Essere Voice API

Authentication

Every request carries an API key in the Authorization header:

Authorization: Bearer $ESSERE_API_KEY

Keys

Scopes

Scope Allows
read All GET endpoints.
read_write Everything in read, plus creating/updating contacts and managing webhook endpoints.

A read key calling a write endpoint gets 403 with code insufficient_scope.

Plan requirement

The API is a Pro-plan feature, checked at key creation and on every request. If the account leaves Pro, requests fail with 403 and code plan_required until the plan is upgraded again — keys are not deleted.

Rate limits

120 requests/minute per key, as a fixed one-minute window (a burst across a window boundary can briefly exceed the nominal rate — throttle to the limit, not the boundary behavior). Every response includes:

X-RateLimit-Limit: 120
X-RateLimit-Remaining: 118
X-RateLimit-Reset: 1752841260

On 429, back off for Retry-After seconds. Steady-state polling should stay well under the limit — prefer webhooks over polling.

Key hygiene

Data processing

Anything you connect through this API — webhook receivers, Zapier or n8n workflows, and any LLM/MCP client — becomes a third-party processor of your call and contact data once you send data to it. Choose processors that meet your own privacy obligations, propagate deletion requests to them, and revoke the API key to cut off access at any time.