openapi: 3.2.0
info:
  title: Media Caption Public Transcripts API
  version: 1.0.0
  description: 'Public API for reading account and credit balance details, fetching YouTube

    transcripts, creating bulk transcript jobs, polling jobs, retrieving retained

    transcriptions, and receiving job-level webhooks.'
  contact:
    name: Media Caption
    url: https://mediacaption.io
  license:
    name: Proprietary
    url: https://mediacaption.io/terms
servers:
- url: https://api.mediacaption.io/v1
  description: Production
security:
- bearerApiKey: []
- headerApiKey: []
tags:
- name: Transcripts
  description: Synchronous and async public YouTube transcript endpoints.
paths:
  /transcripts:
    post:
      tags:
      - Transcripts
      summary: Fetch one public YouTube transcript
      description: Synchronously fetches a public YouTube transcript, reserves 1 credit before processing, and charges 1 credit on success.
      operationId: createTranscript
      security:
      - bearerApiKey: []
      - headerApiKey: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/TranscriptRequest'
            examples:
              url:
                value:
                  url: https://www.youtube.com/watch?v=dQw4w9WgXcQ
                  language: en
              videoId:
                value:
                  videoId: dQw4w9WgXcQ
      responses:
        '200':
          description: Transcript fetched
          headers:
            X-Request-Id:
              $ref: '#/components/headers/XRequestId'
            X-RateLimit-Limit:
              $ref: '#/components/headers/XRateLimitLimit'
            X-RateLimit-Remaining:
              $ref: '#/components/headers/XRateLimitRemaining'
            X-RateLimit-Reset:
              $ref: '#/components/headers/XRateLimitReset'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TranscriptResponse'
        '400':
          $ref: '#/components/responses/InvalidRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/InsufficientCredits'
        '403':
          $ref: '#/components/responses/Forbidden'
        '404':
          $ref: '#/components/responses/NotFound'
        '429':
          $ref: '#/components/responses/RateLimited'
        '500':
          $ref: '#/components/responses/InternalError'
  /transcripts/bulk:
    post:
      tags:
      - Transcripts
      summary: Create a bulk public transcript job
      description: Creates an async job for 1 to 100 public YouTube transcript lookups and requires an active dashboard webhook ID for the final job-level event. The API reserves 1 credit per item when the job is accepted and settles credits after all items finish.
      operationId: createBulkTranscriptJob
      security:
      - bearerApiKey: []
      - headerApiKey: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/BulkTranscriptRequest'
      responses:
        '202':
          description: Job accepted
          headers:
            Location:
              description: Relative URL for polling the accepted job.
              schema:
                type: string
                example: /v1/jobs/job_01jz7m91bxkpbqha0wt8whm76r
            X-Request-Id:
              $ref: '#/components/headers/XRequestId'
            X-RateLimit-Limit:
              $ref: '#/components/headers/XRateLimitLimit'
            X-RateLimit-Remaining:
              $ref: '#/components/headers/XRateLimitRemaining'
            X-RateLimit-Reset:
              $ref: '#/components/headers/XRateLimitReset'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/BulkTranscriptAcceptedResponse'
        '400':
          $ref: '#/components/responses/InvalidRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/InsufficientCredits'
        '429':
          $ref: '#/components/responses/ConcurrentJobLimitExceeded'
        '500':
          $ref: '#/components/responses/InternalError'
components:
  responses:
    NotFound:
      description: Resource not found
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    RateLimited:
      description: Rate limit exceeded
      headers:
        Retry-After:
          $ref: '#/components/headers/RetryAfter'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    Unauthorized:
      description: Missing or invalid API key
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            missing:
              value:
                error:
                  code: missing_api_key
                  message: Missing API key.
            invalid:
              value:
                error:
                  code: invalid_api_key
                  message: Invalid API key.
    InternalError:
      description: Internal server error
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    ConcurrentJobLimitExceeded:
      description: Concurrent bulk job limit exceeded
      headers:
        Retry-After:
          $ref: '#/components/headers/RetryAfter'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          example:
            error:
              code: concurrent_job_limit_exceeded
              message: Concurrent API job limit exceeded. Please wait for active jobs to finish.
    InsufficientCredits:
      description: Not enough credits to start processing
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          example:
            error:
              code: insufficient_credits
              message: Insufficient credits.
