2025-07-07 13:17:48 +02:00

78 lines
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Markdown

---
title: openapi3.Unmarshal
description: Unmarshals the given resource into an OpenAPI 3 document.
categories: []
keywords: []
params:
functions_and_methods:
aliases: []
returnType: openapi3.OpenAPIDocument
signatures: ['openapi3.Unmarshal RESOURCE']
---
Use the `openapi3.Unmarshal` function with [global resources](g), [page resources](g), or [remote resources](g).
[OpenAPI]: https://www.openapis.org/
For example, to work with a remote [OpenAPI] definition:
```go-html-template
{{ $url := "https://raw.githubusercontent.com/OAI/OpenAPI-Specification/main/examples/v3.0/petstore.json" }}
{{ $api := "" }}
{{ with try (resources.GetRemote $url) }}
{{ with .Err }}
{{ errorf "%s" . }}
{{ else with .Value }}
{{ $api = . | openapi3.Unmarshal }}
{{ else }}
{{ errorf "Unable to get remote resource %q" $url }}
{{ end }}
{{ end }}
```
To inspect the data structure:
```go-html-template
<pre>{{ debug.Dump $api }}</pre>
```
To list the GET and POST operations for each of the API paths:
```go-html-template
{{ range $path, $details := $api.Paths.Map }}
<p>{{ $path }}</p>
<dl>
{{ with $details.Get }}
<dt>GET</dt>
<dd>{{ .Summary }}</dd>
{{ end }}
{{ with $details.Post }}
<dt>POST</dt>
<dd>{{ .Summary }}</dd>
{{ end }}
</dl>
{{ end }}
```
> [!warning]
> The unmarshaled data structure is created with [`kin-openapi`](https://github.com/getkin/kin-openapi). Many fields are structs or pointers (not maps), and therefore require accessors or other methods for indexing and iteration.
> For example, prior to [`kin-openapi` v0.122.0](https://github.com/getkin/kin-openapi#v01220) / [Hugo v0.121.0](https://github.com/gohugoio/hugo/releases/tag/v0.121.0), `Paths` was a map (so `.Paths` was iterable) and it is now a pointer (and requires the `.Paths.Map` accessor, as in the example above).
> See the [`kin-openapi` godoc for OpenAPI 3](https://pkg.go.dev/github.com/getkin/kin-openapi/openapi3) for full type definitions.
Hugo renders this to:
```html
<p>/pets</p>
<dl>
<dt>GET</dt>
<dd>List all pets</dd>
<dt>POST</dt>
<dd>Create a pet</dd>
</dl>
<p>/pets/{petId}</p>
<dl>
<dt>GET</dt>
<dd>Info for a specific pet</dd>
</dl>
```