---
title: "Create async speech"
method: POST
path: "/v1/async/audio/speech"
tags: ["Async Jobs"]
---

# Create async speech

`POST /v1/async/audio/speech`

Submits a speech synthesis request for asynchronous execution. Returns a job ID immediately
with HTTP 202. Poll the corresponding GET endpoint with the job ID to retrieve the result.
SSE streaming is not supported for async requests.

## Headers

- `x-bf-async-job-result-ttl` integer
- `x-bf-async-webhook` string

## Request body

- SpeechRequest
  - `model` string, required — Model in provider/model format
  - `input` string, required — Text to convert to speech
  - `fallbacks` string[]
  - `stream_format` 'sse' — Set to "sse" to enable streaming
  - `voice` union, required
    - string
    - object[]
      - `speaker` string, required
      - `voice` string, required
  - `instructions` string
  - `response_format` 'mp3' | 'opus' | 'aac' | 'flac' | 'wav' | 'pcm'
  - `speed` number
  - `language_code` string
  - `pronunciation_dictionary_locators` object[]
    - `pronunciation_dictionary_id` string, required
    - `version_id` string
  - `enable_logging` boolean
  - `optimize_streaming_latency` boolean
  - `with_timestamps` boolean

## Response `202`

Job accepted for processing

- AsyncJobResponse — Response returned when creating or polling an async job
  - `id` string, required — Unique identifier for the async job
  - `status` 'pending' | 'processing' | 'completed' | 'failed', required — The status of an async job
  - `expires_at` string, date-time — When the job result expires and will be cleaned up
  - `created_at` string, date-time, required — When the job was created
  - `completed_at` string, date-time — When the job completed (successfully or with failure)
  - `status_code` integer — HTTP status code of the completed operation
  - `result` unknown
  - `error` BifrostError — Error response from Bifrost
    - `event_id` string
    - `type` string
    - `is_bifrost_error` boolean
    - `status_code` integer
    - `error` ErrorField
      - `type` string
      - `code` string
      - `message` string
      - `param` string
      - `event_id` string
    - `extra_fields` BifrostErrorExtraFields
      - `provider` 'openai' | 'azure' | 'anthropic' | 'bedrock' | 'cohere' | 'vertex' | 'vllm' | 'mistral' | 'ollama' | 'groq' | 'sgl' | 'parasail' | 'perplexity' | 'replicate' | 'cerebras' | 'deepseek' | 'gemini' | 'openrouter' | 'elevenlabs' | 'huggingface' | 'nebius' | 'xai' | 'runway' | 'fireworks' — AI model provider identifier
      - `model_requested` string
      - `request_type` string

## Other responses

- `400` — Bad request
- `500` — Internal server error

---

[API](https://skmtc.net/getbifrost/apis/bifrost-api.md) · [All operations](https://skmtc.net/getbifrost/apis/bifrost-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/getbifrost/bifrost-api/versions/f8cab88f64ea/schema)