Start a web call

POST

/web_calls

import MoreVoice from "@morevoice/sdk";

const mv = new MoreVoice(); // MOREVOICE_API_KEY from the environment

const webCall = await mv.webCalls.create({
  assistant_id: "asst_8tRPaZp5hLMbrGqdJ9AmNa",
  metadata: {
    page: "/pricing",
  },
});
console.log(webCall);

from morevoice import MoreVoice

client = MoreVoice()  # MOREVOICE_API_KEY from the environment

web_call = client.web_calls.create({
    "assistant_id": "asst_8tRPaZp5hLMbrGqdJ9AmNa",
    "metadata": {
        "page": "/pricing",
    },
})
print(web_call)

curl -X POST https://api.morevoice.ai/v1/web_calls \
  -H "Authorization: Bearer $MOREVOICE_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "assistant_id": "asst_8tRPaZp5hLMbrGqdJ9AmNa",
  "metadata": {
    "page": "/pricing"
  }
}'

From the browser with a publishable key (mv_live_pk_…), or from your server with a secret key: returns the call ID and a single-use client token for /ws/call. With a publishable key the assistant must be public, the page must be one of the key’s allowed origins (and of the assistant’s widget origins, when it lists any), and each visitor may start 10 web calls a minute. The org’s concurrent-call quota applies.

Try it in the API playground with a test-mode key.

Authorizations

bearerAuth

Parameters

Header Parameters

MoreVoice-Version

string

/^\d{4}-\d{2}-\d{2}$/

The API version to use for this request. Defaults to the version the API key is pinned to.

Example

2026-11-01

Idempotency-Key

string

>= 1 characters <= 255 characters

A unique key (for example a UUID) that makes this request safe to retry: for 24 hours, a retry with the same key and parameters returns the first response instead of acting twice.

Example

5f0c1e8a-7b2d-4c3e-9f1a-2b6d8e4c0a17

Request Body^required

application/json

The web call to start.

object

assistant_id

required

The assistant to talk to. With a publishable key it must be public (widget settings).

string

<= 200 characters /^asst_[0-9A-Za-z]+$/

metadata

Stored on the call (metadata).

object

<= 50 properties

key

additional properties

string

<= 500 characters

Example

{
  "assistant_id": "asst_8tRPaZp5hLMbrGqdJ9AmNa",
  "metadata": {
    "page": "/pricing"
  }
}

Responses

201

The web call, ready to connect.

application/json

A browser call ready to start: connect to ws_url with the client token and send the WebRTC offer (the @morevoice/web SDK does both).

object

assistant_id

required

A assistant ID (prefix asst_).

string

/^asst_[0-9A-Za-z]+$/

call_id

required

The call this web call will be (GET /v1/calls/{id} once it starts).

string

/^call_[0-9A-Za-z]+$/

client_token

required

Single use; connect within expires_at.

string

expires_at

required

An ISO-8601 timestamp in UTC.

string format: date-time

livemode

required

true in live mode, false in test mode.

boolean

object

required

string

Allowed value: web_call

ws_url

required

Connect to <ws_url>?client_token=<client_token>.

string

Example

{
  "assistant_id": "asst_8tRPaZp5hLMbrGqdJ9AmNa",
  "call_id": "call_3slqGaD2htUzxdRsI",
  "client_token": "<client_token: short-lived JWT, pass it through unchanged>",
  "expires_at": "2026-11-03T09:19:22.000Z",
  "livemode": true,
  "object": "web_call",
  "ws_url": "wss://api.morevoice.ai/ws/call"
}

400

The request is invalid: a parameter is missing, malformed or unknown, or the version header is unknown.

application/json

Every /v1 error.

object

error

required

object

code

required

A stable, machine-readable code from the error-code catalogue.

string

details

Structured context, e.g. required_scope or the compliance verdict.

object

key

additional properties

doc_url

required

A link to the documentation of this code.

string

message

required

A human-readable explanation. Do not parse it.

string

param

The request parameter the error relates to, e.g. to or metadata[order_id].

string

request_id

required

The X-Request-Id of this request. Quote it when you contact support.

string

type

required

The category of the error.

string

Allowed values: invalid_request_error authentication_error permission_error not_found conflict rate_limit_error compliance_error idempotency_error api_error

Example

{
  "error": {
    "code": "parameter_missing",
    "doc_url": "https://docs.morevoice.ai/api/errors#parameter-missing",
    "message": "Missing required parameter: to.",
    "param": "to",
    "request_id": "req_7Hk2LmN9pQ4rS6tV8wX0yZ",
    "type": "invalid_request_error"
  }
}

Headers

X-Request-Id

string

The request’s ID (req_…). Quote it when you contact support.

401

No valid API key was sent.

application/json

Every /v1 error.

object

error

required

object

code

required

A stable, machine-readable code from the error-code catalogue.

string

details

Structured context, e.g. required_scope or the compliance verdict.

object

key

additional properties

doc_url

required

A link to the documentation of this code.

string

message

required

A human-readable explanation. Do not parse it.

string

param

The request parameter the error relates to, e.g. to or metadata[order_id].

string

request_id

required

The X-Request-Id of this request. Quote it when you contact support.

string

type

required

The category of the error.

string

Allowed values: invalid_request_error authentication_error permission_error not_found conflict rate_limit_error compliance_error idempotency_error api_error

Example

{
  "error": {
    "code": "invalid_api_key",
    "doc_url": "https://docs.morevoice.ai/api/errors#invalid-api-key",
    "message": "Invalid API key.",
    "request_id": "req_7Hk2LmN9pQ4rS6tV8wX0yZ",
    "type": "authentication_error"
  }
}

Headers

X-Request-Id

string

The request’s ID (req_…). Quote it when you contact support.

