---
search:
  tags:
    - Actions
    - POST
seo:
  description: >-
    Normalize the input, resolve the exact target, read the provider (never…
    Reference for the POST /api/v2/actions/{ref}/previews endpoint in the Anlyon
    API.
sidebar:
  label: Preview a governed invocation
  badge: POST
title: Preview a governed invocation
type: openapi-operation
---
Normalize the input, resolve the exact target, read the provider (never write), and return a typed, execution-bound preview: environment and target, the exact change (field summaries and text diffs), expected impact against current impact limits, material preconditions with the time they were observed, expiry, and the adapter's guarantees and limitations. Pass its id as `previewId` when invoking; any material difference is refused. For a declared action the preview is the normalized request itself, with every secret still a `{{secret:NAME}}` reference. Anlyon does not read an API it has no adapter for before the write, and the preview lists what a declared action does not guarantee.

`POST /api/v2/actions/{ref}/previews`