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PUT
/
v1
/
agents
/
{agentId}
/
voices
/
{voiceId}
/
tuning-settings
Update voice tuning settings
curl --request PUT \
  --url https://api.us.poly.ai/v1/agents/{agentId}/voices/{voiceId}/tuning-settings \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "stability": 50,
  "similarityBoost": 50,
  "speed": 123,
  "modelId": "<string>",
  "resetToDefault": true
}
'
{
  "stability": 123,
  "similarityBoost": 123,
  "style": 123,
  "optimizeStreamingLatency": 123,
  "speed": 123,
  "modelId": "<string>"
}

Documentation Index

Fetch the complete documentation index at: https://docs.poly.ai/llms.txt

Use this file to discover all available pages before exploring further.

Authorizations

​
x-api-key
string
header
required

Path Parameters

​
agentId
string
required
​
voiceId
string
required

Voice ID from the voice library

Body

application/json

Update tuning settings for a voice. Only fields you include are changed. Set resetToDefault to true to revert all settings to the provider defaults.

​
stability
integer

Voice stability (0–100)

Required range: 0 <= x <= 100
​
similarityBoost
integer

Similarity boost (0–100)

Required range: 0 <= x <= 100
​
speed
number<float>

Playback speed multiplier. The valid range depends on the voice provider; out-of-range values return a 400.

​
modelId
string

Provider model ID override

​
resetToDefault
boolean

Reset all tuning settings to the provider defaults. Overrides other fields when true.

Response

Updated tuning settings

Voice tuning settings for a given voice and purpose. Fields are null when the tuning provider does not support them or no override has been set.

​
stability
integer

Voice stability (0–100). Higher values make the voice more consistent and less expressive.

​
similarityBoost
integer

Similarity boost (0–100). Higher values make the output sound closer to the original voice sample.

​
style
integer

Style exaggeration (provider-specific, 0–100)

​
optimizeStreamingLatency
integer

Streaming latency optimization level (provider-specific)

​
speed
number<float>

Playback speed multiplier. Valid range depends on the voice provider.

​
modelId
string

Provider model ID used for synthesis

Last modified on May 22, 2026