403

The key may not do this (a missing scope, a plan limit, or a compliance block).

application/json

Every /v1 error.

object

error

required

object

code

required

A stable, machine-readable code from the error-code catalogue.

string

details

Structured context, e.g. required_scope or the compliance verdict.

object

key

additional properties

doc_url

required

A link to the documentation of this code.

string

message

required

A human-readable explanation. Do not parse it.

string

param

The request parameter the error relates to, e.g. to or metadata[order_id].

string

request_id

required

The X-Request-Id of this request. Quote it when you contact support.

string

type

required

The category of the error.

string

Allowed values: invalid_request_error authentication_error permission_error not_found conflict rate_limit_error compliance_error idempotency_error api_error

Example

{
  "error": {
    "code": "missing_scope",
    "doc_url": "https://docs.morevoice.ai/api/errors#missing-scope",
    "message": "This API key lacks the calls:write scope.",
    "request_id": "req_7Hk2LmN9pQ4rS6tV8wX0yZ",
    "type": "permission_error"
  }
}

Headers

X-Request-Id

string

The request’s ID (req_…). Quote it when you contact support.

409

The request conflicts with the object’s state, or the Idempotency-Key was reused with other parameters.

application/json

Every /v1 error.

object

error

required

object

code

required

A stable, machine-readable code from the error-code catalogue.

string

details

Structured context, e.g. required_scope or the compliance verdict.

object

key

additional properties

doc_url

required

A link to the documentation of this code.

string

message

required

A human-readable explanation. Do not parse it.

string

param

The request parameter the error relates to, e.g. to or metadata[order_id].

string

request_id

required

The X-Request-Id of this request. Quote it when you contact support.

string

type

required

The category of the error.

string

Allowed values: invalid_request_error authentication_error permission_error not_found conflict rate_limit_error compliance_error idempotency_error api_error

Example

{
  "error": {
    "code": "idempotency_mismatch",
    "doc_url": "https://docs.morevoice.ai/api/errors#idempotency-mismatch",
    "message": "This Idempotency-Key was already used with different parameters.",
    "request_id": "req_7Hk2LmN9pQ4rS6tV8wX0yZ",
    "type": "idempotency_error"
  }
}

Headers

X-Request-Id

string

The request’s ID (req_…). Quote it when you contact support.

429

Too many requests, or no call capacity right now. Retry after the Retry-After delay.

application/json

Every /v1 error.

object

error

required

object

code

required

A stable, machine-readable code from the error-code catalogue.

string

details

Structured context, e.g. required_scope or the compliance verdict.

object

key

additional properties

doc_url

required

A link to the documentation of this code.

string

message

required

A human-readable explanation. Do not parse it.

string

param

The request parameter the error relates to, e.g. to or metadata[order_id].

string

request_id

required

The X-Request-Id of this request. Quote it when you contact support.

string

type

required

The category of the error.

string

Allowed values: invalid_request_error authentication_error permission_error not_found conflict rate_limit_error compliance_error idempotency_error api_error

Example

{
  "error": {
    "code": "rate_limited",
    "doc_url": "https://docs.morevoice.ai/api/errors#rate-limited",
    "message": "Too many requests. Retry after 1 second.",
    "request_id": "req_7Hk2LmN9pQ4rS6tV8wX0yZ",
    "type": "rate_limit_error"
  }
}

Headers

Retry-After

integer

Seconds to wait before retrying.

X-Request-Id

string

The request’s ID (req_…). Quote it when you contact support.

500

Something went wrong on MoreVoice’s side. Retry with the same Idempotency-Key.

application/json

Every /v1 error.

object

error

required

object

code

required

A stable, machine-readable code from the error-code catalogue.

string

details

Structured context, e.g. required_scope or the compliance verdict.

object

key

additional properties

doc_url

required

A link to the documentation of this code.

string

message

required

A human-readable explanation. Do not parse it.

string

param

The request parameter the error relates to, e.g. to or metadata[order_id].

string

request_id

required

The X-Request-Id of this request. Quote it when you contact support.

string

type

required

The category of the error.

string

Allowed values: invalid_request_error authentication_error permission_error not_found conflict rate_limit_error compliance_error idempotency_error api_error

Example

{
  "error": {
    "code": "internal_error",
    "doc_url": "https://docs.morevoice.ai/api/errors#internal-error",
    "message": "Something went wrong on MoreVoice's side.",
    "request_id": "req_7Hk2LmN9pQ4rS6tV8wX0yZ",
    "type": "api_error"
  }
}

Headers

X-Request-Id

string

The request’s ID (req_…). Quote it when you contact support.

Start a web call

Authorizations

Parameters

Header Parameters

Example

Example

Request Bodyrequired

Example

Responses

201

Example

400

Example

Headers

401

Example

Headers

403

Example

Headers

409

Example

Headers

429

Example

Headers

500

Example

Headers

Request Body^required