    InvalidRequest:
      description: Invalid request
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
    Forbidden:
      description: Forbidden request
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  schemas:
    TranscriptSegment:
      type: object
      additionalProperties: false
      required:
      - startSec
      - durationSec
      - text
      properties:
        startSec:
          type: number
          minimum: 0
          example: 0
        durationSec:
          type: number
          minimum: 0
          example: 2.4
        text:
          type: string
          example: Example transcript text
    ErrorCode:
      type: string
      enum:
      - concurrent_job_limit_exceeded
      - geo_restricted
      - invalid_api_key
      - invalid_request
      - insufficient_credits
      - internal_error
      - missing_api_key
      - not_found
      - public_api_rate_limited
      - single_transcript_rate_limited
      - transcription_expired
      - transcript_unavailable
      - video_unavailable
      - webhook_not_found
      - youtube_blocked
      - youtube_rate_limited
    BulkTranscriptAcceptedResponse:
      type: object
      additionalProperties: false
      required:
      - jobId
      - type
      - status
      - itemCount
      - creditsFrozen
      properties:
        jobId:
          type: string
          example: job_01jz7m91bxkpbqha0wt8whm76r
        type:
          type: string
          enum:
          - public_transcripts_bulk
        status:
          $ref: '#/components/schemas/JobStatus'
        itemCount:
          type: integer
          example: 2
        creditsFrozen:
          type: integer
          example: 2
    ErrorResponse:
      type: object
      additionalProperties: false
      required:
      - error
      properties:
        error:
          type: object
          additionalProperties: false
          required:
          - code
          - message
          properties:
            code:
              $ref: '#/components/schemas/ErrorCode'
            message:
              type: string
    LanguageTag:
      type: string
      pattern: ^[A-Za-z]{2,3}(?:-[A-Za-z0-9]{2,8})*$
      example: en
    JobStatus:
      type: string
      enum:
      - queued
      - processing
      - completed
      - completed_with_errors
      - failed
      - canceled
    TranscriptRequest:
      type: object
      additionalProperties: false
      properties:
        url:
          type: string
          format: uri
          description: YouTube video URL. Required when videoId is omitted.
        videoId:
          type: string
          description: YouTube video ID. Required when url is omitted.
          example: dQw4w9WgXcQ
        language:
          $ref: '#/components/schemas/LanguageTag'
      anyOf:
      - required:
        - url
      - required:
        - videoId
    BulkTranscriptItemRequest:
      type: object
      additionalProperties: false
      properties:
        externalId:
          type: string
          description: Customer-provided item ID returned in job results and webhooks.
        url:
          type: string
          format: uri
        videoId:
          type: string
        language:
          $ref: '#/components/schemas/LanguageTag'
      anyOf:
      - required:
        - url
      - required:
        - videoId
    BulkTranscriptRequest:
      type: object
      additionalProperties: false
      required:
      - webhookId
      - items
      properties:
        webhookId:
          type: string
          description: '**Required** active dashboard webhook ID for one final job-level event.'
          example: wh_01jz7m8a3yk9pnx2g6bc8n4a8m
        items:
          type: array
          description: '**Required** array of public transcript requests.'
          minItems: 1
          maxItems: 100
          items:
            $ref: '#/components/schemas/BulkTranscriptItemRequest'
    TranscriptResponse:
      type: object
      additionalProperties: false
      required:
      - transcriptionId
      - source
      - language
      - durationSec
      - expiresAt
      - transcript
      - creditsFrozen
      - creditsCharged
      properties:
        transcriptionId:
          type: string
          example: tr_3f6e5c6a-0d31-4f8c-9b1d-7f3b9e6a2c11
        source:
          type: string
          enum:
          - public
        language:
          type: string
          example: en
        durationSec:
          type: number
          example: 184
        expiresAt:
          type: string
          format: date-time
        transcript:
          type: array
          items:
            $ref: '#/components/schemas/TranscriptSegment'
        creditsFrozen:
          type: integer
          example: 1
        creditsCharged:
          type: integer
          example: 1
  headers:
    XRequestId:
      description: Request ID for troubleshooting.
      schema:
        type: string
        example: req_01jz7mb36gp7h2nm5rwd1ah4zz
    XRateLimitReset:
      description: ISO 8601 timestamp when the current fixed window resets.
      schema:
        type: string
        format: date-time
        example: '2026-05-11T10:01:00.000Z'
    RetryAfter:
      description: Seconds to wait before retrying.
      schema:
        type: integer
        example: 30
    XRateLimitLimit:
      description: Maximum requests allowed in the current fixed window.
      schema:
        type: integer
        example: 60
    XRateLimitRemaining:
      description: Requests remaining in the current fixed window.
      schema:
        type: integer
        example: 58
  securitySchemes:
    bearerApiKey:
      type: http
      scheme: bearer
      bearerFormat: Media Caption API key
      description: 'Use `Authorization: Bearer mc_live_xxx`.'
    headerApiKey:
      type: apiKey
      in: header
      name: X-API-Key
      description: Alternative API key header.