Properties
| Name | Type | Description |
|---|---|---|
| key | string | This is the key of the variable. This variable will be accessible during the call as `{{key}}` and stored in `call.artifact.variableValues` after the call. Rules: - Must start with a letter (a-z, A-Z) |
| value | string | This is the value of the variable. This can reference existing variables, use filters, and perform transformations. Examples: "{{name}}", "{{customer.email}}", "Hello {{name | upcase}}" |
JSON Schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "#/components/schemas/VariableExtractionAlias",
"title": "VariableExtractionAlias",
"type": "object",
"properties": {
"key": {
"type": "string",
"description": "This is the key of the variable.\n\nThis variable will be accessible during the call as `{{key}}` and stored in `call.artifact.variableValues` after the call.\n\nRules:\n- Must start with a letter (a-z, A-Z).\n- Subsequent characters can be letters, numbers, or underscores.\n- Minimum length of 1 and maximum length of 40.",
"minLength": 1,
"maxLength": 40,
"pattern": "/^[a-zA-Z][a-zA-Z0-9_]*$/"
},
"value": {
"type": "string",
"description": "This is the value of the variable.\n\nThis can reference existing variables, use filters, and perform transformations.\n\nExamples: \"{{name}}\", \"{{customer.email}}\", \"Hello {{name | upcase}}\"",
"maxLength": 10000
}
},
"required": [
"key",
"value"
]
}
Work with this as data
Every JSON Schema here is available over the APIs.io API and to AI agents over MCP.
MCP server
One button, every client — Claude, Cursor, VS Code and the rest.
https://apis.io/mcp
Tools for schemas
4 MCP tools reach this
find_json_schemasBrowse and filter every JSON Schema in the catalog.apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.resolveTurn a domain, URL or GitHub org into the provider it belongs to.find_cohortsEvery scored population of providers in the catalog.
Call it yourself
curl for this page
This JSON Schema
curl "https://apis.io/api/v1/json-schemas/vapi-variableextractionalias"
All schemas
curl "https://apis.io/api/v1/json-schemas?limit=25"
Discovery needs no key. Ratings and market analysis are Pro.
Get an API key
Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.
A second provider on the same verified email joins the account you already have.