACHED - CAMPAIGN_NEEDS_IVR - QUEUE_CONTROL_FAILED - QUEUE_SERVICE_UNAVAILABLE - RECORDING_NOT_FOUND - RECORDING_URL_EXPIRED - RECORDING_SERVICE_UNAVAILABLE - CALLFLOW_AUDIO_SERVICE_UNAVAILABLE - CALLFLOW_VERSION_CONFLICT - VOICE_AUTH_DISABLED - VOICE_AUTH_NOT_FOUND - VOICE_AUTH_ASSURANCE_UNSUPPORTED - VOICE_AUTH_RATE_LIMITED - VOICE_AUTH_BLOCKED - VOICE_AUTH_BRAND_NOT_APPROVED - VOICE_AUTH_BRAND_NOT_FOUND - VOICE_AUTH_BRAND_INVALID_STATE - VOICE_AUTH_BRAND_DUPLICATE - VERIFY_DISABLED - VERIFY_NOT_FOUND - VERIFY_INVALID_CODE - VERIFY_MAX_ATTEMPTS - VERIFY_EXPIRED - VERIFY_RATE_LIMITED - VERIFY_SEND_FAILED - VERIFY_BLOCKED - VOICEMAIL_DISABLED - VOICEMAIL_NOT_FOUND - VOICEMAIL_RECORDING_NOT_FOUND - VOICEMAIL_SERVICE_UNAVAILABLE - VOICEMAIL_GREETING_INVALID - DLQ_REPLAY_DISABLED - DLQ_REPLAY_BROKER_UNAVAILABLE - MESSAGES_DISABLED - IVR_DISABLED - SANDBOX_INVALID_QUEUE - SANDBOX_QUEUE_UNAVAILABLE - SANDBOX_SIMULATED_SERVER_ERROR - SANDBOX_DESTINATION_NOT_ALLOWED - SANDBOX_MINUTES_EXCEEDED - WIDGET_ORIGIN_NOT_ALLOWED - PROJECT_NOT_FOUND - WEBHOOK_URL_INVALID - WEBHOOK_UNREACHABLE - WEBHOOK_LIMIT_EXCEEDED - WEBHOOK_URL_DUPLICATE - WEBHOOK_NOT_FOUND - WEBHOOK_VERIFICATION_FAILED - SIGNUP_EMAIL_TAKEN - SIGNUP_VALIDATION_FAILED - VITALPBX_PROVISIONING_FAILED - SIGNUP_FAILED - API_KEY_NOT_FOUND - API_KEY_REVEAL_FORBIDDEN - PRODUCTION_ACCESS_ALREADY_REQUESTED - PRODUCTION_TIER_REQUIRED - PRODUCTION_REQUEST_EXISTS - PRODUCTION_REQUEST_NOT_FOUND - PRODUCTION_REQUEST_INVALID_STATE - VALIDATION_ERROR - INTERNAL_ERROR - NOT_FOUND - PAYLOAD_TOO_LARGE - IDEMPOTENCY_KEY_CONFLICT - INVALID_CREDENTIALS - SESSION_REQUIRED - INVALID_ACCESS_TOKEN - EXPIRED_ACCESS_TOKEN - INVALID_REFRESH_TOKEN - EXPIRED_REFRESH_TOKEN - REFRESH_REUSE_DETECTED - REFRESH_ROTATION_RACE - SESSION_IDLE_TIMEOUT - WEB_CALLING_DISABLED - ORIGIN_NOT_ALLOWED - WEBRTC_CONCURRENCY_LIMIT - WCS_NOT_FOUND - WCS_EXPIRED - WCS_REVOKED - WCS_REUSE_DETECTED - WCS_NOT_ALLOWED_AS_BEARER - WEBRTC_PROVISIONING_FAILED - TURN_UNAVAILABLE - INVALID_IDENTITY - IDENTITY_CONFLICT - PROFILE_VALIDATION_FAILED - PASSWORD_VALIDATION_FAILED - INVALID_CURRENT_PASSWORD - PASSWORD_SSO_ONLY - SETUP_ALREADY_COMPLETE - INVALID_NATIONAL_ID - NAFATH_INITIATE_FAILED - NAFATH_NOT_VERIFIED - NAFATH_REJECTED - NAFATH_EXPIRED - NAFATH_ALREADY_REGISTERED - NAFATH_INVALID_WEBHOOK - NAFATH_ALREADY_VERIFIED - NAFATH_REQUIRED - ADMIN_UNAUTHORIZED - ADMIN_INVALID_CREDENTIALS - ADMIN_ROLE_FORBIDDEN - ORG_TELEPHONY_NOT_CONFIGURED - ADMIN_ORG_OWNER_EMAIL_TAKEN - ADMIN_USER_NOT_FOUND - INSUFFICIENT_ROLE - LAST_OWNER - INVALID_SCOPE - NUMBER_NOT_AVAILABLE - NUMBER_NOT_FOUND - NUMBER_ALREADY_ASSIGNED - NUMBER_PROVIDER_ERROR - PORTING_INVALID_STATE - PORTING_NOT_FOUND - OWN_DID_NUMBER_REQUIRED - OWN_DID_NUMBER_NOT_AUTHORIZED - OWN_DID_NUMBER_UNAVAILABLE - SPEND_CAP_EXCEEDED - RATE_PLAN_NOT_FOUND - PAYMENT_FAILED - DUPLICATE_USAGE_EVENT - INVOICE_NOT_FOUND - PAYMENT_NOT_FOUND - PAYMENT_AMOUNT_MISMATCH - INSUFFICIENT_PROJECT_BALANCE - INSUFFICIENT_POOL_BALANCE - PROJECT_NOT_FOUND_FOR_ALLOCATION - ENGINE_UNAUTHORIZED - CALLFLOW_TENANT_NOT_FOUND - CLI_NOT_OWNED - WEBHOOK_UNAUTHORIZED - CHANNEL_NOT_CONFIGURED - WEBHOOK_PAYLOAD_INVALID - RECIPIENT_OPTED_OUT - QUIET_HOURS_ACTIVE - CONSENT_LOCKED_BY_END_USER - CONTACT_GROUP_NAME_TAKEN - INVITE_NOT_FOUND - INVITE_NOT_PENDING - INVITE_EXPIRED - INVITE_ROLE_INVALID - INVITE_ALREADY_MEMBER - INVITE_EMAIL_OTHER_ORG - INVITE_ACCOUNT_DETAILS_REQUIRED message: type: string description: English message. message_ar: type: string description: Arabic message. request_id: type: string docs_url: type: string format: uri securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: sk_sandbox_* | sk_live_* description: >- Your API key from the Wave dashboard. Sandbox keys start `sk_sandbox_`; production keys start `sk_live_`. Send as `Authorization: Bearer `. Some endpoints require a production key and specific scopes. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.