> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lehar.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Start campaign

> Starts (or resumes a paused) run. Needs at least one recipient and the Campaign Engine available. Any caller with `campaigns:write` can start — no admin role required.



## OpenAPI

````yaml /api-reference/openapi.json post /campaigns/{campaign_id}/start
openapi: 3.1.0
info:
  title: Lehar API
  version: v0
  description: >-
    Customer-facing REST API for the Lehar voice-AI platform. Platform-admin
    endpoints are intentionally excluded from this reference. Regenerate with
    `npm run sync:openapi`.
servers:
  - url: https://api.lehar.ai/ca/api/v0
security:
  - ApiKeyAuth: []
  - BearerAuth: []
paths:
  /campaigns/{campaign_id}/start:
    post:
      tags:
        - Campaigns
      summary: Start campaign
      description: >-
        Starts (or resumes a paused) run. Needs at least one recipient and the
        Campaign Engine available. Any caller with `campaigns:write` can start —
        no admin role required.
      operationId: start_campaign_ca_api_v0_campaigns__campaign_id__start_post
      parameters:
        - name: campaign_id
          in: path
          required: true
          schema:
            type: string
            title: Campaign Id
      responses:
        '200':
          description: Run started (status moves to `scheduled` then `running`)
        '400':
          description: No recipients
          content:
            application/json:
              example:
                error:
                  code: invalid_request
                  message: Campaign requires at least one recipient
        '503':
          description: Campaign Engine unavailable
          content:
            application/json:
              example:
                error:
                  code: service_unavailable
                  message: Campaign engine is not available
components:
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: X-API-KEY
    BearerAuth:
      type: http
      scheme: bearer

````