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WP EngineDocumentation

Generate speech from text

POST
/v1/audio/speech
<?php


$client = new \GuzzleHttp\Client();


$response = $client->request('POST', 'https://api.ai.wpengine.com/v1/audio/speech', [
  'body' => '{ "model": "google/gemini-2.5-flash-tts", "input": "example", "response_format": "pcm", "voice": "Achernar" }',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);


echo $response->getBody();

Converts text input to audio using a text-to-speech model. Returns binary audio data with the appropriate Content-Type header. Requires a valid WP Engine bearer token; API keys must carry the “speech:write” permission.

Authorizations

Section titled “Authorizations”

Request Bodyrequired

Section titled “Request Bodyrequired”
Media typeapplication/json
object
model

Optional model identifier. Defaults to a Gemini TTS model when omitted.

string
Example
google/gemini-2.5-flash-tts
input
required

The text to convert to speech.

string
<= 5000 characters
response_format

Audio encoding format. “pcm” returns raw 16-bit linear PCM as received from the upstream provider. “wav” wraps the PCM data in a WAV container for direct browser playback. Omit for raw PCM (backward compatible).

string
Allowed values: pcm wav
Example
wav
voice

The Chirp 3 HD voice to use for speech synthesis. Defaults to “Kore”. All 30 prebuilt voices are supported across 50+ languages.

string
default: Kore
Allowed values: Achernar Achird Algenib Algieba Alnilam Aoede Autonoe Callirrhoe Charon Despina Enceladus Erinome Fenrir Gacrux Iapetus Kore Laomedeia Leda Orus Pulcherrima Puck Rasalgethi Sadachbia Sadaltager Schedar Sulafat Umbriel Vindemiatrix Zephyr Zubenelgenubi

Responses

Section titled “Responses”

200

Section titled “200”

Generated audio data

string format: binary

400

Section titled “400”

Invalid request body or parameters

Media typeapplication/json
object
error
required
object
message
required
string
type
required
string
code
required
integer
request_id
required

Correlation ID for this request, matching the X-Request-ID response header — a 32-character trace ID behind the load balancer, otherwise a UUID. Quote it in support reports.

string
Example
{
  "error": {
    "type": "invalid_request_error",
    "request_id": "80f1e2c3a4b5c6d7e8f9a0b1c2d3e4f5"
  }
}

401

Section titled “401”

Missing or invalid bearer token

Media typeapplication/json
object
error
required
object
message
required
string
type
required
string
code
required
integer
request_id
required

Correlation ID for this request, matching the X-Request-ID response header — a 32-character trace ID behind the load balancer, otherwise a UUID. Quote it in support reports.

string
Example
{
  "error": {
    "type": "invalid_request_error",
    "request_id": "80f1e2c3a4b5c6d7e8f9a0b1c2d3e4f5"
  }
}

Headers

Section titled “Headers”
WWW-Authenticate
string
Example
Bearer realm="ai-services"

402

Section titled “402”

The account’s credit balance is exhausted. Grant or top up credits before retrying. Distinct from 429, which is edge rate limiting.

Media typeapplication/json
object
error
required
object
message
required
string
type
required
string
code
required
integer
request_id
required

Correlation ID for this request, matching the X-Request-ID response header — a 32-character trace ID behind the load balancer, otherwise a UUID. Quote it in support reports.

string
Example
{
  "error": {
    "type": "invalid_request_error",
    "request_id": "80f1e2c3a4b5c6d7e8f9a0b1c2d3e4f5"
  }
}

403

Section titled “403”

The token is valid, but the caller is not permitted to perform this action — either its scope/permission is insufficient or the authenticated user is not authorized for the target account (error type “permission_error”). On /v1/chat/completions specifically, a 403 with error type “content_policy_violation” instead means the request content was blocked by content moderation policy; that response never identifies which filter or category matched.

Media typeapplication/json
object
error
required
object
message
required
string
type
required
string
code
required
integer
request_id
required

Correlation ID for this request, matching the X-Request-ID response header — a 32-character trace ID behind the load balancer, otherwise a UUID. Quote it in support reports.

string
Example
{
  "error": {
    "type": "invalid_request_error",
    "request_id": "80f1e2c3a4b5c6d7e8f9a0b1c2d3e4f5"
  }
}

429

Section titled “429”

Rate limit exceeded. The request was throttled at the edge; wait and retry later. The response body is a short HTML page generated by the load balancer, not a structured JSON error — clients should rely on the 429 status code rather than parsing the body.

Media typetext/html
string

502

Section titled “502”

Upstream provider returned an error

Media typeapplication/json
object
error
required
object
message
required
string
type
required
string
code
required
integer
request_id
required

Correlation ID for this request, matching the X-Request-ID response header — a 32-character trace ID behind the load balancer, otherwise a UUID. Quote it in support reports.

string
Example
{
  "error": {
    "type": "invalid_request_error",
    "request_id": "80f1e2c3a4b5c6d7e8f9a0b1c2d3e4f5"
  }
}

503

Section titled “503”

A required dependency is temporarily unavailable. Retry after a short delay with exponential back-off.

Media typeapplication/json
object
error
required
object
message
required
string
type
required
string
code
required
integer
request_id
required

Correlation ID for this request, matching the X-Request-ID response header — a 32-character trace ID behind the load balancer, otherwise a UUID. Quote it in support reports.

string
Example
{
  "error": {
    "type": "invalid_request_error",
    "request_id": "80f1e2c3a4b5c6d7e8f9a0b1c2d3e4f5"
  }
}