Analytics1

Assistants5

Board6

Calls12

Campaigns11

Chats5

Eval9

Files5

Insight7

Knowledge Bases V29

Observability/Scorecard5

Phone Numbers6

Provider Resources5

Sessions5

Simulation Personalities5

Simulation Runs8

Simulation Scenarios5

Simulation Suites9

Simulations6

Squads5

Structured Outputs6

Tools5

Traffic Allocations5

Structured Outputs

Update Structured Output

Changed on Oct 29, 2026

patch/structured-output/{id}

Request

Base URL
https://api.vapi.ai
Auth
HTTP bearer

Path parameters

idstring uuid required

The unique identifier for the resource.

Query parameters

schemaOverridestring required

Request body

type'ai' | 'regex'

This is the type of structured output.

'ai': Uses an LLM to extract structured data from the conversation (default).
'regex': Uses a regex pattern to extract data from the transcript without an LLM.

regexstring

This is the regex pattern to match against the transcript.

Simulation evaluations use a canonical transcript built from recorded messages: User: and AI: dialogue, AI: tool_calls: JSON name/arguments records, and AI: tool_call_results: JSON results. System messages are excluded. These fixed labels apply even when custom artifact transcript labels are configured. Tool payloads participate in first-match and all-match extraction in event order. An empty message array falls back to the supplied transcript verbatim. Production-call extraction and call preview use their existing transcripts, so previewing the same output on a simulation's call can return a different result.

Only used when type is 'regex'. Supports both raw patterns (e.g. '\d+') and regex literal format (e.g. '/\d+/gi'). Uses RE2 syntax for safety.

The result depends on the schema type:

boolean: true if the pattern matches, false otherwise
string: the first match or first capture group
number/integer: the first match parsed as a number
array: all matches

namestring

This is the name of the structured output.

descriptionstring

This is the description of what the structured output extracts.

Use this to provide context about what data will be extracted and how it will be used.

assistantIdsstring[]

These are the assistant IDs that this structured output is linked to.

When linked to assistants, this structured output will be available for extraction during those assistant's calls.

workflowIdsstring[]

These are the workflow IDs that this structured output is linked to.

When linked to workflows, this structured output will be available for extraction during those workflow's execution.

Example request

{
  "conditions": [
    {
      "type": "minMessages",
      "count": 4
    },
    {
      "type": "minCallDuration",
      "seconds": 10
    }
  ]
}

Response

type'ai' | 'regex'

This is the type of structured output.

'ai': Uses an LLM to extract structured data from the conversation (default).
'regex': Uses a regex pattern to extract data from the transcript without an LLM.

regexstring

This is the regex pattern to match against the transcript.

Only used when type is 'regex'. Supports both raw patterns (e.g. '\d+') and regex literal format (e.g. '/\d+/gi'). Uses RE2 syntax for safety.

The result depends on the schema type:

boolean: true if the pattern matches, false otherwise
string: the first match or first capture group
number/integer: the first match parsed as a number
array: all matches

idstring required

This is the unique identifier for the structured output.

orgIdstring required

This is the unique identifier for the org that this structured output belongs to.

createdAtstring date-time required

This is the ISO 8601 date-time string of when the structured output was created.

updatedAtstring date-time required

This is the ISO 8601 date-time string of when the structured output was last updated.

namestring required