---
title: "Overview"
description: "Two models sit side by side and can be mixed per agent."
url: "https://nexora.apim.eu/apis/evaluation-sessions/docs/overview"
image: "https://nexora.apim.eu/_og/d/c_Ocean.takumi,title_Overview,description_Two+models+sit+side+by+side+and+can+be+mixed+per+agent.,props_eyJ0aGVtZSI6eyJtb2RlIjoiZGFyayIsImNvbG9ycyI6eyJwcmltYXJ5IjoiIzM5RkYxNCJ9fX0,p_Ii9hcGlzL2V2YWx1YXRpb24tc2Vzc2lvbnMvZG9jcy9vdmVydmlldyI,s_ax4u36w1AEICpRtT.png"
---

# Overview

Two models sit side by side and can be mixed per agent.

## [Fixed sessions](#fixed-sessions)

You create a session and invite specific requesters. For individual evaluations (`type: individual`) and group evaluations (`type: group`, with `slots`), this is the direct route. Once a group session is fully booked, further confirmations automatically land on the waitlist and move up as cancellations come in.

## [Availability windows](#availability-windows)

`GET /availability` returns bookable time slots derived from the responsible reviewer's working hours minus sessions already booked. Requesters pick their own slot - saving the back-and-forth of scheduling by email.

## [Changes and cancellations](#changes-and-cancellations)

A `PATCH` on `start` automatically notifies every confirmed attendee. A `DELETE` cancels the session entirely, also with notification. Both trigger the `session.confirmed` and `session.cancelled` events respectively.

Overlapping sessions for the same agent are rejected by the API with `409`. If you deliberately want to run parallel evaluations, create a group session with more slots instead.

## [Feedback](#feedback)

After the session, use `POST /sessions/{id}/feedback` to record interest and readiness assessment. This feedback is the most reliable basis for a conversation with the agent owner about the rollout timeline - far more informative than the number of clicks a catalog entry received.