---
title: "POST /v1/guest-preview-sessions"
method: POST
path: "/v1/guest-preview-sessions"
tags: ["Conversion"]
---

# POST /v1/guest-preview-sessions

`POST /v1/guest-preview-sessions`

## Request

- Base URL: `https://markovo.net`
- URL: `https://markovo.net/v1/guest-preview-sessions`
- Auth: none required

Starts an ordered browser guest queue. Markovo converts only the longest continuous prefix whose cumulative immutable estimates are at most 5 Credits; it never skips an over-limit item.

## Request body

- GuestPreviewSessionInput
  - `estimates` object[], required
    - `upload_id` string, required
    - `job_token` string, required

## Response `201`

Bounded guest preview queue started

- GuestPreviewSession
  - `session_id` string, required
  - `session_token` string, required
  - `prefix_count` integer, required
  - `estimated_credit_units` integer, required
  - `authentication_required` boolean, required
  - `items` GuestPreviewItem[], required
    - `sequence` integer, required
    - `job_id` string, nullable
    - `status` 'queued' | 'dispatching' | 'dispatched' | 'running' | 'succeeded' | 'failed' | 'cancelled' | 'timed_out' | 'deferred_credit_limit' | 'deferred_after_limit', required
  - `expires_at` string, date-time, required

## Other responses

- `400`: Machine-readable safe error
- `409`: Machine-readable safe error
- `410`: Machine-readable safe error
- `429`: The anonymous UTC-day preview was already used. No work is dispatched; the opaque staged recovery session lets a signed-in user continue the original queue after OAuth.
- `503`: Machine-readable safe error

---

[API](https://skmtc.dev/markovo/apis/markovo-conversion-api.md) · [All operations](https://skmtc.dev/markovo/apis/markovo-conversion-api/llms.txt) · [OpenAPI document](https://skmtc.dev/markovo/apis/markovo-conversion-api/revisions/e080e7b85e2e?raw)